Assessing acute diarrhea from sulfate in drinking water
Amendments to the Safe Drinking Water Act in 1996 directed the US Environmental Protection Agency (USEPA) and the Centers for Disease Control and Prevention to jointly conduct research to explore adverse health effects from exposure to sulfate in drinking water. The studies described here were undertaken to provide USEPA with information about these health effects, especially as they affect sensitive subpopulations such as infants and travelers. A planned study of infants had to be abandoned when the authors were unable to identify enough exposed individuals. Some information was gleaned from a questionnaire that included questions about using tap water to mix infant formula. An experimental trial with adult volunteers did not uncover a significant dose-response association between acute exposure to sodium sulfate and reports of diarrhea. An expert workshop convened to review these findings and the existing sulfate literature concluded there was insufficient scientific evidence on which to base a regulation creating a maximum contaminant level for sulfate in drinking water. On the basis of this work, the literature, and the recommendation of the expert workshop, USEPA will decide whether and at what level to regulate sulfate in drinking water.