Exposure to Ethylene Oxide and Relative Rates of Female Breast Cancer Mortality: 62 Years of Follow-Up in a Large US Occupational Cohort
Year: 2025
Type: article
Study design: Observational Study
Abstract: BACKGROUND: Ethylene oxide (EtO) is a recognized carcinogen of concern in occupational and environmental settings, but evidence of cancer risks in humans remains limited. Since new EtO emission standards and mitigation measures have been proposed, further investigation of EtO cancer risks is needed to inform quantitative risk assessment. OBJECTIVE: Our objective was to estimate the association between cumulative EtO exposure and risk of death from breast cancer. METHODS: We had data on 7,549 women from the largest cohort of EtO-exposed workers who were employed for at least 1 y at one of 13 US facilities, with mortality follow-up from 1 January 1960 to 31 December 2021. We estimated relative rates (RR) of the association between cumulative EtO exposure [parts per million days (ppm-days)] and breast cancer mortality using Cox proportional hazard models, using a matched risk-set sampling design with attained age as the underlying time scale. We further examined a subcohort of women who participated in interviews that contained information about breast cancer risk factors. RESULTS: ; 95% CI: 1.52, 7.13). We observed evidence of variation in RRs by time since exposure and exposure rate. DISCUSSION: This updated analysis of an EtO-exposed worker cohort builds on evidence that EtO is a human breast carcinogen and supports recent exposure reduction proposals. Given the high prevalence of breast cancer, the large number of workers exposed to EtO and the potential for widespread environmental exposure increased risks observed even in the low exposure range are of serious public health importance. https://doi.org/10.1289/EHP15566.
DOI: 10.1289/ehp15566
Language: English
Subfield: Cancer Research
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $4,500
OpenAlex ID: W4409048892