Combined Fluoride and Lead Exposure Linked to Lower Bone Density in Children: Study
China: A recent study found that simultaneous exposure to fluoride and lead was associated with a greater reduction in bone mineral density (BMD) in children and adolescents compared with exposure to either fluoride or lead alone. The findings suggest a possible synergistic adverse effect of these environmental toxins on developing bones.
The study, published in the Journal of Trace Elements in Medicine and Biology, was conducted by Chunxiang Li and colleagues from Zhengzhou University, China. Researchers investigated whether combined exposure to fluoride and lead could amplify skeletal harm during the critical growth period of childhood and adolescence.
For this purpose, the investigators analyzed data from 2,378 participants drawn from the National Health and Nutrition Examination Survey (2013–2016). Levels of fluoride in plasma and water, along with blood and urinary lead concentrations, were assessed. Bone mineral density measurements were taken from multiple skeletal sites, including the lumbar spine, pelvis, and lower limbs. Statistical models, including linear regression and restricted cubic spline analyses, were used to evaluate exposure–response relationships and potential interactions.
The study revealed the following findings:
- Fluoride exposure showed a non-linear U-shaped association with bone mineral density, indicating that both low and high exposure levels may be linked to changes in bone health.
- Lead exposure was consistently associated with lower lumbar spine bone mineral density.
- The decline in lumbar spine BMD with lead exposure was steep at lower levels and became more gradual at higher concentrations.
- Boys had higher blood concentrations of both fluoride and lead compared with girls, indicating sex-based differences in exposure levels.
- Higher lead levels were also associated with reduced bone mineral density in the pelvis and lower limbs, suggesting effects beyond the spine.
- Co-exposure to fluoride and lead resulted in a greater reduction in bone mineral density compared with exposure to either toxicant alone.
- Interaction analyses showed that combined fluoride and lead exposure was significantly linked to reduced BMD in the lumbar spine and both legs.
The findings support a potential synergistic harmful effect of fluoride and lead on skeletal health.
The authors emphasized that adolescence represents a critical window for peak bone mass development, making skeletal tissue particularly vulnerable to environmental insults. Disruption during this period may have long-term implications for bone strength and future fracture risk.
In their conclusion, the researchers noted that co-exposure to fluoride and lead may pose a meaningful threat to bone health in young populations. While fluoride alone showed a complex dose–response pattern, and lead exposure consistently reduced bone density, their combined effects appeared to intensify skeletal damage across multiple anatomical sites.
The study highlights the importance of addressing environmental exposure to heavy metals and fluoride during childhood and adolescence, particularly in regions where such exposures may coexist.
Reference:
Li, C., Niu, Z., Du, Y., Yang, L., Wu, F., Hu, X., Meng, X., Feng, Z., Niu, S., Sun, Q., Wang, Y., Fu, X., Zhou, G., Yu, F., & Ba, Y. (2026). Low-dose fluoride and lead co-exposure alters bone mineral density in youth: A nationally representative cross-sectional study. Journal of Trace Elements in Medicine and Biology, 95, 127889. https://doi.org/10.1016/j.jtemb.2026.127889
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