In the event of a dirty bomb or a nuclear meltdown, emergency responders can safely tolerate radiation levels equivalent to thousands of chest X-rays, the Environmental Protection Agency said in new guidelines that ease off on established safety levels.
The EPA’s determination sets a level ten times the drinking water standard for radiation recommended under President Barack Obama. It could lead to the administration of President Donald Trump weakening radiation safety levels, watchdog groups critical of the move say.
"It’s really a huge amount of radiation they are saying is safe," said Daniel Hirsch, the retired director of the University of California, Santa Cruz’s program on environmental and nuclear policy. "The position taken could readily unravel all radiation protection rules."
The change was included as part of EPA "guidance" on messaging and communications in the event of a nuclear power plant meltdown or dirty bomb attack. The FAQ document, dated September 2017, is part of a broader planning document for nuclear emergencies, and does not carry the weight of federal standards or law.
"According to radiation safety experts, radiation exposures of 5-10 rem (5,000-10,000 mrem or 50-100 mSv) usually result in no harmful health effects, because radiation below these levels is a minor contributor to our overall cancer risk," EPA said in the document. That level is equivalent to as many as 5,000 chest X-rays or seven to 14 chest CT scans, according to a comparison with Food and Drug Administration data.
A 2007 version of the same document stated that no level of radiation is safe, concluding: "The current body of scientific knowledge tells us this."
“EPA has not changed its standards regarding radiation exposure, and no protective guidelines were changed during this administration," EPA spokeswoman Liz Bowman said in a statement. "We are simply providing more supporting resources.”
Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage genetic material and cause cancer, according to the National Cancer Institute. The extent of the damage to the cells depends upon the amount and duration of the exposure, as well as the organs exposed, according to the FDA.
Under the Safe Drinking Water Act, exposure limits are set at four millirem (or mrem) a year, and federal standards for hazardous air pollutants limits radiation exposure to 10 mrem a year, Hirsch said. Federal regulations limit exposure for living near a nuclear power plant to 25 mrem a year, he said.
Even with those lower standards, the EPA had never before said that any level of radiation exposure is safe, according to Jeff Ruch, executive director of the Public Employees for Environmental Responsibility, a watchdog group of government workers and retirees. Ruch linked the EPA’s scientific views on radiation exposure to the skepticism of EPA Administrator Scott Pruitt that humans are the main contributor to climate change.
Scientific Consensus
“I knew that under Scott Pruitt EPA is in climate denial but now it appears to be in radiation denial, as well,” Ruch said. “This appears to be another case of the Pruitt EPA proclaiming conclusions exactly opposite the overwhelming weight of scientific research.”
The Obama administration finalized a document in its waning days increasing the amount of radiation exposure in drinking water during an nuclear emergency to 500 mrem before emergency officials were required to provide bottled water or other alternative drinking water sources.
The latest change for emergency personnel makes sense, given the state of scientific knowledge, according to the agency.
"Although current science suggests there is some cancer risk from any exposure to radiation, it is very hard to tell whether a particular cancer was caused by very low doses of radiation or by some other source," the EPA said in an emailed statement.
Ruch said he was concerned the document signals that in the event of a "Fukushima-type" nuclear meltdown the EPA would allow public consumption of radiation-contaminated drinking water.
"Dr. Strangelove is alive and lurking somewhere in the corridors of EPA," he said.