Exposure assessment 1
Monday 6 October 2025, 16.00 – 17.30 Flash
Chairs: Deborah Glass, Tracy Kirkham
A novel assessment of secondhand drug exposures on Pacific Northwest (USA) transit
Marissa Baker (presenter)
Marc Beaudreau, Pranav Srikanth, Martin Cohen, Edmund Seto, Christopher Simpson, Christopher Zuidema
Abstract
Objective: Transit operators have reported physical and mental health impacts related to drug use on transit. We sought to characterize air and surface concentrations of methamphetamine and fentanyl on transit in Washington and Oregon states to characterize transit operator exposure to these substances and help transit agencies prioritize interventions for operator well-being.
Materials & Methods: We collected 78 total dust air samples (near the transit operator and elsewhere) and 102 surface samples via methanol-wetted swab from 11 buses and 19 trains. Background environmental samples were collected in nearby urban areas. Filters and swabs were analyzed for fentanyl and methamphetamine using LC/MS/MS.
Results: On transit samples, fentanyl was detected in 25% of air samples and 46% of surface samples; methamphetamine was detected in all air samples and 98% of surface samples. No fentanyl was found in environmental air or surface samples; methamphetamine was found in 3 (of 15) environmental air samples and 4 (of 14) environmental surface samples. The highest fentanyl air sample (0.14 µg/m3) was collected in the passenger area of a train, exceeding the ACGIH 8-hr TWA TLV of 0.1 µg/m3. No surface samples exceed the ACGIH fentanyl surface level TLV (10 ng/cm2). Other occupational standards or guidelines do not exist.
Conclusions: Fentanyl and methamphetamine were frequently found in the air and on surfaces of the vehicles in our study, at levels exceeding the environmental samples. Protecting transit operators from second-hand exposures, and from the stressors of witnessing and responding to smoking events, represents appropriate occupational health action consistent with the public health goal of smoke free workplaces. Where elimination is not possible, engineering and administrative controls (ventilation, cleaning) should be evaluated along with training and workplace supports for after operators observe or respond to drug events.
A quantitative algorithm to estimate endotoxin exposure for the spouses in the Agricultural Health Study
Pabitra R. Josse (presenter)
Laura E. Beane Freeman, Shuai Xie, Christine Parks, Dale Sandler, Gabriella Andreotti, Jonathan N. Hofmann, Melissa C. Friesen
Abstract
Objective: Agricultural studies mostly focus on farmers’ exposures, but their family members often conduct similar agricultural tasks. To quantify the endotoxin exposure for spouses of farmers in the Agricultural Health Study (AHS), we modified an algorithm previously developed for AHS farmers in the Biomarkers of Exposure and Effect in Agriculture (BEEA) sub-study.
Methods: The BEEA algorithm quantified endotoxin exposure for 13 bioaerosol-related agricultural tasks queried via questionnaire. It multiplied task frequency by task-specific intensity derived from meta-analyses of published endotoxin measurements. The AHS enrollment questionnaire completed by 32,345 spouses (>99% female) included 5 of these tasks, three with frequency information (‘number of times’: poultry contact, swine contact, milking cows), and two with yes/no information (grinding feed, harvesting grain). We used the median hours/time reported for each task in BEEA to convert ‘number of times’ to hours and the median task hours to derive hours for yes/no tasks. We used the ratio of the 75th/25th percentile of exposure estimates as a measure of contrast. We calculated Spearman correlations between the task-specific and total estimates.
Results: Overall, 39% of spouses reported at least one task, with 12% reporting two or more. Swine contact was the most common (27%); milking cows was the least common (3%). We estimated a 90-fold contrast amongst endotoxin-exposed spouses, with 38-, 10-, and 7-fold contrast amongst those exposed to poultry, swine, and milk cows, respectively. The task-specific estimates had low correlation (<0.25) with each other. The ‘total’ (summed) exposure had high correlation with swine contact, moderate correlation with grinding feed and poultry contact, and low correlation with the remaining tasks.
Conclusions: Although we could not account for all bioaerosol-related tasks, we identified substantial endotoxin exposure variability in the AHS spouses. These estimates will be used to examine exposure-response associations in future etiologic analyses with cancer and other outcomes.
Multiple occupational exposures and mental diagnoses
Laura Salonen (presenter)
Taina Leinonen, Jenny Selander, Svetlana Solovieva
Abstract
Objective: While extensive research has explored the relationship between psychosocial exposures and mental disorders, there is limited understanding of how other occupational exposures, particularly when assessed in combination, influence mental health outcomes. We examine how multiple occupational exposures are associated with mental diagnoses.
Material and Methods: We utilized Finnish register data covering individuals aged 30-62 in 2010 (N=2,184,231) and applied Cox proportional hazards model to examine the association between 12 different occupational exposures assessed by European Job Exposure Matrix (EuroJEM) and incident health care visits due to mental diagnoses in 2011-2021. The analysis was conducted separately for men and women, accounting for age, education and mutual exposures.
Results: Around 11.5% had health care visits due to mental diagnoses, mainly due to depression, anxiety or substance use. Each exposure was associated with at least one health outcome, with most showing positive associations and some negative. The strongest association with any mental diagnoses was found with high likelihood of job demands with hazard ratios of 1.32 (95% confidence intervals 1.23-1.36) in men, and 1.18 (1.13-1.22) in women (compared to low likelihood of exposure to job demands). Fully adjusted models revealed positive associations for high job demands, low decision authority, fast breathing, awkward work posture and noise with mental diagnoses. No significant associations with mental diagnoses were found for diesel, wood dust and nickel in women. Very few associations were observed between occupational exposures and reactive stress in men and sleeping disorders in women.
Conclusions: In addition to psychosocial exposures, also occupational noise and physical workload increased the risk of mental diagnoses. The associations, however, varied across exposures, specific mental health diagnosis, adjustments and gender. Funding: This project has received funding from the Strategic Research Council of Finland (LIFECON 364414) and the European Union’s Horizon 2020 research and innovation programme (grant No 874703).
Occupational microbial health risks in intensive goat farming: airborne microbial exposure, farmers’ respiratory microbiome and fungal sensitization
Aniek Lotterman (presenter)
Myrna M.T. de Rooij, Inge Roof, Beatrice Cornu Hewitt, Mari-Lee Odendaal, Alex Bossers, Inge M. Wouters, Adam Meijer, Thomas J. Hagenaars, Joris C. Ijzermans, Joke W.B. van der Giessen, Arianne B. van Gageldonk-Lafeber, Lidwien A.M. Smit .
Abstract
Objective: Goat farming is a rapidly expanding livestock sector with a unique husbandry system. Little is known about related occupational exposures and health risks. We aimed to 1) assess occupational exposure to particulate matter, endotoxin and airborne pathogens; and 2) characterize goat farmers’ respiratory health based on their upper airway microbiome and fungal sensitization profiles.
Material and Methods: Repeated personal exposure sampling was performed for 41 goat farmers; particulate matter concentrations were measured gravimetrically and endotoxins were quantified by LAL-assay. Airborne microbiota were characterized from 15 farms using 16S rRNA-gene sequencing. Health assessments were performed with 93 goat farmers and evaluated against findings from 200 non-farming neighboring residents. Nasopharyngeal and oropharyngeal swabs were analyzed by qPCR for 35 respiratory pathogens and by 16S rRNA-gene sequencing for microbiota composition. Serum samples were evaluated by ELISA for antibody titers against fungal antigens.
Results: Exposure to particulate matter and endotoxin was prominent, 90% of measurements exceeded the Dutch occupational exposure limit for endotoxin (90 EU/m³). Goat farms harbored large varieties of airborne micro-organisms, including potential respiratory pathogens. Compared to non-farming residents, qPCR indicated elevated prevalence of Salmonella spp. (17.6%) and Staphylococcus aureus (49.5%) among farmers. Respiratory microbiota analysis revealed higher diversity among farmers with increased abundances of Lactococcus, Stenotrophomonas, Fusobacterium, and Micrococcus spp. Farmers also exhibited higher sensitization rates to fungal species relevant to hypersensitivity pneumonitis, particularly Aspergillus spp.
Conclusion: Goat farmers experience significant occupational exposures to airborne micro-organisms and their components, posing both infectious and non-infectious respiratory health risks. Overall, our findings underscore the need for improved occupational health protection and support targeted interventions to reduce microbial air pollution in goat farming. Funding: This research is funded by the Ministry of Health, Welfare and Sport and the Ministry of Agriculture, Nature and Food Quality of The Netherlands
Urinary phthalate metabolite concentrations by occupation and industry: Evidence from the Canadian Health Measures Survey
Patrick Hinton (presenter)
Patrick Hinton, Ryann E Yeo, Joanne Kim, Daniel RS Middleton, Katherine Pullella, Victoria Arrandale, Nathan L DeBono
Abstract
Objective: Phthalates are ubiquitous endocrine-disrupting compounds linked to numerous adverse health outcomes, including hormone-sensitive cancers. Previous studies of phthalates, such as the widely used plasticizer di-2-ethylhexylphthalate (DEHP), have identified important environmental determinants, but few have examined their association with occupational factors. We sought to identify occupations with elevated urinary phthalate biomarker concentrations in a nationally-representative biomonitoring study of adults in Canada.
Methods: We conducted a cross-sectional study of 4,180 individuals aged 20-80 years from the Canadian Health Measures Survey (CHMS) between 2007-2011 (cycles 1-2) and 2016-2019 (cycles 5-6). Spot urine samples were analyzed for concentrations of 11 phthalate metabolites quantified using chromatography and spectrometry. Creatinine-corrected molar sum groups were constructed to describe DEHP and high- and low- molecular weight phthalate (HMWP & LMWP, respectively) exposures. Linear regression models estimated predicted least-squares adjusted geometric means (GMs) and geometric mean ratios by occupation and industry groups. Models were adjusted for dietary, sociodemographic, and anthropometric factors.
Results: Phthalate concentrations (nmol/g creatinine) were elevated among women, older adults, individuals of Asian ethnicities, smokers, urban residents, frequent consumers of grain products, and those in the earliest CHMS cycles. By occupation, LMWP concentrations were highest among labourers in processing, manufacturing, and utilities (GM[LMWP] = 559.92; 95% CI: 333.03-941.40). Workers in these occupations were commonly employed in clothing, electrical, and machinery manufacturing industries. HMWP and DEHP concentrations were highest in trades helpers, construction labourers, and related occupations (GM[HMWP] = 124.94; 95% CI: 88.10-177.18) as well as workers in natural resources, agriculture, and related production (GM[DEHP] = 64.10; 95% CI: 46.39-88.56), respectively. Among women, elevated LMWP and DEHP concentrations were observed in installers, repairers, servicers, and material handlers.
Conclusion: Results suggest heterogeneity in phthalate exposure by occupation and sex. Findings will be used to inform subsequent investigations of breast and prostate cancer risk.
Aggregate exposure assessment of PFAS in occupational settings: Case studies on ski waxers and chemical plant workers
Ruby Vermoolen (presenter)
Ruby Vermoolen, Maxime Birza, Susana Viegas, Amelie Crepet, Remy Franken, Wouter Fransman, Ilse Ottenbros
Abstract
Objective: Chemical exposure can result from multiple routes and sources, including those encountered in the workplace. This study aims to develop and apply a methodology for assessing aggregate exposure to perfluoroalkyl substances (PFAS) in the workplace. By integrating multi-route exposure data, the approach identifies key contributors to internal PFAS concentrations in selected occupational groups. Additionally, it aims to streamline fragmented exposure information, address critical data gaps, and improve alignment with predictive models to support more effective risk assessment.
Methods: Ski wax technicians and chemical plant workers, two occupations with high potential for PFAS exposure, were selected as case studies based on the availability of measurement data and suitable exposure models. External exposure to perfluorooctanoic acid (PFOA) via inhalation and dermal contact was modeled for typical workday scenarios using the Advanced REACH Tool (ART) and dermal ART (dART). These modeled exposures were compared to available measurement data. Combined with background oral intake from daily life, the results were used to estimate serum PFOA concentrations using a physiologically based pharmacokinetic (PBPK) model and compared to human biomonitoring (HBM) data.
Results: In both case studies, inhalation exposure alone underestimated serum concentrations. To address data gaps such as missing task details, fragmented exposure information was integrated and supplemented with assumptions based on similar scenarios. The aggregate exposure approach resulted in serum concentration estimates that aligned well with available HBM data, supporting the methods validity.
Conclusion: This study demonstrates the importance of aggregate exposure assessment for PFAS in occupational settings. Considering multiple exposure routes provides a more comprehensive view than single-route assessments, facilitates better interpretation of biomonitoring data, and supports more targeted and effective exposure control strategies.