Drumbeat of Nuclear Fallout Fear Doesn’t Resound With Experts

Original Article:

http://www.nytimes.com/2011/05/03/sciencehttp://www.blogger.com/img/blank.gif/03radiation.html?src=recg

Snippets:

The nuclear disaster in Japan has sent waves of radiation and dread around the globe, prompting so many people to buy radiation detectors and potassium iodide to fend off thyroid cancer that supplies quickly sold out.

The fear is unwarranted, experts say. People in Japan near the Fukushima Daiichi nuclear power plant may have reason to worry about the consequences of radiation leaks, scientists say, and some reactor workers, in particular, may suffer illness. But outside of Japan, the increase is tiny, compared with numerous other sources of radiation, past and present.

In the world’s oceans, thousands of decomposing drums of radioactive waste pose bigger dangers than the relatively small amounts of radioactive water released from the Fukushima Daiichi plant. And natural radiation from rocks, cosmic rays and other aspects of the environment, experts say, represents the biggest factor of all — far bigger than all the man-made emissions, including the current increase from the crippled Japanese reactors.

Dr. Dale Dewar, executive director of Physicians for Global Survival, a group that advocates the abolition of nuclear arms, said the accident meant future generations would live in a world with higher levels of background radiation.

During the cold war, for example, more than 500 detonations pumped the global atmosphere full of deadly radioactive materials, some of which are still emitting radiation.

Figures from the United Nations put the total bomb radiation from decades of atmospheric testing at almost 70 billion curies. By contrast, the 1986 accident at the Chernobyl nuclear power plant released about 100 million curies of the most dangerous materials.

As for Fukushima Daiichi, Japanese officials said on April 12 that the reactor complex had released about 10 million curies. In 1979, the reactor accident at Three Mile Island released about 50 curies into the environment.

Additionally, many experts say, the threat to the Japanese people is probably low because — unlike the radioactive fallout from the cold war and the Chernobyl accident — most of the radiation is believed to have blown out to sea on the prevailing winds.

The ocean has received many radiological blows over the decades. From 1946 to 1994, when the practice was banned, governments around the globe dumped many thousands of drums of radioactive waste into the abyss, as well as reactors and derelict submarines.

Scientists estimate the dumping in total involved about four million curies of radioactive materials, with the Soviet Union doing a vast majority of the disposal. Decay has lowered the level of that radiological threat over the decades, even as the rotting of drums and barrels has raised the risk of environmental contamination.

At a nuclear dump site near the Farallon Islands off San Francisco, surveys have revealed many fractured drums and evidence that some radioactive materials have spread to sea life. The Environmental Protection Agency found that sponges bore “readily measurable” amounts of plutonium 239 and plutonium 240 — types of man-made radioactive materials that seldom exist in nature. The former has a half-life of 24,360 years, and the latter 6,560 years.