Haloacetic acids are chemical compounds that contain chlorine and bromine. They are formed through the disinfection process of drinking water. Drinking water contaminated with haloacetic acids may cause irritation to your eyes and skin and increase your risk of cancer.
Levels in Water
It is difficult to determine safe and toxic levels of haloacetic acid in water for human consumption because it is consumed in varying amounts over a long period of time, says the University of Minnesota. The amount of haloacetic acid in drinking water in the United States ranges from 0.0053 to 0.016 milligrams per liter. The Environmental Protection Agency standards for haloacetic acid in water are 0.06 milligrams per liter.
Effects on Skin
In high concentrations over a short period of time, exposure to haloacetic acids in drinking water can cause severe irritation to the skin. Trichloroacetic acid, a type of haloacetic acid, is used clinically as a chemical skin peel. Exposure to high levels of this acid causes loss of skin, inflammation and degeneration of the structural protein collagen. In some cases, the skin damage can last from two to 15 weeks.
The Environmental Protection Agency has classified the acid as a Group 2B cancer classification, which means it may cause cancer in humans. However, this classification is based on studies performed on animals, and the evidence to support its carcinogenicity in humans is limited. Experiments on mice exposed to varying levels of haloacetic acid showed an increase in the development of liver tumors and liver cancer.
Exposure to high levels of haloacetic acid also may increase the risk of birth defects. However, as with cancer, only animal studies have been conducted. Fetal rats exposed to high doses of haloacetic acid in their mother's diets had poor fetal growth and a higher incidence of malformation of the heart and kidneys. Pregnant rats exposed to the contaminant also had poor overall maternal weight gain during gestation.