Drinking Water

Lead: Likely the most famous bad guy, this heavy metal can leach from lead pipes and plumbing fixtures, especially when the water flowing through them is corrosive. It can cause neurological and behavioral problems in children and adverse health effects in adults.  It’s a more common problem in cities with older water systems, but what a lot of people don’t realize is that even relatively new brass fixtures and faucets can still contain significant amounts of lead. Just because your home is less than 20 years old doesn’t necessarily mean you’re lead-free.

Pathogens: Bacteria, viruses, and parasites that cause illness can find their way into water supplies that are inadequately treated to kill germs. Fortunately, these pathogens are much better controlled today than they once were. After a 1993 waterborne-disease outbreak in Milwaukee sickened more than 400,000 people. 

Chlorine treatment by-products: Chemicals used in drinking water’s disinfection process, such as trihalomethanes and haloacetic acids, may cause cancer and reproductive problems if present in high quantities. 

Arsenic: The EPA estimated in 2000 that nearly 36 million Americans drank water containing arsenic at or above 3 parts per billion. 

Nitrates: Though nitrates occur naturally in plants and soil at low concentrations, they have become a widespread contaminant due in part to their use as fertilizer. Runoff from factory farms flows into surface and ground water and ends up in our drinking water. The EPA set a limit of 10 parts per million for nitrates, which can be harmful to pregnant women and infants. In rare cases, exposed infants can develop blue baby syndrome, a potentially fatal illness that prevents the blood from carrying oxygen. 

Radioactive contaminants: Most radioactive elements found in drinking water occur naturally, but radioactive material from the production of nuclear weapons, energy, and medicines can also get into drinking supplies through leaks or improper waste storage. Exposure can cause cancer or kidney failure. 

Vinyl chloride: Used to make PVC plastic products, such as some pipes, this cancer-causing contaminant can leach from older PVC piping and has been found in the drinking water of a small number of communities across the country. 

Perchlorate: This widespread toxic chemical, used in rocket fuel, explosives, and road flares, can interfere with thyroid hormone production. Perchlorate has been detected in the water in at least 26 states, yet there is no federal standard for its presence in drinking water. In 2011, after more than a decade of pressure from environmental and health groups. 

Pharmaceuticals: Prescription drugs enter our water supply when patients release traces in their urine or flat-out flush unused medication down the sink or toilet.