What is the Danger from LEAD?
Although it has been used in numerous consumer products, lead is a toxic metal now known to be harmful to human health if inhaled or ingested. Important sources of lead exposure include: ambient air, soil and dust (both inside and outside the home), food (which can be contaminated by lead in the air or in food containers), and water (from the corrosion of plumbing). On average, it is estimated that lead in drinking water contributes between 10 and 20 percent of total lead exposure in young children. In the last few years, federal controls on lead in gasoline have significantly reduced people’s exposure to lead.
The degree of harm depends upon the level of exposure (from all sources). Known effects of exosure to lead range from subtle biochemical changes at low levels of exposure, to severe neurological and toxic effects or even death at extremely high levels.
Young children, infants and fetuses appear to be particularly vulnerable to lead poisoning. A dose of lead that would have little effect on an adult can have a big effect on a small body. Also, growing children will more rapidly adsorb any lead they consume. A child’s mental and physical development can be irreversibly stunted by over-exposure to lead. In infants, whose diet consists of liquids made with water – such as baby formula – lead in drinking water makes up an even greater proportion of total lead exposure (40 to 60 percent).
Typically, lead gets into your water after the water leaves your local treatment plant or your well. That is, the source of lead in your home’s water is most likely pipe or solder in your home’s own plumbing.
The most common cause is corrosion, a reaction between the water and the lead pipes or solder. Dissolved oxygen, low pH (acidity) and low mineral content in water are common causes of corrosion. All kinds of water, however, may have high levels of lead.
One factor that increases corrosion is the practice of grounding electrical equipment (such as telephones) to water pipes. (Nevertheless, wires should not be removed from pipes unless a qualified electrician installs an adequate alternative grounding system.)
Lead-contaminated drinking water is most often a problem in houses that are either very old or very new.
Up through the early 1900’s, it was common practice, in some areas of the country, to use lead pipes for interior plumbing. Also, lead piping was often used for the service connections that join residences to public water supplies. (This practice ended only recently in some localities.) Plumbing installed before 1930 is most likely to contain lead.
Copper pipes have replaced lead pipes in most residential plumbing. However, the use of lead solder with copper pipes is widespread. Experts regard this lead solder as the major cause of lead contamination of household water in U.S. homes today. New brass faucets and fittings can also leach lead, even though they are “lead-free.”
Scientific data indicate that the newer the home, the greater the risk of lead contamination. Lead levels decrease as a building ages. This is because, as time passes, mineral deposits form a coating on the inside of the pipes (if the water is not corrosive). This coating insulates the water from the solder. But, during the first five years (before the coating forms) water is in direct contact with the lead. More likely than not, water in buildings less than five years old has high levels of lead contamination.
You should have your water tested for lead. Since you cannot see, taste, or smell lead dissolved in water, testing is the only sure way of telling whether or not there are harmful quantities of lead in your drinking water.
You should be particularly suspicious if your home has lead pipes (lead is a dull gray metal that is soft enough to be easily scratched with a house key), if you see signs of corrosion (frequent leaks, rust-colored water, stained dishes or laundry, or if your non-plastic plumbing is less than five years old.) Your water supplier may have useful information, including whether or not the service connector used in your home or area is made of lead.
Testing is especially important in high-rise buildings where flushing might not work. You should be sure that the lab you use has been approved by your state or by EPA as being able to analyze drinking water samples for lead contamination.
Federal standards initially limited the amount of lead in water to 50 parts per billion (ppb). In light of new health and exposure data, EPA has set an action level of 15 ppb. If tests show that the level of lead in your household water is in the area of 15 ppb or higher, it is advisable – especially if there are young children in the home – to reduce the lead level in your tap water as much as possible. (EPA estimates that more than 40 million U.S. residents use water that can contain lead in excess of 15 ppb.)
Note: One ppb is equal to 1.0 microgram per liter or 0.001 milligram per liter (mg/l).
If your drinking water is contaminated with lead – or until you find out for sure – there are several things you can do to minimize your exposure. The first step is to refrain from consuming water that has been in contact with your home’s plumbing for more than six hours, such as overnight or during your work day. Before using water for drinking or cooking, “flush” the cold water faucet by allowing the water to run until you can feel that the water has become as cold as it will get. You must do this for each drinking water faucet – taking a shower will not flush your kitchen tap. Buildings builts prior to about 1930 may have service connectors made of lead. Letting the water run for an extra 15 seconds after it cools should also flush this service connector. Flushing is important because the longer water is exposed to lead pipes or lead solder, the greater the possible lead contamination. (The water that comes out after flushing will not have been in extended contact with lead pipes or solder.)
Once you have flushed a tap, you might fill one or more bottles with water and put them in the refrigerator for later use that day.
Note: Flushing may prove ineffective in high-rise buildings that have large-diameter supply pipes joined with lead solder.
The second step is to never cook with or consume water from the hot-water tap. Hot water dissolves more lead more quickly than cold water. So, do not use water taken from the hot tap for cooking or drinking, and especially not for making baby formula. (If you need not water, draw water from the cold tap and heat it on the stove.) Use only thoroughly flushed water from the cold tap for any consumption.
If you own a well or another water source, you can treat the water to make it less corrosive. Corrosion control devices for individual households include calcite filters and other devices.
You can purchase bottled water for home and office consumption.
There are many devices which are certified for effective lead reduction, but devices that are not designed to remove lead will not work.