Supplementary Material for: Blood Levels of the Heavy Metal, Lead, and Caries in Children Aged 24-72 Months: NHANES III

Lead remains a significant pollutant. It has acute toxic and chronic
effects on many tissues and accumulates in teeth and bones. The
researchers for this study investigated the association of blood lead
levels with the extent/severity of caries as measured by the number of
decayed/filled teeth of children aged 24-72 months using data from
NHANES III (the Third National Health and Nutrition Examination Survey),
accounting for the excess zero caries in the analysis and using less
than 2 µg/dl as the reference blood lead level (n = 3,127).
Zero-inflated negative binomial regression models indicated unadjusted
extent/severity mean ratios of 1.79, 1.88 and 1.94 for the number of
decayed/filled teeth in children whose blood lead levels were 2-5, 5-10
and >10 µg/dl, respectively, compared with children having <2
µg/dl blood lead levels. The results did not attenuate when other
variables were added to the model for the 5-10 and >10 µg/dl levels
of exposure. The adjusted extent/severity mean ratios were 1.84, 2.14
and 1.91, respectively, for the categories. This study indicated a
strong association of blood lead levels with increasing numbers of
carious teeth in children aged 24-72 months. These findings support
other studies in an innovative analysis handling cases of children with
no caries. The findings may inform caries risk assessment.