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

Non-cancer health risks in firefighters: a systematic review

osFirefighters are occupationally exposed to hazardous factors that may increase their risk of disease. However, non-cancer disease risk in firefighters has not been systematically examined. This systematic review aimed to identify non-cancer disease risk in firefighters and determine whether the risk differs according to job characteristics. We searched the Cochrane Library, Embase, PubMed, and KoreaMed databases using relevant keywords from their inception to April 30, 2021. The Risk of Bias Assessment Tool for Non-randomized Studies version 2.0 was used to assess the quality of evidence. Due to study heterogeneity, a narrative synthesis was presented. The systematic literature search yielded 2,491 studies, of which 66 met the selection and quality criteria. We confirmed that the healthy worker effect is strong in firefighters as compared to the general population. We also identified a significant increase in the incidence of lumbar disc herniation, lower back pain, angina pectoris, acute myocardial infarction, and post-traumatic stress disorder (PTSD) in firefighters compared to other occupational groups. Contradictory results for the risk of PTSD and anxiety disorders related to rank were reported. Sufficient evidence for increased risk of lumbar disc herniation, lower back pain, angina pectoris, acute myocardial infarction, and PTSD was available. The risk of non-cancer diseases varied depending on job type, years of service, and rank. However, caution should be exercised when interpreting the results because the classification criteria for firefighters' jobs and ranks differ by country.

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.

Occupational hazards for the male reproductive system

The etiology of male infertilities is largely undetermined, and our knowledge of exogenous factors affecting the male reproductive system is still limited. In particular, the role of specific environmental and occupational factors is incompletely elucidated. Various occupational (physical and chemical) agents have been shown to affect male reproductive functions in animals, but large differences in reproductive function and/or xenobiotic handling between species limit extrapolation to humans. When available, human data are often conflicting and, except in a few instances, usually refer to broad and heterogenous occupational categories or to groups of agents (e.g., solvents). It is often difficult to elucidate the role of a single agent because occupational exposure conditions are often complex and various confounding factors related to lifestyle (smoking, alcohol, and diet) or socioeconomic state may also affect sperm quality, fertility, or pregnancy outcomes. The objective of this work is to summarize the main epidemiological and, where relevant, experimental findings pertaining to agents (physical and chemical) encountered in the occupational environment that might affect the male reproductive system (sperm count, motility and morphology, libido, and fertility) and/or related pregnancy outcomes (spontaneous abortion, stillbirth, low birth weight, and birth defects and childhood malignancy in offspring). Some methodological issues related to research on the reproductive effects of toxicants are also discussed briefly.

Reproductive hazards of fire fighting. II. Chemical hazards

Studies of the health of fire fighters have historically focused on non-malignant respiratory disease and cancer. More recently, concerns have surfaced about reproductive health effects in many areas of the workforce, including fire fighting. These concerns prompted this review of chemical exposures that may contribute to adverse reproductive health outcomes in male as well as female fire fighters. A review of the industrial hygiene literature was undertaken to identify agents commonly found in fire smoke. These agents were then examined for evidence of reproductive toxicity or mutagenicity/carcinogenicity. This profile of chemical agents and their reproductive toxicities permits a qualitative determination that fire fighters are exposed to potential reproductive toxicants as a part of their normal fire fighting duties. Considerations for mitigating these risks are also discussed.