Fukushima Evacuees Screened for Radiation

March 13, 2011— -- Evacuees from the 13-mile-radius danger zone surrounding Japan's Fukushima nuclear plant are being screened for radiation.

Japanese health authorities confirmed that at least 22 people have been exposed to radiation following the hydrogen explosion at the plant's No. 1 reactor building early Saturday morning. Up to 160 more are suspected to have been exposed while waiting for evacuation in the nearby town of Futabe, according to Ryo Miyake, a spokesman from Japan's nuclear agency.

A cooling system malfunction at the plant's No. 3 reactor last night could lead to a similar explosion, but Yukio Edano, the nation's Chief Cabinet Secretary, said, "If there is an explosion, however, there would be no significant impact on human health," according to The Associated Press.

Workers wearing masks and protective clothing are using handheld scanners to measure radiation on the nearly 180,000 people who have fled the 450-square mile zone.

Officials have set up evacuation centers bordering the zone and are working to establish decontamination facilities.

Depending on the level of contamination, evacuees are being advised to dispose of clothing and shower.

"They're doing the same thing we would be doing," said ABC News chief medical editor Dr. Richard Besser. "They'll be monitoring them to see if they have radiation on them. They can decontaminate them."

Potassium iodide pills can help guard against thyroid cancer, Besser said.

Iodine is taken up by the thyroid -- a butterfly-shaped gland in the neck that produces hormones that regulate metabolism. Radioactive iodine in environment after a nuclear accident can cause thyroid cancer. But potassium iodide can block the radioactive iodine from entering the gland.

"One of the things after Chernobyl, you saw massive numbers of cancers in children. The radioactive iodine got into the grass, the cows ate the grass, it got into the milk," Besser said. "If there is a big fallout, they'll tell people not to drink milk or eat food from that area."

Children and pregnant women are most at risk, Besser said.