OBJECTIVE: To describe volunteer firefighters' perspectives on how firefighter- and fire department-level factors influence their physical activity and fitness. METHODS: Firefighters (n = 28) were interviewed, stratified by their years of firefighting, using an interview guide. Thematic analysis and systematic coding were employed to analyze the interview transcripts. RESULTS: Five themes were identified: (1) health and firefighting performance; (2) firefighter time and availability; (3) responsibility of the fire department to support volunteer members' physical fitness; (4) fire training drills as a form of functional physical activity, and (5) fitness initiatives at the department. Interviewing by years of experience showed varied perspectives which converged towards similar conclusions. CONCLUSIONS: Incorporating fitness discussions into department meetings and trainings, and identifying fitness advocates within the department, may contribute to overcoming barriers to physical fitness among volunteer firefighters.

Prostate cancer is the leading incident cancer among men in the United States. Firefighters are diagnosed with this disease at a rate 1.21 times higher than the average population. This increased risk may result from occupational exposures to many toxicants, including per- and polyfluoroalkyl substances (PFAS). This study assessed the association between firefighting as an occupation in general or PFAS serum levels, with DNA methylation. Only genomic regions previously linked to prostate cancer risk were selected for analysis: GSTP1, Alu repetitive elements, and the 8q24 chromosomal region. There were 444 male firefighters included in this study, with some analyses being conducted on fewer participants due to missingness. Statistical models were used to test associations between exposures and DNA methylation at CpG sites in the selected genomic regions. Exposure variables included proxies of cumulative firefighting exposures (incumbent versus academy status and years of firefighting experience) and biomarkers of PFAS exposures (serum concentrations of 9 PFAS). Proxies of cumulative exposures were associated with DNA methylation at 15 CpG sites and one region located within FAM83A (q-value <0.1). SbPFOA was associated with 19 CpG sites (q < 0.1), but due to low detection rates, this PFAS was modeled as detected versus not detected in serum. Overall, there is evidence that firefighting experience is associated with differential DNA methylation in prostate cancer risk loci, but this study did not find evidence that these differences are due to PFAS exposures specifically.

BACKGROUND: Although firefighters have increased risk for colon and prostate cancer, limited information exists on screening practices for these cancers in volunteer firefighters who compose two-thirds of the US fire service. We estimated the prevalence of colon and prostate cancer screening among volunteer firefighters using eligibility criteria from 4 evidence-based screening recommendations and evaluated factors influencing screening. METHODS: We evaluated colon (n = 569) and prostate (n = 498) cancer screening prevalence in a sample of US volunteer firefighters using eligibility criteria from the US Preventive Services Taskforce (USPSTF), National Fire Protection Association, American Cancer Society, and National Comprehensive Cancer Network. We assessed associations with fire service experience, demographics, and cancer risk perception based on USPSTF guidelines. RESULTS: For those eligible based on USPSTF guidelines, colon and prostate cancer screening prevalence was 51.7% (95% CI: 45.7, 57.8) and 48.8% (95% CI: 40.0, 57.6), respectively. Higher odds of colon and prostate cancer screening were observed with older age and with some college education compared to those with less education. Fire service experience and cancer risk perception were not associated with screening practices. CONCLUSION: This is the first large study to assess colon and prostate cancer screening among US volunteer firefighters based on different screening guidelines. Our findings suggest gaps in cancer prevention efforts in the US volunteer fire service. Promoting cancer screening education and opportunities for volunteer firefighters by their fire departments, healthcare professionals, and public health practitioners, may help to address the gaps.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) comprise a large group of chemicals that have been integrated into a wide variety of industrial processes and consumer products since the 1950s. Due to their profuse usage and high persistence in human serum, understanding workplace exposures to PFAS is critical. OBJECTIVE: We aimed to characterize the PFAS exposure profiles of relevant occupational populations, elucidate trends in the PFAS exposure characterization process, and identify major research gaps that remain within the occupational PFAS exposure literature. METHODS: A systematic search of four literature databases for peer-reviewed articles published between 1980 and 2021 on PFAS exposure in occupational settings was conducted. RESULTS: Of the 2574 articles identified, 92 met the inclusion criteria. Fluorochemical workers were the target population in most early exposure assessment research; however, studies conducted within the last 10 years have evaluated a wider range of occupational populations and settings. The highest exposures were reported in fluorochemical workers, but, in comparison to reference populations, one or more PFAS were elevated in most workers and in most workplaces that were assessed. PFAS was most frequently assessed in worker serum using a discrete analytical panel of PFAS, with earlier studies restricted to a few long-alkyl chain PFAS while more recent studies have included more expansive panels due to more robust methods. SIGNIFICANCE: Characterization of occupational exposure to PFAS is limited but expanding. Current analytical methods are not robust enough to fully capture the potential range of PFAS present across different workers and workplaces. While exposures to PFAS for certain occupational groups have been studied in detail, exposure information for other occupational groups with high potential for exposure are limited. This review highlights substantial findings and major research gaps within the occupational literature.

BACKGROUND: Firefighters have occupational and environmental exposures to per- and polyfluoroalkyl substances (PFAS). The goal of this study was to compare serum PFAS concentrations across multiple United States fire departments to National Health and Nutrition Examination Survey (NHANES) participants. METHODS: Nine serum PFAS were compared in 290 firefighters from four municipal fire departments (coded A-D) and three NHANES participants matched to each firefighter on sex, ethnicity, age, and PFAS collection year. Only Departments A and C had sufficient women study participants (25 and six, respectively) to compare with NHANES. RESULTS: In male firefighters compared with NHANES, geometric mean perfluorohexane sulfonate (PFHxS) was elevated in Departments A-C, sum of branched perfluoromethylheptane sulfonate isomers (Sm-PFOS) was elevated in all four departments, linear perfluorooctane sulfonate (n-PFOS) was elevated in Departments B and C, linear perfluorooctanoate (n-PFOA) was elevated in Departments B-D, and perfluorononanoate (PFNA) was elevated in Departments B-D, but lower in A. In male firefighters compared with NHANES, perfluoroundecanoate (PFUnDA) was more frequently detected in Departments B and D, and 2-(N-methyl-perfluorooctane sulfonamido) acetate (MeFOSAA) was less frequently detected in Departments B-D. In female firefighters compared with NHANES, PFHxS and Sm-PFOS concentrations were elevated in Departments A and C. Other PFAS concentrations were elevated and/or reduced in only one department or not significantly different from NHANES in any department. CONCLUSIONS: Serum PFHxS, Sm-PFOS, n-PFOS, n-PFOA, and PFNA concentrations were increased in at least two of four fire departments in comparison to NHANES.

Over the past few decades, there has been a growing concern over the health effects associated with per- and polyfluoroalkyl substances (PFAS) exposure especially among worker populations. High levels of PFAS exposure have been linked to various health outcomes including cancer and increased cholesterol levels.1 Existing research on occupational PFAS exposure is limited to only a few industries. Given this, the focus of the American Journal of Industrial Medicine's special issue on occupational PFAS exposures is to review current knowledge of occupational exposures to PFAS; identify newer, emerging, or unstudied sources of exposure; assess gaps in present understanding of their occupational use and hazards; and outline the needs for future research and worker protection. This special issue will help advance the scientific community's understanding of PFAS and aid current and future research projects. However, there are additional critical drivers to the success of reducing occupational exposures to PFAS which need to be addressed. These critical drivers are effective coordination, collaboration, communication, and partnerships.

Background: Per- and polyfluoroalkyl substances (PFASs) are persistent chemicals that firefighters encounter. Epigenetic modifications, including DNA methylation, could serve as PFASs toxicity biomarkers. Methods: With a sample size of 197 firefighters, we quantified the serum concentrations of nine PFASs, blood leukocyte DNA methylation and epigenetic age indicators via the EPIC array. We examined the associations between PFASs with epigenetic age, site- and region-specific DNA methylation, adjusting for confounders. Results: Perfluorohexane sulfonate, perfluorooctanoate (PFOA) and the sum of branched isomers of perfluorooctane sulfonate (Sm-PFOS) were associated with accelerated epigenetic age. Branched PFOA, linear PFOS, perfluorononanoate, perfluorodecanoate and perfluoroundecanoate were associated with differentially methylated loci and regions. Conclusion: PFASs concentrations are associated with accelerated epigenetic age and locus-specific DNA methylation. The implications for PFASs toxicity merit further investigation.

OBJECTIVES: We use a qualitative method to gain further insight into women firefighters' experiences, perceptions of cancer, health and safety risks in the fire service. METHODS: We conducted six focus groups with U.S. women firefighters. Participants engaged in a 60-75-minute, semi-structured discussion and completed a sociodemographic questionnaire. A qualitative descriptive approach was used to inductively create themes. Data collection concluded when saturation was met. RESULTS: Forty-nine women firefighters participated. Qualitative results indicated the main health concerns include: Occupational cancer risks including, risks related to hazardous exposures, sleep disruption and stress; and Women's health concerns including, cancer, pregnancy and breastfeeding and lack of resources. CONCLUSIONS: Women firefighters are concerned about their risk for cancer due to their occupation and identify a lack of resources specific to health and safety needs of women firefighters.

Firefighters are exposed to a variety of environmental hazards and are at increased risk for multiple cancers. There is evidence that risks differ by ethnicity, yet the biological or environmental differences underlying these differences are not known. DNA methylation is one type of epigenetic regulation that is altered in cancers. In this pilot study, we profiled DNA methylation with the Infinium MethylationEPIC in blood leukocytes from 31 Hispanic white and 163 non-Hispanic white firefighters. We compared DNA methylation (1) at 12 xenobiotic metabolizing genes and (2) at all loci on the array (>740 000), adjusting for confounders. Five of the xenobiotic metabolizing genes were differentially methylated at a raw P-value <.05 when comparing the 2 ethnic groups, yet were not statistically significant at a 5% false discovery rate (q-value <.05). In the epigenome-wide analysis, 76 loci exhibited DNA methylation differences at q <.05. Among these, 3 CpG sites in the promoter region of the biotransformation gene SULT1C2 had lower methylation in Hispanic compared to non-Hispanic firefighters. Other differentially methylated loci included genes that have been implicated in carcinogenesis in published studies (FOXK2, GYLTL1B, ZBTB16, ARHGEF10, and more). In this pilot study, we report differential DNA methylation between Hispanic and non-Hispanic firefighters in xenobiotic metabolism genes and other genes with functions related to cancer. Epigenetic susceptibility by ethnicity merits further study as this may alter risk for cancers linked to toxic exposures.