Levels of Calcium Carbonate and Chlorine in Drinking Water May Contribute to Atopic Dermatitis in Infants

High calcium carbonate (CaCO₃) and chlorine levels in public drinking water may be linked to an increased risk for developing atopic dermatitis, according to a recent study released by the Journal of Allergy and Clinical Immunology.

The study evaluated just over 1,300 infants from the general population. Researchers collected data on CaCO₃ and chlorine levels from the water sources serving their homes and neighborhoods. When the infants were enrolled, researchers also examined them for pre-existing atopic dermatitis as well as filaggrin (FLG), a gene mutation affecting the skin barrier.

The effects of CaCO₃ and chlorine levels were strongly correlated, the study found. Three groups were examined: Low CaCO₃/low chlorine, high CaCO₃/low chlorine, and high CaCO₃/high chlorine. Atopic dermatitis was more likely to develop in all three groups as compared to baseline.

As per the study: “Visible AD was more common in all 3 groups versus the baseline group: adjusted odds ratio (AOR) of 1.87 (95% CI, 1.25-2.80; P = .002) for the CaH/ClL group, AOR of 1.46 (95% CI, 0.97-2.21; P = .07) for the CaL/ClH, and AOR of 1.61 (95% CI, 1.09-2.38; P = .02) for the CaH/ClH group. The effect estimates were greater in children carrying FLG mutations, but formal interaction testing between water quality groups and filaggrin status was not statistically significant.”

The results suggest caution in providing municipal drinking water during infancy. While chlorine levels may still have an uncertain impact on AD at this time, it is clear that CaCO₃ in drinking water can have a deleterious effect.

According to the researchers: “An intervention trial is required to see whether installation of a domestic device to decrease CaCO₃ levels around the time of birth can reduce this risk.”