Programs that promote household cleaning, home repairs and parental awareness of lead hazards are not effective at protecting children from exposure to this poison, according to a new review of studies.
The review looked at interventions that attempted to reduce lead exposure for children and found that "none that have been tried so far have been proven to be effective," said lead author Dr. Berlinda Yeoh, a pediatrician at Sydney Children's Hospital in New South Wales, Australia.
Child Health and Safety
Lead poisoning is an important health problem in children, Yeoh said. Children regularly exposed to lead can experience lower intelligence test scores, behavior and growth problems, anemia, kidney damage and other physical, cognitive and behavioral impairments.
The most common cause of lead poisoning in children is ingestion of dust from old lead paint.
The sale of lead paint was banned in 1978 in the United States, but today's children could ingest dust or paint chips from peeling walls, broken plaster or old painted window sills or railings.
The reviewers examined 12 U.S. studies, which included 2,239 children 6 years and younger and their parents or caregivers.
Reviewers analyzed two types of interventions for parents: educational interventions, which emphasized teaching lead poisoning awareness and strategies for preventing dust and lead exposure at home; and environmental interventions, which involved making repairs, cleaning and painting to reduce home lead exposure.
The review appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
The reviewers found that educational programs for parents had no effect on children's blood lead levels, which was also the case for environmental programs.
The reviewers also analyzed the effect of soil abatement, an environmental program that involves removing and replacing lead-contaminated soil around the home. Two studies did show that soil abatement practices significantly reduced children's blood lead levels, but there were not enough data to include in the final analysis and insufficient evidence to recommend these practices as effective, the authors said in the review.
Even studies that combined both educational and environmental interventions failed to reduce children's blood lead levels.
So despite good intentions, why are educational and environmental interventions unsuccessful?
Yeoh said that children might have other sources of lead exposure at day care or relatives' homes, rendering home dust removal programs ineffective. She said it was possible that the interventions failed to remove all of the lead in the home or that lead dust within older homes quickly re-accumulated after cleaning.
Time - or lack of it - might also be a factor in explaining why such interventions are ineffective.
"Families don't necessarily have time to be thoroughly cleaning frequently," Yeoh said.
Based on these results, "it is difficult to support the use of the interventions examined in this review as a general population health measure, given their cost and the lack of data showing positive reductions in blood lead levels," the authors said.
Susan Buchanan, M.D., a clinical assistant professor at the University of Illinois at Chicago School of Public Health, called the review "a very thorough evaluation of current literature."
"It takes so little lead dust to poison a child that it doesn't matter how clean your house is, your child is still going to have exposure to lead dust," she said.
"As adults, our neurological systems are somewhat immune to the dramatic effects of lead," Buchanan said. However, very young children often put objects in their mouths -- increasing their ingestion of house dust and dirt -- that in turn affects their developing neurological systems, she said.
Despite the review's findings, Buchanan noted she would not necessarily stop recommending dust removal techniques in households with children who have high lead levels.
"We have to use the knowledge we have -- there is lead in dust, so as much dust removal as possible should still be recommended," she said. However, to "continue screening is critical because if high blood lead levels are caught, then health department inspectors can be used to point out obvious sources of lead in the home," Buchanan said.
Yeoh also noted that the authors do not want to discourage people from trying to reduce lead exposure: "We need to do more to find comprehensive interventions that will have an effect."