11 April 2011
Perchlorate producers: It's not harmful
 By Lindsay Weaver
Morgan Hill Times


The reliable and widely accepted science already exists, the Perchlorate Information Bureau insists, and it's past due that California recognizes at low levels the natural toxin isn't hazardous to your health. 

The residents affected by San Martin's distressful rocket fuel groundwater contamination of 2003 are still seeing the remnants of the spill by Olin Corp.'s shuttered road flare factory on Tennant Avenue - fewer than 20 wells are still closely monitored and millions of dollars have been spent by local government agencies to clean and monitor South County's drinking water. A few residents are even still dependent on bottled water.

But, according to a new study by Boston University School of Medicine's scientist Dr. Elizabeth Pearce, perchlorate isn't harmful to thyroid function even in pregnant women in their first trimester. The findings depict what the National Academy of Sciences has said for 50 years, the Perchlorate Information Bureau's spokesman Bill Romanelli said; "It doesn't come as a surprise. It's the same as the bulk of overwhelmingly scientific conclusions that say it simply doesn't impact human health," he said Monday.

The Perchlorate Information Bureau represents the interests of the aerospace industry that uses and produces rocket fuel, but Romanelli said the science speaks for itself.

The primary distributor of drinking water in Santa Clara County, the Santa Clara Valley Water District, has reported that adverse health effects aren't expected between levels of 4 to 18 parts per billion. In 2003, just a handful of wells were tested higher than 18 parts per billion. The county's health officer, Dr. Martin Fenstersheib, said exposure to perchlorate can cause thyroid problems and is especially risky to pregnant women and fetuses from high levels of exposure.

Still locals are feeling threatened nine years later by the water flowing from their faucets. Just a few days ago San Martin resident and Perchlorate Citizens Advisory Group chair Sylvia Hamilton said a new resident called her afraid to bathe her baby in the water.

"She was scared to death. Her landlord didn't tell her about the water. It's very unfortunate," Hamilton said. Hamilton said she quelled her fears about bathing her child in water that might have perchlorate. "It has to be ingested, not just taking a shower, not a swimming pool or if bath water splashed into your mouth. It's not going to affect people that way. It takes a more constant ingestion. If the perchlorate is tested at 5 part per billion or more - don't cook with it," Hamilton said - that's in line with what California's current "maximum contaminant level" for perchlorate in drinking water (6 parts per billion.)

Perchlorate is a salt commonly found in the environment that can be dangerous in high concentrations because it can interfere with thyroid gland function, inhibiting the intake of iodine, an essential component of thyroid hormones, according to the California Department of Health. It's also an industrial chemical contaminant that is used in rocket propellant, fireworks, flares; and is present in groundwater, drinking water and the Food & Drug Administration found perchlorate in more than 300 foods in 2008.

In the Boston University School of Medicine study, pregnant women were tested for perchlorate in their urine at higher levels than what the Central Coast Regional Water Quality Control Board is enforcing in the 9.5-mile affected area in San Martin and Morgan Hill. Women were exposed to 7.8 to 13 parts per billion, whereas wells in the affected area are regulated at 4 parts per billion.

The objective of Pearce's study was to find if environmental exposure to perchlorate adversely affects thyroid function in pregnant women because perchlorate does decrease the uptake of iodine into the thyroid gland - critical for neurodevelopment in utero. The result found low levels won't adversely affect pregnant women or unborn children. She added that increased iodine is recommended during pregnancy, which could offset the possible reduction from perchlorate ingested most commonly through eating food due to irrigation water.

Pearce, an endocrinologist, said she has no affiliation with the Perchlorate Information Bureau.

Romanelli and the Perchlorate Information Bureau and its study group which follows the science closely, is supported by Aerojet, American Pacific Corporation, ATK and Lockheed Martin. The Perchlorate Study Group backs Pearce's study as it comes on the heels of the Office of Environmental Health Hazard Assessment that recommends California enforce stricter limits on perchlorate in drinking water from 6 parts per billion to 1 part per billion.

Romanelli said the Perchlorate Information Bureau awaits a peer-review of the OEHHA's study that recommends the stricter rules on perchlorate. In a letter to OEHHA, they say that "nowhere in OEHHA's document does it show that California's current perchlorate standard is not health protective or that lowering the public health goal from 6 parts per billion (ppb) in water to 1 ppb will offer any additional health benefit."

Currently, California has a public health goal - an unenforceable suggestion - that agencies regulate drinking water at 6 parts per billion or 6 micrograms per liter. The OEHHA is suggesting a public health goal of 1 part per billion which is just a recommendation and not the same as the maximum containment level guidelines in place in California now. A federal standard would overrule the state's, however. The OEHHA recommendation is still under review, but backed by Sen. Barbara Boxer, as well as Hamilton.

Pearce's subjects were exposed to levels of perchlorate pharmacologically at much higher doses than can be found on average in the environment and she concluded that "low-level perchlorate exposure is ubiquitous, but is not associated with alteration in thyroid function tests among women in their first trimester of pregnancy," the study reads.

"Reassuringly we really don't see an association," Pearce said.

Despite evidence that perchlorate exposure isn't harmful, the federal government is upping the ante with regulations on how much perchlorate is allowed in drinking water. South County's water distributors such as the city of Morgan Hill and the Santa Clara Valley Water District are sticking with the state's recommendation pending on if the federal government sets a national standard.

If approved by the Senate, it would be the first federal regulation of perchlorate. Just California and Massachusetts have regulations on perchlorate in drinking water.

"We need to protect our most sensitive populations. The low levels probably has no negative affect on healthy adult men or healthy adult women, but if you're talking about pregnant women or children or people who have health challenges - it appears to definitely cause issues and it should be regulated," Hamilton said.


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