Lead can cause serious health problems if too much enters your body from drinking water or other sources. It can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of your body. The greatest risk of lead exposure is to infants, young children, and pregnant women. Scientists have linked the effects of lead on the brain with lowered intelligence quotient (IQ) in children.
Adults with kidney problems and high blood pressure can be affected by low levels of lead more than healthy adults. Additionally, lead is stored in the bones, and it can be released later in life. During pregnancy, the child can receive lead from the mother's bones, which may affect brain development.
Lead is a common metal found in the environment. Sources of exposure are lead-based paint, household dust, soil, and some plumbing materials, including certain types of faucets. It is important to understand that the water source (MWRA reservoirs) and the water mains that distribute your water are lead-free. However, lead can get into tap water through a lead service line (the pipe that connects your home to the main in the street), lead solder typically used in plumbing prior to 1986, and some brass fixtures. The corrosion or wearing away of these lead-based materials can add lead to your tap water, particularly if water sits for a long time in the pipes before use.
A service line is the pipe that connects your house to the water main in the street. Some service lines that run from older homes (usually those built before 1940) to the utility water main are made from lead. Over time, many of these older service lines have been replaced, but your home could still have one.
For more information, view the Environmental Protection "Is There Lead in My Water" Resource page.