September 2011
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
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
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
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
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
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.
December 2010
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
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
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
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
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
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
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
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
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.
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.
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.
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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Last modified: 2012-01-31
