Occupational and Environmental Medicine current issue

COPD and occupation: resetting the agenda 1

Assessment of occupational exposure to pesticides in a pooled analysis of agricultural cohorts within the AGRICOH consortium BackgroundThis paper describes methods developed to assess occupational exposure to pesticide active ingredients and chemical groups, harmonised across cohort studies included in the first AGRICOH pooling project, focused on the risk of lymph-haematological malignancies.MethodsThree prospective agricultural cohort studies were included: US Agricultural Health Study (AHS), French Agriculture and Cancer Study (AGRICAN) and Cancer in the Norwegian Agricultural Population (CNAP). Self-reported pesticide use was collected in AHS. Crop-exposure matrices (CEMs) were developed for AGRICAN and CNAP. We explored the potential impact of these differences in exposure assessment by comparing a CEM approach estimating exposure in AHS with self-reported pesticide use.ResultsIn AHS, 99% of participants were considered exposed to pesticides, 68% in AGRICAN and 63% in CNAP. For all cohorts combined (n=316 270), prevalence of exposure ranged from 19% to 59% for 14 chemical groups examined, and from 13% to 46% for 33 active ingredients. Exposures were highly correlated within AGRICAN and CNAP where CEMs were applied; they were less correlated in AHS. Poor agreement was found between self-reported pesticide use and assigned exposure in AHS using a CEM approach resembling the assessment for AGRICAN ( –0.00 to 0.33) and CNAP ( –0.01 to 0.14).ConclusionsWe developed country-specific CEMs to assign occupational exposure to pesticides in cohorts lacking self-reported data on the use of specific pesticides. The different exposure assessment methods applied may overestimate or underestimate actual exposure prevalence, and additional work is needed to better estimate how far the exposure estimates deviate from reality.

Multidimensional analysis of the effect of occupational exposure to organic solvents on lung cancer risk: the ICARE study BackgroundThe association between lung cancer and occupational exposure to organic solvents is discussed. Since different solvents are often used simultaneously, it is difficult to assess the role of individual substances.ObjectivesThe present study is focused on an in-depth investigation of the potential association between lung cancer risk and occupational exposure to a large group of organic solvents, taking into account the well-known risk factors for lung cancer, tobacco smoking and occupational exposure to asbestos.MethodsWe analysed data from the Investigation of occupational and environmental causes of respiratory cancers (ICARE) study, a large French population-based case–control study, set up between 2001 and 2007. A total of 2276 male cases and 2780 male controls were interviewed, and long-life occupational history was collected. In order to overcome the analytical difficulties created by multiple correlated exposures, we carried out a novel type of analysis based on Bayesian profile regression.ResultsAfter analysis with conventional logistic regression methods, none of the 11 solvents examined were associated with lung cancer risk. Through a profile regression approach, we did not observe any significant association between solvent exposure and lung cancer. However, we identified clusters at high risk that are related to occupations known to be at risk of developing lung cancer, such as painters.ConclusionsOrganic solvents do not appear to be substantial contributors to the occupational risk of lung cancer for the occupations known to be at risk.

Occupations associated with COPD risk in the large population-based UK Biobank cohort study ObjectivesChronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Exposure to occupational hazards is an important preventable risk factor but the contribution of specific occupations to COPD risk in a general population is uncertain. Our aim was to investigate the association of COPD with occupation in the UK population.MethodsIn 2006–2010, the UK Biobank cohort recruited 502 649 adults aged 40–69 years. COPD cases were identified by prebronchodilator forced expiratory volume in 1 s/forced vital capacity<lower limit of normal according to American Thoracic Society (ATS)/ European Respiratory Society (ERS) guidelines. Current occupations were coded using the Standard Occupational Classification (SOC) 2000. Prevalence ratios (PRs) and 95% CIs of COPD for each SOC-coded job were estimated using a robust Poisson model adjusted for sex, age, recruitment centre and lifetime tobacco smoking. Analyses restricted to never-smokers and non-asthmatics were also performed.ResultsOf the 353 occupations reported by 228 614 current working participants, several showed significantly increased COPD risk. Those at highest COPD risk were seafarers (PR=2.64; 95% CI 1.59 to 4.38), coal mine operatives (PR=2.30; 95% CI 1.00 to 5.31), cleaners (industrial: PR=1.96; 95% CI 1.16 to 3.31 and domestic: PR=1.43; 95% CI 1.28 to 1.59), roofers/tilers (PR=1.86; 95% CI 1.29 to 2.67), packers/bottlers/canners/fillers (PR=1.60; 95% CI 1.15 to 2.22), horticultural trades (PR=1.55; 95% CI 0.97 to 2.50), food/drink/tobacco process operatives (PR=1.46; 95% CI 1.11 to 1.93), floorers/wall tilers (PR=1.41; 95% CI 1.00 to 2.00), chemical/related process operatives (PR=1.39; 95% CI 0.98 to 1.97), postal workers/couriers (PR=1.35; 95% CI 1.15 to 1.59), labourers in building/woodworking trades (PR=1.32; 95% CI 1.04 to 1.68), school mid-day assistants (PR=1.32; 95% CI 1.01 to 1.74) and kitchen/catering assistants (PR=1.30; 95% CI 1.10 to 1.53). Associations were similar in analyses restricted to never-smokers and non-asthmatics.ConclusionsSelected occupations are associated with increased COPD risk in a large cross-sectional population-based UK study. Further analyses should confirm the extent to which these associations reflect exposures still of concern and where strengthened preventive action may be needed.

Trends in mortality from occupational hazards among men in England and Wales during 1979-2010 ObjectivesTo monitor the impact of health and safety provisions and inform future preventive strategies, we investigated trends in mortality from established occupational hazards in England and Wales.MethodsWe analysed data from death certificates on underlying cause of death and last full-time occupation for 3 688 916 deaths among men aged 20–74 years in England and Wales during 1979–2010 (excluding 1981 when records were incomplete). Proportional mortality ratios (PMRs), standardised for age and social class, were calculated for occupations at risk of specified hazards. Observed and expected numbers of deaths for each hazard were summed across occupations, and the differences summarised as average annual excesses.ResultsExcess mortality declined substantially for most hazards. For example, the annual excess of deaths from chronic bronchitis and emphysema fell from 170.7 during 1979–1990 to 36.0 in 2001–2010, and that for deaths from injury and poisoning from 237.0 to 87.5. In many cases, the improvements were associated with falling PMRs (suggesting safer working practices), but they also reflected reductions in the numbers of men employed in more hazardous jobs, and declining mortality from some diseases across the whole population. Notable exceptions to the general improvement were diseases caused by asbestos, especially in some construction trades and sinonasal cancer in woodworkers.ConclusionsThe highest priority for future prevention of work-related fatalities is the minority of occupational disorders for which excess mortality remains static or is increasing, in particular asbestos-related disease among certain occupations in the construction industry and sinonasal cancer in woodworkers.

Upper extremity musculoskeletal pain among office workers in three Spanish-speaking countries: findings from the CUPID study ObjectivesTo estimate the prevalence and incidence of upper extremity musculoskeletal pain (UEMP) and related disability among office workers in Costa Rica, Nicaragua and Spain.MethodsData from the multinational Cultural and Psychosocial Influences on Disability (CUPID) study on 947 (93%) participants at baseline with 90% follow-up after 12 months were employed. Logistic regression was used to estimate the associations (ORs and corresponding 95% CIs) between country and six outcomes: baseline prevalence of (1) UEMP in past 12 months, (2) UEMP in past month and (3) disabling UEMP in past month; (4) incidence of new UEMP at follow-up; (5) incidence of new disabling UEMP at follow-up and (6) persistence of UEMP at follow-up, after adjustment for sociodemographic, job-related and health-related covariates.ResultsBaseline prevalence of UEMP in the past month was higher in Costa Rica (53.6%) (OR=1.89; 95% CI 1.36 to 2.62) and Nicaragua (51.9%) (OR=1.74; 95% CI 1.28 to 2.35) than in Spain (38.4%). Compared to Spain (33.2%), the incidence of new UEMP was 50.4% in Costa Rica (OR=2.04; 95% CI 1.34 to 3.12) and 60.2% in Nicaragua (OR=3.04; 95% CI 2.06 to 4.50). The incidence of disabling UEMP was higher in Nicaragua (OR=2.57; 95% CI 1.50 to 4.41) and Costa Rica (OR=2.16; 95% CI 1.22 to 3.84) when compared to Spain.ConclusionsPrevalence of UEMP was approximately twofold higher and its incidence twofold to threefold higher in Costa Rica and Nicaragua as compared with Spain. Between-country differences were only partially explained by the covariates analysed. Research is needed to explore other aspects of work and cultural attributes that might explain the residual differences in UEMP.

Exposure-response relationships between movements and postures of the wrist and carpal tunnel syndrome among male and female house painters: a retrospective cohort study ObjectivesTo investigate exposure–response relationships between measured movements and postures of the wrist and the incidence of carpal tunnel syndrome (CTS), and any modifications by sex.MethodsIn 2011, we established a historical cohort of 9364 members of the Painters’ Union in Denmark. Self-reported task distributions were obtained by questionnaire (53% responded) and combined with sex-specific task exposure matrices to get individual estimates of exposure intensity, that is, velocity of wrist flexion/extension, mean power frequency (MPF) and non-neutral wrist postures. Exposure duration was assessed from yearly working proportions. Registered first-time hospital discharge CTS diagnoses and CTS surgery were collected as outcomes. The cohort was followed from 1994 to 2010. Log-linear Poisson regression was used.ResultsFor CTS diagnoses, the adjusted incidence rate ratios (IRRs) increased with increasing wrist velocity (IRR=1.37 (95% CI 1.10 to 1.71) per °/s) and MPF (IRR=1.53 (95% CI 1.21 to 1.91) per 0.01 Hz). For CTS surgery, the results were similar. The outcomes were not related to non-neutral postures or exposure duration. The adjusted IRRs for women were higher than those for men. There were no multiplicative interaction effects between exposure intensity, exposure duration and sex. However, the absolute incidence rates (IRs) increased at a steeper rate for women than for men, indicating an additive interaction.ConclusionsThe incidence of CTS increased with increasing velocity of wrist flexion/extension and MPF of wrist movements. The relative increase in incidence rates was the same for women and men, but the absolute incidence rates increased at a steeper rate for women than for men.

Intervention to reduce heat stress and improve efficiency among sugarcane workers in El Salvador: Phase 1 BackgroundChronic heat stress and dehydration from strenuous work in hot environments is considered an essential component of the epidemic of chronic kidney disease in Central America.Objective(1) To assess feasibility of providing an intervention modelled on OSHA's Water.Rest.Shade programme (WRS) during sugarcane cutting and (2) to prevent heat stress and dehydration without decreasing productivity.MethodsMidway through the 6-month harvest, the intervention introduced WRS practices. A 60-person cutting group was provided water supplied in individual backpacks, mobile shaded rest areas and scheduled rest periods. Ergonomically improved machetes and efficiency strategies were also implemented. Health data (anthropometric, blood, urine, questionnaires) were collected preharvest, preintervention, mid-intervention and at the end of harvest. A subsample participated in focus group discussions. Daily wet bulb globe temperatures (WBGT) were recorded. The employer provided individual production records.ResultsOver the harvest WBGT was >26°C from 9:00 onwards reaching average maximum of 29.3±1.7°C, around 13:00. Postintervention self-reported water consumption increased 25%. Symptoms associated with heat stress and with dehydration decreased. Individual daily production increased from 5.1 to a high of 7.3 tons/person/day postintervention. This increase was greater than in other cutting groups at the company. Focus groups reported a positive perception of components of the WRS, and the new machete and cutting programmes.ConclusionsA WRS intervention is feasible in sugarcane fields, and appears to markedly reduce the impact of the heat stress conditions for the workforce. With proper attention to work practices, production can be maintained with less impact on worker health.

Computer-based coding of free-text job descriptions to efficiently identify occupations in epidemiological studies BackgroundMapping job titles to standardised occupation classification (SOC) codes is an important step in identifying occupational risk factors in epidemiological studies. Because manual coding is time-consuming and has moderate reliability, we developed an algorithm called SOCcer (Standardized Occupation Coding for Computer-assisted Epidemiologic Research) to assign SOC-2010 codes based on free-text job description components.MethodsJob title and task-based classifiers were developed by comparing job descriptions to multiple sources linking job and task descriptions to SOC codes. An industry-based classifier was developed based on the SOC prevalence within an industry. These classifiers were used in a logistic model trained using 14 983 jobs with expert-assigned SOC codes to obtain empirical weights for an algorithm that scored each SOC/job description. We assigned the highest scoring SOC code to each job. SOCcer was validated in 2 occupational data sources by comparing SOC codes obtained from SOCcer to expert assigned SOC codes and lead exposure estimates obtained by linking SOC codes to a job-exposure matrix.ResultsFor 11 991 case–control study jobs, SOCcer-assigned codes agreed with 44.5% and 76.3% of manually assigned codes at the 6-digit and 2-digit level, respectively. Agreement increased with the score, providing a mechanism to identify assignments needing review. Good agreement was observed between lead estimates based on SOCcer and manual SOC assignments ( 0.6–0.8). Poorer performance was observed for inspection job descriptions, which included abbreviations and worksite-specific terminology.ConclusionsAlthough some manual coding will remain necessary, using SOCcer may improve the efficiency of incorporating occupation into large-scale epidemiological studies.