Most Children With Elevated Levels of Lead in Their Blood Have No Symptoms
According to Lead Poisoning News, the rate of lead poisoning in children age six and younger in Iowa is more than double the national rate, due largely to the state's older housing, much of which was built prior to the 1979 ban on lead-based paint.
"Lead is most commonly found in the dust that accumulates in homes that have lead-based paint on the interior or exterior walls, and children either ingest or inhale the dust. Young children are particularly at risk because of hand-to-mouth activity. They also may ingest chips of lead-based paint or plaster, says Jerold Woodhead, M.D., a pediatric specialist with the Children's Hospital of Iowa.
Houses built before the 1960s have lead-based paint on interior walls, and houses built before 1978 have lead-based paint on exterior walls. Children and adults also may be exposed to lead from job or hobby-related sources, Woodhead says.
Parents may bring lead into the home on clothing after working in battery factories, recycling industries, radiator repair, or hobbies such as stained glass and jewelry-making. "Recently, some toys in vending machines were found to be made of lead. Candies from Mexico often have high levels of lead in the candy itself or in the wrappers. Cosmetics and medications from Mexico, India, and other countries often contain lead. Lead is readily absorbed from the gastrointestinal and respiratory tracts. Children who are anemic may absorb greater amounts of lead than do non-anemic children," Woodhead says.
Most children with elevated levels of lead in their blood have no symptoms. "When levels are high, problems such as anemia, kidney failure, and seizures can occur. The major concern is brain development. A child with lead level greater than 10 mcg/dl has a high likelihood of having reduced developmental progress, although the findings may be very subtle. Some studies relate elevated lead levels with behavioral and educational problems," Woodhead says.
The history can detect high risk environmental exposures: Age of housing, parental job or hobby, family members with documented lead poisoning, travel to high risk areas, use of medications, cosmetics, candies from specific areas.
A blood test is the best screening tool, Woodhead says. When the blood lead level is greater than 10 mcg/dl on a screening test, a confirmatory test must be done. If the level remains elevated, the child is diagnosed with lead poisoning. "We routinely perform a screening at age 12 months and 24 months. Children at higher risk may be screened as early as 6 months and may have repeated screening and follow-up testing later than age 2."
Lead adversely affects brain growth and development. "It may be difficult to detect problems in an individual child, but a population of children who have had high lead levels since infancy may well have slower developmental progress, poorer school performance, more behavioral problems and a variety of medical problems.
If a pregnant woman has a large amount of lead in her system because she was exposed in childhood or as an adult, that lead is mobilized during pregnancy and can cross the placenta and affect the developing brain. Extremely high lead levels can result in loss of the fetus.
"Prevention of exposure is by far the best way to 'treat' lead poisoning and to ensure that children achieve optimal development," Woodhead says. "When lead is elevated in the blood, medication is used for a process called chelation to reduce the level. This is especially important if anemia, seizures, or kidney disease has resulted from the lead poisoning. All of these will respond to reduction in lead level."
Recent studies demonstrate that while some adverse effects such as those mentioned above will respond to treatment with a chelating agent, developmental, behavioral and some other problems cannot be reversed, he adds.
"The best way to avoid lead is to avoid housing in which lead-based paint is found," he says. 'Lead abatement' (i.e. complete removal of lead-based paint) in old housing is the preferred method but can be quite expensive.
If walls, windows, and doors are in good shape, they can be painted with latex-based print to carefully seal all old paint.
- Be sure to prepare the surfaces well.
- Remove any chipped, flaking or damaged paint.
- Keep the dust level as low as possible by wet-mopping areas where dust occurs, especially around windows with sashes that ride in grooves.
- Keep young children out of the house and away from dust and paint chips during any remodeling.
- After repainting, you will still need to monitor the condition of walls to watch out for wear on the new paint that will again expose the lead-based paint.
Also, avoid medications, cosmetics, candies, and toys that contain lead. Supervise young children so that hand-to-mouth activity will not expose them to potential hazards.