Fluoride, lead co-exposure linked to lower youth BMD

Combined low-dose exposure to fluoride and lead was associated with greater reductions in bone mineral density in children and adolescents than exposure to either substance alone, according to a study in Journal of Trace Elements in Medicine and Biology.

Chunxiang Li, PhD, of Zhengzhou University, and colleagues used National Health and Nutrition Examination Survey data from 2013 to 2016. The analysis included 2,378 U.S. participants ages 8 to 19 with fluoride, lead, DEXA, and covariate data.

DEXA measures included bone mineral density of the lumbar spine, pelvis, left leg, and right leg. Exposure data included plasma or water fluoride and blood or urine lead.

Plasma fluoride and water fluoride each showed U-shaped nonlinear associations with bone mineral density, according to the study. BMD decreased as fluoride increased at lower concentrations, with inflection points of about 0.37 µmol/L in plasma and 0.37 mg/L in drinking water.

Lead exposure showed a sharper BMD decline at lower exposure levels, followed by a slower decrease at higher levels. Higher lead levels were associated with lower BMD in the pelvis and legs.

Interaction modeling found that each 1-unit increase in the plasma fluoride and blood lead interaction term was associated with BMD decreases of 1.679 in the lumbar spine, 3.104 in the left leg, and 3.068 in the right leg.

“Co-exposure to fluoride and lead has a more pronounced effect on BMD than exposure to either substance alone,” the authors wrote.

The study is titled “Low-Dose Fluoride and Lead Co-Exposure Alters Bone Mineral Density in Youth: A Nationally Representative Cross-Sectional Study.” Its DOI is 10.1016/j.jtemb.2026.127889.