How did Trichloroacetic Acid get in my water?

Trichloroacetic Acid is widely used in biochemistry for the precipitation of macromolecules, such as proteins, DNA, and RNA. TCA and DCA are both used in cosmetic treatments (such as chemical peels and tattoo removal) and as topical medication for chemoablation of warts, including genital warts. It can kill normal cells as well. It is considered safe for use for this purpose during pregnancy. Its sodium salt was used as an herbicide starting in the 1950s but regulators removed it from the market in the late 1980s and early 1990s.

Trichloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.

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.

Cancer Risk

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.

Birth Defects

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.