Arsenic exposure and cancer risk reduction with local ordinance requiring whole-house dual-tank water treatment systems

ABSTRACT

Arsenic, a known human carcinogen, occurs naturally in groundwater in New Jersey and many other states and countries. A number of municipalities in the Piedmont, Highlands, and Valley and Ridge Physiographic Provinces of New Jersey have a high proportion of wells that exceed the New Jersey maximum contaminant level (MCL) of 5 µg/L. Hopewell Township, located in Mercer County and the Piedmont Province, has a progressive local ordinance which requires the installation of dual-tank, point-of-entry treatment systems on affected wells. This provided a unique study opportunity. Of the 55 homes with dual-tank POE treatment systems recruited into this study, 51 homes (93%) had arsenic levels under the MCL at the kitchen sink, regardless of years in service and/or maintenance schedule adherence. Based on the study participants’ water consumption and arsenic concentrations, we estimate that Hopewell's arsenic water treatment ordinance, requiring POE dual-tank arsenic treatment, reduced the incidence of excess lifetime (70-year) bladder and lung cancers from 121 (1.7 cancer cases/year) to 16 (0.2 cancer cases/year) preventing 105 lifetime cancer cases (1.5 cases/year). Because the high risk of cancer from arsenic can be mitigated with effective arsenic water treatment systems, this ordinance should be considered a model for other municipalities.

KEYWORDS:

• arsenic
• arsenic water treatment
• arsenic exposure
• well water
• New Jersey

Acknowledgments

The authors thank the study participants from Hopewell Township and Gary Guarino and Robert English from the Hopewell Township Health Department. The authors acknowledge support from the New Jersey Geological and Water Survey, NIH-NIEHS P30 ES005022, and the New Jersey Agricultural Experiment Station. Recruitment and study procedures were reviewed and approved by the Institutional Review Board of Rutgers University Biomedical and Health Sciences.