California aims to lower legal limit of thyroid-altering perchlorate in drinking water

Recent reports have shown that high levels of perchlorate - a compound found in rocket fuel - in drinking water may contribute to impaired thyroid function in babies. In an effort to prevent this issue, officials in California are seeking to lower the legal allowable amount of the chemical in drinking water, the Press Enterprise reports.

The current amount that is considered safe for consumption is 6 parts of perchlorate per billion parts of water. However, the state recently proposed that the limit be lowered to 1 part per billion.

One of the major sources of drinking water in California is the Colorado River, which was polluted by a Cold War-era perchlorate factory in Nevada. According to Metropolitan Water District spokesman Bob Muir, the river currently has 1.5 parts per billion and serves approximately 19 million people.

Research from the state Office of Environmental Health Hazard Assessment showed that infants are more susceptible to perchlorate's effects, according to the group's spokesman, Sam Delson. The compound prevents the thyroid gland from absorbing iodide, which is necessary to make hormones that help brain and nerve development, as well as metabolism, the news source reports.

"Adults may go several days without iodide, which is an essential nutrient, but infants cannot store as much, so they need to have more consistent doses," Delson told the media outlet.

Despite these findings, the Perchlorate Information Bureau - which is funded by industries that make or use perchlorate - issued a statement saying that the lower health goal "would jeopardize water supplies and increase costs for water consumers statewide without any corresponding public health benefit."

A study conducted by the Centers for Disease Control and Prevention (CDC) found that perchlorate exposure has been associated with small-to-moderate changes in levels of thyroxine and thyroid stimulating hormone in women with lower levels of iodine. The CDC also discovered that 36 percent of women in the U.S. have lower iodine levels.