An updated job-exposure matrix for occupational noise: development and validation.

OBJECTIVES: The aim of this study was to create a quantitative job-exposure matrix (JEM) for noise including a large set of measurements for the Swedish workforce, a detailed exposure-level assessment, spanning over an extensive time period from 1970 to 2014. METHODS: The JEM was developed by 2 teams, each with an experienced occupational hygienist and an occupational safety engineer. Each pair assessed the exposure using measurements performed and reported by occupational hygienists, occupational safety engineers, or similar, from 1970 to 2014. The measurements included either the original LAeq(8h) measurements or an LAeq(8h) levels calculated from partial measurements of the working day, provided that the measurement targeted a regular task usually performed during a full workday. The collection of measurement reports was done in 2008 and 2012 by contacting clinics working in the area of occupational health or occupational safety engineers and their submitted reports were added to our own material. Noise exposure assessments were inserted at the appropriate time period for the relevant job family. The final matrix was developed in a consensus procedure and the validity was investigated by comparison of the 2 team's individual results. RESULTS: The noise JEM contains 321 job families with information regarding occupational noise from 1970 to 2014. The time-period label has a 5-yr scale starting in 1970. The estimated average 8 h (TWA) noise level in decibels [dB(A)] for every job family and 5-yr period was coded as 1: <70 dB(A), 2: 70 to 74 dB(A), 3: 75 to 79 dB(A), 4: 80 to 84 dB(A) or 5: 85(+) dB(A). The validation showed no systematic difference in relative position and very high agreement in the ordering of paired ordinal classifications. The JEM has also successfully been applied in several epidemiological studies. CONCLUSIONS: We present a JEM for occupational noise using Swedish data from 1970 to 2014 with a higher degree of sensitivity in assessed noise exposure compared with the previously existing version. Repeated application of the JEM, in epidemiological studies, has shown consistent results and contributed to yielding important findings.

Occupational risks associated with severe COVID-19 disease and SARS-CoV-2 infection - a Swedish national case-control study conducted from October 2020 to December 2021.

OBJECTIVE: This study aimed to investigate whether workplace factors and occupations are associated with SARS-CoV-2 infection or severe COVID-19 in the later waves of the pandemic. METHODS: We studied 552 562 cases with a positive test for SARS-CoV-2 in the Swedish registry of communicable diseases, and 5985 cases with severe COVID-19 based on hospital admissions from October 2020 to December 2021. Four population controls were assigned the index dates of their corresponding cases. We linked job histories to job-exposure matrices to assess the odds for different transmission dimensions and different occupations. We used adjusted conditional logistic analyses to estimate odds ratios (OR) for severe COVID-19 and SARS-CoV-2 with 95% confidence intervals (CI). RESULTS: The highest OR for severe COVID-19 were for: regular contact with infected patients, (OR 1.37, 95% CI 1.23-1.54), close physical proximity (OR 1.47, 95% CI 1.34-1.61), and high exposure to diseases or infections (OR 1.72, 95% CI 1.52-1.96). Mostly working outside had lower OR (OR 0.77, 95% CI 0.57-1.06). The odds for SARS-CoV-2 when mostly working outside were similar (OR 0.83, 95% CI 0.80-0.86). The occupation with the highest OR for severe COVID-19 (compared with low-exposure occupations) was certified specialist physician (OR 2.05, 95% CI 1.31-3.21) among women and bus and tram drivers (OR 2.04, 95% CI 1.49-2.79) among men. CONCLUSIONS: Contact with infected patients, close proximity and crowded workplaces increase the risks for severe COVID-19 and SARS-CoV-2 infection. Outdoor work is associated with decreased odds for SARS-CoV-2 infection and severe COVID-19.

Hand eczema and use of snus (moist snuff) - a population-based study.

A possible association between use of snus (Swedish moist snuff) and hand eczema was studied. 27,466 individuals responded to questions regarding hand eczema, tobacco use and other life style factors in a Swedish Public Health Survey in 2006, response rate 58%. Of these persons, 12.2% reported daily snus use (men 22.0%, women 4.3%), 15.5% daily smoking (men 14.4%, women 16.5%). Of snus users 7.5 % reported hand eczema (men 6.5%, women 11.8%), of smokers 11.7% (men 8.6%, women 13.6%) and of non-tobacco-users 9.7% (men 7.9%, women 11.0%). In multivariate analysis hand eczema was significantly less common in snus users, in total prevalence proportion ratio (PPR) = 0.813, in men PPR = 0.820, but significantly more common in smoking women, PPR = 1.238. Physical exercise was a confounder; gender an effect modifier. No positive association was demonstrated between snus use and hand eczema in contrast to the positive association found between smoking and hand eczema in women.

Myocardial infarction and occupational exposure to motor exhaust: a population-based case-control study in Sweden.

There is a well-established association between particulate urban air pollution and cardiovascular disease, but few studies have investigated the risk associated with occupational exposure to particles from motor exhaust. This study investigated the risk of myocardial infarction (MI) after occupational exposure to motor exhaust, using elemental carbon (EC) as a marker of exposure. A population-based case-control study of first-time non-lethal MI was conducted among Swedish citizens in ages 45-70 living in Stockholm County 1992-1994, including 1,643 cases and 2,235 controls. Working histories and data on potential confounders were collected by questionnaire and medical examination. The exposure to EC was assessed through a job-exposure matrix. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated by unconditional logistic regression. We investigated various exposure metrics: intensity, cumulative exposure and years since exposure. There was an exposure-response relation between the highest average exposure intensity during the work history and the risk of MI when adjusting for smoking and alcohol drinking (p for trend 0.034), with an OR of 1.30 (95% CI 0.99-1.71) in the highest tertile of exposure compared to the unexposed. An exposure-response pattern was observed in the analysis of years since exposure cessation among formerly exposed. Additional adjustments for markers of the metabolic syndrome reduced ORs and trends to non-significant levels, although this might be an over-adjustment since the metabolic syndrome may be part of the causal pathway. Occupational exposure to motor exhaust was associated with a moderately increased risk of MI.

A job-exposure matrix for occupational noise: development and validation.

OBJECTIVE: To develop a job-exposure matrix (JEM) for occupational noise in Sweden and to estimate its validity. METHODS: The JEM, developed by a group of experienced occupational hygienists, contains 321 job families with information regarding occupational noise from 1970 to 2004. The occupational noise information derives from measurements collected from different sources. The time period label has a 5-year scale starting in 1970. The estimated average 8h (TWA) noise level in decibel [dB(A)] for every 5-year period was coded either as <75 dB(A), 75-84 dB(A), or ≥85 dB(A) and the risk of peak level exposure assessed. The validity of the JEM is tested, using Svensson's non-parametric methods based on classification consensus, reached by a second group of occupational hygienists. RESULTS/DISCUSSION: Validation results show ~ 80% agreement and no systematic differences, in classification, between the two different groups of occupational hygienists, classifying the occupational noise exposure. However, classification of peak level exposure did show a systematic difference in relative position. The results will give more power to the JEM that it gives a good general estimate for the occupational noise levels in Sweden for different job families during 1970-2004. We, thus, intend to use it in further studies and also make it available to collaborators.

Mortality among Swedish chimney sweeps (1952-2006): an extended cohort study.

OBJECTIVES: We extended a cohort study of Swedish chimney sweeps and prolonged follow-up in order to increase power and study those first employed after 1950 when oil began to replace wood as a main fuel for heating in Sweden. METHODS: Male Swedish chimney sweeps who were members of the national trade union in 1981-2006 were identified (n=1087) and included to a previous cohort of those employed in 1918-1980 (n=5287). All employment histories were updated, and the total extended cohort (n=6374) was linked to the registers of Causes of Death and Total Population and followed for mortality from 1952 through 2006. Standardised mortality ratios (SMRs) were estimated using the Swedish male population as reference. RESULTS: 1841 observed deaths resulted in an SMR for all causes of deaths of 1.29 (95% CI 1.24 to 1.36). Mortality was significantly increased for all malignant tumours, oesophageal cancer, bowel cancer, liver cancer, lung cancer, alcoholism, ischaemic heart disease, non-malignant respiratory diseases, liver cirrhosis, external causes and suicides. The lung cancer SMR remained increased, although attenuated, after adjustment for group-level smoking data, SMR of 1.52 (95% CI 1.26 to 1.89). Duration of employment showed no consistent evidence of dose-response associations. Alcohol-related deaths (liver cirrhosis and alcoholism) were not increased among those employed >30 years. Mortality among those employed after 1950 was similar to that of the entire cohort. CONCLUSIONS: Chimney sweeps are exposed to high levels of toxic substances in the occupation, but excess alcohol and smoking habits were also observed, and the results must be interpreted cautiously. However, group-level data on tobacco smoking indicated that the lung cancer excess only to some extent could be explained by smoking habits, and the increased mortality from oesophageal cancer and ischaemic heart disease among chimney sweeps employed >30 years is less likely to be caused by excess alcohol habits.

Occupational exposure to motor exhaust in Stockholm, Sweden--different grouping strategies using variability in NO2 to create homogenous groups.

AIM: The aim of the present study was to investigate the personal variability in occupational exposure to NO(2), as a marker of exposure to diesel exhaust, and to compare a statistical method of grouping workers in homogenous groups with a grouping performed by a qualified occupational hygienist. METHODS: Forty-seven workers exposed to motor exhaust in their occupation were included. Personal measurements of NO(2) were performed with diffusive samplers over three full working shifts. The results from the measurements were analysed with a linear mixed effects model, taking both between and within-worker variability into consideration. The workers were divided into occupational groups in different ways in order to find a categorization, with maximal homogeneity in exposure in each group. We used (B)R(0.95) as an estimator of the between-worker variability. To study the effect of the divisions on the fit of the statistical model, we used the Akaike Information Criterion. RESULTS: The geometric mean for NO(2) for all 47 workers was 69 µg/m(3) and the between-worker variability (B)R(0.95) was 23.8. In six successive steps, the 47 workers were divided into up to eight groups, based on observed job characteristics. In the final grouping, seven groups were included with geometric means ranging from 32 µg/m(3) for outdoor workers, to 316 µg/m(3) for the most exposed group (tunnel construction workers). The (B)R(0.95) varied between 2.4 and 6.3. The within-worker variability (W)R(0.95) for the last division differed in the groups from 2.0 to 7.9. The Akaike Information Criterion decreased from 246, if all persons were included in one group, to 174 for the final grouping. CONCLUSIONS: The average level of NO(2) varied about 10 times between the different occupational groups, with the highest level for tunnel construction workers (316 µg/m(3)) and lowest for outdoor workers (32 µg/m(3)). For four of the seven groups the between-worker variability was higher than the within-worker variability.