Occupational and Environmental Medicine

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2015

December 2015

Exhaustion-related changes in cardiovascular and cortisol reactivity to acute psychosocial stress

Using the initial definition of groups, none of the three outcome hypotheses was confirmed. Clear HPA-axis (cortisol) and SAM-axis activations were seen in both V-TSST sessions, together with a habituation in the second session, but without any interaction with the factor Group. This means that none of the groups (1) or (2) exhibited a provocation response that deviated from the healthy controls. However, the FB patients, assumed to be essentially recovered from ED, showed a considerable variation in self-reported signs of exhaustion (SMBQ).

Aim
The main aim of this study was to examine whether an impaired flexibility of the stress response in the hypothalamic-pituitary-adrenal-(HPA) axis and sympatho-adrenal-medullary (SAM-) axis may be a vulnerability factor in exhaustion disorder (ED). We examined whether an inadequate stress response is present during early stages of ED, and still is present after recovery. Three alternative outcome patterns concerning a dysfunctional flexibility in stress response (DFS) were hypothesized:
Type 1: DFS is present early on in the stress process and also after essential recovery from ED. This may indicate that DFS is a predisposing factor or has developed early on in the stress process and forms a chronic vulnerability, predisposing for relapse.
Type 2: DFS is present early on in the stress process, but subside after recovery. This may indicate that DFS is a sign of incipient exhaustion but not a predisposing factor for ED.
Type 3: DFS evolves late in the stress process and remains after essential recovery from ED. This may indicate that DFS does not develop until mental "breakdown" and sick-leave, and remains as a chronic vulnerability, predisposing for relapse.

Methods
Three groups were studied:
1. Former burnout patients (FB; n=14).
2. Persons that during the last 6 month had experienced stress at work and had a Shirom-Melamed Burnout Questionnaire (SMBQ) score over 3.75, but had not been in contact with health care (n=17).
3. Persons that not had experienced stress at work during the last 6 months and had a SMBQ score below 2.75 (n=20). The participants were exposed twice, with an approximate one week interval, to the virtual version of Trier Social Stress Test (V-TSST). The main dependent variables were salivary cortisol, high frequency heart rate variability (HRV), heart rate (HR), t-wave amplitude (TWA), and Alpha-Amylase, before and after the V-TSST.

Main results
Using the initial definition of groups, none of the three outcome hypotheses was confirmed. Clear HPA-axis (cortisol) and SAM-axis activations were seen in both V-TSST sessions, together with a habituation in the second session, but without any interaction with the factor Group. This means that none of the groups (1) or (2) exhibited a provocation response that deviated from the healthy controls. However, the FB patients, assumed to be essentially recovered from ED, showed a considerable variation in self-reported signs of exhaustion (SMBQ). After splitting the FB group into those with low SMBQ scores (recovered) and those with high SMBQ scores (insufficiently recovered) the respective group halves were inserted into the initial groups (2) and (3). The new groups were defined as (1) low SMBQ scorers (n=24) and (2) high SMBQ scorers (n=27). When repeating the analyses in the new groups, a different picture emerged; The low SMBQ group showed a stronger cortisol response to the V-TSST than the high SMBQ group. This indicates that persons in a pre-stage of ED and unrecovered former ED patients show signs of DFS, in contrast to healthy controls and recovered former ED patients. This overall pattern most closely resembles the Outcome type 2 described above: DFS in the HPA-axis is present early on in the stress process, but subside after recovery. This finding has several implications for the understanding of ED:
1. Because a DFS was not found among recovered former ED patients, there is no support for DFS as a predisposing factor representing for example a genetically based vulnerability. Having recovered well from ED seems to be associated with regaining normal stress response flexibility.
2. That a DFS is associated with pre-stages of ED and with lacking recovery from ED, seems to indicate that the DFS is related to ongoing (acute/chronic) exhaustion symptomatology. This finding supports the allostatic load aspect “inadequate response” according to McEwen’s  “Allostatic load” model.

http://www.sciencedirect.com/science/article/pii/S0031938415300342

Contact: Kai Österberg


November 2015

Phthalate exposure and reproductive parameters in young men from the general Swedish population

In animals, exposure to certain phthalates negatively affects the male reproductive function. Human results are conflicting and mostly based on subfertile males, in whom the association between exposure and reproductive function may differ from the general population. The objectives is to study if levels of phthalate metabolites were associated with semen quality and reproductive hormones in general Swedish men.

Methods: We recruited 314 young men delivering semen, urine and blood samples at the same visit. We analysed five different reproductive hormones and seven semen parameters including progressive motility and high DNA stainability (HDS)—a marker for sperm immaturity. In urine, we analysed ten metabolites of five different phthalates, including metabolites of diethylhexyl phthalate (DEHP). We studied associations between urinary levels of the metabolites and seminal as well as serum reproductive parameters, accounting for potential confounders.

Results: DEHP metabolite levels, particularly urinary mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), were negatively associated with progressive sperm motility, which was 11 (95% CI: 5.0-17) percentage points lower in the highest quartile of MECPP than in the lowest (46% vs 57%). Further, men in the highest quartile of the DEHP metabolite monoethylhexyl phthalate had 27% (95% CI: 5.5%-53%) higher HDS than men in the lowest quartile (12% vs 9.6%).

Conclusions: DEHP metabolite levels seemed negatively associated with sperm motility and maturation.

http://resolver.ebscohost.com.ludwig.lub.lu.se/openurl?sid=EBSCO%3aedselp&genre=article&issn=01604120&ISBN=&
volume=85&issue=&date=20151201&spage=54&pages=54-60&title=Environment+International&atitle=
Phthalate+exposure+and+reproductive+parameters+in+young+men+from+
the+general+Swedish+population&aulast=
Axelsson%2c+Jonatan&id=DOI%3a10.1016%2fj.envint.2015.07.005&site=ftf-live

 Contact: Jonatan Axelsson


October 2015

Health surveillance under adverse ergonomics conditions – validity of a screening method

A new health surveillance protocol for work-related upper-extremity musculoskeletal disorders has been validated by comparing the results with a reference protocol.

A new health surveillance protocol for work-related upper-extremity musculoskeletal disorders has been validated by comparing the results with a reference protocol. The studied protocol, Health Surveillance in Adverse Ergonomics Conditions (HECO), is a new version of the reference protocol modified for application in the Occupational Health Service (OHS). The HECO protocol contains both a screening part and a diagnosing part. Sixty-three employees were examined. The screening in HECO did not miss any diagnosis found when using the reference protocol, but in comparison to the reference protocol considerable time savings could be achieved. Fair to good agreement between the protocols was obtainedfor one or more diagnoses in neck/shoulders (86%, k ¼ 0.62) and elbow/hands (84%, k ¼ 0.49). Therefore, the results obtained using the HECO protocol can be compared with a reference material collected with the reference protocol, and thus provide information of the magnitude of disorders in an examined work group.
The HECO protocol is a relatively simple physical examination protocol for identification of musculoskeletal disorders in the neck and upper extremities. The protocol is a reliable and cost-effective tool for the OHS to use for occupational health surveillance in order to detect workplaces at high risk for developing musculoskeletal disorders.

http://www.tandfonline.com/doi/pdf/10.1080/00140139.2015.1019575

Contact: Catarina Nordander


September 2015

No increased risk of coronary heart disease in relation to higher levels of perfluorinated compounds

Lately, there has been increasing interest for a certain type of environmental pollutants known as endocrine disruptors. These compounds are present in a variety of common materials, such as plastics, fire fighting foam, Gore-Tex and Teflon, but we still know very little regarding any potential negative health effects following exposure to these substances. Studies have linked exposure to some of these compounds and coronary heart disease, however, very few studies have been able to follow individuals over time, which makes the previous findings uncertain.

We aimed to investigate if there is a relationship between higher levels of a certain type of endocrine disruptors – the perfluorinated compounds – and the risk of coronary heart disease, when we were able to study the participants over time.
In a previous research material on men living in rural areas, we were able through the use of national registers, to identify all men who received a diagnosis of coronary heart disease between 1992 and 2009. For 253 of these men we could analyze levels of environmental pollutants in saved blood samples from the time before they received their diagnosis. For each case, we analyzed the levels in one healthy control born the same year as comparison.
We did not find an increased risk for coronary heart disease in relation to levels of perfluorinated compounds. However, it is not note that this study investigated men only.

http://www.ncbi.nlm.nih.gov/pubmed/26142720

Contact: Kristina Mattsson


July 2015

Car commuters have lower social capital than pedestrian, cyclist and public commuters 

It has been claimed that commuting, traveling from the home to the workplace, increases material wealth. Enlarged job regions create more opportunities for work and strengthen the economy for both individuals and society.

A more flexible and accessible labor market for companies is created by making the workforce available over larger geographical areas. Individuals are given increased opportunities to find jobs and select places to live, but commuting can be stressful due to the commute in itself, but also due to loss of time. Increased stress and less time means worse conditions for social interaction and makes it harder to form social capital. Social capital is a resource emerging from social relations in a society that can be used to solve problems of an individual or a collective nature. The aim of the study is to examine associations between commuting mode, commuting time and social capital, measured as social participation and generalized trust in other people, among men and women in the Swedish county Scania. The study is based on a retrospective dataset from two population-based public health questionnaires that was sent out in 2004 and 2008. Commuting was measured with two questions one about mode and one about duration. Social capital was also measured with two questions one about social participation the last 12 month and one about general trust in other people. Logistic regression was used to study the association between commuting and social capital. The results of the study shows that there is a stronger association between lower social participation and lower general trust in other people and car commuting in comparison to active and public commuting. Separate models for men and women showed similar results (but not as strong) and including an interaction variable for gender in the overall model did not show any statistical significant differences between gender. The conclusion of the study is that car commuters have lower social participation than active and public commuters, which is something that should be considered in policy decision about regional enlargement. 

http://eab.sagepub.com/content/47/7/734

Contact: Kristoffer Mattisson


May 2015

Manganese and selenium concentrations in umbilical cord serum and attention deficit hyperactivity disorder in childhood

Manganese and selenium are essential trace elements involved in many metabolic functions in the body. Exposures to high levels of manganese, however, have been linked to hyperactivity and ADHD in children. Selenium has a protective effect on neurotoxicity through its antioxidant effect and has recently been found to protect from prenatal manganese neurotoxicity. Manganese and selenium both cross the placenta and the fetal blood-brain barrier. The potential associations between manganese and selenium exposures during pregnancy and child neurodevelopment are relatively unexplored. The hypotheses raised in the present study are that manganese is associated with ADHD diagnosis, while selenium has a protective function against having ADHD.
The study base comprised children born in Malmö, Sweden, between 1978 and 2000 that were followed up until 2005. Children with ADHD (n=206) were identified at the Department of Child and Adolescent Psychiatry in Malmö. Controls (n=206) were selected from Medical Birth Register and were matched for year of birth and maternal country of origin. Concentrations of PFCs were measured in umbilical cord serum samples collected from a maternity unit biobank in Malmö.
No association between manganese concentrations in fetal life and ADHD was observed, but surprisingly, high selenium concentrations increased the odds of having an ADHD diagnosis in childhood. The association between ADHD diagnoses in children with relatively high cord selenium was unexpected and should be interpreted with caution.

http://www.ncbi.nlm.nih.gov/pubmed/25601741

Contact: Amanda Ode


April 2015

Effects of changing exposure to neighbourhood greenness on general and mental health: A longitudinal study

Green neighbourhood environments have been associated with physical and psychological wellbeing in adults. Access to greenness is potentially more important in vulnerable subgroups. In this study based on longitudinal survey data from southern Sweden the cohort was divided into prognostic groups for good self-reported general (n=8891) and mental (n=9444) health. We used independent survey data to assess perceived neighbourhood greenness in 1km2 areas, and estimated effects of changing exposure longitudinally stratified by prognostic group. The overall effect on health was small and statistically uncertain (for general health OR 1.04, 95% CI 0.98-1.10, for mental health OR 1.07, 95% CI 1.00-1.14). A more beneficial effect of increased greenness was indicated among subjects with lowest prognostic of good general health (OR 1.24, 95% CI 1.01-1.52). The study provided only weak evidence for beneficial effects of increased neighbourhood greenness triggered by changing residence. It seems that altered life circumstances, e.g. changed civil or socioeconomic status that often trigger a decision to move, are also the key determinants of the health consequences of changing residence.

Weimann H, Rylander L, Albin M, Skärbäck E, Grahn P, Östergren PO, Björk J. Effects of changing exposure to neighbourhood greenness on general and mental health: A longitudinal study. doi: 10.1016/j.healthplace.2015.02.003. [Epub ahead of print]

Contact: Hanna Weimann


March 2015

Neighbourhood environment and physical activity among young children: A cross-sectional study from Sweden

Aims: The aims of this study were to investigate the association between the neighbourhood environment and physical activity among young children in a Scandinavian setting, and to assess the influences of seasonal variations, age, sex and parental education.
Methods: Physical activity was assessed with an accelerometer and neighbourhood resources were estimated using geographic information systems for 205 Swedish children aged 4–11 years. Neighbourhood resources were generated as the sum of three neighbourhood attributes: (a) foot and bike paths, (b) non-restricted destinations and (c) recreational area, all within 300 m of each child’s home. Physical activity was assessed as: (a) total volume of physical activity (i.e. counts per minute), (b) sedentary time and (c) moderate to vigorous physical activity (MVPA). The association between neighbourhood resources and physical activity was analysed using mixed linear models weighted by measurement time and adjusted for sex, age, season of activity measurement, type of housing and parental education.
Results: Children were more physically active in areas with intermediate access to neighbourhood resources for physical activity compared to areas with worst access, while the difference between intermediate and best neighbourhood resource areas was less clear. The association between physical activity and neighbourhood resources was weaker than with seasonal variations but compatible in magnitude with sex, age, type of housing and parental education. Among specific neighbourhood attributes, the amount of foot and bike paths was associated with less sedentary time and more MVPA. Conclusions: This study provides some, not entirely consistent, evidence overall for an association between the neighbourhood environment and physical activity among young
children in Scandinavia.

Weimann H, Björk J, Rylander L, Bergman P, Eiben G. Neighbourhood environment and physical activity among young children: A cross-sectional study from Sweden SJP 2015 DOI: 10.1177/1403494815570515

Contact: Hanna Weimann


February 2015

Higher risk for the child to develop Type 1 diabetes if the mother smoked during her pregnancy

Prior research regarding the risk for the child to develop Type 1 diabetes if the mother smoked during the pregnancy has presented inconsistent results, where some studies even find a reduced risk of Type 1 diabetes in relation to fetal smoking exposure. These findings have been difficult to explain, in particular when considering the vast range of other detrimental health effects that have been linked to smoking exposure during fetal life.
The aim of this study was to examine if these puzzling findings could be due to previous studies being unable to account for genetic risk for Type 1 diabetes when examining the effects of fetal smoking exposure.
We identified all children in the region of Skåne with Type 1 diabetes born 1999-2005. For each child we chose three control children, matched for genetic risk profile (HLA type) and birth year, from a prospective cohort where all children born in Skåne 2000-2004 were invited to participate.
We found that smoking exposed children had a higher risk to develop Type 1 diabetes compared to their controls with similar genetic risk for the disease. This study highlights the importance of considering genetics when investigating environmental risk factors for complex diseases.

Mattsson K, Jonsson I, Malmqvist E, Larsson HE, Rylander L. Maternal smoking during pregnancy and offspring type 1 diabetes mellitus risk: accounting for HLA haplotype. Eur J Epidemiol. Jan 10 2015. DOI: 10.1007/s10654-014-9985-1

Contact: Kristina Mattsson


2014

December 2014/January 2015

Exploring inter-rater reliability and measurement properties of environmental ratings using kappa and colocation quotients

Available evidence suggest that perceptions or ratings of the neighborhood, e.g. as being green, walkable or noisy, are important for effects on health and wellbeing, also after controlling for objective measures of identical or similar features. When evaluating effects of the perceived environment, it is important that measurement properties and the reliability of the environmental ratings are evaluated before decisions about how these ratings should be handled in the statistical analyses are made. In this paper we broaden the usage of two association measures, the well-known kappa statistic and the novel colocation quotient (CLQ), to studies of inter-rater reliability and of associations between different categorical ratings in spatial contexts.
 We conducted reliability analysis of a survey instrument for assessing perceived greenness at geographical point locations, here the close outdoor environment within 5-10 minutes walking distance from home. Data were obtained from a public health survey conducted in 2008 in Scania, southern Sweden (n =27 967 participants).
 The results demonstrate the usefulness of kappa and CLQ as tools for assessing reliability and measurement properties of environmental rating scales when used at geographical point locations. We further show that the two measures are interchangeable, i.e. kappa can be accurately approximated from CLQ and vice versa, but can be used for somewhat different purposes in reliability analyses. Inter-rater reliability between the nearest neighbors was demonstrated for all five items of the evaluated instrument for assessing perceived greenness, albeit with clear differences across the items.
 Reliability analysis employing kappa and CLQ can be used as a basis for informed decisions about, for instance, how dichotomizations of the ratings should be defined and how missing or indefinite ratings should be handled. Such reliability analyses can thus serve as guidance for subsequent epidemiological studies of associations between environmental ratings, health and wellbeing.

Björk J, Rittner R, Cromley E. Exploring inter-rater reliability and measurement properties of environmental ratings using kappa and colocation quotients.Environ Health, 2014 Oct 23;13:86. doi: 10.1186/1476-069X-13-86.

Contact: Ralf Rittner


November 2014

Assessing ozone exposure for epidemiological studies in Malmö and Umeå, Sweden

Ground level ozone [ozone] is considered a harmful air pollutant but there is a knowledge gap regarding its long term health effects. The main aim of this study is to develop local Land Use Regression [LUR] models that can be used to study long term health effects of ozone. The specific aim is to develop spatial LUR models for two Swedish cities, Umeå and Malmö, as well as a temporal model for Malmö in order to assess ozone exposure for long term epidemiological studies. For the spatial model we measured ozone, using Ogawa passive samplers, as weekly averages at 40 sites in each study area, during three seasons. This data was then inserted in the LUR-model with data on traffic, land use, population density and altitude to develop explanatory models of ozone variation. To develop the temporal model for Malmö, hourly ozone data was aggregated into daily means for two measurement stations in Malmö and one in a rural area outside Malmö. Using regression analyses we inserted meteorological variables into different temporal models and the one that performed best for all three stations was chosen. For Malmö the LUR-model had an adjusted model R2 of 0.40 and cross validation R2 of 0.17. For Umeå the model had an adjusted model R2 of 0.67 and cross validation adjusted R2 of 0.48. When restricting the model to only including measuring sites from urban areas, the Malmö model had adjusted model R2 of 0.51 (cross validation adjusted R2 0.33) and the Umeå model had adjusted model R2 of 0.81 (validation adjusted R2 of 0.73). The temporal model had adjusted model R2 0.54 and 0.61 for the two Malmö sites, the cross validation adjusted R2 was 0.42. In conclusion, we can with moderate accuracy, at least for Umeå, predict the spatial variability, and in Malmö the temporal variability in ozone variation.

Malmqvist E, Olsson D, Hagenbjörk-Gustafsson A, Forsberg B, Mattisson K, Stroh E, Strömgren M, Swietlicki E, Rylander L, Hoek G, Tinnerberg H, Modig L. Assessing ozone exposure for long term epidemiological studies. 2014. Atmospheric Environment 94:241-248.

Contact: Ebba Malmqvist


October 2014

Aerial Application of Mancozeb and Urinary Ethylene Thiourea (ETU) Concentrations among Pregnant Women in Costa Rica: The Infants' Environmental Health Study (ISA)

Pregnant women living nearby banana plantations in Costa Rica have elevated concentrations of ethylene thiourea (ETU) in their urine. ETU is a metabolite of the pesticide mancozeb that is aerially sprayed at large-scale banana plantations. Current regulations for aerial spraying seem insufficient to prevent women from being exposed. The bananas produced at the plantations are principally exported to Europe and North America. This is the first study to evaluate pesticide exposure metabolites in pregnant women living near agricultural fields with aerial spraying.
From March 2010 to June 2011 451 pregnant women were enrolled, of which 445 provided urine samples during pregnancy that were analyzed for ETU. The amounts of ETU in their urine were higher than those found in the general population of United States, Italy and England; on average the pregnant women from Costa Rica had about five times more ETU in their urine. A small part of the women worked in agriculture - mostly banana - during pregnancy, whereas more than half of their partners worked on banana plantations. A quarter of women lived within 50 meters of a banana plantation. Some of the women had higher amounts of ETU in their urine than others because they lived closer to banana plantations, worked in agriculture during pregnancy, and / or washed clothes of their relatives who primarily worked at banana plantations.
Based on the amount of ETU found in the urine, the estimated daily dose entering the body was higher than the Reference Dose established by the Integral Risk Information (IRIS) from the Environmental Protection Agency of the United States (US-EPA) for 72% of the women.
The concentrations found in this study are of concern; previous studies in agricultural workers from Mexico and the Philippines have determined that exposure to mancozeb and its metabolite ETU might alter thyroid function. Thyroid hormones are essential for the development of the fetus and newborn.
The main source of exposure is likely the aerial spraying of mancozeb on the banana plantations, since the women did not use this product at home and diet also did not appear to be a main source of contact.
Current regulations for aerial spraying appear to be insufficient to prevent women from being exposed to pesticides.

van Wendel de Joode B, Mora AM, Córdoba L, Cano JC, Quesada R, Faniband M, Wesseling C, Ruepert C, Oberg M, Eskenazi B, Mergler D, Lindh CH. Aerial Application of Mancozeb and Urinary Ethylene Thiourea (ETU) Concentrations among Pregnant Women in Costa Rica: The Infants' Environmental Health Study (ISA). Environ Health Perspect. 2014 Sep 8.

Contact: Christian Lindh


September 2014

Inflammatory biomarkers in serum in subjects with and without work related neck/shoulder complaints

Background Although it has recently been recognised that inflammation is important in the development of work-related musculoskeletal disorders (MSDs), the exact pathophysiological pathways are unknown.

Methods We investigated serum concentrations of inflammatory cytokines in 35 female supermarket cashiers with repetitive work tasks and work related neck/shoulder complaints, compared with those from 25 women without MSDs (6 supermarket cashiers and 19 middle-school teachers or faculty staff). None of the subjects were pregnant or lactating, and showed no signs of rheumatoid arthritis, systemic lupus erythematosus, cancer, diabetes, coronary artery disease or inadequately controlled hypertension. Serum levels of IL-1α, IL-1β, IL-6, IL-8, IL-10, IL-12, MCP-1, MIP-1α, MIP-1β, TNF-α, GM-CSF, CTGF and CRP were analysed.

Results The women with pain related to MSD had higher serum concentrations of MIP-1β (median, 25th-75th percentile: 90.0 pg/mL, 62.5-110 vs. 73.1 pg/mL, 54.6-88.3; p = 0.018), IL-12 (0.26 pg/mL, 0.26-0.26 vs. 0.26 pg/mL, 0.26-0.26; p = 0.047) and CRP (0.5 mg/L, 0.5-1.6 vs. 0.5 mg/L, 0.5-0.5; p = 0.003), than control subjects. Levels of MIP-1α, MIP-1β and CRP were correlated with the reported intensity of neck/shoulder pain (r = 0.29, p = 0.03 for MIP-1α; r = 0.29, p = 0.02 for MIP-1β and r = 0.43, p = 0.001 for CRP). No statistically significant differences in serum levels were found for the remaining cytokines.

Conclusions Otherwise healthy females with ongoing work-related neck/shoulder pain showed higher serum concentrations of MIP-1β, IL-12 and CRP than controls, and the levels of MIP-1α, MIP-1β and CRP were correlated to pain intensity. These results support previous findings that inflammatory processes play a part in work related MSDs.

Inflammatory biomarkers in serum in subjects with and without work related neck/shoulder complaints. Matute Wilander A, Kåredal M, Axmon A, Nordander C

Contact: Catarina Nordander


July/August 2014

Fetal Exposure to Perfluorinated Compounds and Attention Deficit Hyperactivity Disorder in Childhood

Background: The association between exposure to perfluorinated compounds (PFCs) and attention deficit hyperactivity disorder (ADHD) diagnosis has been sparsely investigated in humans and the findings are inconsistent.
Objectives: A matched case-control study was conducted to investigate the association between fetal exposure to PFCs and ADHD diagnosis in childhood.
Methods: The study base comprised children born in Malmo¨ , Sweden, between 1978 and 2000 that were followed up until 2005. Children with ADHD (n = 206) were identified at the Department of Child and Adolescent Psychiatry. Controls (n = 206) were selected from the study base and were matched for year of birth and maternal country of birth. PFC concentrations were measured in umbilical cord serum samples. The differences of the PFC concentrations between cases and controls were investigated using Wilcoxon’s paired test. Possible threshold effects (above the upper quartile for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) and above limit of detection [LOD] for perfluorononanoic acid (PFNA)) were evaluated by conditional logistic regression.
Results: The median umbilical cord serum concentrations of PFOS were 6.92 ng/ml in the cases and 6.77 ng/ml in the controls. The corresponding concentrations of PFOA were 1.80 and 1.83 ng/ml. No associations between PFCs and ADHD were observed. Odds ratios adjusted for smoking status, parity, and gestational age were 0.81 (95% confidence interval [CI] 0.50 to 1.32) for PFOS, 1.07 (95% CI 0.67 to 1.7) for PFOA, and 1.1 (95% CI 0.75 to 1.7) for PFNA.
Conclusions: The current study revealed no support for an association between fetal exposure to PFOS, PFOA, or PFNA and ADHD.

Fetal exposure to perfluorinated compunds and attention deficit hyperactivity disorder in childhood

Contact: Amanda Ode


Paltform for Sustainable work as a resource for health, innovation and growth in EC´s Horizon 2020

Platform for Sustainable work as a resource for health, innovation and growth in the EC's Horizon 2020

Supported by strategic funding from Vinnova we have developed a platform to promote ”Sustainable work as a resource for health, innovation and growth” within the Horizon 2020 program. Sustainable work is an important production factor to increase economic growth and to stimulate long-term competitiveness.
Sustainable work is a strong Swedish and Nordic research area. Together with other Nordic countries, Sweden can generate European added value and strengthen future European competitiveness.
Through a stable and competent network of Swedish researchers from all universities, labor market interest groups, companies and authorities, the platform will identify possible openings for the research area of “Sustainable work” within Horizon 2020, implement a strategy to impact Horizon 2020 and build a broad network of European researchers. Sustainable work as political area and as concept has been developed in specific documents. Suggestions for possible cooperation on European level have been developed and the platform was constituted during a workshop with international participants.

In order to be able to continue the development of the platform during the next two years, we have applied for financial support to VINNOVA. During this time we will:

  • Strengthen the cooperation between Swedish research environments and the rest of Europe plus deepen the cooperation between labor market interest groups and other stakeholders.
  • Work towards increasing space for this research area within Horizon 2020 and towards Swedish researchers with this type of competence to get leading roles in the European cooperation.
  • Function as a meeting place for Swedish and European researchers.

 The platform welcomes new initiatives and partners!
The project is coordinated by Maria Albin, Occupational and Environmental Medicine, Lund University. The project cooperates with all other researchers through three nodes, and contact persons are Mats Bohgard, Lunds Tekniska Högskola, Southern node, Per Gustavsson, Karolinska Institute, Middle-Swedish Node, Bengt Järvholm, Umeå University, Northern node.

Contacts of persons within the platform


March/April 2014

Effects of diesel exposure on lung function and inflammation biomarkers from airway and peripheral blood of healthy volunteers in a chamber study

Background: Exposure to diesel exhaust causes inflammatory responses. Previous controlled exposure studies at a concentration of 300 μg/m3 of diesel exhaust particles mainly lasted for 1 h. We prolonged the exposure period and investigated how quickly diesel exhaust can induce respiratory and systemic effects.
Methods: Eighteen healthy volunteers were exposed twice to diluted diesel exhaust (PM1 ~300 μg/m3) and twice to filtered air (PM1 ~2 μg/m3) for 3 h, seated, in a chamber with a double-blind set-up. Immediately before and after exposure, we performed a medical examination, spirometry, rhinometry, nasal lavage and blood sampling. Nasal lavage and blood samples were collected again 20 h post-exposure. Symptom scores and peak expiratory flow (PEF) were assessed before exposure, and at 15, 75, and 135 min of exposure.
Results: Self-rated throat irritation was higher during diesel exhaust than filtered air exposure. Clinical signs of irritation in the upper airways were also significantly more common after diesel exhaust exposure (odds ratio=3.2, p<0.01). PEF increased during filtered air, but decreased during diesel exhaust exposure, with a statistically significant difference at 75 min (+4 L/min vs. -10 L/min, p=0.005). Monocyte and total leukocyte counts in peripheral blood were higher after exposure to diesel exhaust than filtered air 20 h post-exposure, and a trend (p=0.07) towards increased serum IL-6 concentrations was also observed 20 h post-exposure.
Conclusions: Diesel exhaust induced acute adverse effects such as symptoms and signs of irritation, decreased PEF, inflammatory markers in healthy volunteers. The effects were first seen at 75 min of exposure.

Effects of diesel exposure on lung function and inflammation biomarkers from airway and peripheral blood of healthy volunteers in a chamber study
Yiyi Xu, Lars Barregard, Jörn Nielsen, Anders Gudmundsson, Aneta Wierzbicka, Anna Axmon, Bo AG Jönsson, Monica Kåredal and Maria Albin

Contact: Bo Jönsson


February 2014

Exposure and Emission Measurements During Production, Purification, and Functionalization of Arc-Discharge-Produced Multi-walled Carbon Nanotubes

Background: The production and use of carbon nanotubes (CNTs) is rapidly growing. With increased production, there is potential that the number of occupational exposed workers will rapidly increase. Toxicological studies on rats have shown effects in the lungs, e.g. inflammation, granuloma formation, and fibrosis after repeated inhalation exposure to some forms of multi-walled CNTs (MWCNTs). Still, when it comes to health effects, it is unknown which dose metric is most relevant. Limited exposure data for CNTs exist today and no legally enforced occupational exposure limits are yet established. The aim of this work was to quantify the occupational exposures and emissions during arc discharge production, purification, and functionalization of MWCNTs. The CNT material handled typically had a mean length <5 μm. Since most of the collected airborne CNTs did not fulfil the World Health Organization fibre dimensions (79% of the counted CNT-containing particles) and since no microscopy-based method for counting of CNTs exists, we decided to count all particle that contained CNTs. To investigate correlations between the used exposure metrics, Pearson correlation coefficient was used.
Methods: Exposure measurements were performed at a small-scale producer of MWCNTs and respirable fractions of dust concentrations, elemental carbon (EC) concentrations, and number concentrations of CNT-containing particles were measured in the workers’ breathing zones with filterbased methods during work. Additionally, emission measurements near the source were carried out during different work tasks. Respirable dust was gravimetrically determined; EC was analysed with thermal–optical analysis and the number of CNT-containing particles was analysed with scanning electron microscopy.
Results: For the personal exposure measurements, respirable dust ranged between <73 and 93 μg m−3, EC ranged between <0.08 and 7.4 μg C m−3, and number concentration of CNT-containing particles ranged between 0.04 and 2.0 cm−3. For the emission measurements, respirable dust ranged between <2800 and 6800 μg m−3, EC ranged between 0.05 and 550 μg C m−3, and number concentration of CNT-containing particles ranged between <0.20 and 11 cm−3.
Conclusions: The highest exposure to CNTs occurred during production of CNTs. The highest emitted number concentration of CNT-containing particles occurred in the sieving, mechanical work-up, pouring, weighing, and packaging of CNT powder during the production stage. To be able to quantify exposures and emissions of CNTs, a selective and sensitive method is needed. Limitations with measuring EC and respirable dust are that these exposure metrics do not measure CNTs specifically. Only filter-based methods with electron microscopy analysis are, to date, selective and sensitive enough. This study showed that counting of CNT-containing particles is the method that fulfils those criteria and is therefore the method recommended for future quantification of CNT exposures. However, CNTs could be highly toxic not only because of their length but also because they could contain, for example transition metals and polycyclic aromatic hydrocarbons, or have surface defects. Lack of standardized counting criteria for CNTs to be applied at the electron microscopy analysis is a limiting factor, which makes it difficult to compare exposure data from different studies.

Exposure and Emission Measurements During Production, Purification, and Functionalizationof Arc-Discharge-Produced Multi-walled Carbon Nanotubes Maria Hedmer, Christina Isaxon, Patrik T. Nilsson, Linus Ludvigsson, Maria E. Messing, Johan Genberg, Vidar Skaug, Mats Bohgard, Håkan Tinnerberg and Joakim H. Pagels Ann Occup Hyg. doi:10.1093/annhyg/met072

http://annhyg.oxfordjournals.org/content/early/2014/01/02/annhyg.met072.long

Contact: Maria Hedmer, maria.hedmer@med.lu.se


January 2014

Menstrual cycle characteristics in fertile women from Greenland, Poland and Ukraine exposed to perfluorinated chemicals: a cross-sectional study

Study question: Does perfluorooctane sulfonate (PFOS) and perfluorooctanate (PFOA) exposure disrupt the menstrual cyclicity?
Summary answer: The female reproductive system may be sensitive to PFOA exposure, with longer menstrual cycle length at higher exposure.
What is known already: PFOS and PFOA are persistent man-made chemicals. Experimental animal studies suggest they are reproductive toxicants but epidemiological findings are inconsistent.
Study design, size, duration: A cross-sectional study including 1623 pregnant women from the INUENDO cohort enrolled during antenatal care visits between June 2002 and May 2004 in Greenland, Poland and Ukraine.
Participants/materials, setting, methods: Information on menstrual cycle characteristics was obtained by questionnaires together with a blood sample from each pregnant woman. Serum concentrations of PFOS and PFOA were measured by liquid chromatography tandem mass spectrometry. Multiple imputations were performed to account for missing data. The association between PFOS/PFOA and menstrual cycle length (short cycle: ≤24 days, long cycle: ≥32 days) and irregularities (≥7 days in difference between cycles) was analyzed using logistic regression with tertiles of exposure. Estimates are given as adjusted odds ratios (ORs) with 95% confidence intervals (CIs).
Main results and the role of chance: Higher exposure levels of PFOA were associated with longer menstrual cycles in pooled estimates of all three countries. Compared with women in the lowest exposure tertile, the adjusted OR of long cycles was 1.8 (95% CI: 1.0; 3.3) among women in the highest tertile of  PFOA exposure. No significant associations were observed between PFOS exposure and menstrual cycle characteristics. However, we observed a tendency toward more irregular cycles with higher exposure to PFOS [OR 1.7 (95% CI: 0.8; 3.5)]. The overall response rate was 45.3% with considerable variation between countries (91.3% in Greenland, 69.1% in Poland and 26.3% in Ukraine).
Limitations, reasons for caution: Possible limitations in our study include varying participation rates across countries; a selected study group over representing the most fertile part of the population; retrospective information on menstrual cycle characteristics; the determination of cut-points for all three outcome variables; and lacking information on some determinants of menstrual cycle characteristics, such as stress, physical activity, chronic diseases and gynecological disorders, thus confounding cannot be excluded.
Wider implications of the findings: The generalizability of the study results is restricted to fertile women who manage to conceive and women who do not use oral contraceptives when getting pregnant or within 2 months before getting pregnant. To our knowledge only one previous epidemiological study has addressed the possible association between perfluorinated chemical exposure and menstrual disturbances. Though pointing toward different disturbances incyclicity, both studies suggest that exposure to PFOA may affect the female reproductive function. This study contributes to the limited knowledge on effects of exposure to PFOA and PFOS on female reproductive function and suggests that the female reproductive system may be affected by environmental exposure to PFOA.

http://humrep.oxfordjournals.org/content/early/2013/10/25/humrep.det390.full.pdf+html 

Lyngsø J, Ramlau-Hansen CH, Høyer BB, Støvring H, Bonde JP, Jönsson BA, Lindh CH, Pedersen HS, Ludwicki JK, Zviezdai V, Toft G.

Contact: Christian Lindh, christian.lindh@med.lu.se 


2013

December 2013

Asthma incidence in children growing up close to traffic

Background: A number of long-term studies have shown associations between air pollution from traffic and asthma incidence among children. These studies have almost exclusively relied on survey data, with parental-reported prevalence of asthma in their children. The purpose of the present study was to investigate if living close to traffic is associated with asthma incidence among children, when using register-based outcome data.
Method: The Swedish Prescribed Drug Register contains information on all asthma medications that has been dispensed at pharmacies in Sweden, and dispense of asthma medication was used as a proxy variable for asthma incidence and other obstructive respiratory disease. Outcome variables were also hospital and primary health care visits with primary diagnoses  of bronchiolitis, obstructive bronchitis or asthma (The Scania Health Care Register). Covariate information was collected in surveys  distributed on child health care centers at the children’s 8 month checkups, and contained questions about environmental tobacco smoke, breastfeeding, allergic heredity, socio-economic status etc. Exposure measures was traffic intensity on heaviest road within 100m from residence, and dispersion modeled concentrations of NOx (100x100m grid) on the residential address, modeled with Geographical Information systems. The birth cohort included 26128 children with outcome- and exposure data, born july 2005-2010 in Scania. Of these, 7898 also had covariate information from a survey. The cohort was followed to the end of 2011, i.e. the oldest children were followed to the age of 6 years.
Results: Living close to a road with high traffic intensity, was not associated with higher incidence of single (Hazard ratio=0.9, 95% CI: 0.8-1.0)  or continuous dispense uttag (Hazard ratio=0.7, 95% CI: 0.6-0.9) of inhaled B2-agonists, or inhaled corticosteroids. It was not associated with higher incidence of the diagnoses bronchiolitis, obstructive bronchitis, or asthma. Similar results were seen for living in areas with high levels of NOx.
Conclusion: Growing up close to traffic was not associated with higher incidence of asthma medication or diagnosis of asthma, bronchiolitis, or obstructive bronchitis, among children 0-6 years old in Scania. 

http://www.ncbi.nlm.nih.gov/pubmed/24160449

Lindgren A, Stroh E, Björk J, Jakobsson K. 

Contact: Anna Lindgren, anna.lindgren@med.lu.se 


November 2013

Exposure to respirable dust and manganese and prevalence of airways symptoms, among Swedish mild steel welders in the manufacturing industry

Purpose: Welding fume consists of metal fumes, e.g., manganese (Mn) and gases, e.g., ozone. Particles in the respirable dust (RD) size range dominate. Exposure to welding fume could cause short- and long-term respiratory effects. The prevalence of work-related symptoms among mild steel welders was studied, and the occupational exposure to welding fumes was quantified by repeated measurements of RD, respirable Mn, and ozone. Also the variance components were studied.
Method: A questionnaire concerning airway symptoms and occupational history was answered by 79 % of a cohort of 484 welders. A group of welders (N = 108) were selected and surveyed by personal exposure measurements of RD and ozone three times during 1 year.
Results: The welders had a high frequency of work-related symptoms, e.g., stuffy nose (33 %), ocular symptoms (28 %), and dry cough (24 %). The geometric mean exposure to RD and respirableMnwas 1.3mg/m3 (min–max 0.1–38.3mg/m3) and 0.08 mg/m3 (min–max\0.01–2.13 mg/m3), respectively. More than 50 % of the Mn concentrations exceeded the Swedish occupational exposure limit (OEL). Mainly, low concentrations of ozone were measured, but 2 % of the samples exceeded the OEL. Of the total variance for RD, 30 and 33 % can be attributed to within-worker variability and between-company variability, respectively.
Conclusions: Welders had a high prevalence of workrelated symptom from the airways and eyes. The welders’ exposure to Mn was unacceptably high. To reduce the exposure further, control measures in the welding workshops are needed. Correct use of general mechanical ventilation and local exhaust ventilation can, for example, efficiently reduce the exposure.

http://rd.springer.com/content/pdf/10.1007%2Fs00420-013-0896-3.pdf


October 2013

The Impact of Paternal and Maternal Smoking on Semen Quality of Adolescent Men.

Background: Maternal smoking during pregnancy has been reported to negatively impact sperm counts of the sons. Sufficient data on the effect of paternal smoking is lacking.

Objectives: We wished to elucidate the impact of maternal and paternal smoking during pregnancy and current own smoking on reproductive function of the male offspring.

Methods: Semen parameters including sperm DNA integrity were analyzed in 295 adolescents from the general population close to Malmö, Sweden, recruited for the study during 2008-2010. Information on maternal smoking was obtained from the Swedish Medical Birth Register, and regarding own and paternal smoking from questionnaires. The impacts of maternal, paternal and own smoking were evaluated in a multivariate regression model and by use of models including interaction terms. Totally, three exposures and five outcomes were evaluated.

Results: In maternally unexposed men, paternal smoking was associated with 46% lower total sperm count (95%CI: 21%, 64%). Both paternal and maternal smoking were associated with a lower sperm concentration (mean differences: 35%; 95%CI: 8.1%, 55% and 36%; 95%CI: 3.9%, 57%, respectively) if the other parent was a non-smoker. No statistically significant impact of own smoking on semen parameters was seen.

Conclusions: Prenatal both maternal and paternal smoking were separately associated with some decrease in sperm count in men of whom the other parent was not reported to smoke.

http://www.ncbi.nlm.nih.gov/pubmed/23840528

Axelsson J, Rylander L, Rignell-Hydbom A, Silfver KA, Stenqvist A, Giwercman A.


June 2013

Exposure to smoking during fetal life and risk of developing gestational diabetes and obesity in adulthood
 

Exposure to smoking during fetal life has been associated with several negative outcomes for the offspring, including lower birthweight, shorter gestational length and obesity in childhood. It is unclear, however, if these adverse effects persist until adulthood. The main objective of this study was to examine the risk of developing gestational diabetes (pregnancy diabetes) and obesity in women who were exposed to tobacco smoking during their fetal life. Especially the risk of gestational diabetes is insufficiently investigated in the literature.

Data were retrieved from the Medical Birth Register of Sweden, which contains information on almost all births in Sweden since 1973. Women born 1982 (data on pregnancy smoking first registered) or later, who have given birth to atleast one child of their own were included in the study; 80 189 pregnancies were included.

The study found that women exposed to smoking in their fetal life were at higher risk of developing gestational diabetes and obesity, compared to non-exposed. The associations remained after adjustment for maternal age at childbirth, parity (=birth order), BMI, mode of delivery, birthweight and gestational length. If these associations are causal or due to something else cannot be determined in the present setting.

  Mattsson K, Källén K, Longnecker MP, Rignell-Hydbom A, Rylander L. 

Contact: Kristina Mattsson, kristina.mattsson@med.lu.se


May 2013

Polymorphisms in Iron Homeostasis Genes and Urinary Cadmium Concentrations among Nonsmoking Women in Argentina and Bangladesh

Background: Cadmium (Cd) is a human toxicant and carcinogen. Genetic variation might affect long-term accumulation. Cd is absorbed via iron transporters.

Objectives: We evaluated the impact of iron homeostasis genes [divalent metal transporter 1 (SLC11A2), transferrin (TF), transferrin receptors (TFR2 and TFRC), and ferroportin (SLC40A1)] on Cd accumulation.

Methods: Subjects were nonsmoking women living in the Argentinean Andes [n = 172; median urinary Cd (U-Cd) = 0.24 µg/L] and Bangladesh (n = 359; U-Cd = 0.54 µg/L) with Cd exposure mainly from food. Concentrations of U-Cd and Cd in whole blood or in erythrocytes (Ery-Cd) were measured by inductively coupled plasma mass spectrometry. Fifty polymorphisms were genotyped by Sequenom. Gene expression was measured in whole blood (n = 72) with Illumina DirectHyb HumanHT-12 v4.0.

Results: TFRC rs3804141 was consistently associated with U-Cd. In the Andean women, mean U-Cd concentrations were 22% (95% CI: –2, 51%), and they were 56% (95% CI: 10, 120%) higher in women with GA and AA genotypes, respectively, relative to women with the GG genotype. In the Bangladeshi women, mean U-Cd concentrations were 22% (95% CI: 1, 48%), and they were 58% (95% CI: –3, 157%) higher in women with GA and AA versus GG genotype, respectively [adjusted for age and plasma ferritin in both groups; ptrend = 0.006 (Andes) and 0.009 (Bangladesh)]. TFRC expression in blood was negatively correlated with plasma ferritin (rS = –0.33, p = 0.006), and positively correlated with Ery-Cd (significant at ferritin concentrations of < 30 µg/L only, rS = 0.40, p = 0.046). Rs3804141 did not modify these associations or predict TFRC expression. Cd was not consistently associated with any of the other polymorphisms evaluated.

Conclusions: One TFRC polymorphism was associated with urine Cd concentration, a marker of Cd accumulation in the kidney, in two very different populations. The consistency of the findings supports the possibility of a causal association.

Gerda Rentschler, Maria Kippler, Anna Axmon, Rubhana Raqib, Eva-Charlotte Ekström, Staffan Skerfving, Marie Vahter, Karin Broberg


April 2013

Occupational posture exposure among construction electricians

Objective: To record, objectively describe and compare working postures of Brazilian and Norwegian construction electricians.
Methods: Postures of the upper arms, head, and neck during work and breaks were quantified by means of inclinometry for a representative sample of 12 Brazilian and 12 Norwegian electricians in the construction industry during a full work-shift.
Results: Despite that differences were found between specific work-related factors, Brazilian and Norwegian workers revealed a high and very similar level and pattern of postures for all evaluated body regions, suggesting that our results can be extrapolated to other electricians. Upper arm elevation was high and similar for both groups and head flexion and extension was pronounced compared to other occupations.

Conclusion: Extreme postures were identified for construction electricians in both countries, with similar exposure pattern also for defined tasks (planning, support and wiredraw), suggesting that this job is risky regardless of organizational differences.

Moriguchi CS, Carnaz L, Veiersted KB, Hanvold TN, Hæg LB, Hansson G-Å, Coury HJCG


March 2013

Cancer Incidence in a Cohort of Swedish Chimney Sweeps,1958–2006

Objectives.
We examined cancer incidence in an expanded cohort of Swedishchimney sweeps.

Methods.
We added male chimney sweep trade union members (1981–2006) to an earlier cohort (employed 1918–1980) and linked them to nationwide registersof cancer, causes of deaths, and total population. The total cohort (n=6320) was followed from 1958 through 2006. We estimated standardized incidence ratios (SIRs) using the male Swedish population as reference. We estimated exposure as years of employment and analyzed for exposure–response associations by poisson regression.

Results.
A total of 813 primary cancers were observed vs 626 expected (SIR =1.30; 95% confidence interval = 1.21, 1.39). As in a previous follow-up, SIRs were significantly increased for cancer of the esophagus, liver, lung, bladder, and all hematopoietic cancer. New findings included significantly elevated SIRs for cancer of the colon, pleura, adenocarcinoma of the lung, and at unspecified sites.
Total cancer and bladder cancer demonstrated positive exposure–response associations.

Conclusions.
Exposure to soot and asbestos are likely causes of the observed cancer excesses, with contributions from adverse lifestyle factors. Preventive actions to control work exposures and promote healthier lifestyles are an important priority.

Christer Hogstedt, Catarina Jansson,  Marcus Hugosson, Håkan Tinnerberg, Per Gustavsson


January/ February 2013

Gestational Diabetes and Preeclampsia in Association with Air Pollution at Levels below Current Air Quality Guidelines

Background: Several studies have estimated associations between air pollution and birth outcomes, but few have evaluated potential effects on pregnancy complications.

Objective: To investigate whether low-level exposure to air pollution is associated with gestational diabetes and preeclampsia.

Method: High quality registry information on 81,110 non-selected singleton pregnancy outcomes in southern Sweden during 1999-2005 was linked to individual-level exposure estimates with high spatial resolution. Modeled exposure to nitrogen oxides (NOx), expressed as mean concentrations per trimester, and proximity to roads of different traffic densities, were used as proxy indicators of exposure to combustion-related air pollution. The data were analyzed by logistic regression, with and without adjusting for potential confounders.

Results: The prevalence of gestational diabetes increased with each NOx quartile, with an adjusted odds ratio (OR) of 1.69 (95% CI: 1.41, 2.03) for the highest (>22.7 μg/m3) compared to the lowest quartile (2.5-8.9 μg/m3) of exposure during the second trimester. The adjusted OR for acquiring preeclampsia after exposure during the third trimester, was 1.51 (1.32, 1.73) in the highest quartile of NOx compared to the lowest. Both outcomes were associated with high traffic density, but ORs were significant for gestational diabetes only.

Conclusion: NOx exposure during pregnancy was associated with gestational diabetes and preeclampsia in an area with air pollution levels below current air quality guidelines.

Ebba Malmqvist, Kristina Jakobsson, Håkan Tinnerberg, Anna Rignell-Hydbom, Lars Rylander


2012 

December 2012

Air pollution and stroke
Oudin A, Forsberg B, Jakobsson K. Air pollution and stroke. Epidemiology 2012, 23:505-6.

In a previous study in Scania we observed that increased levels of ambient particulate matter (PM10) were associated with an increase in the number of patients admitted for ischemic stroke the next day. We now have investigated whether that effect was modified by stroke history.
We found that elevated levels of PM10 increased the number of ischemic stroke events on the same day and the following day only in patients with a history of stroke, not in patients with first-time stroke. The estimated increase was 4% for an PM10 increase from 12 till 21 μg/mμ - that is at levels substantially lower than the present European air quality guidelines.
These results suggest that susceptibility to short-term exposure to air-pollution exposure depends on disease history. The evidence for interaction between air pollution and comorbid factors on stroke risk is growing; recent research from our group also suggests that the diabetes-induced risk of first-time ischemic stroke depends on air-pollution levels in the neighbourhood of the patient.


June 2012

Rationalization in meat cutting – Consequences on physical workload

Meat cutting is associated with several ergonomic risk factors and a high risk of musculoskeletal disorders. The development of new production systems points to an increased degree of mechanization; instead of subdividing split carcasses of pigs with a knife, the halves are trisected by an electrical saw into ‘sixth-parts’, resulting in shorter work cycles for the workers. Recently, machine-directed line-production

systems have been implemented. This study evaluates differences in the physical workload between the production systems.

  The postures and movements (inclinometry and goniometry) and muscular load (electromyography) of workers in the split-carcass- (five subjects), sixth-part- (ten) and line-production systems (five) were recorded.

  Most measures showed a statistically significant trend of declining physical exposure with increasing degrees of mechanization. For example, movement velocities of the upper arm were higher in the splitcarcass system (50th percentile: mean 209º/s) than in the sixth-part (103º/s) and line production (81º/s). However, the latter two were not statistically significantly different.

  A novel method for quantifying posture variation, based on inclinometry, showed that the split-carcass system implied the highest variation of the upper arm postures “within-minute” (i.e., a high range of motion each minute), but the lowest “between-minute” (i.e., a low variation during the course of the workday).

  In conclusion, the physical workload in the line-production system was significantly lower than in the split-carcass one, and tended also to be lower than in the sixth-part system. However, there may be disadvantages in line production, such as machine-directed work pace and shorter work cycles.


May 2012

Blood serum concentrations of perfluorinated compounds in men from Greenlandic Inuit and European populations.

Perfluorinated compound (PFCs), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are used in large quantities. They are persistent and found in measurable levels in human serum around the world. They have been associated with developmental, hepatic, and carcinogenic effects in animal studies. The aim of the present study was to describe levels of PFCs in serum among Inuits from Greenland and inhabitants from Warsaw, Poland and Kharkiv, Ukraine. Furthermore, the aim was to define social- and lifestyle related determinants of exposure for these compounds. Serum levels of seven PFCs were analysed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). The concentrations of PFOS and PFOA were the highest of all PFCs in all three populations with a total amount of almost 90% of the PFCs. The mean levels of PFOS and PFOA were in the Greenlandic Inuits 52 and 4.8 ng/ml, in Poland 19 and 5.2 ng/ml and in Ukraine 8.1 and 1.9 ng/ml, respectively. Thus, levels of PFCs in the serum of Inuits on Greenland were among the highest described in a general population whereas the levels in Poland were similar to other industrialized countries. The exposure in Ukraine was rather low. In the Greenlandic Inuit population, intake of seafood, tea, age and area of living were significant determinants of PFOS concentrations and explained about 22% of the variation. For the other populations no strong determinants were found.


April 2012

Phthalates and Perfluorooctanesulfonic Acid in Human Amniotic Fluid: Temporal Trends and Timing of Amniocentesis in Pregnancy

Background: Measures of prenatal environmental exposures are important, and amniotic fluid levels may directly reflect fetal exposures during hypothesized windows of vulnerability. We aimed to detect various phthalate metabolites and perfluorooctanesulfonic acid (PFOS) in human amniotic fluid, to study temporal exposure trends, and to estimate potential associations with gestational week of amniocentesis, maternal age and parity at amniocentesis.

Methods: We studied 300 randomly selected second trimester amniotic fluid samples from a Danish pregnancy-screening biobank covering 1980 to 1996. We used only samples from male offspring pregnancies. We assayed the environmental pollutants by liquid chromatography tandem mass spectrometry, and analyzed data using generalized linear regression models.

Results: We detected the di(2-ethylhexyl) phthalate (DEHP) metabolite mono(2-ethyl-5-carboxypentyl) phthalate (5-cx-MEPP) at a median concentration of 0.27 ng/ml, the diisononyl phthalate (DiNP) metabolite mono(4-methyl-7-carboxyheptyl) phthalate (7-cx-MMeHP) at 0.07 ng/ml and PFOS at 1.1 ng/ml. An increase of one calendar year was associated with 3.5% lower 5-cx-MEPP levels and with 7.1% higher 7-cx-MMeHP levels. No change was seen for PFOS. For each later gestational week of amniocentesis 5-cx-MEPP was 9.9% higher, 7-cx-MMeHP was 8.6% higher and PFOS was 9.4% higher. We observed no associations with maternal age or parity.

Conclusions: Measured metabolite levels appeared to parallel decreasing DEHP exposure and increasing DiNP exposure during the study period. The environmental pollutant levels were positively associated with later gestational age at amniocentesis during pregnancy weeks 12-22.


March 2012

Assessment of long-term and recent pesticide exposure among rural school children in Nicaragua

Rodríguez T, van Wendel de Joode B, Lindh CH, Rojas M, Lundberg I, Wesseling C

Objective: This study assessed pesticide exposure of children in rural Nicaragua in relation to parental pesticide use, from around conception to current school age, as part of an epidemiological evaluation of neurodevelopment effects.

Methods We included 132 children whose parents were subsistence farmers or plantation workers, or had an agricultural history. As proxies for children’s long-term exposures, we constructed cumulative parental pesticide-specific use indices for periods before and after the child’s birth from data obtained using an icon-calendar-based questionnaire, of application hours (h) for  plantation workers and subsistence farmers, and of kilograms of active ingredients (ai) only for subsistence farmers. Pesticide residues of TCPY, 3-PBA and 2,4-D were analysed in children’s urine as indicators for current exposures.

Results: Life-time indices were highest for the organophosphates chlorpyrifos (median 114 h (min 2; max 1584), 19.2 kg ai (min 0.37; max 548)) and methamidophos (84 h (6; 1964), 12.2 kg ai (0.30; 780)). The P50 values of children’s urinary residues were 3.7 mg/g creatinine for TCPY, 2.8 for 3-PBA and 0.9 for 2,4-D; TCPY values are comparable with those in other countries, but 3-PBA and 2,4-D are considerably higher. The maximum levels for all three pesticides are the highest reported for children. Residues increased on days after application, but most high residue levels were unrelated to parental pesticide applications.

Conclusion: Urinary pesticide residues reveal high environmental exposure among children in rural Nicaragua. The quantitative parental pesticide use indices as proxies for children’s exposures during different periods may be useful for the evaluation of developmental health effects.


February 2012

A follow-up of cognitive performance and diurnal salivary cortisol changes in former burnout patients.

Österberg K, Karlson B, Malmberg B, Hansen AM.

The purpose of the study was to determine whether recovery from burnout is associated with improved cognitive functioning, and whether such improvement is associated with changes in hypothalamic-pituitary-adrenal (HPA) axis activity and return to work. Forty-five former burnout patients were followed up after 1.5 years with a neuropsychological examination, diurnal salivary cortisol measurements, dexamethasone suppression test (DST), and self-ratings of cognitive problems. At follow-up, improved cognitive performance was observed on several tests of short-term memory and attention. Self-rated cognitive problems decreased considerably, but this decrease was unrelated to the improvement on neuropsychological tests. Diurnal salivary cortisol concentrations at awakening, 30 min after awakening, and in the evening, did not change from baseline to follow-up, nor did the cortisol awakening response. However, slightly, but significantly, stronger suppression of cortisol in response to the DST was observed at follow-up. Improvements in subjective or objective cognitive functioning and changes in diurnal cortisol concentration were unrelated to the extent of work resumption. However, a decreased DST response at follow-up was partially related to improved cognitive performance and work resumption. The clinical implications are that burnout seems to be associated with slight and significantly reversible cognitive impairment, and that self-rated cognitive change during recovery poorly reflects objective cognitive change.


January 2012

Effects of prismatic glasses including optometric correction on head and neck kinematics, perceived exertion and comfort during dental work in the oral cavity--a randomised controlled intervention.

Lindegård A, Gustafsson M, Hansson GÅ.

AIM: To quantify the effects of using prismatic glasses including optometric correction, on head and neck kinematics, perceived exertion and comfort, during work in the oral cavity.

METHODS: The study population consisted of forty-five participants. After a basic ergonomic education, baseline measurements of head and neck kinematics were made using inclinometers. Perceived exertion and comfort were rated by the participants. An intervention group (n = 25), selected at random from the participants, received prismatic glasses and optometric correction when needed and were compared with a control group (n = 20). Follow up assessments were made after the intervention.

RESULTS: At follow up there was a reduction in both the intervention group (8.7°) and in the control group (3.6°) regarding head flexion. Neck flexion was reduced by 8.2° in the intervention group and 3.3° in the control group. The difference between the intervention and the control groups, i.e. the effect of the intervention, was statistically significant for both head (5.1°; p = 0.009) and neck (4.9°; p = 0.045) flexion. No effect of the intervention was seen regarding perceived exertion and comfort.

CONCLUSION: The reduction in head and neck flexion achieved by the prismatic glasses is likely to reduce the risk of neck pain during dental work. The effect of the prismatic lenses could not be separated from the effect of the optometric correction. The possible effect of the ergonomic education was not evaluated.


2011

December 2011

Association between Pregnancy Loss and Urinary Phthalate Levels around the Time of Conception

Background: Animal studies indicate that some phthalate metabolites may harm female reproductive function.

Objectives: We assessed the associations between exposure to phthalate metabolites and pregnancy loss.

Methods: In a previously established cohort of first pregnancy planners, we analyzed four primary and two oxidized secondary phthalate metabolites in urine samples collected on day 10 after the first day of the last menstrual period before conception occurred (n=128) and during the previous cycle (if any, n=111). Subclinical embryonal loss was identified by repeated urinary hCG measurements and information on clinical spontaneous abortions was obtained by telephone interview with the mother.

Results: Pregnancy loss (n = 48) was increased among women with urinary concentration of monoethylhexyl phthalate (MEHP) in the upper tertile in the conception sample compared with women in the lowest tertile [adjusted odds ratio 2.9; 95% confidence interval (CI) 1.1; 7.6]. The corresponding odds ratio for subclinical embryonal loss (n=32) was 40.7 (CI 4.5; 369.5).

Conclusions: The phthalate metabolite MEHP was associated with higher occurrence of pregnancy loss. Since this is the first human study to show this association and the sample size is small, the findings need to be corroborated in independent studies.


November 2011

Commuting - bad for your health?

A mobile workforce can help improve a country’s economy but the effects of commuting on the health of commuters and on the costs to industry in terms of sick days is largely unknown. From a commuter’s point of view, the better paid job or better housing conditions daily travel allows need to be weighed against adverse health effects. New research published in BioMed Central’s open access journal BMC Public Health shows that commuting by car or public transport compared to walking or cycling is associated with negative health.

Researchers from Lund University looked at 21,000 people, aged between 18 and 65, who worked more than 30 hours a week and commuted either by car, train or bus, or were active commuters, who travelled by walking or cycling. ‘One way’ journey time was compared to the volunteer’s perceived general health, including sleep quality, exhaustion and everyday stress.

Erik Hansson from the Faculty of Medicine at Lund University explained, "Generally car and public transport users suffered more everyday stress, poorer sleep quality, exhaustion and, on a seven point scale, felt that they struggled with their health compared to the active commuters. The negative health of public transport users increased with journey time. However, the car drivers who commuted 30 – 60 minutes experienced worse health than those whose journey lasted more than one hour. "

Erik continued "One explanation for the discrepancy between car and public transport users might be that long-distance car commuting, within our geographical region, could provide more of an opportunity for relaxation. However, it could be that these drivers tended to be men, and high-income earners, who travelled in from rural areas, a group that generally consider themselves to be in good health. More research needs to be done to identify how exactly commuting is related to the ill health we observed in order to readdress the balance between economic needs, health, and the costs of working days lost."


September 2011

Factors influencing the decision to extend working life or to retire

The aim of this study was to evaluate factors within nine identified areas that influence why some older workers want to (or believe they can) work until age 65 years or beyond, whereas others leave the workforce earlier.

The questionnaire-based, cross-sectional study included 1792 respondents aged 55–64 years, employed in the healthcare sector in Sweden. Using logistic regression, we investigated the associations between statements within nine areas and two outcome measures: (i) Whether the individual wanted to work until age 65 years or beyond and (ii) whether the individual believed they can work until age 65 years or beyond.

Of the 1792 respondents, 54% stated that they "can" and 38% that they "want to" work until age 65 years or beyond. Three areas were significantly associated with both these outcomes: worker health, economic incentives, and retirement decisions by life partners or close friends. Mental and physical working environment, work pace and skills/competence were associated with the "can" outcome, whereas work as an important part of life, working time, and management attitude to older workers were associated with the "want to" outcome.

Although there were differences regarding the associations between six of the areas and the two outcomes (ie, "can" and "want to" go on working until age 65 years or beyond), three of the areas were important to both outcomes. Among those, it was interesting that life partner or close social environment gave higher odds ratios than for example health, physical work environment or work satisfaction.


June 2011

Differences in socioeconomic and gender inequalities in tobacco smoking in Denmark and Sweden; a cross sectional comparison of the equity effect of different public health policies

Background: Denmark and Sweden are considered to be countries of rather similar socio-political type, but public health policies and smoking habits differ considerably between the two neighbours. A study comparing mechanisms behind socioeconomic inequalities in tobacco smoking, could yield information regarding the impact of health policy and -promotion in the two countries.

Methods: Cross-sectional comparisons of socioeconomic and gender differences in smoking behaviour among 6 995 Danish and 13 604 Swedish persons aged 18-80 years.

Results: The prevalence of smoking was higher in Denmark compared to Sweden. The main finding of the study was that the socioeconomic patterning of smoking, based on level of education and expressed as the relative contribution to the total burden of smoking exposure, was rather different in Sweden and Denmark. Moreover, these differences were modified by gender and age. As a general pattern, socioeconomic differences in Sweden tended to contribute more to the total burden of this habit among women, especially in the younger age groups. In men, the patterns were much more similar between the two countries. Regarding continued smoking/unsuccessful quitting, the patterns were similar for women, but somewhat different for men. Here we found that socioeconomic differences contributed more to overall continued smoking in Danish men, especially in the middle-age and older age strata.

Conclusion: The results imply that Swedish anti-smoking policy and/or implemented measures have been less effective in a health equity perspective among the younger generation of women, but more effective among men, compared to Danish policy implementation. The results also raises the more general issue regarding the possible need for a trade-off principle between overall population efficacy versus equity efficacy of anti-tobacco, as well as general public health policies and intervention strategies.


May 2011

Maternal Exposure to Air Pollution and Birth Outcomes

Background: The knowledge about air pollution effects on birth weight, prematurity, and small for gestational age (SGA) in low-exposure areas is insufficient.
Objectives: The aim of this study was to investigate whether low-level exposure to air pollution was associated with prematurity and fetal growth.
Method: We combined high quality registry information on 81110 births in Scania (Skåne) during the period 1999-2005 with individually modelled exposure data at residence for nitrogen oxides (NOx) and proximity to roads with differing traffic density.
Results: We observed an increased risk for babies being SGA when we compared highest and lowest NOx exposure categories. After taken maternal country of origin and parity (which were highly intercorrelated) in consideration, the increased risk was no longer statistically significant. However, in subgroup analyses when we compared highest and lowest NOx exposure categories, we still observed an increased risk for SGA for girls (odds ratios [OR] 1.12; 95% confidence interval [CI], 1.01-1.24); we also observed an increased risk among mothers who had not changed residency during pregnancy (OR 1.09; 95% CI, 1.01–1.18). Concerning prematurity, the prevalence was lower in the highest NOx exposure categories compared to the lowest category.
Conclusion: We could not observe any clear association between air pollution and birth outcomes. For future studies on air pollution effects on birth outcomes, careful control of confounding variables (such as country of origin) is crucial.

Environmental Health Perspectives 119:553-559(2011)


March - April 2011

Area-aggregated assessments of perceived environmental attributes may overcome single-source bias in studies of green environments and health: results from a cross-sectional survey in southern Sweden

In this study we demonstrate how self-assessments of green neighborhood environments aggregated to narrow area units may serve as an appealing compromise between objective measures and individual self-assessments of neighborhood characteristics. The study uses cross-sectional data (N = 24,847) from a public health survey conducted in the county of Scania, southern Sweden, in 2008 and validates the Scania Green Score (SGS), a new index comprising five self-reported green neighborhood qualities (Culture, Lush, Serene, Spacious and Wild). Perceived and objectively assessed qualities (based on Geographical Information Systems) of the green neighborhood environment correlate but do not agree. The correlation was even more evident for the area-aggregated SGS and clear associations with neighborhood satisfaction were found. An index score based on self-reports but aggregated to narrow area units can therefore be a valid approach to assess perceived green neighborhood qualities in settings where objective assessments are not possible or feasible.


February 2011

Lithium in Drinking Water and Thyroid Function

High concentrations of lithium in drinking water were previously discovered in the Argentinean Andes Mountains. Other studies of lithium in drinking water suggest that the findings in Argentina are not unique. However, there appears to be neither drinking water standards, nor risk assessments for lithium in drinking water. Lithium is used worldwide for treatment of bipolar disorder and treatment-resistant depression. One known side effect is altered thyroid function. The aim with this study was to assess associations between exposure to lithium from drinking water and thyroid function.

Included in the study were women (N=202) recruited in 4 Andean villages in Northern Argentina. Lithium exposure was assessed based on concentrations in spot urine samples, measured by inductively coupled plasma mass spectrometry. Thyroid function was evaluated by plasma free thyroxine (T4) and pituarity gland thyroid-stimulating hormone (TSH). The results demonstrated that the median urine lithium concentration was 3,910µg/L (5th/95th percentiles 270/10,400 µg/L). Urine lithium was statistically significantly inversely associated with T4 and positively associated with TSH. Both associations persisted after adjustment. Urine selenium was positively associated with T4.

The conclusions with the study was that exposure to lithium via drinking water and other environmental sources may affect thyroid function, consistent with known side effects of medical treatment with lithium. This stresses the need to screen for lithium in all drinking water sources.


January 2011

Time-dependent proteomic iTRAQ analysis of nasal lavage of hairdressers challenged by persulfate

Hairdressers are frequently exposed to bleaching powder containing persulfates, a group of compounds that may induce hypersensitivity in the airways. The mechanism causing this reaction is not clear. The aim of this study was to identify changes in the nasal lavage fluid proteome after challenge with potassium persulfate in hairdressers with bleaching powder-associated rhinitis. Furthermore, we aimed to compare their response to that of hairdressers without nasal symptoms, and atopic subjects with pollen-associated nasal symptoms. To study the pathogenesis of persulfate-associated rhinitis, the response in protein expression from the upper airway was assessed by time-dependent proteomic expression analysis of nasal lavage fluids. Samples were prepared by pooling nasal lavage fluids from the groups at different time points after challenge. Samples were depleted of high-abundant proteins, labeled with iTRAQ and analyzed by online 2D-nanoLC-MS/MS. Differences in the protein pattern between the three groups were observed. Most proteins with differentially expressed levels were involved in pathways of lipid transportation and antimicrobial activities. The major finding was increased abundance of apolipoprotein A-1, 20 min postchallenge, detected solely in the group of symptomatic hairdressers. Our results suggest there may be differences between the mechanisms responsible for the rhinitis in the symptomatic and atopic group.


2010

December 2010

Human exposure to persistent organic pollutants in West Africa

The Stockholm Convention on Persistent Organic Pollutants (POPs) is a framework designed to reduce the global spread of POPs. 150 countries have agreed to ban or restrict production and use of some of the most dangerous chemicals, including the insecticide DDT and other pesticides, industrial chemicals like PCBs, and certain types of brominated flame retardants (PBDEs). These substances are globally distributed. There is abundant data on exposure levels in the ecosystem and humans from Europe and North America, and to some extent also from industrialized parts of Asia, while the exposure situation in developing countries is almost entirely unknown.

We had access to biobanked serum samples from an open cohort of police officers in Guinea-Bissau, participating in health examinations for HIV regularly since the early 1990s. The serum levels of chlorinated POPs decreased during the observation period. Thus, the restricted use of the legacy POPs have resulted in a measurable decrease in human exposure even in one of the poorest countries in Africa. In contrast, PBDE levels increased, and were surprisingly high for a non-industrialized country.

The study is unique. A time-trend study in which concentrations of POPs have been analyzed in a group of individuals followed for such a long period of time has to our knowledge never been performed before.


November 2010

Heavy metals in kidney of living kidney donors; impact of different exposure sources

Most current knowledge on kidney concentrations of nephrotoxic metals like cadmium, mercury and lead come from autopsy studies. In this study metal concentrations in 109 kidney biopsies from living subjects in Sweden have been assessed and combined with information about exposure sources supplied by the subjects themselves. The results show that the kidney mercury levels increased with the total number of amalgam fillings, but was not associated with fish consumption. The lead concentrations in the kidneys were low compared to earlier autopsy studies due to decreased exposure. Smoking was highly associated with the kidney cadmium concentration but the levels have deceased during the years due to changed smoking habits, however, levels in never-smokers seems to be stable. Low iron stores increase the kidney cadmium concentration, indicating that this is the major reason for higher kidney cadmium in females compared to male non-smokers.


October 2010

Systematic evaluation of observational methods assessing biomechanical exposure at work

Numerous observational methods have been developed in order to, e.g. identify risk factors for developing musculoskeletal disorders, and to monitor the effects of ergonomic interventions. The choice of method has often been based on tradition rather than on a critical evaluation. The aim was to systematically and critically evaluate observational methods, and to provide recommendations for their use.

Based on search in scientific databases, a total of 30 eligible observational methods were identified. Generally, the observations showed good to moderate agreement with corresponding assessments made from video recordings, agreement being the best for large scale body postures and work actions. Postures of wrist and hand as well as trunk rotation seemed to be more difficult to observe accurately. Intra- and inter-observer repeatability were reported for 7 and 17 methods, respectively, and were mostly judged to be good or moderate.

With sufficient training, observers can reach consistent results on clearly visible body postures and work activities. Many tools exist but none of the evaluated methods seem to be generally superior to the others. When selecting an observation method, users should thoroughly define their needs and how the obtained information will influence decision making.


September 2010

Novel methods to identify adducts on proteins using LC/MS/MS techniques.

Acrylates are used in vast quantities, for instance in paints, adhesive glues, molding. They are potent contact allergens and known to cause respiratory hypersensitivity and asthma. Here we study ethyl 2-cyanoacrylate (ECA), methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA).

The aim of the study was to investigate adducts formed after reaction of hemoglobin (Hb) with the acrylates. Hb conjugates were synthesized in vitro and digested. Adducted peptides were characterized and analyzed using several liquid chromatography and mass spectrometry (LC/MS/MS) methods. The search for adducted peptides was facilitated by visualizing the MS data using different computer programs.

The results showed that the acrylates binds covalently to cysteines. The adducted peptides were also possible to measure using LC/MS/ MS in selected reaction monitoring mode. These peptides may be used for biological monitoring of exposure.


June 2010

Work site intervention facilitates return to work after sick leave due to burnout

Development of clinical burnout after long-term work stress has often implied prolonged sick leave, or even loss of employment. The few international publications in the area suggest that interventions oriented towards the individual do not facilitate return to work.

We developed and evaluated a simple work site oriented intervention model including interview of the patient as well as his or her supervisor about changes needed to facilitate return to work. The core intervention was a following dialogue between the two parties aiming to result in agreement about this matter.

At a follow-up 1.5 years after the intervention about 90% of the intervention group had returned to work compared to about 70% in a control group who did not receive the intervention. The study indicates that treatment of the individual should be completed with intervention oriented towards the work place, in order to facilitate return to work.


May 2010

Air pollution in Skåne causes increased risk of stroke

In Sweden, and in Skåne, the concentrations of air pollution are relatively low in an international perspective. To large part, current air quality guidelines are followed. We investigated if the levels of particulate air pollution in Skåne increase stroke risk during the study period between 2001 and 2005. We obtained information on hospital admitted patients with stroke from Riks-stroke, the national quality register for stroke care in Sweden. The number of hospital admitted stroke patients was then compared with levels of air pollution with time series analysis. We observed that the ischemic stroke risk increased with 13% when the levels of air pollution was in the highest category (PM 10 > 30µg/m³) compare to when the levels were in the lowest category (PM 10 <= 15 µg/m³). The risk increase was even higher for patients with a history of stroke. Our study indicates that air pollution in Skåne causes severe health effects, despite the fact that air pollution levels mainly are within current guide lines. 


April 2010

Chronic exposure to cadmium and arsenic affect the oxidative stress levels

Arsenic (As), cadmium (Cd) and lead (Pb) are among the most commonly encountered toxic metals for humans following environmental or dietary exposure. Inorganic As exposure often occurs via drinking water, but also via certain foods, while Cd and Pb exposure mainly comes from food. These metals may generate oxidative stress, which may lead to pathological effects, e.g. carcinogenesis. Oxidative stress can be assessed by 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in urine. The metal research group in at Occupational and Environmental medicine has evaluated 8-oxodG induced by mixed chronic exposure to As, Cd, and Pb, as well as the influence of As metabolism and nutritional status, i.e. ferritin, selenium, zinc, manganese and body weight, in 212 women in early pregnancy from Matlab, rural Bangladesh. 8-oxodG was positively associated with urinary Cd (ß=0.32, p<0.001), urinary As (ß=0.0007, p=0.001), fraction of the monomethylated arsenic metabolite (MMA) in urine (ß=0.0026, p=0.004) and plasma ferritin (ß = 0.20, p<0.001). The results from the present study demonstrate that there is a background of oxidative stress, partly from iron, among these malnourished women with low antioxidant levels. The combined chronic exposure to several toxic metals in this population may result in a too high body burden of oxidative stress with subsequent adverse toxic effects. 


March 2010

Physical workload on neck, shoulders and upper arm in various types of work

Constrained and awkward postures of the neck and upper arms, as well as high muscular loads and lack of rest/recovery for the muscles are potential risk factors for work-related upper extremity musculoskeletal disorders. To obtain quantitative exposure-response relationships, and giving priority to and evaluating interventions, objective and quantitative measures of the physical workload are needed. The research group in the program "Work related musculoskeletal disorders" at Occupational and Environmental Medicine has performed physical workload measurements in 43 types of work, using inclinometry for the head and upper arms, and electromyography (EMG) for the trapezius muscles. The variations were large: head: flexion 9°–63°, extension -39°–4°, movements 2.3–33 °/s; arm: elevation 49°–124°, movements 3.0–103 °/s; trapezius: muscular rest 0.8%–52% of time, peak load 3.1%–24% of maximal EMG. Even within work categories, e.g. "repetitive industrial", there were large variations. 


January 2010

Genetic differences in the GSTP1 gene control the metabolism of toluene diisocyanate

Toluene diisocyanate (TDI) is used world-wide in the production of plastic foam. Exposure to TDI is associated with symptoms in the airways, in worst cases with asthma. Not all exposed are affected and that may partly depend on individual differences in metabolism of TDI. The research group in the program "Environmental, respiratory disease and exposure" at Occupational and Environmental Medicine studied if sequence differences (polymorphisms) in genes involved in metabolism of TDI influenced the levels of TDI in plasma and urine of 128 TDI-exposed workers. The findings showed that a polymorphism in the GSTP1 gene had a significant impact on the levels of TDI in plasma and urine. Approximately 50% of the Swedish population carries polymorphism variant that results in higher levels of TDI. It is the same variant that in previous studies has been associated with higher risk of developing TDI-related asthma. It should therefore be considered if this polymorphism should be measured in exposure assessment of TDI using biological monitoring in the future. 


 

Improved well-being in shift workers

Twenty-four hour rotating shift schedules disturb inner biological rhythms, the normal sleep-wake cycle, and often also social life and family life. The Behavior Medicine Section studied the effects of a changed shift schedule at a manufacturing plant in 118 shift workers with 67 daytime workers as a control group. The new schedule had shorter cycles of each type of shift (three consecutive shifts), and three days off between each type of shift. After 15 months there was an improvement in sleep, recovery, and fatigue, and a reduced negative influence from work on family life, and a reduction of subjective health complaints, all to similar levels as in the control group. The latter did not change in the measures used. 


 

Exposure to p,p'-DDE: A Risk Factor for Type 2 Diabetes

Persistent organic pollutants (POPs), such as PCBs, DDT and dioxins have in several cross-sectional studies shown strong associations with type 2 diabetes mellitus. Reversed causality can not be excluded. The aim of this case-control study was to evaluate whether POPs concentration is a risk factor for type 2 diabetes.

A case-control study was performed within a cohort of women, age 50-59 years, from the Southern part of Sweden. Biomarkers for POP exposure were analyzed in serum samples, collected when the cohort was established. For 107 out of the 371 cases, serum samples were stored at least three years before their type 2 diabetes was diagnosed.

In this data set, CB-153 and p,p'-DDE were not associated with an increased risk to develop type 2 diabetes. However, when only the cases (n = 39) that were diagnosed more than six years after the baseline examination and their controls were studied, the women in the highest exposed quartile showed an increased risk to develop type 2 diabetes (OR of 1.6 [95% 0.61, 4.0] for CB-153 and 5.5 [95% CI 1.2, 25] for p,p'-DDE).

The results confirm that p,p'-DDE exposure can be a risk factor for type 2 diabetes. 


 

Road traffic noise and hypertension

A group of researchers from the section for epidemiology investigated the association between living close to noisy roads and having raised blood pressure. Road traffic is the most important source of community noise. Approximately 30% of the population in the European Union is exposed to a day-night average of traffic noise exceeding 55dB(A), and this number is increasing. Non-auditory physical health effects that are related to noise include sleep disturbance and cognitive problems among children. Recent studies have also investigated the relation to hypertension and myocardial infarction. In this study self-reported hypertension data was collected from a public health survey in Scania including 24 238 persons. Noise exposure at each respondent's home was calculated using geographical information systems (GIS). We found that among persons 40-59 years of age, day-night average exposure of 60-64 dB was associated with a 27% increased risk for high blood pressure compared to the reference group (<45dB), also after adjusting for confounding factors, including age, sex, BMI, exercise, smoking and education. Levels above 65 dB were associated with nearly twice the risk of having hypertension although this group included few individuals and the results therefore should be interpreted with caution. The study explored the modifying effect of age, which few have investigated earlier. Middle aged persons had a stronger association between road traffic noise and hypertension compared to young and old persons. This is an important finding that this study due to limitations in design could not investigate further. One hypothesis however, is that middle-aged persons are exposed to more stressors in life that lowers the ability to cope with noise exposure. Therefore this group might be vulnerable and important to focus in further research within the field.
The research paper is available on-line, free of charge, at 

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