Job Exposure Matrix Research Articles

Job Exposure Matrix, a Solution for Retrospective Assessment of Particle Exposure in a Subway Network and Their Long-Term Effects.

Health effects after long-term exposure to subway particulate matter (PM) remain unknown due to the lack of individual PM exposure data. This study aimed to apply the job exposure matrix (JEM) approach to retrospectively assess occupational exposure to PM in the Parisian subway. Job, the line and sector of the transport network, as well as calendar period were four JEM dimensions. For each combination of these dimensions, we generated statistical models to estimate the annual average PM10 concentration using data from an exhaustive inventory of the PM measurement campaigns conducted between 2004 and 2020 in the Parisian subway and historical data from the Parisian air pollution monitoring network. The resulting JEM and its exposure estimates were critically examined by experts using the uncertainty analysis framework. The resulting JEM allows for the assignment of the estimated annual PM10 concentration to three types of professionals working in the subway: locomotive operators, station agents, and security guards. The estimates' precision and validity depend on the amount and quality of PM10 measurement data used in the job-, line-, and sector-specific models. Models using large amounts of personal exposure measurement data produced rather robust exposure estimates compared to models with lacunary data (i.e., in security guards). The analysis of uncertainty around the exposure estimates allows for the identification of the sources of uncertainty and parameters to be addressed in the future in order to refine and/or improve the JEM. The JEM approach seems relevant for the retrospective exposure assessment of subway workers. When applied to available data on PM10, it allows for the estimation of this exposure in locomotive operators and station agents with an acceptable validity. Conversely, for security guards, the current estimates have insufficient validity to recommend their use in an epidemiological study. Therefore, the current JEM should be considered as a valid prototype, which shall be further improved using more robust measurements for some jobs. This JEM can also be further refined by considering additional exposure determinants.

Exploration of associations between occupational exposures and current adult eczema

ObjectivesThere is a scarcity of evidence on occupational exposures that may increase eczema in adults. We aimed to investigate potential associations between occupational exposures and eczema in middle-aged adults.MethodsA lifetime...

A cross-sectional study of sensory-motor neuropsychological function among sewage plant and sewage net workers exposed to hydrogen sulphide when handling wastewater.

Workers at sewage treatment plants are exposed to a complex mixture of toxins, including hydrogen sulphide (H2S). An issue of concern among sewage workers, is possible negative nervous system effects from low-level H2S exposure. Empirical neuropsychological evidence indicates both that low-dose exposure to H2S exposure affects the nervous system, and the contrary, that such exposure may facilitate nervous system function, since H2S is an endogenously produced central nervous system (CNS) gasotransmitter. The aim of this study is to describe a possible association between the H2S component of the total exposure and long-term effects on neuropsychological motor function among wastewater workers. Workers (N = 138) treating wastewater in 6 sewage-treatment plants, or in the sewer net system participated in a cross-sectional study. H2S exposure was expressed in a dichotomous exposure variable defining currently H2S-exposed (N = 112) and unexposed referent workers (N = 26), and a variable defining a job-exposure matrix for long-term total typical workplace H2S exposure. The participants went through neuropsychological tests for hand coordination, reaction time (SRT), and balance, and completed questionnaires. Pearson chi-square test or independent samples t-test was used when comparing the currently H2S-exposed workers with the unexposed control group. Multiple linear regression was used to assess associations between the independent variables age, smoking and exposure variables, and the neuropsychological tests. The analyses indicate increased SRT in the currently H2S-exposed group compared to controls (mean [SD] = 225.8 [29.9] versus 210.7 [26.3] ms, P = 0.019), and an association between increased SRT and current H2S-exposure in the total study sample (β = 14.7, P = 0.026, R2 = 0.06, P = 0.050). Blindfolded balance testing indicates a nonsignificant trend in the total study sample, of reduced balance in the highest versus lowest H2S total long-term exposure-index group (Sway area [mean {SD}, mm2: 702 [410] versus 581 [278]), and a significant association between total long-term H2S exposure and reduced balance among smokers (Sway area, mm2 [β = 38.7, P = 0.039], mean sway, mm [β = 0.3, P = 0.015]). The observed trends and associations may be due to exposure peaks in certain work operations and pinpoint the importance of minimizing and avoiding exposure peaks, also when H2S time-weighted average measurements do not exceed an occupational exposure limit of 5 ppm.

Development and evaluation of the gender-specific CONSTANCES job exposure matrix for physical risk factors in France.

This study aimed to construct and evaluate a gender-specific job exposure matrix (JEM) for 27 physical work exposures, based on self-report. We constructed a JEM using questionnaire data on current physical exposures from 29 381 male and 35 900 female asymptomatic workers aged 18-69 years in the French CONSTANCES cohort study. We excluded workers with musculoskeletal pain to reduce potential reporting bias. We grouped 27 self-reported physical exposures using the French national job codes and stratified by gender. We compared individual and group-based exposures using the performance indicators Cohen's kappa (κ), sensitivity, specificity, and area under the receiver operating curve (AUC). JEM validation showed fair-to-moderate agreement (κ 0.21-0.60) for most physical exposures for both genders except for 'reach behind' (poor), 'bend neck' (poor), 'finger pinch' (poor), standing' (good), 'use computer screen' (good), and 'use keyboard or scanner' (good). We found the highest AUC for 'standing' (men 0.85/ women 0.87), 'kneel/squat' (men 0.80/women 0.81), 'use computer screen' (men/women 0.81), and 'use keyboard or scanner' (men 0.82/ women 0.84). The AUC was <0.60 for only three exposures: 'bend neck' (men 0.58/women 0.57), 'finger pinch' (men 0.56/ women 0.55), and 'reach behind' (men 0.54/ women 0.51). The constructed JEM validation measures were comparable for men and women for all exposures. Further research will examine the predictive ability of this gender-specific JEM for musculoskeletal disorders and the relevance of gender-stratification in this process, knowing accuracy of each exposure.

Personal exposure to radiofrequency electromagnetic fields in various occupations in Spain and France

BackgroundA preliminary job-exposure matrix (JEM) for radiofrequency electromagnetic fields (RF-EMF) was created based on self-reported occupational information from a multi-country population-based study of approximately 10,000 participants combined with available measurement data compiled in a source-exposure matrix (spot measurements). In order to address the limited personal occupational RF-EMF measurement data available in the literature, we performed a measurement campaign among workers in various occupations in Spain and France. MethodsPersonal full-shift measurements were conducted using RadMan 2XT™ (Narda) devices. A worker diary was used to capture information on occupational and background sources of RF exposure during the shift. Inclusion of occupations to be measured was initially based on exposure prevalence and level information in the preliminary JEM and expert judgment. ResultsPersonal full-shift measurements were conducted among 333 workers representing 46 ISCO88 occupations. Exposure to electric (E) and magnetic (H) fields was infrequent with >99% of measurements below the detection limit of the device (≥1% of the 1998 ICNIRP standards). A total of 50.2% and 77.2% of workers were ever exposed to E and H fields respectively (having at least one recorded 1-second measurement above the detection limit). Workers in elementary occupations, technicians and associate professionals, plant and machine operators and assemblers had somewhat greater numbers of measurements above the detection limit, higher maximum values and longer exposure durations. A small proportion of measurements were ≥100% of the standards, though these exceedances were brief (generally a few seconds in duration). Female workers and workers reporting use of any RF-EMF emitting source were more likely to have a measured exposure to E and H fields. ConclusionWe conducted personal RF-EMF measurements among workers in various occupations in Spain and France. Overall, RF-EMF exposure ≥1 % ICNIRP was infrequent, despite some intermittent exposures ≥100% observed among workers in some occupations.

Occupational exposure to silica dust in France: an ongoing concern.

Crystalline silica is found in many construction materials. Although it is one of the oldest known occupational exposures, new exposure contexts have emerged in recent years. In 2021, France classified work involving exposure to respirable crystalline silica (ie, silica dust) generated by a work process as carcinogenic. In order to assess exposure in the French workforce between 1947 and 2020, we developed a silica job-exposure matrix (JEM) for the Matgéné program. The JEM was linked with occupational data from different population censuses (1982, 1990, 1999, 2007 and 2017). The proportions and numbers of workers exposed to silica dust in France at these various census time points were estimated and described by sex and industry for 2017. After decreasing between 1982 and 1999, the proportion of workers exposed to silica dust remained stable at 4%, representing 975 000 workers in 2017. Exposed workers were mostly men (93%), and most worked in the construction industry (64%). This was also the industry where the majority of workers were exposed to a level above the French 8-hour time weighted average occupational exposure limit (TWA-OEL). A large number of workers in France were still exposed (some highly) to silica dust in 2017 so this agent still poses an occupational health concern. The results of this study provide key information about the continued surveillance of the evolution of exposure to silica dust. In a few years, it will be possible to quantify the impact of the 2021 regulation in terms of proportions and number of workers exposed to silica dust.

History of working conditions and the risk of old-age dependency: a nationwide Swedish register-based study.

There is substantial evidence that previous working conditions influence post-retirement health, yet little is known about previous working conditions' association with old-age dependency. We examined job strain, hazardous and physical demands across working life, in relation to the risk of entering old-age dependency of care. Individually linked nationwide Swedish registers were used to identify people aged 70+ who were not receiving long-term care (residential care or homecare) at baseline (January 2014). Register information on job titles between the years 1970 and 2010 was linked with a job exposure matrix of working conditions. Random effects growth curve models were used to calculate intra-individual trajectories of working conditions. Cox regression models with age as the timescale (adjusted for living situation, educational attainment, country of birth, and sex) were conducted to estimate hazard ratios for entering old-age dependency during the 24 months of follow-up (n = 931,819). Having initial adverse working conditions followed by an accumulation throughout working life encompassed the highest risk of entering old-age dependency across the categories (job strain: HR 1.23, 95% CI 1.19-1.27; physical demands: HR 1.36, 95% CI 1.31-1.40, and hazardous work: HR 1.35, 95% CI 1.30-1.40). Initially high physical demands or hazardous work followed by a stable trajectory, or initially low-level physical demand or hazardous work followed by an accumulation throughout working life also encompassed a higher risk of dependency. A history of adverse working conditions increased the risk of old-age dependency. Reducing the accumulation of adverse working conditions across the working life may contribute to postponing old-age dependency.

A cohort study of retinal detachment among Swedish construction workers.

Retinal detachment (RD) has been associated with exposure to heavy lifting. Many occupations within the construction industry are likely to involve lifting tasks. We investigated the association between occupational heavy lifting and rhegmatogenous RD in a retrospective cohort study of Swedish construction workers. We studied Swedish construction workers who participated in an industry-wide health and safety program from 1971 to 1993. Individual occupation codes were linked to a job exposure matrix, assigning intensity of exposure to heavy lifting to each worker. The Swedish National Patient Register was used to identify cases of RD that occurred during follow-up through the end of 2012. We used Poisson regression modeling to calculate incidence rates of RD associated with heavy lifting, age and other covariates. A subcohort of those age ≤25 years at enrollment was studied to reduce bias from missing exposure information from work prior to enrollment. Of 256 241 construction workers, 17% were classified with high exposure to heavy lifting in their occupation. Within the cohort, 1588 cases of RD were identified. Average exposure intensity of heavy lifting was not associated with risk of RD. However, RD risk increased with increasing cumulative exposure to heavy lifting, both in the full cohort and subcohort of those who were ≤25 years old at entry into the construction-worker cohort. Construction workers' risk of RD appeared to increase with time spent exposed to heavy lifting.

Parental occupational exposure to metals and risk of cancer in the offspring: A register-based case-control study from Sweden

BackgroundCancer risks in the offspring of mothers and fathers exposed to metals are unknown. We estimated the relative risks of childhood cancer, overall and by type, associated with parental occupational exposure to arsenic, cadmium, chromium, nickel, and lead. MethodsWe conducted a nested case-control study (1960–2015) of children born in Sweden aged 0–19 years diagnosed with cancer (National Cancer Register) matched 25:1 to controls on birth year and sex. We obtained parental occupational data around their birth from censuses and a nationwide register and identified exposure to each metal (yes/no, or higher/lower/no exposure) using the Swedish job-exposure matrix (SWEJEM). Adjusted odds ratios (OR) and 95% confidence intervals (CIs) were estimated separately for maternal and paternal exposures using conditional logistic regression. ResultsWe compared 9653 cases to 1,72,194 controls in maternal and 12,521 cases to 2,74,434 controls in paternal analyses, respectively. We found a 38% increased risk of cancer associated with maternal occupational exposure to arsenic (OR 1.38 [95% CI 1.06, 1.82]), likely driven by higher risks for lymphoma (OR 1.52 [0.73, 3.15]), central nervous system (CNS) (OR 1.49 [0.88, 2.54]) and other solid malignancies (OR 1.74 [1.14, 2.65]). There were also indications of higher risks of lymphoma in children of mothers exposed to nickel and iron, and of CNS tumours due to chromium exposure. No associations were observed from paternal occupational exposure to any of the metals. ConclusionsWe found evidence of increased risks of cancer in children of mothers but not fathers occupationally exposed to arsenic and potentially other metals.

Occupational environment and ovarian cancer risk

ObjectivesTo investigate employment in an occupation or industry and specific occupational exposures in relation to ovarian cancer risk.MethodsIn a population-based case–control study conducted in Montreal, Canada (2011–2016), lifetime occupational histories...

Cancer incidence among workers in soft paper mills:A cohort study.

To elucidate whether occupational exposure to soft paper dust increases the incidence of cancer. We studied 7988 workers in Swedish soft paper mills from 1960 to 2008, of whom 3233 (2 187 men and 1046 women) had more than 10 years of employment. They were divided into high exposure (>5 mg/m3 for >1 year) or lower exposure to soft paper dust based on a validated job-exposure matrix. They were followed from 1960 to 2019, and person-years at risk were stratified according to gender, age, and calendar-year. The expected numbers of incident tumors were calculated using the Swedish population as the reference, and standardized incidence ratios (SIR) with 95% confidence intervals (95% CI) were assessed. Among high-exposure workers with more than 10 years of employment, there was an increased incidence of colon cancer (SIR 1.66, 95% CI 1.20-2.31), small intestine cancer (SIR 3.27, 95% CI 1.36-7.86), and thyroid gland cancer (SIR 2.68, 95% CI 1.11-6.43), as well as lung cancer (SIR 1.56, 95% CI 1.12-2.19). Among the lower-exposed workers there was an increased incidence of connective tissue tumors (sarcomas) (SIR 2.26, 95% CI 1.13-4.51) and pleural mesothelioma (SIR 3.29, 95% CI 1.37-7.91). Workers in soft paper mills with high exposure to soft paper dust have an increased incidence of large and small intestine tumors. Whether the increased risk is caused by paper dust exposure or some unknown associated factors is unclear. The increased incidence of pleural mesothelioma is probably linked to asbestos exposure. The reason for increased incidence of sarcomas is unknown.

Changes in physical performance according to job demands across three cohorts of older workers in the Longitudinal Aging Study Amsterdam

This study set out to evaluate the association between job demands at baseline and physical performance over a six-year period across three cohorts of older Dutch workers examined 10 years apart. Data were drawn from three cohorts (1992–1999, 2002–2009 and 2012–2019) of the Longitudinal Aging Study Amsterdam. Individuals aged 55–65 years from each cohort who worked for pay were included (n = 274, n = 416, n = 618, respectively). Physical performance was measured using gait speed and chair stand performance. A population-based job exposure matrix was used to indicate levels of exposure probability of physical (use of force and repetitive movements) and psychosocial (cognitive demands and time pressure) job demands. We found that psychosocial job demands increased and physical demands decreased across the three cohorts. No between cohort differences were found for how job demands affected changes in physical performance over follow-up. For men, faster decline in gait speed was observed when comparing higher and lower use of force at baseline (β −0.012, 95% CI −0.021, −0.004). Greater use of force and repetitive movements were associated with faster decline in chair stand performance (β −0.012, 95% CI −0.020, −0.004 and β −0.009, 95% CI −0.017, −0.001, respectively). In women, no association of job demands on change in physical performance was observed. The study concluded that higher physical job demands were associated with stronger decline in physical performance across six years for men in all cohorts, while no associations were found among women.

Wood dust in France. Trends in the population of exposed workers between 1982 and 2017 based on a job-exposure matrix assessment.

Many occupations and industries use wood as a raw material and wood dust is a well-known carcinogen. This study presents trends in occupational exposure to wood dust for all workers (employees and self-employed workers) in France between 1982 and 2017 and focuses on the exposed workers in 2017. Exposures to this carcinogen were assessed using the Matgéné job-exposure matrix. Trends in the prevalence and proportion of exposure over the study period were estimated by linking the matrix with population data from the 1982, 1990, 1999, 2007, and 2017 censuses and are described for selected industry groups. The number of exposed workers to wood dust has decreased significantly over the last 40 years, from 466,900 potentially exposed workers in 1982 to 305,000 workers in 2017. The proportion of exposed workers has also decreased over time, although not uniformly across industries. Increases in the proportion of exposed workers are observed in certain industries, such as "Sawmilling and logging" (from 61.2% to 73.6% over the period for men) and "Finishing of sale premises" (from 3.3% to 6.2% for women). This article is the first to describe occupational exposure to wood dust in France for all workers and to follow its evolution over the last 40 years. Occupations and industries still at risk in 2017 are also described with the aim of helping to improve prevention policies.

The association of forced expiratory volume in one second with occupational exposures in a longitudinal study of adults in a rural community in Iowa.

The Keokuk County Rural Health Study (KCRHS) is a longitudinal population-based study conducted in rural Iowa. A prior analysis of enrollment data identified an association of airflow obstruction with occupational exposures only among cigarette smokers. The current study used spirometry data from all three rounds to investigate whether level of forced expiratory volume in one second (FEV1) and longitudinal change in FEV1 were associated with occupational vapor-gas, dust, and fumes (VGDF) exposures, and whether these associations were modified by smoking. This study sample comprised 1071 adult KCRHS participants with longitudinal data. A job-exposure matrix (JEM) was applied to participants' lifetime work histories to assign exposures to occupational VGDF. Mixed regression models of pre-bronchodilator FEV1 (millimeters, ml) were fit to test for associations with occupational exposures while adjusting for potential confounders. Mineral dust had the most consistent association with change in FEV1, including ever/never ( - 6.3ml/year) and nearly every level of duration, intensity, and cumulative exposure. Because 92% of participants with mineral dust also had organic dust exposure, the results for mineral dust may be due to a combination of the two. An association of FEV1 level with fumes was observed for high intensity ( - 91.4ml) among all participants, and limited to cigarette smokers with results of - 104.6ml ever/never exposed, - 170.3ml high duration, and - 172.4ml high cumulative. The current findings suggest that mineral dust, possibly in combination with organic dust, and fumes exposure, especially among cigarette smokers, were risk factors for adverse FEV1 results.

Occupational noise exposure and tinnitus: the HUNT Study

Objective We aimed to assess the association between occupational noise exposure and tinnitus. Further, to assess whether the association depends on hearing status. Design In this cross-sectional study, tinnitus (>1 h daily) was regressed on job exposure matrix (JEM)-based or self-reported occupational noise exposure, adjusted for confounders. Study sample The 14,945 participants (42% men, 20–59 years) attended a population-based study in Norway (HUNT4, 2017-2019). Results JEM-based noise exposure, assessed as equivalent continuous sound level normalised to 8-h working days (LEX 8 h), over the working career or as minimum 5 years ≥85 dB) was not associated with tinnitus. Years of exposure ≥80 dB (minimum one) was not associated with tinnitus. Self-reported high noise exposure (>15 h weekly ≥5 years) was associated with tinnitus overall and among persons with elevated hearing thresholds (prevalence ratio (PR) 1.3, 1.0–1.7), however not statistically significantly among persons with normal thresholds (PR 1.1, 0.8–1.5). Conclusions Our large study showed no association between JEM-based noise exposure and tinnitus. This may to some extent reflect successful use of hearing protection. High self-reported noise exposure was associated with tinnitus, but not among normal hearing persons. This supports that noise-induced tinnitus to a large extent depends on audiometric hearing loss.

Development of a quantitative North and Central European job exposure matrix for wood dust.

Wood dust is an established carcinogen also linked to several non malignant respiratory disorders. A major limitation in research on wood dust and its health effects is the lack of (historical) quantitative estimates of occupational exposure for use in general population-based case-control or cohort studies. The present study aimed to develop a multinational quantitative Job Exposure Matrix (JEM) for wood dust exposure using exposure data from several Northern and Central European countries. For this, an occupational exposure database containing 12653 personal wood dust measurements collected between 1978 and 2007 in Denmark, Finland, France, The Netherlands, Norway, and the United Kingdom (UK) was established. Measurement data were adjusted for differences in inhalable dust sampling efficiency resulting from the use of different dust samplers and analysed using linear mixed effect regression with job codes (ISCO-88) and country treated as random effects. Fixed effects were the year of measurement, the expert assessment of exposure intensity (no, low, and high exposure) for every ISCO-88 job code from an existing wood dust JEM and sampling duration. The results of the models suggest that wood dust exposure has declined annually by approximately 8%. Substantial differences in exposure levels between countries were observed with the highest levels in the United Kingdom and the lowest in Denmark and Norway, albeit with similar job rankings across countries. The jobs with the highest predicted exposure are floor layers and tile setters, wood-products machine operators, and building construction labourers with geometric mean levels for the year 1997 between 1.7 and 1.9 mg/m3. The predicted exposure estimates by the model are compared with the results of wood dust measurement data reported in the literature. The model predicted estimates for full-shift exposures were used to develop a time-dependent quantitative JEM for exposure to wood dust that can be used to estimate exposure for participants of general population studies in Northern European countries on the health effects from occupational exposure to wood dust.

Associations between an international COVID-19 job exposure matrix and SARS-CoV-2 infection among 2 million workers in Denmark.

This study investigates the associations between the Danish version of a job exposure matrix for COVID-19 (COVID-19-JEM) and Danish register-based SARS-CoV-2 infection information across three waves of the pandemic. The COVID-19-JEM consists of four dimensions on transmission: two on mitigation measures, and two on precarious work characteristics. The study comprised 2 021 309 persons from the Danish working population between 26 February 2020 and 15 December 2021. Logistic regression models were applied to assess the associations between the JEM dimensions and overall score and SARS-CoV-2 infection across three infection waves, with peaks in March-April 2020, December-January 2021, and February-March 2022. Sex, age, household income, country of birth, wave, residential region and during wave 3 vaccination status were accounted for. Higher risk scores within the transmission and mitigation dimensions and the overall JEM score resulted in higher odds ratios (OR) of a SARS-CoV-2 infection. OR attenuated across the three waves with ranges of 1.08-5.09 in wave 1, 1.06-1.60 in wave 2, and 1.05-1.45 in those not (fully) vaccinated in wave 3. In wave 3, no associations were found for those fully vaccinated. In all waves, the two precarious work dimensions showed weaker or inversed associations. The COVID-19-JEM is a promising tool for assessing occupational exposure to SARS-CoV-2 and other airborne infectious agents that mainly spread between people who are in close contact with each other. However, its usefulness depends on applied restrictions and the vaccination status in the population of interest.

12 Exposure to Metals and Particles in Welding and Episodes of Asthma/Wheeze and Rhinitis: a Canadian Cohort Study.

Abstract Introduction Welders are exposed through welding fume to particles and metals, including nickel and chromium, that may act as respiratory sensitizers. In a Canadian study of male and female welders we investigated the relation of modelled welding exposures to episodes of asthma/wheeze and rhinitis. Methods Welders who had been registered in an apprenticeship were recruited and followed up at 6-month intervals for up to five years. Women were recruited from across Canada, men just from Alberta. At each contact participants were asked about their health and specifically about symptoms of asthma and rhinitis and age these had first occurred. A complete job history was taken and at each contact after recruitment the participant completed a detailed welding task questionnaire. A job exposure matrix was developed, reflecting type of welding, base metal and consumables. This was validated against urinary metal concentration. Results 1001 welders, including 447 women, were recruited. In bivariate analyses, hours of welding/week, hours grinding/day and estimated exposures to total particles, manganese, nickel and aluminum were related to episodes of asthma/wheeze. Hours welding, grinding and nickel exposure were related to rhinitis. In multivariable models, including all exposures and confounders, the number of hours welding/week and hours grinding/day were related to asthma/wheeze episodes and hours grinding and nickel exposure to rhinitis. Conclusions Duration of welding tasks was related to episodes of asthma/wheeze and rhinitis. There was less evidence that estimated metal concentrations were associated with respiratory ill-health, having adjusted for hours welding.

65 The Adverse Health Effects of Exposure to PM2.5 on the London Underground

Abstract Transport for London (TfL) employed 36,506 staff between 2014 and 2019, 22,202 worked within the London Underground (LU). Employees were regularly exposed to PM2.5 concentrations 15-fold higher than those found above ground in London. However, PM2.5 in the LU differs in physical and chemical characteristics relative to outdoor air, and the health impacts are largely unquantified. This project aims to quantify LU PM exposure of staff and measure its impact on cardiorespiratory sickness absence. A job exposure matrix was developed to model TfL employee PM2.5 exposure based on their jobs. Measurement campaigns were deployed across the LU network to validate and revise staff PM2.5 exposure, which was then linked to sickness absence records. Poisson models were developed to explore the relationship with cardiorespiratory sickness absence. PM2.5 exposure of customer service staff varied depending on their grade and tasks they undertake. Concentrations ranged from 2 to 138 µg/m3 in the offices and 3 to 1,036 µg/m3 on the platforms. Drivers’ PM2.5 exposure was dependent on the line they worked on and the amount of time the train spent underground. Drivers have the highest PM2.5 exposure (median: 130 µg/m3) among all TfL staff and the highest mean number of all-cause (6.7) and respiratory (1.5) sickness absence episodes. This is the largest study to quantify LU PM exposure and the associated health effects within a London occupational cohort. It will contribute to a safer working environment for staff and to a better understanding of the potential health impact on the commuting population.

Exposure to volatile hydrocarbons and neurologic function among oil spill workers up to 6 years after the Deepwater Horizon disaster

BackgroundDuring the 2010 Deepwater Horizon (DWH) disaster, oil spill response and cleanup (OSRC) workers were exposed to toxic volatile components of crude oil. Few studies have examined exposure to individual volatile hydrocarbon chemicals below occupational exposure limits in relation to neurologic function among OSRC workers. ObjectivesTo investigate the association of several spill-related chemicals (benzene, toluene, ethylbenzene, xylene, n-hexane, i.e., BTEX-H) and total petroleum hydrocarbons (THC) with neurologic function among DWH spill workers enrolled in the Gulf Long-term Follow-up Study. MethodsCumulative exposure to THC and BTEX-H across the oil spill cleanup period were estimated using a job-exposure matrix that linked air measurement data to detailed self-reported DWH OSRC work histories. We ascertained quantitative neurologic function data via a comprehensive test battery at a clinical examination that occurred 4–6 years after the DWH disaster. We used multivariable linear regression and modified Poisson regression to evaluate relationships of exposures (quartiles (Q)) with 4 neurologic function measures. We examined modification of the associations by age at enrollment (<50 vs. ≥50 years). ResultsWe did not find evidence of adverse neurologic effects from crude oil exposures among the overall study population. However, among workers ≥50 years of age, several individual chemical exposures were associated with poorer vibrotactile acuity of the great toe, with statistically significant effects observed in Q3 or Q4 of exposures (range of log mean difference in Q4 across exposures: 0.13–0.26 μm). We also observed suggestive adverse associations among those ≥ age 50 years for tests of postural stability and single-leg stance, although most effect estimates did not reach thresholds of statistical significance (p < 0.05). ConclusionsHigher exposures to volatile components of crude oil were associated with modest deficits in neurologic function among OSRC workers who were age 50 years or older at study enrollment.