An ecological study of the association between environmental indicators and early childhood caries.

In 61 countries, 55.5% of 3-5-year-old children had ECC. Eight factors had a small effect-size association with ECC: percentage of area that is marine-protected (partial eta squared; ƞ2 = 0.03); species habitat index (ƞ2 = 0.06); percentage of tree-cover loss (ƞ2 = 0.03); regional marine trophic index (ƞ2 = 0.03); total carbon dioxide emission intensity (ƞ2 = 0.03); methane emission intensity (ƞ2 = 0.04); nitrous oxide emission intensity (ƞ2 = 0.06); and sulfur dioxide emission intensity (ƞ2 = 0.03). Regression analysis revealed that two of these factors were significantly associated with the prevalence of ECC: methane emission intensity was inversely associated with ECC prevalence (B = - 0.34, 95% CI = - 0.66, - 0.03; p = 0.03), and nitrous oxide had a direct association with ECC prevalence (B = 0.35, 95% CI = 0.04, 0.67; p = 0.03).