EPA re-evaluates rocket fuel chemical’s effect on children

By Mary Manning

Wednesday, Aug. 5, 2009 | 1:33 p.m.

The Environmental Protection Agency plans to re-evaluate the rocket fuel chemical perchlorate, once made near Lake Mead, because of its potential health impacts on infants and children.

Under the Bush administration, the EPA made a preliminary decision not to regulate perchlorate in drinking water. In the 1990s scientists discovered perchlorate from two chemical plants in Henderson in Las Vegas Wash and Lake Mead waters. Lake Mead supplies 90 percent of Las Vegas Valley's drinking water.

EPA Administrator Lisa P. Jackson said today that the agency is seeking public comment as it begins to put an emphasis on evaluating perchlorate's effects on infants and young children, who were left out of the previous analysis.

"It is critically imporant to protect sensitive populations, particularly infants and children, from perchlorate in drinking water," Jackson said. "As we re-evaluate the science around perchlorate, we will seek public input before making a regulatory determination based on the best science."

Perchlorate occurs both naturally and as a man-made chemical used in making solid rocket fuel, fireworks and flares.

Perchlorate is found in just 4 percent of public water systems nationwide in 26 states and two territories, the EPA said.

Water researchers found between four and nine parts per billion of perchlorate in Colorado River water flowing to Southern California from Lake Mead in the 1990s.

The highest level of the chemical salt found in Lake Mead hit 16 parts per billion before 1997. Last year perchlorate was measured at 2.6 parts per billion in the lake, said Roger Buehrer, spokesman for the Southern Nevada Water Authority said.

The water authority had not studied the EPA's announcement but welcomed any review done by sound science, Buehrer said.

Federal, state and local water agencies began a coordinated effort to keep perchlorate from getting into the drinking water in 2000.

Two companies, Kerr-McGee, an oil and gas company, and American Pacific Company, formerly known as Pacific Engineering and Production Company, made ammonium perchlorate in Henderson during the 1950s and 1960s. After an explosion and fire destroyed PEPCON's plant in May 1988, it moved to Cedar City, Utah.

Kerr-McGeen has spent millions of dollars to remove perchlorate from the Las Vegas Wash. Contaminated water is captured and removed in 34 wells drilled near the wash.

Perchlorate competes with and replaces iodides in the thyroid gland and breast tissue, medical research shows.

Too much perchlorate can damage the thyroid gland, which controls growth, development and metabolism. Fetuses, infants and children with thyroid damage may suffer mental retardation, loss of hearing, speech defects or poor motor skills.

A 1999 study in Arizona comparing infants in Flagstaff consuming water free of perchlorate, and Yuma, which is supplied by perchlorate-laced water from the Colorado River, found changes in the Yuma babies' thyroids.

Perchlorate was suspected of causing cancer in 1966, when the first long-term study of its effects in drinking water was conducted. Perchlorate did not directly cause cancer, but induced tumors resulting from hormone changes in lab animals, while none occurred in control animals.