Risk of cancer among firefighters in California, 1988-2007

Exposure to Perfluoroalkyl Substances in a Cohort of Women Firefighters and Office Workers in San Francisco

Studies of firefighters have shown increased exposures to carcinogenic compounds and elevated rates of certain cancers compared to the general population, yet this research has focused almost exclusively on men. To address this gap, the Women Firefighters Biomonitoring Collaborative created a biological sample archive and analyzed levels of perfluoroalkyl substances (PFAS) among women firefighters (N = 86) and office workers (N = 84) in San Francisco. Serum samples were collected and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure and compare PFAS levels between firefighters and office workers. 7 of 12 PFAS congeners were detected in the least 70% of the study population, and 4 congeners were detected in 100% of participants. In regression models comparing PFAS levels by occupation and adjusting for potential confounders, firefighters had higher geometric mean concentrations of PFAS compared to office workers PFHxS (2.22 (95% CI = 1.55, 3.18)), PFUnDA (1.83 (95% CI = 0.97, 3.45)), and PFNA (1.26 (95% CI = 1.01, 1.58)). Among firefighters, occupational position predicted exposure-firefighters and officers had higher PFNA, PFOA, PFDA, and PFUnDA levels compared to drivers. Women firefighters are exposed to higher levels of some PFAS compared to office workers, suggesting that some of these exposures may be occupationally related.

Firefighters' absorption of PAHs and VOCs during controlled residential fires by job assignment and fire attack tactic

To better understand the absorption of combustion byproducts during firefighting, we performed biological monitoring (breath and urine) on firefighters who responded to controlled residential fires and examined the results by job assignment and fire attack tactic. Urine was analyzed for metabolites of polycyclic aromatic hydrocarbons (PAHs) and breath was analyzed for volatile organic compounds (VOCs) including benzene. Median concentrations of PAH metabolites in urine increased from pre-firefighting to 3-h post firefighting for all job assignments. This change was greatest for firefighters assigned to attack and search with 2.3, 5.6, 3.9, and 1.4-fold median increases in pyrene, phenanthrene, naphthalene, and fluorene metabolites. Median exhaled breath concentrations of benzene increased 2-fold for attack and search firefighters (p < 0.01) and 1.4-fold for outside vent firefighters (p = 0.02). Compared to interior attack, transitional attack resulted in 50% less uptake of pyrene (p = 0.09), 36% less uptake phenanthrene (p = 0.052), and 20% less uptake of fluorene (p < 0.01). Dermal absorption likely contributed to firefighters' exposures in this study. Firefighters' exposures will vary by job assignment and can be reduced by employing a transitional fire attack when feasible.

Mortality in a cohort of US firefighters from San Francisco, Chicago and Philadelphia: an update

OBJECTIVES

To update the mortality experience of a previously studied cohort of 29 992 US urban career firefighters compared with the US general population and examine exposure-response relationships within the cohort.

METHODS

Vital status was updated through 2016 adding 7 years of follow-up. Cohort mortality compared with the US population was evaluated via life table analyses. Full risk-sets, matched on attained age, race, birthdate and fire department were created and analysed using the Cox proportional hazards regression to examine exposure-response associations between select mortality outcomes and exposure surrogates (exposed-days, fire-runs and fire-hours). Models were adjusted for a potential bias from healthy worker survivor effects by including a categorical variable for employment duration.

RESULTS

Compared with the US population, mortality from all cancers, mesothelioma, non-Hodgkin's lymphoma (NHL) and cancers of the oesophagus, intestine, rectum, lung and kidney were modestly elevated. Positive exposure-response relationships were observed for deaths from lung cancer, leukaemia and chronic obstructive pulmonary disease (COPD).

CONCLUSIONS

This update confirms previous findings of excess mortality from all cancers and several site-specific cancers as well as positive exposure-response relations for lung cancer and leukaemia. New findings include excess NHL mortality compared with the general population and a positive exposure-response relationship for COPD. However, there was no evidence of an association between any quantitative exposure measure and NHL.

Management of Firefighters' Chemical & Cardiovascular Exposure Risks on the Fireground

The fire service research community around the world has focused substantial resources on reducing firefighter risk for sudden cardiac events and chemical exposures that may lead to cancer. Research presented here summarizes important lessons learned from a full-scale residential Fire Study that allowed quantification of the risks as well as the effectiveness of interventions to reduce those risks. To address fireground exposure concerns, personal protective equipment (PPE) and administrative controls exist. But, these controls are not always straightforward to apply. Leadership and management concerns with ongoing implementation of these controls are introduced and opportunities for change management are discussed. While research provides a solid basis upon which to institute policy and practice, fireground leadership and management is critical to ensure appropriate implementation.

Polycyclic aromatic hydrocarbon (PAH) and metal contamination of air and surfaces exposed to combustion emissions during emergency fire suppression: Implications for firefighters' exposures

This study examined occupational exposures of Ottawa firefighters to combustion by-products and selected metals. We measured exposures to polycyclic aromatic hydrocarbons (PAHs), antimony, cadmium, and lead using (1) personal air samplers worn by firefighters during emergency fire suppression; (2) wipe samples from skin, personal clothing, and personal protective equipment (PPE) collected before and after emergency firefighting (n = 29); and (3) air samples collected in three fire stations vehicle bays, truck cabs, and one administration office. We assessed OFS PPE decontamination procedures using wipe samples collected before and after laundering (n = 12). Air concentrations exceeded occupational exposure limits at two fire events for lead and nine for PAHs. After fire suppression, PAH concentrations were significantly higher on skin and PPE (p < 0.001), skin, clothing, and PPE for antimony (p < 0.001, 0.01, and 0.05, respectively), and skin and PPE for lead (p < 0.001). Air concentrations of PAHs and antimony were significantly higher in vehicle bays compared to the office (p < 0.05), but significantly lower compared to fire truck cabs (p < 0.05). Washing PPE was effective in removing, on average, 61% of PAHs, 55% of antimony, 97% of lead, and 90% of cadmium. These results indicate that firefighters are significantly exposed, via multiple routes, to combustion by-products during on-shift fire suppression.

Evaluation of the Effect of an Exhaust Reduction System in Fire Stations

Firefighters are known to be exposed to a variety of hazardous materials and combustion products during operational and training activities, as well as in fire stations. However, exposure to diesel exhaust emissions, classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC), is also present in the fire station environment. In this study, concentrations of elemental carbon (EC), which is a surrogate of diesel exhaust and indoor air pollutants, has been measured to compare the effect of an exhaust reduction system (ERS) that was installed in the engine bays of two fire stations to mitigate indoor air pollution levels in the garage, duty offices, and dormitory/shower areas. The levels of most pollutants were reduced after the installation of the ERS. Pollutants may disperse inside of fire stations. Therefore, the ERS is a valuable strategy to mitigate pollutant exposure among firefighters and outdoor air pollution using the filtration ability of an ERS. The results of this study suggest that all truck bays should install an ERS to reduce pollutant exposure and that installation is especially necessary for EURO 3 fire vehicles.

Recovery and reactivity of polycyclic aromatic hydrocarbons collected on selected sorbent tubes and analyzed by thermal desorption-gas chromatography/mass spectrometry

This article describes the optimization of methodology for extending the measurement of volatile organic compounds (VOCs) to increasingly heavier polycyclic aromatic hydrocarbons (PAHs) with a detailed focus on recent sorbent tube technology. Although PAHs have lower volatility than compounds such as benzene, toluene, ethylbenzene and xylenes, these semi-volatile compounds can be detected in air and breath samples. For this work, PAHs were captured on sorbent tubes and subsequently analyzed using automated thermal desorption gas chromatography - mass spectrometry (ATD-GC/MS). While many different sorbent tubes are commercially available, optimization for airborne PAH sampling using sorbent tubes has not been previously considered. Herein, several commercially available sorbent tubes, including Carbograph 2 TD/1TD, Tenax TA, XRO-440, and inert-coated PAH tubes are compared to determine the relative recovery for eight PAHs commonly found in the environment. Certain types of sorbent materials were found to be better suited for PAH recovery during thermal desorption, and PAH reaction products were observed on several types of sorbent tubes, including graphitized carbon black sorbents with stainless steel tube materials. As such, selection of sorbent tube media should be carefully considered prior to embarking on a PAH study.

Firefighters' and instructors’ absorption of PAHs and benzene during training exercises

Introduction:

Training fires may constitute a major portion of some firefighters’ occupational exposures to smoke. However, the magnitude and composition of those exposures are not well understood and may vary by the type of training scenario and fuels.

Objectives:

To understand how structure fire training contributes to firefighters’ and instructors’ select chemical exposures, we conducted biological monitoring during exercises involving combustion of pallet and straw and oriented strand board (OSB) or the use of simulated smoke.

Methods:

Urine was analyzed for metabolites of polycyclic aromatic hydrocarbons (PAHs) and breath was analyzed for volatile organic compounds (VOCs) including benzene.

Results:

Median concentrations of nearly all PAH metabolites in urine increased from pre-to 3-hr post-training for each scenario and were highest for OSB, followed by pallet and straw, and then simulated smoke. For instructors who supervised three trainings per day, median concentrations increased at each collection. A single day of OSB exercises led to a 30-fold increase in 1-hydroxypyrene for instructors, culminating in a median endof-shift concentration 3.5-fold greater than median levels measured from firefighters in a previous controlledresidential fire study. Breath concentrations of benzene increased 2 to 7-fold immediately after the training exercises (with the exception of simulated smoke training). Exposures were highest for the OSB scenario and instructors accumulated PAHs with repeated daily exercises.

Conclusions:

Dermal absorption likely contributed to the biological levels as the respiratory route was well protected. Training academies should consider exposure risks as well as instructional objectives when selecting training exercises.

Impact of Fire Suit Ensembles on Firefighter PAH Exposures as Assessed by Skin Deposition and Urinary Biomarkers

Over the past 10 years, a number of safety measures for reducing firefighters’ exposure to combustion particles have been introduced in Sweden. The most important measure was the reduction in the time firefighters wear suits and handle contaminated equipment after turn-outs involving smoke diving. This study was divided into two parts, those being to investigate the level of protection obtained by multiple garment layers and to assess exposure during a standardized smoke diving exercise. First, realistic work protection factors (WPFs) were calculated by comparing air concentrations of the full suite of gaseous and particle-bound polycyclic aromatic hydrocarbons (PAHs) inside and outside structural ensembles, including jacket and thick base layer, during a tough fire extinguishing exercise using wood as the fuel. Second, during a standardized smoke diving exercise, exposure was assessed by measuring PAH skin deposition and levels of eight urinary PAH metabolites in 20 volunteer student firefighters before and after the exercise. The average WPF for the sum of 22 PAHs was 146 ± 33 suggesting a relatively high protective capacity but also indicating a substantial enrichment of contaminants with a risk of prolonged dermal exposure. Accordingly, in the second exercise, the median levels of skin-deposited Σ14-PAHs and urinary 1-hydroxypyrene significantly increased 5-fold (21 to 99 ng/wipe) and 8-fold (0.14 to 1.1 µmol mol⁻¹ creatinine), respectively, post exposure. Among the PAH metabolites investigated, 1-hydroxypyrene proved to be the most useful indicator of exposure, with significantly elevated urinary levels at both 6 h and 20 h after the exercise and with the strongest correlation to dermal exposure. Metabolites from two-ring and three-ring PAHs were eliminated faster while levels of 3-hydroxy-benzo[a]pyrene did not meet the detection criteria. The results from correlation studies indicated that dermal uptake was a major route of exposure in accordance with previous findings. To summarize, this study shows that some of the newly adopted protective measures were correctly implemented, and should continue to be followed and be more widely adopted.

Placing prostate cancer disparities within a psychosocial context: challenges and opportunities for future research

Black men are more likely to be diagnosed with prostate cancer compared with White men. Despite advances in prevention and treatment strategies, disparities in prostate cancer among Black men persist. While research on the causes of higher incidence and mortality is ongoing, there is limited evidence in the existing literature that clearly speaks to the potential psychological or social factors that may contribute to disparities in prostate cancer incidence. Given the lack of attention to this issue, we review scientific evidence of the ways in which social factors, including socioeconomic status and racial segregation, as well as psychological factors, like depression and anxiety, are related to subsequent prostate cancer risk, which could occur through behavioral and biological processes. Our objective is to illuminate psychosocial factors and their context, using a racial disparity lens, which suggests opportunities for future research on the determinants of prostate cancer. Ultimately, we aim to contribute to a robust research agenda for the development of new prostate cancer prevention measures to reduce racial disparities.

Targeted GC-MS analysis of firefighters' exhaled breath: Exploring biomarker response at the individual level

Biomarker measurements can provide unambiguous evidence of environmental exposures as well as the resultant biological responses. Firefighters have a high rate of occupational cancer incidence, which has been proposed to be linked in part to their increased environmental exposure to byproducts of combustion and contaminants produced during fire responses. In this article, the uptake and elimination of targeted volatile organic compounds were investigated by collecting the exhaled breath of firefighters on sorbent tubes before and after controlled structure burns and analyzing samples using automated thermal desorption-gas chromatography (ATD-GC/MS). Volatile organic compounds exposure was assessed by grouping the data according to firefighting job positions as well as visualizing the data at the level of the individual firefighter to determine which individuals had expected exposure responses. When data were assessed at the group level, benzene concentrations were found to be elevated post-exposure in both fire attack, victim search, and outside ventilation firefighting positions. However, the results of the data analysis at the individual level indicate that certain firefighters may be more susceptible to post-exposure volatile organic compounds increases than others, and this should be considered when assessing the effectiveness of firefighting protective gear. Although this work focuses on firefighting activity, the results can be translated to potential human health and ecological effects from building and forest fires.

Availability and accuracy of occupation in cancer registry data among Florida firefighters

OBJECTIVES

Occupational exposures significantly contribute to the risk of adverse cancer outcomes, and firefighters face many carcinogenic exposures. Occupational research using cancer registry data, however, is limited by missing and inaccurate occupation-related fields. The objective of this study is to determine the frequency and predictors of missing and inaccurate occupation data for a cohort of career firefighters in a state cancer registry.

METHODS

We conducted a linkage between data from the Florida Cancer Data System (1981-2014) and the Florida State Fire Marshal's Office (1972-2012). The percentage and the odds of having a firefighting-related occupation code in the cancer record were calculated, adjusting for other occupation and cancer-related factors.

RESULTS

Among 3,928 career firefighters, nearly half (47%) were missing a registry-dervived occupation code and only 17% had a firefighting-related code. Males were more likely to have a firefighting-related code (OR = 2.31;95%CI: 1.41-3.76), as were those with more recent diagnoses (OR1992-2002 = 2.98;95%CI: 1.57-5.67; OR2003-2014 = 11.40;95%CI: 6.17-21.03), and those of younger ages (OR45-64y = 1.26;95%CI: 1.03-1.54; OR20-44y = 2.26;95%CI: 1.73-2.95).

CONCLUSIONS

Accurate occupation data is key for identifying increased risk of advserse cancer outcomes. Cancer registry occupation fields, however, are overwhelmingly missing for firefighters and are missing disproportionally by sociodemographic and diagnosis characteristics. This study highlights the lack of accurate occupation data available for hypothesis-driven cancer research. Cancer registry linkage with external occupational data sources represents an essential resource for conducting studies among at-risk populations such as firefighters.

DNA methylation among firefighters

Firefighters are exposed to carcinogens and have elevated cancer rates. We hypothesized that occupational exposures in firefighters would lead to DNA methylation changes associated with activation of cancer pathways and increased cancer risk. To address this hypothesis, we collected peripheral blood samples from 45 incumbent and 41 new recruit non-smoking male firefighters and analyzed the samples for DNA methylation using an Illumina Methylation EPIC 850k chip. Adjusting for age and ethnicity, we performed: 1) genome-wide differential methylation analysis; 2) genome-wide prediction for firefighter status (incumbent or new recruit) and years of service; and 3) Ingenuity Pathway Analysis (IPA). Four CpGs, including three in the YIPF6, MPST, and PCED1B genes, demonstrated above 1.5-fold statistically significant differential methylation after Bonferroni correction. Genome-wide methylation predicted with high accuracy incumbent and new recruit status as well as years of service among incumbent firefighters. Using IPA, the top pathways with more than 5 gene members annotated from differentially methylated probes included Sirtuin signaling pathway, p53 signaling, and 5' AMP-activated protein kinase (AMPK) signaling. These DNA methylation findings suggest potential cellular mechanisms associated with increased cancer risk in firefighters.

Cancer incidence and mortality among firefighters

Firefighters are exposed to both known and suspected carcinogens. This study aims to systematically review the literature on the association of firefighting occupation and cancer incidence and mortality, overall and for specific cancer sites. A systematic review using PubMed, Embase, and Web of Science was performed up to January 1, 2018. We extracted risk estimates of cancers and calculated summary incidence risk estimates (SIRE), summary mortality risk estimates (SMRE), and their 95% confidence intervals (CI). Publication bias and risk of bias in individual studies were assessed using Begg's and Egger's tests and the Newcastle-Ottawa scale (NOS), respectively. We included 50 papers in the review and 48 in the meta-analysis. We found significantly elevated SIREs for cancer of the colon (1.14; CI 1.06 to 1.21), rectum (1.09; CI 1.00 to 1.20), prostate (1.15; CI 1.05 to 1.27), testis (1.34; CI 1.08 to 1.68), bladder (1.12; CI 1.04 to 1.21), thyroid (1.22; CI 1.01 to 1.48), pleura (1.60; CI 1.09 to 2.34), and for malignant melanoma (1.21; CI 1.02 to 1.45). We found significant SMREs of 1.36 (1.18 to 1.57) and 1.42 (1.05 to 1.90) for rectal cancer and Non-Hodgkin's lymphoma, respectively. Considering the significantly elevated risk of some cancers in this occupational group, we suggest improving preventive measures and securing adequate and relevant medical attention for this group. Further studies with more accurate and in-depth exposure assessments are indicated.

Mortality and cancer incidence among female Australian firefighters

OBJECTIVES

To investigate the mortality and cancer incidence of female firefighters, a group where there are limited published findings.

METHODS

Participating fire agencies supplied records of individual firefighters including the number and type of incidents attended. The cohort was linked to the Australian National Death Index and Australian Cancer Database. Standardised mortality ratios and standardised cancer incidence ratios were calculated separately for paid and volunteer firefighters. Volunteer firefighters were grouped into tertiles by the duration of service and by a number of incidents attended and relative mortality ratios and relative incidence ratios calculated.

RESULTS

For volunteer firefighters (n=37 962), the overall risk of mortality and risk from all major causes of death were reduced when compared with the general population whether or not they had ever attended incidents. Volunteer firefighters had a similar cancer incidence when compared with the general population for most major cancer categories. Female volunteer firefighters have usually attended few fires. Of those who had turned out to incidents, only one-third had attended more than 12 fires about half the number for male volunteers. Mortality and cancer incidence for paid female firefighters (n=1682) were similar to the general population but the numbers were small and so power was limited.

CONCLUSIONS

Female volunteer firefighters have a cancer incidence similar to the general population but a reduced risk of mortality which is likely to be a result of a 'healthy volunteer' effect.Most of the paid female firefighters were relatively recent recruits and it will be important to monitor the health of this group as more women are recruited to front-line firefighting roles.

Surveillance of cancer risks for firefighters, police, and armed forces among men in a Canadian census cohort

BACKGROUND

Firefighters, police, and armed services may be exposed to hazards such as combustion by-products and shift work.

METHODS

The CanCHEC cohort linked 1991 census data to the Canadian cancer registry for follow up. Cox proportional hazards modeling was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) to estimate risks for firefighter, police, or armed forces compared to workers in other occupations.

RESULTS

The cohort of 1 108 410 men included 4535 firefighters, 10 055 police, and 9165 armed forces. For firefighters, elevated risks were noted for Hodgkin's lymphoma (HR: 2.89, 95%CI: 1.29-6.46), melanoma (HR: 1.67, 95%CI: 1.17-2.37), and prostate cancer (HR: 1.18, 95%CI: 1.01-1.37). Police had elevated risks for melanoma (HR:1.69, 95%CI: 1.32-2.16) and prostate cancer (HR:1.28, 95%CI: 1.14-1.42). No significant associations were found for armed forces workers.

CONCLUSIONS

Canadian firefighters, police, and armed services, may be at an increased risk of developing certain cancers. Results suggested that a healthy worker effect may influence risk estimates.

Health Information on Firefighter Websites: Structured Analysis

Background

Owing to the fact that firefighters have unique health risks, access to firefighter-specific internet-based health information is a potential mechanism for achieving better health and work outcomes.

Objective

The objective of our study was to identify the amount and nature of health information resources available on Canadian firefighter-specific websites and the extent to which resources are consistent across websites as a surrogate indicator of diffusion of information.

Methods

A search of health resources on firefighter websites (union and employer) for all Canadian provinces, major cities and a subset of smaller cities, and the International Association of Fire Fighters (IAFF) website was conducted on Google (July 2017). Content was identified and classified based on the type of resource, health focus, and location. The quantity and nature of the resources were summarized using descriptive statistics.

Results

Among all (N=313) websites reviewed, 41 websites had health information with a cumulative total of 128 resources that addressed firefighter mental (59/128, 46.1%), physical (43/128, 33.6%), and work health (26/128, 20.3%). The highest density of information was found on international and national websites (13 resources per website) and the least on local websites (1 resource per 7 websites). Three provinces (Ontario, Québec, and British Columbia) hosted 81% (65/80) of the provincial, territorial and local resources. General mental health (20/59, 34%), posttraumatic stress disorder (14/59, 24%), and suicide (14/59, 24%) were the most prevalent topics within the mental health resources, whereas half (21/43, 49%) of all physical health resources were on cancer. No resources from Northern Canada were found. Musculoskeletal health was not mentioned in any of the resources identified. There was minimal cross-linking of resources across sites (only 4 resources were duplicated across sites), and there was no clear indication of how the content was vetted or evaluated for quality.

Conclusions

There was wide variation in the amount and type of information available on different firefighter websites with limited diffusion of information across jurisdictions. Quality evaluation and coordination of resources should be considered to enhance firefighters’ access to quality health information to meet their specific needs. Mental health and cancer information aligned with high rates of these health problems in firefighters, whereas the lack of information on musculoskeletal health was discordant with their high rate of work injury claims for these problems.

Prostate cancer characteristics in the World Trade Center cohort, 2002-2013

An increased incidence of prostate cancer was reported in three cohorts of World Trade Center (WTC) respondents. It is uncertain whether this increase is because of WTC-related exposures or enhanced surveillance. Prostate cancer cases (2002-2013) were obtained from the WTC Health Program. Age, race, and Gleason score distribution were compared with New York State Cancer Registry cases from the same time period. Multivariate models were adjusted for age and race. Analyses of clinical characteristics of prostate cancer cases within the cohort were also carried out, adjusting for age, race, and WTC exposure categories. WTC respondents had a prostate cancer age-standardized rate ratio of 1.65 [95% confidence interval (CI): 1.37-1.93] compared with New York State; age-specific ratios were highest for ages 30-49 (2.28; 95% CI: 1.51-3.43), 70-74 (2.05; 95% CI: 1.03-4.10), and 80-84 years (5.65; 95% CI: 1.41-22.58). High WTC exposure was associated with advanced clinical stage (5.58; 95% CI: 1.05-29.76; Ptrend=0.03). WTC respondents continue to have a higher prostate cancer rate compared with New York State as a whole. Respondents with a higher WTC exposure level may have had more advanced clinical stage of prostate cancer.

Codability of industry and occupation information from cancer registry records: Differences by patient demographics, casefinding source, payor, and cancer type

INTRODUCTION

Industry and occupation (I&O) information collected by cancer registries is useful for assessing associations among jobs and malignancies. However, systematic differences in I&O availability can bias findings.

METHODS

Codability by patient demographics, payor, identifying (casefinding) source, and cancer site was assessed using I&O text from first primaries diagnosed 2011-2012 and reported to California Cancer Registry. I&O were coded to a U.S. Census code or classified as blank/inadequate/unknown, retired, or not working for pay.

RESULTS

Industry was codable for 37% of cases; 50% had "unknown" and 9% "retired" instead of usual industry. Cases initially reported by hospitals, covered by preferred providers, or with known occupational etiology had highest codable industry; cases from private pathology laboratories, with Medicaid, or diagnosed in outpatient settings had least. Occupation results were similar.

CONCLUSIONS

Recording usual I&O for retirees and improving linkages for reporting entities without patient access would improve I&O codability and research validity.

Airborne contaminants during controlled residential fires

In this study, we characterize the area and personal air concentrations of combustion byproducts produced during controlled residential fires with furnishings common in 21^st century single family structures. Area air measurements were collected from the structure during active fire and overhaul (post suppression) and on the fireground where personnel were operating without any respiratory protection. Personal air measurements were collected from firefighters assigned to fire attack, victim search, overhaul, outside ventilation, and command/pump operator positions. Two different fire attack tactics were conducted for the fires (6 interior and 6 transitional) and exposures were compared between the tactics. For each of the 12 fires, firefighters were paired up to conduct each job assignment, except for overhaul that was conducted by 4 firefighters. Sampled compounds included polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs, e.g., benzene), hydrogen cyanide (HCN), and particulate (area air sampling only). Median personal air concentrations for the attack and search firefighters were generally well above applicable short-term occupational exposure limits, with the exception of HCN measured from search firefighters. Area air concentrations of all measured compounds decreased after suppression. Personal air concentrations of total PAHs and benzene measured from some overhaul firefighters exceeded exposure limits. Median personal air concentrations of HCN (16,300 ppb) exceeded the exposure limit for outside vent firefighters, with maximum levels (72,900 ppb) higher than the immediately dangerous to life and health (IDLH) level. Median air concentrations on the fireground (including particle count) were above background levels and highest when collected downwind of the structure and when ground-level smoke was the heaviest. No statistically significant differences in personal air concentrations were found between the 2 attack tactics. The results underscore the importance of wearing self-contained breathing apparatus when conducting overhaul or outside ventilation activities. Firefighters should also try to establish command upwind of the structure fire, and if this cannot be done, respiratory protection should be considered.

Prostate cancer surveillance by occupation and industry: the Canadian Census Health and Environment Cohort (CanCHEC)

As there are no well-established modifiable risk factors for prostate cancer, further evidence is needed on possible factors such as occupation. Our study uses one of the largest Canadian worker cohorts to examine occupation, industry, and prostate cancer and to assess patterns of prostate cancer rates. The Canadian Census Health and Environment Cohort (CanCHEC) was established by linking the 1991 Canadian Census Cohort to the Canadian Cancer Database (1969-2010), Canadian Mortality Database (1991-2011), and Tax Summary Files (1981-2011). A total of 37,695 prostate cancer cases were identified in men aged 25-74 based on age at diagnosis. Cox proportional hazards models were used to estimate hazards ratios and 95% confidence intervals. In men aged 25-74 years, elevated risks were observed in the following occupations: senior management (HR = 1.12, 95% CI: 1.04-1.20); office and administration (HR = 1.19, 95% CI: 1.11-1.27); finance services (HR = 1.09, 95% CI: 1.04-1.14); education (HR = 1.05, 95% CI: 1.00-1.11); agriculture and farm management (HR = 1.12, 95% CI: 1.06-1.17); farm work (HR = 1.11, 95% CI: 1.01-1.21); construction managers (HR = 1.07, 95% CI: 1.01-1.14); firefighting (HR = 1.17, 95% CI: 1.01-1.36); and police work (HR = 1.22, 95% CI: 1.09-1.36). Decreased risks were observed across other construction and transportation occupations. Results by industry were consistent with occupation results. Associations were identified for white-collar, agriculture, protective services, construction, and transportation occupations. These findings emphasize the need for further study of job-related exposures and the potential influence of nonoccupational factors such as screening practices.

Prostate cancer in firefighting and police work: a systematic review and meta-analysis of epidemiologic studies

OBJECTIVES

We conducted a systematic review and meta-analysis to evaluate potential associations between firefighting and police occupations, and prostate cancer incidence and mortality.

METHODS

Original epidemiological studies published from 1980 to 2017 were identified through PubMed and Web of Science. Studies were included if they contained specific job titles for ever/never firefighting and police work and associated prostate cancer risk estimates with 95% confidence intervals (CI). Study quality was assessed using a 20-point checklist. Prostate cancer meta-risk estimates (mRE) and corresponding 95% CIs were calculated for firefighting and police work separately and by various study characteristics using random effects models. Between-study heterogeneity was evaluated using the I² score. Publication bias was assessed using Begg's and Egger's tests.

RESULTS

A total of 26 firefighter and 12 police studies were included in the meta-analysis, with quality assessment scores ranging from 7 to 19 points. For firefighter studies, the prostate cancer incidence mRE was 1.17 (95% CI = 1.08-1.28, I² = 72%) and the mortality mRE was 1.12 (95% CI = 0.92-1.36, I² = 50%). The mRE for police incidence studies was 1.14 (95% CI = 1.02-1.28; I² = 33%); for mortality studies, the mRE was 1.08 (95% CI = 0.80-1.45; I² = 0%). By study design, mREs for both firefighter and police studies were similar to estimates of incidence and mortality.

CONCLUSION

Small excess risks of prostate cancer were observed from firefighter studies with moderate to substantial heterogeneity and a relatively small number of police studies, respectively. There is a need for further studies to examine police occupations and to assess unique and shared exposures in firefighting and police work.

Long-term follow-up for cancer incidence in a cohort of Danish firefighters

Objectives

To examine cancer incidence among Danish firefighters using several employment-related exposure subgroups.

Methods

A historical cohort of 9061 male Danish firefighters was established from collected personnel and membership records from employers and trade unions. Using the unique Danish personal identification number, information on additional previous employment, cancer and vital status was linked to members of the cohort from the Supplementary Pension Fund Register, the Danish Cancer Registry and the Danish Civil Registration System. SIRs were calculated for specific cancer types using rates for the general population, a sample of the working population and military employees, respectively.

Results

Compared with the selected reference groups, the overall observed incidence of cancer among the firefighters was at level with the expected (SIR 1.02, 95% CI 0.96 to 1.09 vs the general population). The SIR for colon cancer was consistently significantly reduced, while the slight excess seen for melanoma of the skin, prostate and testicular cancer compared with the general population was not reproduced using the military as reference.

Conclusions

Previous associations with melanoma of the skin, prostate and testicular cancer are supported by our main results. However, the increase in incidence of these cancers is not reproduced using the military as reference. Similarities in cancer profile for the firefighters and the military point to shared risk factors in either lifestyle or work environment.

Assessment of Ambient Exposures Firefighters Encounter While at the Fire Station: An Exploratory Study

OBJECTIVE

Firefighters are at an increased risk for many types of cancer. Although most studies on this topic focus on exposures encountered while fighting fires, exposures at the fire station are also cause for concern. This pilot study aimed to describe air quality within a few fire stations in and around Boston, Massachusetts, and to investigate physical and organizational factors that may influence levels of contaminants in stations.

METHODS

Air sampling of particulate matter less than 2.5 μm in diameter (PM2.5) and particle-bound polycyclic aromatic hydrocarbons (PAHs) was completed at four fire stations in Spring, 2016. Sampling occurred in the kitchen, truck bay, and just outside the station. Data were analyzed to assess differences between and within stations. Interviews (n =7) were conducted with officers at each station to explore health and safety-related organizational policies and practices. Interviews were transcribed and analyzed for thematic content.

RESULTS

At each station, levels of contaminants were higher in the truck bays than either the outdoors or kitchen, and varied the most throughout the day. The station with the highest exposures in the truck bay had the lowest levels in the kitchen, which was possibly explained by new building materials and effective separation between building zones. The age and layout of the stations appeared to determine the extent to which policies favoring exhaust capture were implemented.

CONCLUSION

Levels of PM2.5 and PAH inside fire stations may contribute to firefighter cancer risk. Through understanding contaminant variability, we can begin to design and test interventions that improve cancer prevention.

Contamination of firefighter personal protective equipment and skin and the effectiveness of decontamination procedures

Firefighters' skin may be exposed to chemicals via permeation/penetration of combustion byproducts through or around personal protective equipment (PPE) or from the cross-transfer of contaminants on PPE to the skin. Additionally, volatile contaminants can evaporate from PPE following a response and be inhaled by firefighters. Using polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) as respective markers for non-volatile and volatile substances, we investigated the contamination of firefighters' turnout gear and skin following controlled residential fire responses. Participants were grouped into three crews of twelve firefighters. Each crew was deployed to a fire scenario (one per day, four total) and then paired up to complete six fireground job assignments. Wipe sampling of the exterior of the turnout gear was conducted pre- and post-fire. Wipe samples were also collected from a subset of the gear after field decontamination. VOCs off-gassing from gear were also measured pre-fire, post-fire, and post-decon. Wipe sampling of the firefighters' hands and neck was conducted pre- and post-fire. Additional wipes were collected after cleaning neck skin. PAH levels on turnout gear increased after each response and were greatest for gear worn by firefighters assigned to fire attack and to search and rescue activities. Field decontamination using dish soap, water, and scrubbing was able to reduce PAH contamination on turnout jackets by a median of 85%. Off-gassing VOC levels increased post-fire and then decreased 17-36 min later regardless of whether field decontamination was performed. Median post-fire PAH levels on the neck were near or below the limit of detection (< 24 micrograms per square meter [µg/m²]) for all positions. For firefighters assigned to attack, search, and outside ventilation, the 75^th percentile values on the neck were 152, 71.7, and 39.3 µg/m², respectively. Firefighters assigned to attack and search had higher post-fire median hand contamination (135 and 226 µg/m², respectively) than other positions (< 10.5 µg/m²). Cleansing wipes were able to reduce PAH contamination on neck skin by a median of 54%.

Capture and coding of industry and occupation measures: Findings from eight National Program of Cancer Registries states

BACKGROUND

Although data on industry and occupation (I&O) are important for understanding cancer risks, obtaining standardized data is challenging. This study describes the capture of specific I&O text and the ability of a web-based tool to translate text into standardized codes.

METHODS

Data on 62 525 cancers cases received from eight National Program of Cancer Registries (NPCR) states were submitted to a web-based coding tool developed by the National Institute for Occupational Safety and Health for translation into standardized I&O codes. We determined the percentage of sufficiently analyzable codes generated by the tool.

RESULTS

Using the web-based coding tool on data obtained from chart abstraction, the NPCR cancer registries achieved between 48% and 75% autocoding, but only 12-57% sufficiently analyzable codes.

CONCLUSIONS

The ability to explore associations between work-related exposures and cancer is limited by current capture and coding of I&O data. Increased training of providers and registrars, as well as software enhancements, will improve the utility of I&O data.

Firefighter perceptions of cancer risk: Results of a qualitative study

BACKGROUND

Recent epidemiological research on firefighters indicates an increased incidence of specific types of cancer. Intervention is needed in the fire service yet little is known about how firefighters perceive their cancer risk.

METHODS

Participant observation (150 h, n = 100) and focus group (n = 17) data were collected from 15 fire stations in South Florida. Firefighters had at least 3 years of experience, ranks included drivers, captains, lieutenants, and specialty captains, with a median age of 51 years.

RESULTS

From the qualitative analysis, two major categories (direct and indirect factors) for cancer risks emerged based on participant notions of cancer risk and cancer prevention behaviors as they relate to firefighting.

CONCLUSIONS

Firefighters perceive cancer risks as the result of performing essential job tasks and from indirect job factors related to being a firefighter. The two categories of cancer risks suggest different points of entry for intervention.

Occupation and risk of prostate cancer in Canadian men: A case-control study across eight Canadian provinces

BACKGROUND

The etiology of prostate cancer continues to be poorly understood, including the role of occupation. Past Canadian studies have not been able to thoroughly examine prostate cancer by occupation with detailed information on individual level factors.

METHODS

Occupation, industry and prostate cancer were examined using data from the National Enhanced Cancer Surveillance System, a large population-based case-control study conducted across eight Canadian provinces from 1994 to 1997. This analysis included 1737 incident cases and 1803 controls aged 50 to 79 years. Lifetime occupational histories were used to group individuals by occupation and industry employment. Odds ratios and 95% confidence intervals were calculated and adjustments were made for known and possible risk factors.

RESULTS

By occupation, elevated risks were observed in farming and farm management (OR=1.37, 95% CI 1.02-1.84), armed forces (OR=1.33, 95% CI 1.06-1.65) and legal work (OR=2.58, 95% CI 1.05-6.35). Elevated risks were also observed in office work (OR=1.20, 95% CI 1.00-1.43) and plumbing (OR=1.77, 95% CI 1.07-2.93) and with ≥10 years duration of employment. Decreased risks were observed in senior management (OR=0.65, 95% CI 0.46-0.91), construction management (OR=0.69, 95% CI 0.50-0.94) and travel work (OR=0.37, 95% CI 0.16-0.88). Industry results were similar to occupation results, except for an elevated risk in forestry/logging (OR=1.54, 95% CI 1.06-2.25) and a decreased risk in primary metal products (OR=0.70, 95% CI 0.51-0.96).

CONCLUSION

This study presents associations between occupation, industry and prostate cancer, while accounting for individual level factors. Further research is needed on potential job-specific exposures and screening behaviours.

Lung Cancer Among Firefighters: Smoking-Adjusted Risk Estimates in a Pooled Analysis of Case-Control Studies

OBJECTIVES

The aim of this study was to explore lung cancer risk among firefighters, with adjustment for smoking.

METHODS

We used pooled information from the SYNERGY project including 14 case-control studies conducted in Europe, Canada, New Zealand, and China, with lifetime work histories and smoking habits for 14,748 cases of lung cancer and 17,543 controls. We estimated odds ratios by unconditional logistic regression with adjustment for smoking and having ever been employed in a job known to present an excess risk of lung cancer.

RESULTS

There was no increased lung cancer risk overall or by specific cell type among firefighters (n = 190), neither before nor after smoking adjustment. We observed no significant exposure-response relationship in terms of work duration.

CONCLUSIONS

We found no evidence of an excess lung cancer risk related to occupational exposure as a firefighter.

Ten-year cancer incidence in rescue/recovery workers and civilians exposed to the September 11, 2001 terrorist attacks on the World Trade Center

BACKGROUND

Cancer incidence in exposed rescue/recovery workers (RRWs) and civilians (non-RRWs) was previously reported through 2008.

METHODS

We studied occurrence of first primary cancer among World Trade Center Health Registry enrollees through 2011 using adjusted standardized incidence ratios (SIRs), and the WTC-exposure-cancer association, using Cox proportional hazards models.

RESULTS

All-cancer SIR was 1.11 (95% confidence interval (CI) 1.03-1.20) in RRWs, and 1.08 (95% CI 1.02-1.15) in non-RRWs. Prostate cancer and skin melanoma were significantly elevated in both populations. Thyroid cancer was significantly elevated only in RRWs while breast cancer and non-Hodgkin's lymphoma were significantly elevated only in non-RRWs. There was a significant exposure dose-response for bladder cancer among RRWs, and for skin melanoma among non-RRWs.

CONCLUSIONS

We observed excesses of total and specific cancers in both populations, although the strength of the evidence for causal relationships to WTC exposures is somewhat limited. Continued monitoring of this population is indicated. Am. J. Ind. Med. 59:709-721, 2016. © 2016 Wiley Periodicals, Inc.

Post-9/11 cancer incidence in World Trade Center-exposed New York City firefighters as compared to a pooled cohort of firefighters from San Francisco, Chicago and Philadelphia (9/11/2001-2009)

BACKGROUND

We previously reported a modest excess of cancer in World Trade Center (WTC)-exposed firefighters versus the general population. This study aimed to separate the potential carcinogenic effects of firefighting and WTC exposure by comparing to a cohort of non-WTC-exposed firefighters.

METHODS

Relative rates (RRs) for all cancers combined and individual cancer subtypes from 9/11/2001 to 12/31/2009 were modeled using Poisson regression comparing 11,457 WTC-exposed firefighters to 8,220 urban non-WTC-exposed firefighters.

RESULTS

Compared with non-WTC-exposed firefighters, there was no difference in the RR of all cancers combined for WTC-exposed firefighters (RR = 0.96, 95%CI: 0.83-1.12). Thyroid cancer was significantly elevated (RR = 3.82, 95%CI: 1.07-20.81) from 2001 to 2009; this was attenuated (RR = 3.43, 95%CI: 0.94-18.94) and non-significant when controlling for possible surveillance bias. Prostate cancer was elevated during the latter half (2005-2009; RR = 1.38, 95%CI: 1.01-1.88).

CONCLUSIONS

Further follow-up is needed to assess the relationship between WTC exposure and cancers with longer latency periods. Am. J. Ind. Med. 59:722-730, 2016. © 2016 Wiley Periodicals, Inc.

Cancer in World Trade Center responders: Findings from multiple cohorts and options for future study

BACKGROUND

Three longitudinal studies of cancer incidence in varied populations of World Trade Center responders have been conducted.

METHODS

We compared the design and results of the three studies.

RESULTS

Separate analyses of these cohorts revealed excess cancer incidence in responders for all cancers combined and for cancers of the thyroid and prostate. Methodological dissimilarities included recruitment strategies, source of cohort members, demographic characteristics, overlap between cohorts, assessment of WTC and other occupational exposures and confounders, methods and duration of follow-up, approaches for statistical analysis, and latency analyses.

CONCLUSIONS

The presence of three cohorts strengthens the effort of identifying and quantifying the cancer risk; the heterogeneity in design might increase sensitivity to the identification of cancers potentially associated with exposure. The presence and magnitude of an increased cancer risk remains to be fully elucidated. Continued long-term follow up with minimal longitudinal dropout is crucial to achieve this goal.