Age at Exposure to Arsenic in Water and Mortality 30–40 Years After Exposure Cessation

Abstract

Arsenic in drinking water is known to cause cancer and non-cancer diseases, but little is known about the effect of age at exposure. Here, we investigated age at arsenic exposure and mortality in Antofagasta, Chile, 30–40 years after a distinct period of very high arsenic water concentrations in 1958–1970. We calculated standardized mortality ratios (SMRs) comparing Antofagasta with the rest of Chile for 2001–2010 by sex and age at potential first exposure. A remarkable relationship with age at first exposure was found for bronchiectasis with increased risk in adults 30–40 years after exposure being confined to those who were in utero (SMR=11.7, 95% confidence interval (CI): 4.3, 25.4) or aged 1–10 (SMR=5.4, 95% CI: 1.1, 15.8) during the high exposure period. Increased SMRs for lung, bladder and laryngeal cancer were evident for exposures starting at all ages, but the highest SMRs were for exposures beginning at birth (bladder cancer SMR=16.0, 95% CI: 10.3, 23.8; laryngeal cancer SMR=6.8, 95% CI: 2.2, 15.8; lung cancer SMR=3.8, 95% CI: 2.9, 4.9). These findings suggest that interventions targeting early life arsenic could have major impacts on reducing long-term mortality due to arsenic 30–40 years after exposures end.