Drinking water often comes with contaminants such as microorganisms, disinfection byproducts, disinfectants, inorganic chemicals and organic chemicals. The Environmental Protection Agency (EPA) tightly regulates municipal water systems and requires them to publish information on the contaminants in the tap water they deliver to their customers. You can check on the quality of your local drinking water at www.epa.gov/safewater/dwinfo/index.html.
Following is a list of contaminants that may be in your water, their source, and potential health effects.
Contaminant | Source | Potential Health Effects |
Asbestos |
Decay of asbestos cement in water mains; erosion of natural deposits |
Increased risk of developing benign intestinal polyps |
Benzene |
Discharge from factories; leaching from gas storage tanks and landfills |
Anemia; decrease in blood platelets; increased risk of cancer |
Chlordane |
Residue of banned termiticide |
Liver or nervous system problems; increased risk of cancer |
Chlorine (as Cl2) |
Water additive used to control microbes |
Eye/nose irritation; stomach discomfort |
Cryptosporidium |
Human and animal fecal waste |
Gastrointestinal illness (e.g., diarrhea, vomiting, cramps) |
Giardia |
Human and animal fecal waste |
Gastrointestinal illness (e.g., diarrhea, vomiting, cramps) |
Lead |
Corrosion of household plumbing systems; erosion of natural deposits |
Infants and children: Delays in physical or mental development; children could show slight deficits in attention span and learning abilities Adults: Kidney problems; high blood pressure |
Lindane |
Runoff/leaching from insecticide used on cattle, lumber, gardens |
Liver or kidney problems |
Trihalomethanes (TTHMs) |
Byproduct of drinking water disinfection |
Liver, kidney or central nervous system problems; increased risk of cancer |
2,4-D |
Runoff from herbicide used on row crops |
Kidney, liver, or adrenal gland problems |
Source: EPA