Year: 2018
Type: article
Study design: Observational Study
Abstract: Background: Region II in northern Chile (population 442 570) experienced a sudden major increase in arsenic water concentrations in 1958 in the main city of Antofagasta, followed by a major reduction in exposure when an arsenic removal plant was installed in 1970.It provides a unique opportunity to study latency effects of exposure to arsenic, and this is the first study with mortality data up to 40 years after exposure reduction.Methods: We previously identified high mortality rates in Region II up to the year 2000.Here we present rate ratios (RRs) for Region II compared with all the rest of Chile from 2001 to 2010, and with unexposed Region V (population 1 539 852) for all years from 1950 to 2010.All statistical tests were one-sided.Results: From 2001 to 2010, comparing Region II with the rest of Chile, lung and bladder mortality were still greatly elevated (RR ¼ 3.38, 95% confidence interval [CI] ¼ 3.19 to 3.58, P < .001for lung cancer in men; RR ¼ 2.41, 95% CI ¼ 2.20 to 2.64, P < .001for lung cancer in women; RR ¼ 4.79, 95% CI ¼ 4.20 to 5.46, P < .001for bladder cancer in men; RR ¼ 6.43, 95% CI ¼ 5.49 to 7.54, P < .001for bladder cancer in women).Kidney cancer mortality was also elevated (RR ¼ 1.75, 95% CI ¼ 1.49 to 2.05, P < .001for men; RR ¼ 2.09, 95% CI ¼ 1.69 to 2.57, P < .001for women).Earlier short latency acute myocardial infarction mortality increases had subsided.Conclusions: Lung, bladder, and kidney cancer mortality due to arsenic exposure have very long latencies, with increased risks manifesting 40 years after exposure reduction.Our findings suggest that arsenic in drinking water may involve one of the longest cancer latencies for a human carcinogen.Inorganic arsenic is naturally present at high levels in the groundwater of many countries, creating an important public health issue affecting millions of people (1,2).Severe health effects have been observed in populations drinking arseniccontaminated water over long periods, and research has established that drinking water contaminated with arsenic causes skin cancer and several internal cancers such as lung, bladder, and kidney cancer, as well as cardiovascular disease and other adverse outcomes (3-7).Major efforts have been made to reduce arsenic exposure, but with long latency patterns, increased risks will continue for many years.Although little is known about the latency period between exposure to arsenic and the risk of many arsenic-associated noncancer diseases, a few earlier studies in Taiwan and Japan and our own studies in Chile are consistent in suggesting that internal cancers associated with arsenic ingestion have substantial latency periods, frequently in excess of 20 years from the beginning of exposure (8-13).The knowledge of latency effects is an important factor in assessing the public health implications of arsenic exposure.Our mortality study in Region II from 1950 to 2000 found marked increased mortality from many cancers and other
Source: American Journal of Epidemiology
DOI: 10.1093/aje/kwy159
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2885770580