Nitrate levels in community drinking waters and risk of IDDM. An ecological analysis

Diabetes Care. 1992 Nov;15(11):1505-8. doi: 10.2337/diacare.15.11.1505.


Objective: To investigate whether higher IDDM incidence rates occurred in areas with high nitrate levels in their potable water supplies.

Research design and methods: Incidence rates for the 63 counties in Colorado were calculated using the Colorado IDDM Registry of children diagnosed < 18 yr of age between 1978 and 1988 (n = 1280). A weighted average of the nitrate levels from each water district within each county was calculated using data collected by the Colorado Department of Health between 1984 and 1988.

Results: The rs between nitrate levels and IDDM incidence was 0.26 (P = 0.03). After controlling for differences in ethnicity, counties with water nitrate levels in the third tertile (0.77-8.2 mg/L) had a significantly increased risk of IDDM compared with those in the first tertile (0.0-0.084 mg/L) (rp = 0.29, P = 0.02).

Conclusions: This ecological analysis suggests that low-level nitrate exposure through drinking water may play a role in the etiology of IDDM, perhaps as a promoter through the generation of free radicals.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Child
  • Colorado / epidemiology
  • Diabetes Mellitus, Type 1 / epidemiology*
  • Ethnicity
  • Humans
  • Incidence
  • Nitrates / analysis*
  • Registries
  • Regression Analysis
  • Risk Factors
  • Water Supply / analysis*


  • Nitrates