California’s air, water and milk have been tainted by radiation that erupted from a damaged nuclear power plant in Japan, but government officials and anti-nuclear activists are sharply divided over whether the contamination poses public health concerns here.
Invisible radioactive atoms that are swirling through the globe’s atmosphere and falling to the earth in rain, snow and fog in the wake of the world’s worst nuclear accident in 25 years can strike the cells of humans and other animals with energy and subatomic particles, if they get close enough, potentially damaging DNA and leading to cancer.
The cancer risks, which are acknowledged but described as minuscule by government officials, are exacerbated if radioactive material becomes embedded within bodily tissues after being swallowed. Once the material is embedded inside a person, it relentlessly bombards surrounding cells with radioactivity. Children are especially vulnerable.
The U.S. Environmental Protection Agency is publishing spotty monitoring data from across the nation revealing that radioisotopes from Japan have become an inescapable presence in the environment since the Fukushima power plant was struck by a tsunami last month, though the concentrations have been decreasing this month.
Some levels of radiation in water and milk measured exceed normal long-term safety limits, but EPA officials say they don’t pose dangers, pointing out that they are lower than short-term safety thresholds established for nuclear catastrophes. Activists interviewed by The Bay Citizen said they believed the current worldwide contamination would result in a future cancer epidemic. Independent experts expressed views that lay between the two extremes, often arguing that any hazards pale in comparison with other environmental dangers that plague the modern world.
The radioactive material circling the world is not naturally found in the air at current concentrations. It split off from nuclear fuel at the Fukushima power plant and was ejected into the air during uncontrolled nuclear reactions.
Some of the radioactive isotopes thrown into the atmosphere from Japan, such as iodine, have short half-lives and will begin disappearing from the environment within weeks after the damaged nuclear facility stops emitting radiation, according to Kyaw Tha Paw U, a professor of atmospheric science at UC Davis. Other isotopes, such as cesium, which has a half-life of 30 years, will stay in the environment longer.
Fukushima power plant operator Tepco says it could take nine more months to achieve substantial reductions in the levels of radiation emanating from the facility. Explosive blasts during the early days of the disaster helped propel radioactive material high into the atmosphere, where it began circling the world. Those blasts are no longer occurring, and declining measurements of radioactive material in the United States suggests that the worst phases of the air pollution have passed.
Paw U characterized the amount of Japanese radiation in the United States’ environment as “pretty low-level stuff” that should be viewed in the context of other ubiquitous radiation sources, such as cell phones, x-ray machines and the sun. He said the radiation joins a long list of other environmental hazards, such as a slew of chemicals surrounding modern Americans and substantial radioactive fallout that followed above-ground nuclear weapons tests in the 1950s and '60s.
“Those of who those who are still around in their 60s and older grew up in a period where this stuff was out there quite a bit — it was in the milk and in a variety of other sources,” Paw U said. “Since then, our public perception of radiation issues has changed.”
The EPA, which took the unusual step of deferring all radiation-related public relations activities in the initial days after the Fukushima disaster to the Nuclear Regulatory Commission, a federal government agency that licenses U.S. nuclear facilities and is characterized by critics as an advocate of the nuclear power industry, says levels of radiation emanating from Fukushima are so low and will be so fleeting that any health risks are negligible.