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Lead is a natural metallic element that occurs in rocks and soils and has been put to industrial use for a few thousand years. Lead has been used in metal alloys, paint, batteries, solders, ceramic glazes, bullets, metal toys, and building materials. Currently, most lead exposure comes from old lead paint dust from Maine homes built before 1978. Sanding or burning old paint during renovations dramatically increases exposure, which also results from normal wear and tear around lead-painted window frames and doorways Water pipes in some older homes may contain lead solder that can leach out into the water. Other sources of lead exposure include making and firing ammunition, handling lead-containing plastics, metal products, and lead acid batteries. Some cosmetics and folk remedies have been found to contain lead. Many PVC (vinyl plastic) products can contain lead, including electrical wires and cables, mini-blinds and children’s lunch boxes. Handling these products can result in lead exposure. Lead can also be released to the environment from disposal of PVC products, television sets, and older computer monitors in landfills and incinerators.

Exposure to lead can occur from breathing contaminated air or dust, eating contaminated foods, or drinking contaminated water. Children can be exposed from eating lead-based paint dust or playing in contaminated soil. Children from low-income families or who live in older homes are especially at risk.

Lead in Maine People

Lead was measured in the blood of twelve of the Maine participants (one sample was lost). The Maine results were generally below or near the median (or middle value) of the blood lead results for nearly 9,000 randomly selected Americans tested by the federal Centers for Disease Control and Prevention (CDC).

The blood lead level tends to indicate an exposure that occurred during the previous three to five months. However, these results could reflect recent exposures to lead or residual exposure from cumulative exposure to lead over a lifetime.

Lead bioaccumulates in bone as a result of exposure to multiple sources over time. Lead in the blood is taken up by the bones or is very slowly excreted, so once exposure to lead stops, the blood lead level will decrease gradually over the following months. Adults who were exposed to high levels of lead as children when leaded gasoline and paint were in widespread use still have lead stored in their bones. Bone lead leaches out over a period of years or less during pregnancy and in conditions of high bone turnover such as osteoporosis. This lead leaching from bone may be a factor in the lead levels seen in this survey.


Figure 5: Lead levels, measured in whole blood.

HEALTH EFFECTS: Lowered Intelligence and Lifelong Health Threats

The toxic nature of lead has been well known for hundred of years, with childhood lead poisoning from lead paint first documented a century ago. Yet adults and especially children continue to be exposed to this dangerous metal. The toxic effects of lead are well documented in both children and adults.

Lead causes damaging health effects at extremely low doses, and the main target is the central nervous system. Recent research shows that accumulated bone lead also leaches out faster during pregnancy and breastfeeding, exposing the fetus and infant to higher lead levels. Proven harmful effects include impaired brain development, premature births, smaller babies, learning difficulties, and reduced growth in young children. Children exposed to lead at a young age are more likely to suffer from shorter attentions spans and are less able to read and learn than their peers. Studies in children show that reducing blood lead levels by 10 ug/dL significantly raises the IQ by an average of 2.6 points, which across a large population has a huge effect.

Lead in adult bones leaches out over years and is one of the risks for hypertension. Long-term exposure of adults can result in decreased mental performance, or cause weakness in fingers, wrists, or ankles. Besides affecting the brain, lead exposure also causes kidney damage, anemia, increased blood pressure in older adults, and ultimately death. High-level exposure in men can damage the organs responsible for sperm production, and in pregnant women may cause miscarriage. Workers in construction, police protection, and other industries are at especially high risk of adult lead poisoning.

The federal government has concluded that lead and lead compounds are “reasonably anticipated to be human carcinogens,” due to increased lung and stomach cancer in humans and cancer of the kidney, brain and lung in lab animals.

Policy Changes Needed

Had the warnings of public health scientists been heeded in the 1920s, leaded gasoline would have never entered the marketplace and the use of leaded paint would have ended 50 years earlier in the United States. In a triumph of politics and profits over public health, an epidemic of lead poisoning ensued through the twentieth century, resulting in many deaths and disabilities in both children and adults. Although eliminating the use of lead in gasoline and paint by the late 1970s also marked one of the great public health successes of the last century, the toxic legacy of low-level lead poisoning continues to this day.

Average blood lead levels in American children have dropped by 85% since unleaded gasoline was first introduced in 1979, when the average U.S. child lead level was 16 ug/dL. Still, the U.S. Centers for Disease Control and Prevention estimates that more than 300,000 American children remain at risk of being exposed to harmful lead levels. And the latest science shows toxic effects on childhood brain development at levels much lower than the current federal action level of 10 ug/dL of lead in blood, suggesting that there is no safe level of exposure to lead.

Therefore, policy action is needed to eliminate current exposures to lead and remaining uses of lead in commerce. Maine has begun to make recent progress to further reduce lead. Legislation enacted in 2005 creates a lead-poisoning prevention fund for education and outreach programs aimed at reducing lead exposure. And, as of January 1, 2006, cathode ray tubes from computer monitors and televisions, which can contain four to eight pounds of lead, can no longer be thrown in Maine landfills and incinerators. Tubes must be collected and recycled instead.

Much more is needed. Maine should follow the lead of Rhode Island’s successful lawsuit to force lead pigment manufacturers to pay the enormous costs of lead cleanup at the 240,000 homes in the state that still have lead paint. In the interim, all renovations of lead-painted houses should be required to use lead-smart procedures to minimize lead exposures. Unnecessary uses of lead in wheel weights, PVC plastic, ammunition, and other sources should be phased out by law in favor of safer alternatives.

Reducing Your Exposure to Lead

Test for Lead. Children should be tested for lead at age one and two years, and at under six years of age if they have never been tested. Test soil within 20 feet of your house for lead before growing edible plants. If you have an older home (pre-1978), test your painted surfaces and drinking water for lead.

Make you home lead-safe. In a lead-painted home, consider replacing window frames and door frames which are a constant source of lead dust. All renovations should be done using lead-safe methods preferably by a certified contractor and at a time when young children or pregnant women are not living in the home. Do not allow children to chew or mouth painted surfaces. If you believe your home contains lead-based paint, clean the house regularly of dust and tracked in dirt and wash children's hands and faces often to remove lead dust. If you have a water lead problem, run water that has been standing overnight before drinking or cooking with it.

Avoid lead-containing products. Some types of paints and pigments used in makeup or hair coloring contain lead. Keep these away from children. Do not use imported glazed ceramic containers for eating or drinking. Avoid PVC plastic products. Watch out for cheap jewelry and kids toys that may contain lead. For more information on avoiding lead hazards, see resources at http://www.preventharm.org/take.redu.shtml#aroundthehome.


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