Occupational radiation exposure and risk of cataract incidence in a cohort of US radiologic technologists

• Published in: European journal of epidemiology Vol. 33; no. 12; pp. 1179 - 1191
• Main Authors: Little, Mark P., Kitahara, Cari M., Cahoon, Elizabeth K., Bernier, Marie-Odile, Velazquez-Kronen, Raquel, Doody, Michele M., Borrego, David, Miller, Jeremy S., Alexander, Bruce H., Simon, Steven L., Preston, Dale L., Hamada, Nobuyuki, Linet, Martha S., Meyer, Craig
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.12.2018; Springer Netherlands; Springer Nature B.V; Springer Verlag
• Subjects: Adult; Allied Health Personnel - statistics & numerical data; Body mass index; Body size; Cancer; Cardiology; Cataract - epidemiology; Cataract - etiology; Cataracts; Diabetes mellitus; Diagnosis; Environmental Sciences; Epidemiology; Exposure; Eye lens; Hazards; Health hazards; Humans; Incidence; Infectious Diseases; Ionizing radiation; Male; Medical personnel; Medicine; Medicine & Public Health; Melanoma; Middle Aged; Occupational Diseases - epidemiology; Occupational Diseases - etiology; Occupational exposure; Occupational Exposure - adverse effects; Occupational Exposure - analysis; Occupational health; Oncology; Public Health; Radiation dosage; Radiation effects; RADIATION EPIDEMIOLOGY; Radiation Exposure - adverse effects; Radiation Exposure - statistics & numerical data; Radiology; Risk analysis; Risk Factors; Skin; Smoking; Statistical analysis; Statistical models; Surgery; Technologists; Technology, Radiologic - statistics & numerical data; United States; Young Adult; United States; Cataract surgery; Low dose rate; Cataract; Ionising radiation; Questionnaire-based assessment; Tissue reaction effects; Diabetes; Threshold
• ISSN: 0393-2990; 1573-7284; 1573-7284
• DOI: 10.1007/s10654-018-0435-3

It has long been known that relatively high-dose ionising radiation exposure (> 1 Gy) can induce cataract, but there has been no evidence that this occurs at low doses (< 100 mGy). To assess low-dose risk, participants from the US Radiologie Technologists Study, a large, prospective cohort, were followed from date of mailed questionnaire survey completed during 1994–1998 to the earliest of self-reported diagnosis of cataract/cataract surgery, cancer other than non-melanoma skin, or date of last survey (up to end 2014). Cox proportional hazards models with age as timescale were used, adjusted for a priori selected cataract risk factors (diabetes, body mass index, smoking history, race, sex, birth year, cumulative UVB radiant exposure). 12,336 out of 67,246 eligible technologists reported a history of diagnosis of cataract during 832,479 person years of follow-up, and 5509 from 67,709 eligible technologists reported undergoing cataract surgery with 888,420 person years of follow-up. The mean cumulative estimated 5-year lagged eye-lens absorbed dose from occupational radiation exposures was 55.7 mGy (interquartile range 23.6-69.0 mGy). Five-year lagged occupational radiation exposure was strongly associated with self-reported cataract, with an excess hazard ratio/mGy of 0.69 × 10⁻³ (95% CI 0.27 × 10⁻³ to 1.16 × 10⁻³, p < 0.001). Cataract risk remained statistically significant (p = 0.030) when analysis was restricted to < 100 mGy cumulative occupational radiation exposure to the eye lens. A non-significantly increased excess hazard ratio/mGy of 0.34 × 10⁻³ (95% CI – 0.19 × 10⁻³ to 0.97 × 10⁻³, p = 0.221) was observed for cataract surgery. Our results suggest that there is excess risk for cataract associated with radiation exposure from low-dose and low dose-rate occupational exposures.