Police officers wear gas masks while on patrol in a vehicle at the Fukushima nuclear power plant on March 12. Experts are concerned about the safety of the nuclear workers, but they say that so far, there's no risk for others in Japan or in the U.S.
Police officers wear gas masks while on patrol in a vehicle at the Fukushima nuclear power plant on March 12. Experts are concerned about the safety of the nuclear workers, but they say that so far, there's no risk for others in Japan or in the U.S. Kaname Yoneyama/AP
Events at the Fukushima Dai-ichi nuclear plant in Japan have people as far away as California worrying about exposure to radiation. But experts say they shouldn't. Right now, the only people in danger are the ones who actually work at the nuclear plant itself.
That still hasn't stopped people on the U.S. West Coast from stocking up on potassium iodide pills to protect themselves from radiation.
Jonathan Links, director of the Center for Public Health Preparedness at the Bloomberg School of Public Health at Johns Hopkins University, says not only do the pills offer limited protection, but the nuclear plant hasn't released enough radiation to cause health problems in most of Japan, let alone in the U.S. He says the people he's worried about are the workers still trying to gain control of the overheating nuclear reactors at Dai-ichi.
"I think it likely that they've gotten doses worth paying attention to," Links says.
At one point, a reading at the plant indicated there was enough radiation to cause acute radiation sickness for anyone exposed for more than a couple of hours. But Links says that was a peak level, and subsequent readings have shown much less radiation.
"The critical piece of information that's missing is the length of time they were exposed to that rate," he says.
Links says he would have been concerned about exposure among people who live near the plant, but the government quickly evacuated everyone within 12 miles.
"The group that would otherwise be at risk — those local residents — were evacuated very early on. And I think at this point, it's very unlikely they received any noticeable dose at all," he says.
Comparing Long-Term Effects
As for people in the rest of Japan, Links says something extraordinary would have to happen at the plant before they would face any risk. And even then, he says, the situation in Fukushima would not resemble Chernobyl, where a nuclear reactor exploded in 1986 and released enough radiation to sicken or kill dozens of people within hours.
"Were there to be releases, the concern would not be about acute effects, it would be about the main delayed effect, which is cancer," Links says.
In Chernobyl, the biggest problem was thyroid cancer in people who were exposed to radioactive iodine as children. Links says the situation in Fukushima is more like what happened at Three Mile Island, where in 1979, a nuclear reactor overheated and released radioactive steam.
Evelyn Talbott, an epidemiologist at the University of Pittsburgh, studied what happened to 32,000 people who lived near that reactor.
"There was radiation leakage during the 10 days after the accident," Talbott says. "The exposure was an average of about 25 millirem, which is a couple of chest X-rays."
That's not much, though some scientists believe it may have been more. In any case, Talbott was part of a team who tracked the health of people in the area for decades.
"So the good news was after 20 years, we really didn't see any overall cancer increase, comparing the 32,000 people at Three Mile Island with the rest of the individuals in Pennsylvania," she says.
Keeping Radiation In Context
Experts say workers at the Fukushima plant probably won't be so lucky, but the Japanese public should be OK. It's important, though, to keep the problem of radiation in context.
Luis Echavarri, the director general of the Nuclear Energy Agency at the Organization for Economic Cooperation and Development, says the biggest problems in Japan are still the earthquake and the tsunami.
"The number of people killed by these natural events is rising and rising," Echavarri says. "So far the effects of the radiation on people have nothing to do with that."
The Japanese government has confirmed that more than 4,000 people died in the earthquake and tsunami, and many thousands more remain missing.