Reproductive hazards of fire fighting. II. Chemical hazards

Anti-Müllerian Hormone Levels among Female Firefighters

Female firefighters have occupational exposures which may negatively impact their reproductive health. Anti-müllerian hormone (AMH) is a clinical marker of ovarian reserve. We investigated whether AMH levels differed in female firefighters compared to non-firefighters and whether there was a dose-dependent relationship between years of firefighting and AMH levels. Female firefighters from a pre-existing cohort completed a cross-sectional survey regarding their occupational and health history and were asked to recruit a non-firefighter friend or relative. All participants provided a dried blood spot (DBS) for AMH analysis. Linear regression was used to assess the relationship between firefighting status and AMH levels. Among firefighters, the influence of firefighting-related exposures was evaluated. Firefighters (n = 106) and non-firefighters (n = 58) had similar age and BMI. Firefighters had a lower mean AMH compared to non-firefighters (2.93 ng/mL vs. 4.37 ng/mL). In multivariable adjusted models, firefighters had a 33% lower AMH value than non-firefighters (-33.38%∆ (95% CI: -54.97, -1.43)). Years of firefighting was not associated with a decrease in AMH. Firefighters in this study had lower AMH levels than non-firefighters. More research is needed to understand the mechanisms by which firefighting could reduce AMH and affect fertility.

Pregnancy, childbirth, and puerperium outcomes in female firefighters in Korea

Background

Female firefighters are exposed to hazardous environmental (chemical and physical) and working (shift work, psychological, and ergonomic factors) conditions that have reported or are suspected of adverse effects on reproductive health. However, no previous studies have reported on pregnancy, childbirth, and puerperium outcomes (PCPOs) in female firefighters.

Methods

The present study compared hospital admissions for PCPOs, based on 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) codes, among Korean female firefighters with those of the general Korean population. Standardized admission ratios (SARs) and their 95% confidence intervals (CIs) were calculated.

Results

The study population included 1,766 female firefighters. Total follow-up duration was 9,659 person-years. Compared to the general female population, the female firefighters' SARs were higher in all admissions for PCPOs (SAR, 1.92; 95% CI: 1.79–2.05); pregnancy and abortive outcomes (SAR, 1.56; 95% CI: 1.12–2.12); other maternal disorders predominantly related to pregnancy (SAR, 2.65; 95% CI: 1.99–3.46); maternal care related to the fetus, amniotic cavity, and possible delivery problems (SAR, 2.13; 95% CI: 1.74–2.57); labor and delivery complications (SAR, 1.55; 95% CI: 1.15–2.06); delivery (SAR, 1.94; 95% CI: 1.80–2.08); and complications predominantly related to puerperium (SAR, 4.68; 95% CI: 2.02–9.23).

Conclusion

The results of this study showed high SARs in all and specific subcategories of PCPOs in female firefighters.

Women Firefighters' Health and Well-Being: An International Survey

OBJECTIVES

This study aimed to identify specific health and well-being issues that women firefighters may experience as part of their daily working practices. Issues identified from this under-represented population can drive future research, education, and strategy to guide safety and health practices.

METHODS

A total of 840 women firefighters from 14 separate countries (255 United Kingdom and Ireland, 320 North America, 177 Australasia, and 88 mainland Europe) completed the survey over a 4-month period. Questions related to general health and well-being and role-specific health concerns, gender-related issues, and available exercise facilities.

RESULTS

Women firefighters in North America reported a higher prevalence of lower back (49%) and lower limb (51%) injuries than all other groups. North American respondents reported more heat illnesses (45%) than respondents from other places (36%). Although many participants did not respond, of those who did, 39% thought the menstrual cycle (199/512) or menopause (55/151) affected their work, and 36% were concerned for their ability to meet future job demands. Sixteen percent felt confident they could complete the role after 60 years of age. Women firefighters identified a lack of strength and conditioning support (50%) or lack of gym access (21%). There appears to be poor availability of female-specific personal protective equipment, with availability greatest in the United Kingdom (66%) compared with the sample as a whole (42%).

CONCLUSIONS

There is a need for female-specific strength and conditioning support and facilities to decrease injury and illness risk and improve longevity. Research and education into gynecological issues, heat exposure, and their effects on women firefighters' fertility and cancer risk is required.

Infertility in a Cohort of Male Danish Firefighters: A Register-Based Study

Our aim in this study was to examine infertility among male firefighters in Denmark. Thus, we established a cohort of 4,710 past and present male Danish firefighters through personnel and membership records obtained from employers and trade unions. Information on vital status and infertility from the Danish Civil Registration System, the In Vitro Fertilisation Register, and the National Patient Register for the period 1984-2017 was linked to cohort members using their Danish personal identification numbers. Hazard ratios and corresponding 95% confidence intervals were estimated for male-factor infertility and overall infertility through Cox regression analyses comparing the firefighters with 2 reference groups: a sample of employees and military men. Among the full-time firefighters, the risk of male-factor infertility was increased in comparison with the sample of employees (In Vitro Fertilisation Register model: hazard ratio = 1.46 (95% confidence interval: 1.10, 1.94); National Patient Register model: hazard ratio = 1.53 (95% confidence interval: 1.18, 1.98)). Results were less consistent using the military men as the reference group. Further, the increase in infertility seemed restricted to duration of time employed as a firefighter. No increase in risk of either male-factor infertility or overall infertility was seen among the part-time/volunteer firefighters. Thus, full-time firefighting was associated with a greater risk of being diagnosed with male-factor infertility in our cohort.

Maternal and Child Health Among Female Firefighters in the U.S

Objectives Despite increasing attention to the occupational impact of firefighting, little is known specific to the health of women firefighters. In particular, quantitative data is lacking on the impact firefighting has on maternal and child health for women who become pregnant while working as firefighters. Methods A total of 1821 women firefighters responded to requests to complete a self-report survey of questions about pregnancy. Women answered questions about their departments' policies and practices and their own experiences of pregnancy. Those participants who reported a pregnancy while serving as a firefighter were asked detailed questions about their pregnancy and outcomes. Results Female firefighters reported that nearly a quarter of their first pregnancies while in the fire service ended in miscarriage and that increased to a third of pregnancies by the fourth. Rates of pre-term delivery also were high among this population. Conclusions Findings have important implications for policy and practice among women who become pregnant while actively serving in the fire service.

Organophosphate flame retardants in dust collected from United States fire stations

Firefighters are exposed to chemicals during fire events and we previously demonstrated that fire station dust has high levels of polybrominated diphenyl ethers (PBDEs). In conducting the Fire Station Dust Study, we sought to further characterize the chemicals to which firefighters could be exposed - measuring the emerging class of phosphorous-containing flame retardants (PFRs) in fire stations, for the first time, as well as PBDEs. Dust samples from 26 fire stations in five states were collected from vacuum-cleaner bags and analyzed for PFRs and PBDEs. PFR concentrations were found to be on the same order of magnitude as PBDE concentrations (maximum PFR: 218,000ng/g; maximum PBDE: 351,000ng/g). Median concentrations of tri-n-butyl phosphate (TNBP), tris (2-chloroisopropyl) phosphate (TCIPP), and tris(1,3-dichloroisopropyl)phosphate (TDCIPP) in dust from fire stations were higher than those previously reported in homes and other occupational settings around the world. Total PFR levels did not vary significantly among states. Levels of TDCIPP were higher in stations where vacuum cleaners were used to clean surfaces other than the floor. PBDE levels were comparable to those found in our previous study of 20 California fire stations and much higher than levels in California residences. PFR and PBDE levels in fire station dust are higher than in other occupational and residential settings, underscoring the need to identify and control sources of this contamination.

High levels of polybrominated diphenyl ethers in vacuum cleaner dust from California fire stations

Firefighters are exposed to chemicals during fire events and may also experience chemical exposure in their fire stations. Dust samples from used vacuum cleaner bags were collected from 20 fire stations in California and analyzed for polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) using gas chromatography-mass spectrometry. Median dust concentrations were higher for PBDEs (e.g., 47 000 ng/g for BDE-209) than for PAHs (e.g., 220 ng/g for benzo[a]pyrene) or PCBs (e.g., 9.3 ng/g for PCB-180). BDE-209 concentrations in dust from California fire stations were among the highest of any previously documented homes or occupational settings in the world. We examined factors such as the frequency of emergency responses, the number of fire vehicles on site, and building age, but we could not account for the high levels of BDE-209 observed in fire station dust. Based on the findings of our pilot study, we hypothesize that possible sources of BDE-209 in fire stations include contaminated ash tracked back from fire events via boots, clothing, and other equipment as well as specialized equipment treated with BDE-209, including turnout gear and fire vehicles. We suggest possible follow-up studies to confirm these hypotheses.

The health of women in the US fire service

BACKGROUND

Despite statements from national fire service organizations, including the International Association of Fire Fighters (IAFF) and the International Association of Fire Chiefs (IAFC), promoting a diverse work force related to gender within the fire service, rates of women firefighters remain very low. Thus, research into why this extensive gender disparity continues is a high priority. Recent years have seen a number of large scale studies on firefighter health and health risk behaviors however, none have focused on the health of women firefighters and nearly all have eliminated women from the sample due to small sample size. Data from the present report is drawn from all females in a large, randomly selected cohort of firefighters in an epidemiological study designed to assess health outcomes and health risk behaviors identified as most important to the fire service.

METHODS

Data reported for the present study were collected as baseline data for the Firefighter Injury and Risk Evaluation (FIRE) Study, a longitudinal cohort study examining risk factors for injury in both career and volunteer firefighters in the IAFC Missouri Valley Region. Of the departments assessed, only 8 career and 6 volunteer departments had any women firefighters. All the women solicited for participation chose to enroll in the study. The number of women ranged from 1 to 7 in career departments and 1 to 6 in volunteer departments.

RESULTS

Where possible, comparisons are made between female firefighters and published data on male firefighters as well as comparisons between female firefighters and military members. Compared to male firefighters, females had more favorable body composition among both career and volunteer firefighters. Tobacco use rates were generally higher among females than males and rates among female firefighters were similar to the rates of female military members. While rates of alcohol use were higher than the general population, only one of the participants evidenced responses in the range of concern on the CAGE screening.

CONCLUSIONS

In general, the findings offer an interesting glimpse of the health of women in the fire service as a generally healthy occupational workforce with some unique health risk behavior challenges. They also highlight some of the similarities and differences between male and female firefighters and bolster the argument for studying female firefighters as a unique occupational sub-population.

Chemical characterization of ambient particulate matter near the World Trade Center: elemental carbon, organic carbon, and mass reconstruction

Concentrations of elemental carbon (EC), organic carbon matter (OM), particulate matter less than 2.5 microm (PM2.5), reconstructed soil, trace element oxides, and sulfate are reported from four locations near the World Trade Center (WTC) complex for airborne particulate matter (PM) samples collected from September 2001 through January 2002. Across the four sampling sites, daily mean concentrations ranged from 1.5 to 6.8 microg/m3 for EC, from 10.2 to 31.4 microg/m3 for OM, and from 22.6 to 66.2 microg/m3 for PM2.5. Highest concentrations of PM species were generally measured north and west of the WTC complex. Total carbon matter and sulfate constituted the largest fraction of reconstructed PM2.5 concentrations. Concentrations of PM species across all sites decreased from the period when fires were present at the WTC complex (before December 19, 2001) to the period after the fires. Averaged over all sites, concentrations decreased by 25.6 microg/m3 for PM2.5, 2.7 microg/m3 for EC, and 9.2 microg/m3 for OM from the fire period to after fire period.

Determination of firefighter exposure to polycyclic aromatic hydrocarbons and benzene during fire fighting using measurement of biological indicators

In accomplishing their duties, firefighters are potentially exposed to a vast array of toxic combustion and pyrolysis products such as benzene, carbon monoxide, acrolein, nitrogen dioxide, and polycyclic aromatic hydrocarbons. Exposure to PAH and benzene was assessed by means of urinary measurements of 1-hydroxypyrene and t,t-muconic acid, respectively. All urine samples were collected from 43 firefighters during a period extending for 20 h following the end of exposure during a fire. A control sample was also obtained from each participant after at least four days without involvement in fire fighting activities. Only one control 1-hydroxypyrene measurement exceeded the value of 0.32 micromol/mol creatinine considered as the 95th percentile of a normal reference population in this study. Following exposure, 38 percent of the maximum values of all samples collected from each firefighter exceeded this reference value. The highest single value observed in this study was 3.6 micromol/mol creatinine. None of the control samples had a t,t-muconic acid concentration above the limit of detection. A large number (81%) of post-fire samples also had nonquantifiable concentrations of this metabolite. Among 43 firefighters in this study, 17 had measurable excretion of this metabolite in any of the urine samples after fire fighting and, of the latter group, only 6 had t,t-muconic acid concentrations exceeding 1.1 mmol/mol creatinine, a value considered to correspond to a benzene-air concentration of approximately 1 ppm according to the literature. There is clear evidence that fire fighting activities are associated with exposure to PAH above environmental background, as assessed by 1-hydroxypyrene measurements, despite the use of protective equipment. However, in comparison with observations made in other cohorts of industrial workers with known polycyclic aromatic hydrocarbons exposure, firefighters' exposure in this study was low. Similarly, based on t,t-muconic acid determinations, exposure to benzene was rather low in this study. For both contaminants, observation of low exposure could be due to either low concentrations of the contaminant during fire fighting or to the efficiency of protective equipment worn.

Cohort mortality study of Philadelphia firefighters

BACKGROUND

Fire fighters are exposed to a wide variety of toxic chemicals. Previous studies have reported excess risk of some cancers but have been limited by small numbers or little information on employment characteristics.

METHODS

We conducted a retrospective cohort mortality study among 7,789 Philadelphia firefighters employed between 1925 and 1986. For each cause of death, the standardized mortality ratios (SMRs) and 95% confidence intervals were estimated. We also compared mortality among groups of firefighters defined by the estimated number of career runs and potential for diesel exposure.

RESULTS

In comparison with U.S. white men, the firefighters had similar mortality from all causes of death combined (SMR = 0.96) and all cancers (SMR = 1.10). There were statistically significant deficits of deaths from nervous system diseases (SMR = 0.47), cerebrovascular diseases (SMR = 0.83), respiratory diseases (SMR = 0.67), genitourinary diseases (SMR = 0.54), all accidents (SMR = 0.72), and suicide (SMR = 0.66). Statistically significant excess risks were observed for colon cancer (SMR = 1.51) and ischemic heart disease (SMR = 1.09). The risks of mortality from colon cancer (SMR = 1.68), kidney cancer (SMR = 2.20), non-Hodgkin's lymphoma (SMR = 1.72), multiple myeloma (SMR = 2.31), and benign neoplasms (SMR = 2.54) were increased among firefighters with at least 20 years of service.

CONCLUSIONS

Our study found no significant increase in overall mortality among Philadelphia firefighters. However, we observed increased mortality for cancers of the colon and kidney, non-Hodgkin's lymphoma and multiple myeloma. There was insufficient follow-up since the introduction of diesel equipment to adequately assess risk.

Paternal exposures: impact on reproductive and developmental outcome. An overview

Experimental and epidemiologic investigations document the adverse consequences of an array of paternal exposures on the development of subsequent offspring. Male-mediated abnormalities have been reported after exposure to therapeutic and recreational drugs, to chemicals in the workplace and environment and to ionizing radiation. The impact on progeny outcome includes: an increase in congenital malformations, spontaneous abortions, fetal resorptions; low birth weight; increase in childhood cancers; developmental, neurobehavioral, neuroendocrine, neurochemical abnormalities; effects in F2 generation progeny. Fertility is often unaffected. The comparative influence of genetic, epigenetic and nongenetic mechanisms in the etiology of paternally-mediated adverse outcomes is unknown. There is no a priori reason to assume that male-mediated effects are limited to the agents studied to date. The broad spectrum of alterations recorded after exposure to a variety of unrelated agents suggests the need for a more focused effort and multidisciplinary exploration of the potential impact of the male parent on reproductive outcome.

Mortality amongst Paris fire-fighters

This paper is the first mortality cohort study undertaken in France to examine the association between fire-fighting and cause of death. The cohort investigated in this study consisted of 830 male members of the Brigade des sapeurs-pompiers de Paris (BSPP). These professional had served for a minimum of 5 years on 1 January 1977. They were monitored for a 14 year period, finishing 1 January 1991. When compared to the average French male, the Paris fire-fighters were found to have a far lower overall mortality (SMR = 0.52 [0.35-0.75]). None of the cause specific SMRs were significantly different from unity. However a greater number of deaths than expected was observed for genito-urinary cancer (SMR = 3.29), digestive cancer (SMR = 1.14), respiratory cancer (SMR = 1.12) and 'cerebrovascular disease' (SMR = 1.16). The low overall SMR observed was consistent with the healthy worker effect. As for cause specific SMRs, they will be confirmed or invalidated by a further analysis as the follow-up of this cohort is being carried on.

Mortality among fire fighters in metropolitan Toronto

Fire fighters are exposed to substances which are recognized or suspected causal agents in cancer or heart disease. The purpose of this study was to determine whether or not fire fighters experience increased risk for any specific cause of death. A retrospective cohort study was conducted, with 5,995 subjects recruited from all six fire departments within Metropolitan Toronto. The mortality experience of the cohort was ascertained through computerized record linkage and compared to that of the male Ontario population specific to cause, age, and calendar period from 1950 through 1989. Average duration of follow-up was 21 years, and there were 777 deaths among the 5,414 males included in the analysis, giving an all-cause standardized mortality ratio of 95 (95% confidence interval: 88-102). Three specific causes of death exhibit statistically significant excesses (brain tumors, "other" malignant neoplasms, and aortic aneurysms). There are also slight increases in risk for some other sites of cancer, and for various diseases of the respiratory, circulatory, and digestive systems. This study is consistent with others in demonstrating that fire fighters experience increased risk of death from cancer of the brain, and in suggesting increased risk for various other causes of death.

Reproductive hazards of fire fighting. I. Non-chemical hazards

Fire fighters are regularly exposed to chemical and non-chemical agents that have known or suspected adverse effects on reproductive health. Although chemical agents have received some attention, non-chemical hazards such as heat, noise, and physical exertion have only recently been examined for their reproductive effects. There is evidence that heat, noise, and physical exertion may affect various endpoints of reproductive health, including fertility, fetal loss, and growth parameters of the offspring. In particular, hyperthermia, a major fire fighting hazard, has been shown to impair male fertility and may also be teratogenic. Further study of the potential reproductive effects of this and other common non-chemical agents in the fire environment is needed to ensure the reproductive health of male and female fire fighters.