Norbert Kersten

Traffic noise and risk of myocardial infarction.

Background: The biologic plausibility for noise stress-related cardiovascular responses is well established. Epidemiologic studies on the relationship between transportation noise and ischemic heart disease suggest a higher risk of myocardial infarction in subjects exposed to high levels of traffic noise. Methods: To determine the risk of road traffic noise for the incidence of myocardial infarction (MI), we carried out a hospital-based case-control study in the city of Berlin. We enrolled consecutive patients (n = 1881), age 20–69 years, with confirmed diagnosis of MI from 1998 through 2001. Controls (n = 2234) were matched according to sex, age, and hospital. Outdoor traffic noise level was determined for each study subject based on noise maps of the city. Standardized interviews were conducted to assess possible confounding factors and the annoyance from various noise sources. Results: The adjusted odds ratio for men exposed to sound levels of more than 70 dB(A) during the day was 1.3 (95% confidence interval = 0.88–1.8) compared with those where the sound level did not exceed 60 dB(A). In the subsample of men who lived for at least 10 years at their present address, the odds ratio was 1.8 (1.0–3.2). Noise-exposed women were not at higher risk. Conclusions: The results support the hypothesis that chronic exposure to high levels of traffic noise increases the risk for cardiovascular diseases.

Chronic obstructive pulmonary disease and longitudinal changes in pulmonary function due to occupational exposure to respirable quartz

Objectives The present study sought to examine the long-term effects of exposure to respirable quartz on pulmonary function with particular focus on chronic obstructive pulmonary disease (COPD). Methods The study is based on the Wismut cohort of former uranium miners. Spirometric data were ascertained together with quantitative estimates of cumulative exposure to respirable quartz for each of 1421 study subjects born between 1954 and 1956. The case definition for COPD is based on the criteria of the Global Initiative for Chronic Obstructive Lung Disease. Linear mixed regression models were fitted to identify significant determinants of longitudinal changes in lung function parameters. Results An average of five spirometries were available for each miner. It was shown that cumulative exposure to 1 mg/m3-year respirable quartz leads, on average, to a relative reduction in forced expiratory volume in 1 s/ orced vital capacity (FEV1/FVC) of 2.75% (p<0.001). A nested case–control approach demonstrated that the risk for COPD stage I increases with increasing cumulative exposure to respirable quartz (OR 1.81 per 1 mg/m3-year). Conclusions This paper adds further evidence on the long-term effects of exposure to respirable quartz, which include a decline in pulmonary function parameters and an increase in the incidence of COPD.

Re: Clinically significant lung function impairment due to current levels of respirable quartz? (authors’ response)

We would like to thank the journal for the opportunity to respond to a letter to the editor concerning our study.1 ,2 The original criterion for inclusion into the cohort was employment time of ≥180 days.3 But this includes also apprenticeship (started usually at age <18 years) and military service. For the analysis, we only considered data from those spirometries performed at age ≥18 years. The time series of spirometric data were validated for each study subject by one of us (NK) blinded with respect to the exposure. If there were two or more spirometries during a period of less than 6 months, only the spirometry with the higher values was kept. Moreover, the time series were checked for outliers using Cook’s distance. Outliers, almost exclusively low values, were also excluded. These procedures sometimes resulted in only one data record …

Does age modify the association between psychosocial factors at work and deterioration of self-rated health?

Objectives Few epidemiological studies have examined whether associations of psychosocial working conditions with risk of poor health differ by age. Based on results from mostly cross-sectional studies, we test whether (i) psychosocial relational factors (social support) are more strongly associated with declining health of older than younger employees and (ii) psychosocial job factors (workpace, influence, possibilities for development) are more strongly associated with declining health of younger than older employees. Methods We extracted two cohorts from the Danish Work Environment Cohort Study (DWECS): the 2000-2005 and 2005-2010 cohorts. The participating 5281 employees with good self-rated health (SRH) at baseline were observed in 6585 5-year time windows. Using log-binomial regression analyses, we analysed whether psychosocial factors at work predicted 5-year deterioration of SRH. Effect modification by age was estimated by calculating relative excess risk due to interaction (RERI). Results High workpace among men, low influence at work as well as low social support from colleagues among women, and low possibilities for development and low social support from supervisors among both genders predicted 5-year decline in SRH. Of the 20 interaction analyses, only 1 was statistically significant and in the opposite direction of what was hypothesized (higher risk for declining SRH among middle-aged men with low possibilities for development compared to the young men with high possibilities for development). Conclusions Psychosocial working conditions predicted decline in SRH in this 5-year follow-up study. The model did not support our hypotheses about modifying effects by age.

0305 Occupational exposure to respirable quartz and radon and the risk of acute myocardial infarction

Objectives The aim of this study is to investigate the effect of occupational exposure to radon and respirable quartz (RQ) on the risk of acute myocardial infarction. Methods This individually matched case-control-study is nested into the Wismut cohort of former uranium miners. Acute myocardial infarction (AMI) was ascertained from hospital discharge diagnoses coded in ICD-10 and validated according to WHO criteria (1979) by patient records. Exposure to RQ, radon, long-lived radionuclides, Gamma-radiation, and arsenic was estimated by a corresponding job-exposure-matrix. Information on silicosis was included in the dataset to reduce a possible Healthy-worker-effect. To exclude effects of possible exposures before hire in uranium mining, a second analysis was performed limited to miners born after 1930. Conditional logistic regression was used for risk modelling. Results In total, 467 cases of AMI and 467 controls, matched by year of birth, were ascertained. The analysis of the full dataset shows only a weak increase of AMI-risk with increasing exposure to RQ. But the second analysis, based on 126 matched pairs, revealed a positive dose-response relationship with RQ. The odds ratio for the highest quintile (>15 mg/m3·year) was 4.91 (95%CI: 1.43–16.8). Including RQ as a linear term yields OR=1.05 per mg/m³·year. The analysis of the cumulative radon exposure produced similar findings. Conclusions This study shows elevated risk of AMI due to radon and RQ exposure. Because of the high correlation between both exposures, a differentiation between the corresponding effects is not possible.

0184 Considering giving up gainful employment as predictor for early exit from the labour force

Introduction I ll health, socio-economic status and working conditions are important determinants for labour market participation. But this perspective neglects the subjective view of individuals and the role of cognitive processes. The aim of the present study is to investigate the contribution of these considerations for the prediction of subsequent exit from the labour force. Method The sampling frame is defined by all German employees being subject to social security contributions and born between 1951 and 1980. The sample consists of 4511 survey participants of whom 4182 employees are with full- or part-time employment. At the time of the first interview they were asked how often they have thought about giving up gainful employment within the last year. The analysis focusses on the prediction of employment status five years later. Results At baseline 8% of female and of 7.2% male employees reported having “sometimes thoughts within the last year” and 4.4% of the female and 3.7% of the male employees reported a frequency up to “every day”. The follow-up interviews are currently underway and are expected to end May 2017. Results on associations between considerations at baseline and status of employment at follow-up and will be presented at the conference. Discussion Research on the association between cognitive processes and subsequent behaviour is very limited. We assume that the inclusion of these aspects will improve the prediction of labour force participation. However, there are strong limitations by the sample size and the number of observations at the second wave of assessment.

Dosis-Wirkungsbeziehungen von Exposition und Lungenfunktion bei Kalibergarbeitern — vergleichende Auswertung einer Längsschnittstudie im linearen und gemischten Modell

A longitudinal study in two salt mines in Germany suggested effects of the mixed exposure of salt dust, diesel exhaust and nitrogen oxides on lung function of the miners. With regard to the discussion of occupational exposure limit values an additional analysis of the considerable data should analyse effects of the single components of exposure separately as far as possible. 70% of the first cohort (568 miners, mean age 45.0 years) was reexamined after a 5 year period. Mean individual lifetime exposure concentrations were 10.1 mg/m3 of inhalable and 1.46 mg/m3 of respirable salt dust, 0.12 mg/m3 of diesel exhaust (EC), 0.78 ppm of NO2 and 1.59 ppm of NO. Dose response relationships were calculated by multiple linear model and linear mixed model analysis. Analyses indicated clear dose response relationships in both models and confirmed the results of the previous study. Effects pointed out in the direction of chronic obstructive lung disease. With the linear regression a loss of FEV1 of 11.5 ml/year could predicted in relation to an average exposure in the 5-year-periode. In the mixed model some exposure effects could be modelled as random effects. E. g. there was a mean effect of -74.2 (SD=40.5) ml per mg/m3 respirable dust on FEV1. A stronger effect of more than -100 ml per mg/m3 on FEV1 was found when FEV1 was lower at the start of the study. As in the first analysis it was impossible to determine the effect of a single exposure component separately in these models because of the high correlation of the individual concentrations (>0.8) as well as to contribute to recommendations for occupational exposure limit values. However, results give infomation about the situation of employees, exposed in the ranges of concentrations of individual substances described here. With the mixed model a widened understanding of exposure effects is enabled. With the view to occupational health and safety technical and medical preventive measures should be continued in the mines.

0202 The impact of respirable dust and respirable quartz on pulmonary function - results of a longitudinal study

Objectives The present study sought to examine the long-term effects of exposure to respirable dust, in particular of respirable quartz on pulmonary function. Method The study is based on the Wismut cohort of former uranium miners. Spirometric data, including forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC) were ascertained together with quantitative estimates of cumulative exposure to respirable dust and respirable quartz for each of the 1421 study subjects born between 1954 and 1956. Linear mixed regression models were fitted to identify significant determinants of longitudinal changes in lung function parameters. Point estimators and confidence intervals for the exposure concentration threshold value were fitted by partial likelihood profiles of the corresponding models. Results Overall, 7122 data records were included in the analysis - on average five spirometries for each miner. The mean annual exposure concentration to respirable quartz was 0.072 mg/m³. It was shown that cumulative exposure to 1 mg/m³-year respirable quartz leads, on average, to a relative reduction in FEV1 of 2.07% and in the quotient of FEV1/FVC of 2.75% (p < 0.001). The analysis of the whole respirable dust shows, that the fraction of quartz in the dust is the decisive determinant for the impact of dust. A significant improvement of model fit by applying threshold models could not be observed. Conclusions This study adds further evidence on the long-term effects of exposure to respirable quartz. Current exposure limits for respirable quartz require a critical review.

Dosis-Wirkungsbeziehungen von Exposition und Lungenfunktion bei Kalibergarbeitern — vergleichende Auswertung einer Längsschnittstudie im linearen und gemischten Modell@@@Dose response relationships of exposure and lung function of salt miners — comparative analysis of a longitudinal study with a linear and a mixed model

A longitudinal study in two salt mines in Germany suggested effects of the mixed exposure of salt dust, diesel exhaust and nitrogen oxides on lung function of the miners. With regard to the discussion of occupational exposure limit values an additional analysis of the considerable data should analyse effects of the single components of exposure separately as far as possible. 70% of the first cohort (568 miners, mean age 45.0 years) was reexamined after a 5 year period. Mean individual lifetime exposure concentrations were 10.1 mg/m3 of inhalable and 1.46 mg/m3 of respirable salt dust, 0.12 mg/m3 of diesel exhaust (EC), 0.78 ppm of NO2 and 1.59 ppm of NO. Dose response relationships were calculated by multiple linear model and linear mixed model analysis. Analyses indicated clear dose response relationships in both models and confirmed the results of the previous study. Effects pointed out in the direction of chronic obstructive lung disease. With the linear regression a loss of FEV1 of 11.5 ml/year could predicted in relation to an average exposure in the 5-year-periode. In the mixed model some exposure effects could be modelled as random effects. E. g. there was a mean effect of -74.2 (SD=40.5) ml per mg/m3 respirable dust on FEV1. A stronger effect of more than -100 ml per mg/m3 on FEV1 was found when FEV1 was lower at the start of the study. As in the first analysis it was impossible to determine the effect of a single exposure component separately in these models because of the high correlation of the individual concentrations (>0.8) as well as to contribute to recommendations for occupational exposure limit values. However, results give infomation about the situation of employees, exposed in the ranges of concentrations of individual substances described here. With the mixed model a widened understanding of exposure effects is enabled. With the view to occupational health and safety technical and medical preventive measures should be continued in the mines.

Dose response relationships of exposure and lung function of salt miners — comparative analysis of a longitudinal study with a linear and a mixed model

A longitudinal study in two salt mines in Germany suggested effects of the mixed exposure of salt dust, diesel exhaust and nitrogen oxides on lung function of the miners. With regard to the discussion of occupational exposure limit values an additional analysis of the considerable data should analyse effects of the single components of exposure separately as far as possible. 70% of the first cohort (568 miners, mean age 45.0 years) was reexamined after a 5 year period. Mean individual lifetime exposure concentrations were 10.1 mg/m3 of inhalable and 1.46 mg/m3 of respirable salt dust, 0.12 mg/m3 of diesel exhaust (EC), 0.78 ppm of NO2 and 1.59 ppm of NO. Dose response relationships were calculated by multiple linear model and linear mixed model analysis. Analyses indicated clear dose response relationships in both models and confirmed the results of the previous study. Effects pointed out in the direction of chronic obstructive lung disease. With the linear regression a loss of FEV1 of 11.5 ml/year could predicted in relation to an average exposure in the 5-year-periode. In the mixed model some exposure effects could be modelled as random effects. E. g. there was a mean effect of -74.2 (SD=40.5) ml per mg/m3 respirable dust on FEV1. A stronger effect of more than -100 ml per mg/m3 on FEV1 was found when FEV1 was lower at the start of the study. As in the first analysis it was impossible to determine the effect of a single exposure component separately in these models because of the high correlation of the individual concentrations (>0.8) as well as to contribute to recommendations for occupational exposure limit values. However, results give infomation about the situation of employees, exposed in the ranges of concentrations of individual substances described here. With the mixed model a widened understanding of exposure effects is enabled. With the view to occupational health and safety technical and medical preventive measures should be continued in the mines.