Updated: High Demand for Anti-Radiation Pills in San Juan

Updated at 2:40 p.m. win information from Michael Cantor.

There's been a surge in the number of people calling into City Hall looking for potassium iodide, a pill that is said to protect against the radiation some fear could be coming their way from Japan.

"I just spoke with Michael Cantor [the city's emergency services coordinator], and apparently the city has gotten tons of calls from people wanting the KI," said San Juan Capistrano spokeswoman Kelly Tokarski. "All they have have to do is call the city to get it."

Potassium iodide is a salt—the chemical symbol is KI—similar to table salt. It can be used to protect the human thyroid gland from radioactive iodine.

"I think because of all the media and TV, [the callers] want to get the KI, because they’re concerned about nuclear radiation fallout from Japan," Cantor said.

The calls began pouring in on Friday. "We have a certain supply right now, and we're getting an additional supply tomorrow," he said.

The U.S. Nuclear Regulatory Commission officials have said that the country is not expected to experience any harmful levels of radioactivity from the nuclear power plant explosions in Japan, but pharmacies up and down the West Coast "have been stripped bare of their stock," due to the high demand, the Huffington Post reports.

The pills are a commercial product that are available over the counter, so residents should also be able to pick up the pills at their neighborhood pharmacy, the California Department of Public Health said. The Rite Aid locations here in San Juan, however, do not carry them.

in Laguna Niguel and filled about half since Tuesday.

In late 2009, a supply of KI was made available to to all states with . San Juan Capistrano, San Clemente and Dana Point distributed the pills in the mail and recommended they be included in emergency supply kits.

The supply at San Juan Capistrano's City Hall is only available to residents, Tokarski said.

Potassium iodide, if taken within the appropriate time and at the appropriate dosage, blocks the thyroid gland's uptake of radioactive iodine and thus reduces the risk of thyroid cancers and other diseases that might otherwise be caused by thyroid uptake of radioactive iodine that could be dispersed in a severe reactor accident.

According to the Centers for Disease Control, when the pills are ingested, "the stable iodine in the medicine gets absorbed by the thyroid. Because [potassium iodide] contains so much stable iodine, the thyroid gland becomes 'full' and cannot absorb any more iodine—either stable or radioactive—for the next 24 hours."