Lifetime occupational history and risk of endometriosis

Marino, Holt, Chen, Davis


Endometriosis is the presence of functioning endometrial glands and stroma outside the uterine cavity, most often in the pelvic peritoneal cavity. Women with endometriosis commonly have dysmenorrhea, dyspareunia, pain, menorrhagia and/or metrorrhagia; disease complications can include adhesions, chronic pain, and infertility. This exploratory case-control study investigated the relationship between lifetime occupational history and surgically confirmed endometriosis in a population-based sample.
Interviews were conducted with cases, all reproductive-aged female enrollees of a large health-maintenance organization first diagnosed with surgically confirmed endometriosis between April 1, 1996 and March 31, 2001 and randomly selected controls from the reproductive-aged female enrollee list from the same time period. Each reported job was coded using US Census Occupations and Industries codes, and jobs were classed into categories. Having ever worked an occupation in a given job class was compared to never having done so using unconditional logistic regression.Results:
Having ever worked as a flight attendant, service station attendant, or health worker, particularly as a nurse or health aide, was associated with increased risk of endometriosis (flight attendant: OR 9.80, 95% CI 1.08 – 89.02; service station attendant: OR 5.77, 95% CI 1.03 -32.43; health worker: OR 1.49, 95% CI 1.03 – 2.15). Income and education did not make a difference in the odds ratio estimates for the occupations examined.

This exploratory study suggests that having ever worked as a flight attendant, service station attendant, or health worker, particularly as a nurse, may be associated with an increased risk of endometriosis


Miscarriage among flight attendants

Barbara Grajewski, Elizabeth A. Whelan, Christina C. Lawson, Misty J. Hein, Martha A. Waters, Jeri L. Anderson, Leslie A. MacDonald, Christopher J. Mertens, Chih-Yu Tseng, Rick T. Cassinelli II, and Lian Luo


Cosmic radiation and circadian disruption are potential reproductive hazards for flight attendants.

Flight attendants from 3 US airlines in 3 cities were interviewed for pregnancy histories and lifestyle, medical, and occupational covariates. We assessed cosmic radiation and circadian disruption from company records of 2 million individual flights. Using Cox regression models, we compared respondents (1) by levels of flight exposures and (2) to teachers from the same cities, to evaluate whether these exposures were associated with miscarriage.

Of 2654 women interviewed (2273 flight attendants and 381 teachers), 958 pregnancies among 764 women met study criteria. A hypothetical pregnant flight attendant with median firsttrimester exposures flew 130 hours in 53 flight segments, crossed 34 time zones, and flew 15 hours during her home-base sleep hours (10 pm–8 am), incurring 0.13 mGy absorbed dose (0.36 mSv effective dose) of cosmic radiation. About 2% of flight attendant pregnancies were likely exposed to a solar particle event, but doses varied widely. Analyses suggested that cosmic radiation exposure of 0.1 mGy or more may be associated with increased risk of miscarriage in weeks 9–13 (odds ratio = 1.7 [95% confidence interval = 0.95–3.2]). Risk of a first-trimester miscarriage with 15 hours or more of flying during home-base sleep hours was increased (1.5 [1.1–2.2]), as was risk with high physical job demands (2.5 [1.5–4.2]). Miscarriage risk was not increased among flight attendants compared with teachers.

Miscarriage was associated with flight attendant work during sleep hours and high physical job demands and may be associated with cosmic radiation exposure.