Occupational and Environmental Medicine

Occupational exposures among hairdressers and the occurrence of hormone-related conditions

Objective To investigate the association between hairdresser exposures and hormone-related conditions. Methods Using data from 50 800 eligible Sister Study participants (enrolled 2003–2009, aged 35–74 years), we estimated ORs and 95% CIs for associations between ever working as a hairdresser (n=1803) and prevalent fibroids, endometriosis, hysterectomy and oophorectomy. We estimated HRs and 95% CI for incident fibroids, endometriosis, breast, uterine and ovarian cancers among ever hairdressers versus never hairdressers. We also examined associations of hormone-related diseases and professional use of products such as bleach, perms, chemical straighteners, permanent hair colour, hairspray, barbicide, formaldehyde and alcohol, comparing data from 985 long-term hairdressers who worked ≥2 years to non-long-term hairdressers (never workers and those working <2 years). Results Ever-hairdressers were more likely than never-hairdressers to have had a prebaseline hysterectomy (OR=1.23: 95% CI 1.11 to 1.36). Hysterectomies were more common among long-term hairdressers with more frequent applications of perms, chemical straighteners and permanent hair colour compared with less frequent applicators or never hairdressers. Ever-hairdressers had higher rates of incident endometriosis (477 cases, HR=1.61: 95% CI 1.08 to 2.38) compared with never-hairdressers, but there were no notable associations between working as a hairdresser and fibroids (1805 cases, HR=1.04: 95% CI 0.80 to 1.34), breast cancer (4628 cases, HR=0.98: 95% CI 0.83 to 1.16), ovarian cancer (300 cases, HR=1.33: 95% CI 0.77 to 2.29) or uterine cancer (447 cases, HR=1.04: 95% CI 0.60 to 1.77). In race-stratified analyses, Black hairdressers were more likely to be diagnosed with fibroids than Black never-hairdressers (201 cases, HR=1.56: 95% CI 0.93 to 2.62). Conclusions Hairdresser occupation was associated with increased odds of hysterectomy and increased rates of incident endometriosis and possibly fibroids among Black women.

Agricultural exposure and risk of ovarian cancer in the AGRIculture and CANcer (AGRICAN) cohort

BackgroundOvarian cancer is rare with a poor prognosis and few established risk factors. Hormones and reproductive factors significantly impact its development, suggesting a potential link with endocrine disrupters.MethodsIn the AGRICAN cohort, 59 391 female farmers completed data on lifelong agricultural exposures and reproductive life. Cox models with attained age as timescale (HR and 95% CI) were used. The role of hormonal factors as potential confounders was considered along with specific time windows for exposure (childhood, puberty and menopause). Female farmers were the reference group (for the principal analyses).ResultsBetween enrolment (2005–2007) and the end of follow-up (31 December 2017), 262 incident ovarian cancers were identified. An increased risk was observed for females involved in pigs (HR=2.12 (95% CI 1.27 to 3.52)) including during puberty (HR=1.83 (95% CI 1.13 to 2.94)), fruit-growing (HR=2.17 (95% CI 1.09 to 4.30)) and potato seed treatment (HR=2.81 (95% CI 1.29 to 6.09)). Conversely, females born on farms growing grain cereals (HR=0.64 (95% CI 0.46 to 0.90)) or pig-breeding (HR=0.78 (95% CI 0.55 to 1.12)) presented a reduced risk of ovarian cancer. Triazine herbicide exposure was not associated with ovarian cancer. The effect of agricultural exposures remained unchanged in multivariate models considering contraception, parity, puberty age, menopause age and body mass index.ConclusionThis study is the first to assess the association between specific agricultural exposures and ovarian cancer comprehensively. Some of the positive associations observed suggest that some pesticide exposure (especially during puberty) could play a role in the development of ovarian cancer. On the other hand, agricultural exposure during early life could have a protective effect, as observed for lung cancer among farmers. Finally, we did not confirm the previous putative effect of exposure to triazine herbicides.

Occupational environment and ovarian cancer risk

ObjectivesTo investigate employment in an occupation or industry and specific occupational exposures in relation to ovarian cancer risk.MethodsIn a population-based case–control study conducted in Montreal, Canada (2011–2016), lifetime occupational histories were collected for 491 cases of ovarian cancer and 897 controls. An industrial hygienist coded the occupation and industry of each participant’s job. Associations with ovarian cancer risk were estimated for each of several occupations and industries. Job codes were linked to the Canadian job-exposure matrix, thereby generating exposure histories to many agents. The relationship between exposure to each of the 29 most prevalent agents and ovarian cancer risk was assessed. Odds ratios and 95% confidence intervals (OR (95% CI)) for associations with ovarian cancer risk were estimated using logistic regression and controlling for multiple covariates.ResultsElevated ORs (95% CI) were observed for employment ≥10 years as Accountants (2.05 (1.10 to 3.79)); Hairdressers, Barbers, Beauticians and Related Workers (3.22 (1.25 to 8.27)); Sewers and Embroiderers (1.85 (0.77 to 4.45)); and Salespeople, Shop Assistants and Demonstrators (1.45 (0.71 to 2.96)); and in the industries of Retail Trade (1.59 (1.05 to 2.39)) and Construction (2.79 (0.52 to 4.83)). Positive associations with ORs above 1.42 were seen for high cumulative exposure versus never exposure to 18 agents: cosmetic talc, ammonia, hydrogen peroxide, hair dust, synthetic fibres, polyester fibres, organic dyes and pigments, cellulose, formaldehyde, propellant gases, aliphatic alcohols, ethanol, isopropanol, fluorocarbons, alkanes (C5–C17), mononuclear aromatic hydrocarbons, polycyclic aromatic hydrocarbons from petroleum and bleaches.ConclusionsCertain occupations, industries and specific occupational exposures may be associated with ovarian cancer risk. Further research is needed to provide a more solid grounding for any inferences in this regard.

Ovarian cancer deaths attributable to asbestos exposure in Lombardy (Italy) in 2000–2018

ObjectivesWe aimed to estimate the fraction of deaths from ovarian cancer attributable to asbestos exposure in Lombardy Region, Italy, using a novel approach that exploits the fact that ovarian cancer asbestos exposure is associated with pleural cancer and other risk factors for breast cancer.MethodsThis ecological study is based on the Italian National Institute of Statistics mortality data. We formulate a trivariate Bayesian joint disease model to estimate the attributable fraction (AF) and the number of ovarian cancer deaths attributable to asbestos exposure from the geographic distribution of ovarian, pleural and breast cancer mortality at the municipality level from 2000 to 2018. Expected deaths and standardised mortality ratios were calculated using regional rates.ResultsWe found shared dependencies between ovarian and pleural cancer, which capture risk factors common to the two diseases (asbestos exposure), and a spatially structured clustering component shared between ovarian and breast cancer, capturing other risk factors. Based on 10 462 ovarian cancer deaths, we estimated that 574 (95% credibility interval 388–819) were attributable to asbestos (AF 5.5%; 95% credibility interval 3.7–7.8). AF reaches 34%–47% in some municipalities with known heavy asbestos pollution.ConclusionsThe impact of asbestos on ovarian cancer occurrence can be relevant, particularly in areas with high asbestos exposure. Estimating attributable cases was possible only by using advanced Bayesian modelling to consider other risk factors for ovarian cancer. These findings are instrumental in tailoring public health surveillance programmes and implementing compensation and prevention policies.