Where It Comes From
Formed during water chlorination; the five are mono-, di-, and trichloroacetic acid and mono- and dibromoacetic acid. Levels rise with more natural organic matter or bromide; EPA’s limit is 60 µg/L (0.060 mg/L) [1][2].
How You Are Exposed
Mostly by drinking tap water and drinks/foods made with it; smaller amounts from skin contact or inhalation while bathing. Ingestion is the main route [1][3].
Why It Matters
Long-term exposure above standards may raise cancer risk and affect the liver and development; several HAAs cause tumors in lab animals [1][3][4].
Who Is at Risk
Infants and pregnant people; people who drink a lot of tap water; communities with higher bromide or organic matter that drive HAA5 formation [1][3].
How to Lower Your Exposure
Check your water utility’s Consumer Confidence Report; use a certified filter (NSF/ANSI 53 carbon or 58 reverse osmosis) for HAAs; use filtered cold water for drinking and infant formula; boiling is not effective for HAAs [2][3].
References
- [1]U.S. EPA. National Primary Drinking Water Regulations: Disinfectants and Disinfection Byproducts (Stage 1 & 2 DBPR). https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations
- [2]U.S. EPA. Haloacetic Acids (HAA5) in Drinking Water – Basic Information. https://www.epa.gov/dwreginfo/haloacetic-acids-haa5
- [3]CDC. Disinfection By-Products (DBPs) in Drinking Water. https://www.cdc.gov/healthywater/drinking/private/wells/disinfection_byproducts.html
- [4]WHO. Guidelines for Drinking-water Quality, 4th ed. https://www.who.int/publications/i/item/9789241549950