Study Links Lead to Tooth Decay
NEW YORK (Reuters Health)--Environmental
exposure to lead may increase the risk of
developing cavities, results of a new study suggest.
The study of nearly 25,000 people found that those
with high levels of lead in their blood were more
likely to have cavities than their counterparts with
lower blood levels of lead.
The findings, published in Wednesday's issue of The
Journal of the American Medical Association,
indicate that approximately 2.7 million excess cases
of dental caries (cavities) in older children and
adolescents may be related to environmental lead
exposure.
Tooth decay and dental caries are an important
public health problem. By age 17, 84 percent of
U.S. adolescents have experienced tooth decay in
their permanent teeth, involving an average of eight
tooth surfaces. The annual treatment costs for
dental caries in the United States are estimated to
be at least $4.5 billion.
The new study does not definitively show that lead
exposure causes cavities or how it may do so but if
it is proved that environmental lead exposure
causes dental caries, "it would have important
implications concerning the need to broaden the
focus of health interventions for dental caries
beyond modifying dietary habits, improving personal
oral hygiene behaviors, and increasing fluoride
exposure in high-risk groups," conclude Dr. Mark E.
Moss of the University of Rochester School of
Medicine and Dentistry in Rochester, New York, and
colleagues.
The researchers point out that disadvantaged
children and adults are known to have higher rates
of cavities than their wealthier counterparts.
"The results of the present analyses suggest that
environmental lead exposure may explain, at least in
part, the disproportionately high rate of dental
caries among disadvantaged children and
adolescents," according to the report.
To arrive at their findings, Moss and colleagues
compared findings from dental examinations with
blood lead levels among 24,901 people aged two
and older. Elevated blood lead levels were
associated with risk of cavities in baby and
permanent teeth in all age groups, the study found.
Among children aged five to 17, a 5 microgram per
deciliter of blood increase in blood lead level was
associated with an 80 percent higher risk of tooth
decay.
Researchers estimate that 13.5 percent of tooth
decay among five to 17 year olds is attributable to
high levels of lead exposure and 9.6 percent of the
tooth decay is attributable to moderate levels of
lead exposure.
While previous studies have linked lead exposure to
cavities in animals, this is the first study to identify
such a link in humans.
In an editorial accompanying the study, Dr. Thomas
D. Matte of the Centers for Disease Control and
Prevention in Atlanta, Georgia, writes that "by
focusing prevention efforts on vulnerable
populations exposed to immediate lead hazards,
progress toward the virtual eradication of childhood
lead toxicity can be greatly accelerated."
Source: The Journal of the American Medical
Association 1999;281:2294-2298.