Cumulative risk analysis of carcinogenic contaminants in United States drinking water.
Level 5 - mechanism / opinion, no new human data
Mathematical risk assessment and exposure modeling without direct human health outcome measurement
PubMed 31687532 · doi:10.1016/j.heliyon.2019.e02314
What was done
A cumulative risk assessment was conducted using contaminant occurrence data in United States drinking water from 2010 to 2017 to estimate lifetime cancer risks and total attributable cancer cases across states and nationally.
What was found
The analysis estimated that over 100,000 lifetime cancer cases could be attributable to carcinogenic chemicals in US tap water, driven predominantly by arsenic, disinfection byproducts, and radioactive contaminants. Cumulative lifetime cancer risk across US states ranged from 1 × 10⁻⁴ to 1 × 10⁻³, with an overall national attributable risk of approximately 4 × 10⁻⁴, two orders of magnitude above the standard 1 × 10⁻⁶ de minimis risk benchmark.
Why it matters
This study provides an aggregate estimate of cancer burden from combined drinking water contaminants, suggesting that cumulative exposure exceeds standard single-pollutant safety thresholds.
Limits
The findings are derived from risk projection models rather than observed clinical or epidemiological cancer outcomes. The abstract does not report individual-level water consumption, account for multi-chemical toxicological interactions, or specify the exact number of water systems sampled.
Cited by
- context The Environmental Working Group showed that over 122 million Americans drink tap water containing high levels of chemicals known to cause cancer.