‘Low levels’ of Japan’s radiation reach suburbs

Low levels of radiation from Japan have been discovered in test samples taken in unincorporated DuPage and Will counties, officials said Tuesday.

Warrenville-based Exelon Nuclear said small amounts of radioiodine 131, a type of radioactive isotope associated with the troubled Japanese plants, were discovered March 22 during testing at Dresden, its nuclear plant near Morris in Will County.

Also, Argonne National Laboratory, near Darien, found a small amount of the isotope in its regular air test samples last week.

“You wouldn’t find that kind of evidence in normal operations here,” said Marshall Murphy, a spokesman for Exelon Nuclear.

The amount is low and not considered harmful to humans, crops or the water supply, but samples here indicate how the catastrophe from Japanese nuclear reactors has reached the United States, experts said.

Various amounts of radioiodine 131 have been discovered along the West and East coasts, as well as in Ohio, South Carolina, Alabama and now Illinois.

Exelon said the positive sample had “very low levels, which is not unusual, considering what’s happening in Japan,” Murphy said.

The U.S. Environmental Protection Agency and the U.S. Nuclear Regulatory Commission are monitoring the radioiodine 131 discoveries nationwide.

At Argonne, regular air tests indicated a spike in radioiodine 131 last week, said S.Y. Chen, senior environmental systems engineer at Argonne.

He said that when this isotope travels, it begins to decay after eight days. So it’s not expected to cause any problems with our water and food supplies, he said.

“It is very minuscule, not even on the level of a chest x-ray,” Chen said.

Also, other organizations that ordinarily test precipitation for chemicals have stepped up their efforts as well.

One such testing network includes the National Atmospheric Deposition Program based at the University of Illinois in Champaign, which has taken more samples of precipitation around Illinois, including near DeKalb. It has about 300 sampling locations in North America.

Samples are then sent to the U.S. Geological Survey, part of the Department of the Interior.

Results aren’t yet in, but program coordinator David Gay suspects some radioiodine 131 could be found in Illinois samples.