Fluid Consumption Related to Climate among Children in the United States


  • This study was a part of Dr. Woosung Sohn's dissertation at the University of Michigan, School of Public Health. The authors wish to acknowledge the contribution from the dissertation committee members: Drs. Steve Eklund, MaryFran Sowers, and Xihong Lin in the School of Public Health, and Dr. Amid Ismail in the School of Dentistry.

Send correspondence and reprint requests to Dr. Sohn, Department of Cariology, Restorative Sciences, and Endodontics, School of Dentistry, University of Michigan, 1101 North University Street, Ann Arbor, MI 48109-1078. E-mail: woosung@umich.edu. Drs. Heller and Burt are with the Program in Dental Public Health, Department of Epidemiology, School of Public Health, University of Michigan. This paper was awarded second place in the 1999 Leverett Graduate Student Merit Award and presented as a poster at the 62nd AAPHD meeting on October 6, 1999, in Honolulu, HI.


Objective: Recommended fluoride concentrations in US public water systems are between 0.7–1.2 ppm, depending on the mean daily maximum temperature. This range assumes that water intake is higher in warmer than in cooler climates, based on research from the 1950s. The aim of this analysis is to relate fluid consumption among American children aged 1–10 years to the local climate under modern conditions. Methods: The quantities of daily total fluid intake per body weight (ml/kg) and plain water intake per body weight (ml/kg) of children were calculated from the 24-hour recall diet survey in the third National Health and Nutrition Examination Survey (NHANES III, 1988–94). The mean daily maximum temperature from 1961 to 1990, averaged for the month during which the NHANES III exam was conducted, was obtained for each survey location from the US Local Climate Historical Database. Multiple regression analysis was conducted using SAS and SUDAAN. Results: Fluid intake was significantly associated with age, sex, socioeconomic status (SES), and race and ethnicity. No significant association could be found between the amount of either total fluid or plain water intake and mean daily maximum temperature, either before and after controlling for sex, age, SES, and race or ethnicity. Conclusions: Results indicate that there is no evidence that fluid consumption among children is significantly related to mean temperature in modern conditions. This suggests that the national temperature-related guidelines for fluoride concentration in drinking water may be due for reevaluation.