Leaked report reveals agency doesn't plan to limit levels in drinking water

The US Environmental Protection Agency (EPA) is facing criticism after a leaked draft report revealed that the agency may not set public water safety standards for perchlorate - a propellant used in everything from rocket fuel to fireworks that has been linked to thyroid problems and abnormal brain development of foetuses, newborns and young children.

EPA plans to publish the proposed rule in October with a final ruling expected by 2009, after the agency solicits public comments over at least 30 days.

There is currently no national water standard for perchlorate, with just a few states including California and Massachusetts imposing their own permissible levels of the chemical.

But Benjamin Grumbles, EPA’s assistant administrator for water, emphasises that the agency has reached no final decision. ’Science, not the politics of fear in an election year, will drive our final decision,’ he says. ’We know perchlorate in drinking water presents some degree of risk and we’re committed to working with states and scientists to ensure public health is protected and meaningful opportunities for reducing risk are fully considered.’ EPA’s decision will also not preclude states from pursuing their own legislation on the issue, Grumbles adds.

"Science, not the politics of fear in an election year, will drive our final decision" - Benjamin Grumbles

A 2006 US Centers for Disease Control and Prevention (CDC) study of around 2200 Americans indicated increasing levels of urine perchlorate (from 2.54-3.18 microgrammes per litre) picked up from food, water and the environment is associated with decreased thyroid function in women aged 12 years and older. Perchlorate exposure in pregnant and nursing women is a particular concern because of the potential impact on the brain development of foetuses and babies.

Some toxicologists, however, suggest regulating the amount of perchlorate in public water supplies would be fruitless and expensive because levels in the environment and food are much higher and most people’s exposure levels are below the current EPA safety limit.

’Perchlorate poses a hypothetical risk, but I am not convinced that it is causing an actual risk in the range of the exposures that we are contemplating,’ says Jonathan Borak, an environmental toxicologist at Yale University an industry consultant.

But Senator Barbara Boxer, the Democratic chairwoman of the influential Senate Environment and Public Works committee, disagrees.

’This is a widespread contamination problem, and to see the Bush EPA just walk away is shocking. EPA’s job is to protect the health of our families, not to stand by while people - especially children - are permanently injured,’ she says. According to Boxer, the EPA’s administrator, Stephen Johnson, has refused to appear before the committee.

Rebecca Trager, US correspondent for Research Day USA