Cancer
Carcinogenic industrial air pollution and breast cancer risk in the NIH-AARP Diet and Health Study Caroline Pruitt* Jessica Madrigal Caroline Pruitt Jared A. Fisher Linda M. Liao Barry I. Graubard Gretchen L. Gierach Debra T. Silverman Mary H. Ward Rena R. Jones
Background: Emissions from industrial facilities include known mammary carcinogens, but these exposures are not well studied with respect to breast cancer. We evaluated associations between air emissions of multiple carcinogenic chemicals and post-menopausal breast cancer risk in a large prospective U.S. cohort.
Methods: We used the US Environmental Protection Agency’s Toxics Release Inventory to estimate historical airborne emissions (1987-1995) of 19 known and probable carcinogens for participants enrolled (1995-1996) in the NIH-AARP Diet and Health Study. A total of 15,124 breast cancers were diagnosed among 170,402 women through 2018. We constructed inverse distance- and wind-weighted average emissions metrics within 5 and 10km of the enrollment address for each chemical. We estimated multivariable adjusted HRs and 95% CIs for quintiles of each chemical in association with breast cancer overall and separately by disease type [invasive vs. ductal carcinoma in situ (DCIS)] and estrogen receptor (ER) status.
Results: We observed a suggestive association between asbestos emissions within 10km and breast cancer (HRQ5 vs. non-exposed=1.08, 0.97-1.20; p-trend=0.10) that was stronger for invasive disease (HRQ5 vs. non-exposed=1.12, CI=1.00-1.26; p-trend=0.02); but there was no association with DCIS (HRQ5 vs. non-exposed=0.89, CI=0.67-1.19; p-trend=0.50). We found a non-statistically significant increased risk of DCIS associated with trichloroethylene (TCE) in the top exposure quintiles at 10km (HRQ3=1.15, CI=0.99-1.34 and HRQ4=1.14, CI=0.97-1.33; p-trend=0.15), and a pattern of elevated risk across TCE quintiles for ER+, but not ER- tumors; these associations were stronger within 5km, though less precise. Associations with other chemicals were generally null or lacked clear patterns.
Conclusions: Our novel investigation suggests a small increased risk of breast cancer in association with asbestos and TCE emissions from industrial sources that warrants additional study.