by Linda Mason Hunter

On top of contaminants that leach into drinking water from outside the plumbing system, we've got a pipe system throughout this country that is full of lead, a heavy metal that is extremely dangerous when ingested. The Environmental Protection Agency (EPA) estimates that more than 42 million U.S. residents consume water that contains unsafe levels of lead. That's one out of every five Americans. This excess alone, according to the EPA, may be responsible annually for lower IQ scores for 240,000 children, hypertension for 130,000 males, and pregnancy complications for 680,000 women. Lead gets into drinking water from two major sources: (1) lead pipes, usually connecting the main water pipe to the house, and (2) the lead solder used to connect copper pipes inside the house. Copper pipes themselves can also be a problem. Water with a low pH (meaning it is more acidic) tends to dissolve heavy metals, like copper. Since water is a solvent, traces of copper get into the water and are then ingested when the water is used for drinking or cooking. Though trace amounts of copper are needed for good health, copper in excess amounts is toxic in the human body.

Old galvanized pipe can be a source of health problems, too. Trace amounts of cadmium are often found in water from these pipes. In the human body, cadmium is known to displace zinc, which we need for good health. Cadmium has been implicated as a possible cause of hypertension, and is suspected of inhibiting the body's immune system and causing various serious illnesses.

Plastic pipes can contaminate drinking water, too. Solvent glues used to join sections of polyvinyl chloride (PVC) pipe contain dimethylformamide, a chemical linked to birth defects in lab animals. PVC pipe, as well as polybutylene and polyethylene pipes, may also allow organic chemicals to leach into the water at concentrations higher than recommended federal safety levels. Tests have also detected several other suspected carcinogens in water flowing through plastic pipe, including DEHP, a plasticizer used to make pipe more flexible. So what kind of pipe is best? Copper pipe with mechanical fittings appears to be the healthiest plumbing system to date. Though it's more costly, it eliminates lead from your water. A more practical answer is copper pipe with lead-free (and antimony-free) solder, available at hardware stores and plumbing supply companies. When using copper pipe, be sure your water has a normal pH, about 7 or so. If pH is low, water will have to be treated to raise the pH so traces of copper won't leach into the water.

© 2007 Green Home, Inc.