Long-term exposure to trihalomethanes in drinking water and breast cancer in the Spanish multicase-control study on cancer (MCC-SPAIN)

• Published in: Environment international Vol. 112; pp. 227 - 234
• Main Authors: Font-Ribera, Laia, Gràcia-Lavedan, Esther, Aragonés, Nuria, Pérez-Gómez, Beatriz, Pollán, Marina, Amiano, Pilar, Jiménez-Zabala, Ana, Castaño-Vinyals, Gemma, Roca-Barceló, Aina, Ardanaz, Eva, Burgui, Rosana, Molina, Antonio José, Fernández-Villa, Tania, Gómez-Acebo, Inés, Dierssen-Sotos, Trinidad, Moreno, Victor, Fernandez-Tardon, Guillermo, Peiró, Rosana, Kogevinas, Manolis, Villanueva, Cristina M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.03.2018; Elsevier
• Subjects: Adult; Aged; Aged, 80 and over; breast neoplasms; Breast Neoplasms - epidemiology; bromination; Case-Control Studies; Case-control study; chloroform; chronic exposure; Drinking water; Drinking Water - adverse effects; Drinking Water - chemistry; Environmental Exposure - analysis; exposure assessment; Exposure routes; Female; females; hospitals; Humans; Long-term exposure; Middle Aged; risk factors; Spain; Spain - epidemiology; Trihalomethanes; Trihalomethanes - adverse effects; Trihalomethanes - analysis; urinary bladder neoplasms; Water Pollutants, Chemical - adverse effects; Water Pollutants, Chemical - analysis; women; Young Adult; Spain; Exposure routes; Drinking water; Long-term exposure; Case-control study; Trihalomethanes
• ISSN: 0160-4120; 1873-6750; 1873-6750
• DOI: 10.1016/j.envint.2017.12.031

Exposure to trihalomethanes (THMs) in drinking water has consistently been associated with an increased risk of bladder cancer, but evidence on other cancers including the breast is very limited. We assessed long-term exposure to THMs to evaluate the association with female breast cancer (BC) risk. A multi case-control study was conducted in Spain from 2008 to 2013. We included 1003 incident BC cases (women 20–85years old) recruited from 14 hospitals and 1458 population controls. Subjects were interviewed to ascertain residential histories and major recognized risk factors for BC. Mean residential levels of chloroform, brominated THMs (Br-THMs) and the sum of both as total THM (TTHMs) during the adult-lifetime were calculated. Mean adult-lifetime residential levels ranged from 0.8 to 145.7μg/L for TTHM (median=30.8), from 0.2 to 62.4μg/L for chloroform (median=19.7) and from 0.3 to 126.0μg/L for Br-THMs (median=9.7). Adult-lifetime residential chloroform was associated with BC (adjusted OR=1.47; 95%CI=1.05, 2.06 for the highest (>24μg/L) vs. lowest (<8μg/L) quartile; p-trend=0.024). No association was detected for residential Br-THMs (OR=0.91; 95%CI=0.68, 1.23 for >31μg/L vs. <6μg/L) or TTHMs (OR=1.14; 95%CI=0.83, 1.57 for >48μg/L vs. <22μg/L). At common levels in Europe, long-term residential total THMs were not related to female breast cancer. A moderate association with chloroform was suggested at the highest exposure category. This large epidemiological study with extensive exposure assessment overcomes several limitations of previous studies but further studies are needed to confirm these results. •Exposure to trihalomethanes (THMs) in drinking water increases bladder cancer risk.•We assessed life-time exposure to THMs and breast cancer (BC) risk in Spain.•A case-control study with extensive exposure assessment was conducted in 2461 women.•Residential chloroform appeared to be associated with BC.•This epidemiological study overcomes several limitations of previous studies.