Lead is highly toxic.  Our total lead exposure is much lower than it was a decade ago, thanks to bans on lead-based paints, the removal of lead from gasoline, and our no longer using lead solder in food cans.  These improvements have however increased the relative importance of lead in drinking water.  Water now accounts for 15 to 25 percent of a child’s total exposure.

Very little lead occurs naturally in water.  It gets there primarily from corrosion of plumbing that contains lead.  The severity of lead contamination also depends on the water's chemistry.   Very soft or acidic water corrodes plumbing and fixtures and leaches out lead.

Service pipes from the main
Many homes built from about 1910 to 1940 have service pipes made of lead.  Newer homes may have lead pipes too, especially in colder regions.  In Chicago, lead pipes were required until 1986, when a nationwide ban on lead pipes took effect.

Leaded solder in plumbing
Most household plumbing consists of copper pipes connected by solder that is ½  lead and ½  tin.  Lead-soldered plumbing less than five years old is particularly likely to leach lead into drinking water.  A 1986 federal law banned further use of leaded solder on drinking water pipes.

Brass faucets
Most chrome-plated faucets are made of brass, which contains 3% - 8% lead.

It’s a good idea to have your water tested for lead.  Mail-order labs charge about $15.  Ideally, lead concentration should not exceed 5 parts per billion (ppb).  A few simple steps can reduce levels: 

• When you use your tap for the first time, let the water run for about a minute, or until it is as cold as possible.  Water sitting in pipes overnight accumulates lead.

• During the day, let tap water run for a few seconds before drinking.  Better yet, keep a pitcher of drinking water in the refrigerator. 

• Use only cold water for cooking and drinking; hot water dissolves more lead from pipes.  Using cold water is especially important when preparing baby formula.

If your lead levels are over 20 ppb,  you should consider drinking bottled water or installing a treatment device.  Reverse-osmosis devices, distillers and activated alumina cartridges can be quite effective at lowering lead levels.