WASHINGTON — The EPA is pursuing rule changes that specialists say would weaken the way radiation exposure is regulated, turning to scientific outliers who argue that a bit of radiation damage is actually good for you — like a little bit of sunlight.
The government’s current, decades-old guidance says that any exposure to harmful radiation is a cancer risk. And critics say the proposed change could lead to higher levels of exposure for workers at nuclear installations and oil and gas drilling sites, medical workers doing X-rays and CT scans, people living next to Superfund sites, and any members of the public who one day might find themselves exposed to a radiation release.
The Trump administration already has targeted a range of other rules on toxins and pollutants, including coal power plant emissions and car exhaust, that it sees as costly for businesses. Supporters of the EPA’s proposal argue the government’s current model that there is no safe level of radiation — the so-called linear no-threshold model — forces unnecessary spending for handling exposure in accidents, at nuclear plants, in medical centers, and at other sites.
At issue is the Environmental Protection Agency’s proposed rule on transparency in science. EPA spokesman John Konkus said Tuesday, ‘‘The proposed regulation doesn’t talk about radiation or any particular chemicals. And as we indicated in our response, EPA’s policy is to continue to use the linear-no-threshold model for population-level radiation protection purposes which would not, under the proposed regulation that has not been finalized, trigger any change in that policy.’’
But in an April news release announcing the proposed rule the agency quoted Edward Calabrese, a toxicologist at the University of Massachusetts who has said weakening limits on radiation exposure would save billions of dollars and have a positive impact on human health.
The proposed rule would require regulators to consider ‘‘various threshold models across the exposure range’’ when it comes to dangerous substances. While it doesn’t specify radiation, the release quotes Calabrese calling the proposal ‘‘a major scientific step forward’’ in assessing the risk of ‘‘chemicals and radiation.’’ Konkus said the release was written during the tenure of former EPA Administrator Scott Pruitt. He could not explain why Calabrese was quoted citing the impact on radiation levels if the agency does not believe there would be any.
Calabrese was to be the lead witness at a congressional hearing Wednesday on the EPA proposal.
Radiation is everywhere, from potassium in bananas to the microwaves popping popcorn. Most of it is benign. But what’s of concern is the higher-energy, shorter-wave radiation, like X-rays, that can penetrate and disrupt living cells, sometimes causing cancer.
As recently as this March, the EPA’s online guidelines for radiation effects advised: ‘‘Current science suggests there is some cancer risk from any exposure to radiation.’’
But that online guidance — separate from the rule-change proposal — was edited in July to add a section emphasizing the low individual odds of cancer: ‘‘According to radiation safety experts, radiation exposures of . . . 100 millisieverts usually result in no harmful health effects, because radiation below these levels is a minor contributor to our overall cancer risk,’’ the revised policy says.
Calabrese and his supporters argue that smaller exposures of cell-damaging radiation and other carcinogens can serve as stressors that activate the body’s repair mechanisms and can make people healthier. They compare it to physical exercise or sunlight.
EPA spokesman Konkus said in an e-mail that the proposed rule change is about ‘‘increasing transparency on assumptions’’ about how the body responds to different doses of dangerous substances and that the agency ‘‘acknowledges uncertainty regarding health effects at low doses’’ and supports more research on that.
Jan Beyea, a physicist whose work includes research with the National Academies of Science on the 2011 Fukushima nuclear power plant accident, said the EPA science proposal represents voices ‘‘generally dismissed by the great bulk of scientists.’’
The EPA proposal would lead to ‘‘increases in chemical and radiation exposures in the workplace, home, and outdoor environment, including the vicinity of Superfund sites,’’ Beyea wrote. ‘‘The individual risk will likely be low, but not the cumulative social risk,’’ Beyea said.