Tooth Decay Linked to Persistent Lead Pollution
Reprinted from New Scientist, 18/1/97, with kind
permission.
Lead pollution
from traffic fumes and tap water may cause tooth decay, say Spanish researchers Francisco
Gil and his colleagues at the University of Granada have found that teeth from children
and adults that contain high concentrations of lead have more caries, plaque and dental
staining Measuring the lead content of
children’s milk teeth as they are shed is a standard test for exposure to
environmental lead and its accumulation in the body. Gil’s team also found that
children with 10 or more sites of decay in their mouths had three times as much lead in
their blood as children with no decay.
The researchers, whose results appear in the December
issue of The Science of the Total Environment, suggest that lead either goes
directly into the mouth, where it replaces traces of metals that are natural constituents
of tooth enamel, or that it reaches teeth via the blood. Once present in the tooth, the
researchers believe that lead makes the enamel more susceptible to attack by bacteria.
Their discovery may explain why older people, who over the years accumulate more and more
lead in their teeth, suffer most from tooth decay.
The study is the first published analysis to find a
significant correlation between lead and dental decay. But Lindsay Paterson and Philip
Sutcliffe of the University of Edinburgh say that they made a similar finding in the early
1990s. "We also found a statistically significant association," says Paterson.
"We had intended to publish the results, but Sutcliffe, the lead author, got involved
in a long campaign to save the university’s dental school."
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