The Risks of Polyfluoroalkyl Chemicals (PFAS) Contaminated Water Sources on Human Health in Colorado

Abstract

Polyfluoroalkyl chemicals (PFAS) are harmful chemicals that bioaccumulate in humans, animals, and the environment. Therefore, contamination of drinking water with PFAS poses health and environmental risks. The state of Colorado has seen PFAS contamination in drinking water sources due to fire suppression products used at several military bases. Given the abundant contamination of PFAS in Colorado, this paper provides a human health risk assessment of PFAS in Colorado drinking water, analyzes PFAS removal methods, and discusses recommendations for mitigating exposure to PFAS in drinking water. Based on toxicology data from the European Food Safety Authority, the maximum daily intake for humans is 4.4 ng/kg body weight/week total perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). These particular values were chosen given the limited guidance from the US EPA on maximum safe intake levels for PFAS (as only drinking water advisory limits are provided). In 2022, the United States EPA announced health advisory limit of 0.004 parts per trillion for PFAO and 0.002 parts per trillion for PFOS in drinking water. Data sources to inform my analysis include the Colorado Department of Health and Environment “PFAS Concentration Map Series”, US EPA exposure factors handbook, and information I obtained directly from Colorado water treatment plants. My results highlight that (1) the detectable PFAS values at the drinking water locations in Colorado exceed the US EPA advisory values, and (2) the risks of average consumption (using the European standards) are below 1, indicating a low exposure risk. Given the inconsistencies in PFAS exposure limits across various regulatory organizations (with the trend toward lower exposure limits) and removal methods of varying efficacy, at home filters to remove PFAS from contaminated drinking water should be considered for mitigating exposure.