Low Radiation Levels Found in U.S. Rainwater

Radiation from the Soviets’ stricken Chernobyl nuclear plant is now showing up in rainwater in the United States, but at levels that do not pose health concerns, U.S. officials said Tuesday.

Government monitors found Monday that rainwater in Oregon and Washington contained radioactive iodine-131, which can accumulate in the thyroid gland and--at doses substantially higher than the amounts detected--eventually cause cancer.

At the levels found, a person would have to drink more than a quart of the rainwater to get a radiation dose of half the amount received from a chest X-ray.

“We think we’ll see, over the next number of subsequent days, those readings become more widespread across the country,” Environmental Protection Agency Administrator Lee M. Thomas said. He added that the readings are “way, way, way below anything that would trigger” government health warnings.

“But if for some reason those levels went up--and we don’t have anything to indicate that they would--we have protective action standards that have been established,” Thomas said.

No Abnormal Radiation

In California, no abnormal radioactivity levels were detected Tuesday, according to Kenneth W. Kizer, director of the Department of Health Services.

“There has been no increase in radiation in California at all, nor do we expect any in the future,” Kizer said in press briefings in Berkeley and Sacramento.

There are 18 monitoring sites around the state, up from the normal 12 because of the Chernobyl accident. Readings are reported each morning.

Government monitors detected the radiation in Portland, Ore., and Richland, Wash., at levels of 630 and 500 picocuries per liter, respectively. But contamination of milk, for example, would not be a concern unless the level reached 15,000 picocuries per liter, officials said. John A. Norris, deputy commissioner of the Food and Drug Administration, predicted that the level in milk will reach only about 50 picocuries per liter.

‘Prefer Not to Drink It’

Dr. Donald Ian Macdonald, acting assistant secretary for health for the Department of Health and Human Services, was pressed at a news conference to say whether he would drink the rainwater at the level of contamination now detected.

“It really depends on how thirsty I was,” Macdonald said. “I would drink it.” He added: “I would prefer not to drink it. I would prefer to have a zero level” of radiation.

Government aircraft discovered patches of radioactive clouds at high altitudes off the West Coast on Sunday, and the contamination showed up in the rainwater Monday. Officials say they do not yet have a complete analysis of the samples to determine what other isotopes, in addition to iodine-131, are present.

Patches of more concentrated radioactivity at lower altitudes remain over the Pacific and will reach the West Coast in the next few days, officials said.

Higher Readings Possible

Lester Machta, director of the National Oceanic and Atmospheric Administration’s air resources laboratory, said he would “not be surprised” if higher readings are eventually detected in the United States.

But he noted that there is no way to determine how much the patches may dissipate before they arrive. While the cloud was over Japan, samples of rainwater were found to have 10,000 picocuries per liter of iodine-131.

So far, Machta said, the radioactive cloud patches have moved from the West Coast to as far east as Michigan.

Officials in the Energy Department, meanwhile, announced that in response to the Chernobyl accident they will accelerate technical safety appraisals of five plutonium-producing reactors that do not have containment buildings.

Safety Review Panel

Energy Secretary John S. Herrington established a special safety review panel to examine the safety of the department’s nuclear reactor near Richland, Wash. Herrington said the graphite-moderated reactor is the only department reactor with “design characteristics even remotely similar” to the Chernobyl plant.

In testimony before a House subcommittee, Energy Under Secretary J. F. Salgado said a scheduled evaluation of the four other department reactors at the Savannah River will start in September rather than in December, as was initially planned.

Salgado told the House Energy and Water Appropriations subcommittee on nuclear safety that the department believes that the five reactors are safe even though they do not have containment walls.