Ingestion of inorganic arsenic in drinking water is recognized as a cause of bladder cancer when levels are relatively high (e.g. >~150 µg/L).
The epidemiologic evidence is less clear at the low-to-moderate concentrations typically observed in the United States. Accurate retrospective exposure assessment over a long time period is a major challenge in conducting epidemiologic studies of environmental factors and diseases with long latency, such as cancer.
Objective: Estimate arsenic concentrations in water supplies of 2,611 participants in a population-based case-control study in northern New England.
Estimates covered the lifetimes of most study participants and were based on a combination of arsenic measurements at participants' homes and statistical modeling of arsenic concentrations in the water supply of both past and current homes. We assigned a residential water supply arsenic concentration for 165,138 (95%) of the total 173,361 lifetime exposure years (E-Y), and a workplace water supply arsenic level for 85,195 E-Y (86% of reported occupational years).
Three methods accounted for 93% of the residential estimates of arsenic concentration: direct measurement of water samples (27%; median: 0.3 µg/L; range: 0.1-11.5), statistical models of water utility measurement data (49%; median 0.4 µg/L; range: 0.3-3.3), and statistical models of arsenic concentrations in wells using aquifers in New England (17%; median:1.6 µg/L; range: 0.6-22.4).
We used a different validation procedure for each of the three methods, and found our estimated levels to be comparable with available measured concentrations, thus allowing calculation of potential drinking water exposure over long periods.
Written by:
Nuckols JR, Beane Freeman LE, Lubin JH, Airola MS, Baris D, Ayotte JD, Taylor A, Paulu C, Karagas MR, Colt J, Ward MH, Huang AT, Bress W, Cherala S, Silverman DT, Cantor KP. Are you the author?
Reference: Environ Health Perspect. 2011 Mar 21. Epub ahead of print.
doi: doi:10.1289/ehp.1002345
PubMed Abstract
PMID: 21421449
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