Translate this page to any language by choosing a language in the box below.
Bottled water, city tap water, well water, rain water... people are trying to find the cleanest source of drinking water. By what are the possible contaminants and what are the health effects of drinking them? The EPA has set standards for more than 80 contaminants that may occur in drinking water and pose a risk to human health. The EPA sets these standards to protect the health of everybody, including vulnerable groups like children. The contaminants fall into two groups according to the health effects that they cause. Your local tap water supplier must alert you through the media, mail, or other means if there is a potential acute or chronic health effect from compounds in the drinking water. You may want to contact the supplier for additional information specific to your area.
Acute effects occur within hours or days of the time that a person consumes a contaminant. People can suffer acute health effects from almost any contaminant if they are exposed to extraordinarily high levels (as in the case of a spill). In drinking water, microbes, such as bacteria and viruses, are the contaminants with the greatest chance of reaching levels high enough to cause acute health effects. Most people's bodies can fight off these microbial contaminants the way they fight off germs, and these acute contaminants typically don't have permanent effects. Nonetheless, when high enough levels occur, they can make people ill, and can be dangerous or deadly for a person whose immune system is already weak due to HIV/AIDS, chemotherapy, steroid use, or another reason.
Chronic effects occur after people consume a contaminant at levels over the EPA's safety standards for many years. The drinking water contaminants that can have chronic effects are chemicals (such as disinfection by-products, solvents, and pesticides), radionuclides (such as radium), and minerals (such as arsenic). Examples of the chronic effects of drinking water contaminants are cancer, liver or kidney problems, or reproductive difficulties.