CHICAGO, June 22 ? Children exposed to lead in the environment appear more likely to develop cavities, according to a study published today.
?Some 2.7 million (U.S.) children between the ages of five and 17 may have tooth decay because of lead exposure,? said Mark Moss of the University of Rochester School of Medicine and Dentistry, lead author of the study.
?If a causal association between environmental lead exposure and cavities is substantiated, it would have important implications concerning the need to broaden the focus of dental health interventions beyond modifying dietary habits, improving personal oral hygiene and increasing fluoride exposure,? Moss said.
Some Contact Through Paint
Children, especially those living in older, urban neighbourhoods, are sometimes exposed to lead-based paint, which was banned in 1978 but remains widespread on household surfaces. Lead from deteriorating paint also is found in dust and soil.
The Moss study, published in this week?s Journal of the American Medical Association, was based on a survey covering nearly 25,000 U.S. adults and children conducted from 1988 to 1994. It found that for every 5 microgram-per-deciliter increase in blood lead levels, there was an 80 percent increase in tooth decay.
?Lead is a systemic toxin that affects virtually every organ system, even at levels previously thought to be low,? said co-author Bruce Lanphear, associate professor of pediatrics at Children?s Hospital Medical Centre of Cincinnati. ?This study helps to explain the disproportionately high rate of cavities among inner-city children.
Problem Still Around
?Despite the decline in children?s blood lead levels, lead exposure remains a major public health problem that persists throughout adulthood and entails major medical and dental costs to the United States population,? he said.
A second lead study published in the same journal on Tuesday uncovered signs that vitamin C ? found in fresh fruits and vegetables ? may help reduce blood lead levels.
Researchers at the University of California at San Francisco said they inferred the effect from data from the same 1988-1994 study that yielded the tooth decay information.
?To our knowledge this report is the first population-based study to establish such an association,? said Joel Simon, a principal author of the study. ?If a causal relation is confirmed, increased consumption of ascorbic acid (vitamin C) may have public health implications for the prevention of lead toxicity.?
About 0.5 percent of all people in the United States ? more than a million in all ? are believed to have elevated lead levels in their blood, said the study, which was financed in part by the Hoffmann-La Roche pharmaceutical company.