Pregnant women exposed to too much nitrate in their drinking water are at greater risk of giving birth prematurely, according to a Stanford University study of more than 1.4 million California births.
Agricultural runoff containing fertilizer and animal waste can greatly increase the nitrate level in groundwater, which naturally contains a low level of the chemical.
“We found that higher concentrations of nitrate in drinking water during pregnancy were associated with an increased risk of spontaneous preterm birth, even at nitrate concentrations below the federal regulatory limit,” said Allison Sherris, a graduate student in the Emmett Interdisciplinary Program in Environment and Resources at Stanford. “That was surprising.”
Study lead author Allison Sherris is a 2016 SGF Fellow.