Perchlorate seems to be everywhere these days. It is in a lot of water supplies, in fruits and vegetables, in Chile's Atacama Desert, and even on Mars.

That is good and bad news for the Defense Department and military contractors battling accusations that they have polluted groundwater with perchlorate, a primary component of rocket fuel.

The fact that perchlorate -- a salt comprising a chlorine atom and four oxygen atoms -- occurs naturally makes it difficult to draw simple conclusions about whether to regulate it or remove it from the drinking-water supplies of at least 35 states and the District of Columbia.

On the other hand, that perchlorate is more widespread than previously thought suggests to proponents of federal water regulations that there is all the more need to regulate its presence in drinking water.

The debate over perchlorate now moves to U.S. EPA, which requested public comments this week on possible regulation of perchlorate in drinking water. EPA is asking whether there are alternative ways to evaluate if perchlorate occurs at a frequency and at levels to cause health concerns and whether a national drinking-water regulation would lead to a "meaningful opportunity for health risk reduction." 

The agency said it is particularly concerned about the possible impact of perchlorate on the health of very young children. Perchlorate has been known to inhibit the thyroid gland's iodine uptake and interfere with fetal development at high doses.

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

But the science behind perchlorate has grown complicated in recent years. Notably, researchers were stunned last year when they discovered perchlorate on Mars.

"The last thing anyone expected was to have almost all of the chloride in Martian soil as perchlorate," said Dave Stonestrom, a research hydrologist with the U.S. Geological Survey.

The Martian perchlorate was formed naturally, Stonestrom said, but no one can say whether Martian perchlorate is found all around the planet or whether its formation is ongoing or is a relic from past conditions.

New technology sparks regulatory debate

The debate over perchlorate began after EPA began noticing it in groundwater at certain California Superfund sites in the 1980s, said Kevin Mayer, the Superfund project manager at the EPA Region 9 office in San Francisco.

There were huge gaps then in what was known about the chemical's toxicology and detection.

But in 1997, scientists developed a way of detecting concentrations of the chemical at 4 parts per billion, a level far lower than levels detectable previously. Almost overnight, it seemed, perchlorate was turning up everywhere, including the Colorado River, which provides water for 20 million people.

"It was pretty clear by the middle of 1997 that Region 9 had a big issue on its hands, bigger than the Superfund program was set up to deal with on a site-by-site basis," Mayer said. "We needed some really good science."

Science was critical because DOD and other parties that were being accused of polluting water and soil with perchlorate were arguing that they were not responsible for contamination nor for the extremely expensive cleanups.

"A lot of people like to know whose perchlorate it is when they find perchlorate where it isn't supposed to be," said Andrew Jackson, an engineering professor and perchlorate researcher at Texas Tech University.

5 Comments

1. 1. pgtruspace 12:53 AM 8/7/09

   In the early 1970's Bell Labs got into trouble with the Bay Area pollution control people because of perclorate in their waste water. After considerable testing and research it was found that the clorinated city water flowing in cement asbestos water mains created perclorates. Oh yes, at the time Bell Labs used no perclorates!

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2. 2. stefanharjes 11:02 AM 8/7/09

   What about chlorine containing bleach? Might this not be a major source as there seem to be a lot of people in the US using it. In Germany for example its use is prohibited for nearly 20 years.

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3. 3. ME-TECH-2 07:47 PM 8/7/09

   In my view -- this is a good ongoing story for SA.
   
   We live by Las Vegas and Colorado River which supplies 30 million people with water in multi states.
   
   Hydrologists have detected 1000+ chemicals polluting waters that orginates from the Rocky Mountains.
   
   I do not want to pound so hard on rocket fuel because there
   is plenty of other stuff in the water.
   
   Orange County California is said to be starting the most
   advanced sewer plant in the United Staes to detect bad
   chemicals in the water.
   
   Rocket fuel is obvious. Look past the Rocket fuel.
   
   There are 1000's + of other pollutents in American water systems.
   
   Peace.

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4. 4. stjabc 10:47 PM 8/7/09

   First, I want to say that the article is so long that I don't have the patience to read it through.
   
   And, secondly, I want to say something about the topic.
   
   As we all know, the technology is developing ing better and better but when we consider its advantages, it's there somebody thinking about the disadvantages?
   
   Yes, it has, I mean, the tech. So I think we should think more about the two-extreme-side contradictions in mass's developing and based on it we can do better.
   
   Yours,
   stjabc.
   
   Chinese Sophomore.
   
   My msn:hefeistjabc@hotmail.com
   
   

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5. 5. Der Kopf 02:55 PM 8/11/09

   Is this Scientific American? Perchlorate atoms? A high school chemistry student could spot that error!! Is the editor asleep?

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