State Study: Low Levels of Perchlorate Affect Infants

A new analysis by state scientists found that low levels of a rocket fuel chemical common in Inland drinking water supplies appear to be more harmful to newborn babies than previously believed, prompting calls for a tougher limit for tap water.

Scientists with the Office of Environmental Health Hazard Assessment examined records of blood samples drawn from the heels of 497,458 newborns in 1998 as part of a California disease-screening program.

The researchers found that the babies born in areas where tap water was contaminated with perchlorate — including babies in Riverside and San Bernardino — had a 50 percent chance of having a poorly performing thyroid gland, said Dr. Craig Steinmaus, lead author of the study published in this month’s Journal of Occupational and Environmental Medicine.

Though perchlorate is in many Inland groundwater supplies, water providers aggressively treat and blend water to meet the state standard for the pollutant. The study’s authors, however, said they saw thyroid issues in babies born in areas where tap water met the current state standard.

The finding is important because the thyroid, a butterfly-shaped gland in the throat, produces the hormones fetus and babies need for proper nerve and brain development. Other studies have found that small declines in the production of thyroid hormone may negatively affect intelligence, Steinmaus said.