Aggregated cumulative county arsenic in drinking water and associations with bladder, colorectal, and kidney cancers, accounting for population served

Alison K Krajewski; Monica P Jimenez; Kristen M Rappazzo; Danelle T Lobdell; Jyotsna S Jagai

doi:10.1038/s41370-021-00314-8

Aggregated cumulative county arsenic in drinking water and associations with bladder, colorectal, and kidney cancers, accounting for population served

J Expo Sci Environ Epidemiol. 2021 Nov;31(6):979-989. doi: 10.1038/s41370-021-00314-8. Epub 2021 Mar 10.

Authors

Alison K Krajewski^{1

2}, Monica P Jimenez³, Kristen M Rappazzo⁴, Danelle T Lobdell⁴, Jyotsna S Jagai⁵

Affiliations

¹ Oak Ridge Institute for Science and Education (ORISE) Postdoctoral Fellow at United States Environmental Protection Agency (US EPA), Research Triangle Park, NC, USA. krajewski.alison@epa.gov.
² US EPA, Office of Research and Development, Center for Public Health & Environmental Assessment, Research Triangle Park, NC, USA. krajewski.alison@epa.gov.
³ Oak Ridge Associated Universities (ORAU) Student Services Contractor at US EPA, Research Triangle Park, NC, USA.
⁴ US EPA, Office of Research and Development, Center for Public Health & Environmental Assessment, Research Triangle Park, NC, USA.
⁵ Division of Environmental and Occupational Health Sciences, University of Illinois at Chicago, School of Public Health, Chicago, IL, USA.

Abstract

Background: Many studies neglect to account for variation in population served by community water systems (CWSs) when aggregating CWS-level contaminant concentrations to county level.

Objective: In an ecological epidemiologic analysis, we explored two methods-unweighted and weighted (proportion of CWS population served by county population)-to account for population served by CWS in association between arsenic and three cancers to determine the impact of population served on aggregated measures of exposure.

Methods: CWS arsenic concentration data for 19 states were obtained from Centers for Disease Control and Prevention (CDC) National Environmental Public Health Tracking Network for 2000-10, aggregated to county level, and linked to county-level cancer data for 2011-5 from National Cancer Institute and CDC State Cancer Profiles. Negative binomial regression models estimated adjusted risk ratios (aRR) and 95% confidence intervals (CI) between county-level bladder, colorectal, and kidney cancers and quartiles of aggregated cumulative county-level arsenic concentration (ppb-years).

Results: We observed positive associations between the highest quartile of exposure, compared to the lowest, of aggregated cumulative county-level arsenic concentration (ppb-year) for bladder [weighted aRR: 1.89(1.53, 2.35)], colorectal [1.64(1.33, 2.01)], and kidney [1.69(1.37, 2.09)] cancers. We observed stronger associations utilizing the weighted exposure assessment method. However, inferences from this study are limited due to the ecologic nature of the analyses and different analytic study designs are needed to assess the utility that the weighted by CWS population served metric has for exposure assessment.

Significance: Weighting by CWS population served accounts for some potential exposure assignment error in epidemiologic analysis.

Keywords: Arsenic; Bladder cancer; Cancer; Drinking water; Population served.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Arsenic* / analysis
Arsenic* / toxicity
Colorectal Neoplasms* / chemically induced
Colorectal Neoplasms* / epidemiology
Drinking Water* / analysis
Environmental Exposure / statistics & numerical data
Humans
Kidney Neoplasms* / chemically induced
Kidney Neoplasms* / epidemiology
Urinary Bladder / chemistry
Water Pollutants, Chemical* / analysis
Water Pollutants, Chemical* / toxicity

Substances

Drinking Water
Water Pollutants, Chemical
Arsenic

Grants and funding

EPA999999/ImEPA/Intramural EPA/United States