Blood levels of the heavy metal, lead, and caries in children aged 24-72 months: NHANES III

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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 and the extent/severity of caries as measured by the number of decayed/filled teeth of children 24 to72 months using data from the Third National Health and Nutrition Examination Survey (NHANES III) accounting for the excess zero caries in the analysis and using less than 2 μg/dL as the reference blood lead level (N=3127). Zero-inflated negative binomial (ZINB) 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 μg/dL, 5-10 μg/dL, and >10 μg/dL, respectively when compared with children having less than 2 μg/dL blood lead levels. The results did not attenuate when other variables were added to the model for the 5-10 μg/dL, 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 and increasing numbers of carious teeth in children 24 to72 months. These findings support other studies in an innovative analysis handling cases children with no caries. The findings may inform caries risk assessment.