(来源：http://www.EnglishCN.com)

Japan crisis spikes demand for radiation pills

日本大地震及海啸引发核泄露事故后，与受灾地区相邻的国家和地区近日出现了抢购碘化钾（即“碘片”）的热潮。美国多家药店碘片脱销，主要供应商也不断接到订单和求购电话。在俄罗斯，因为25年前切尔诺贝利事件仍让人心有余悸，药店中的碘片也被人抢购一空。美国和加拿大的卫生部门表示，人们无需储备大量碘片，而且人们对碘片的用途也存在很多误区，它其实并不属于防辐射药物，而只是能够防止辐射性碘引发甲状腺癌。美国核管理委员会主席称，放射性物质漂洋过海到达美国时威力已大减，民众不用担心被辐射。

碘片小知识

碘化钾，俗称碘片，其唯一用途就是防止放射性碘进入甲状腺。碘片不能防止其它类型的辐射，也无法保护身体其它部位免受辐射。

碘化钾有药片和液体两种形态，均为非处方药，部分人服用后会有过敏症状。

碘化钾对儿童和怀孕女性尤其重要，因为发育中的甲状腺更活跃也更容易吸收辐射性碘，应在被辐射后几小时内服用，不过对40岁以上的人药效并不明显。

Japan's nuclear crisis is spiking demand in the U.S. and a few other places for a cheap drug that can protect against one type of radiation damage — even though the risk is only in Japan.

Health agencies in California and western Canada warned Tuesday that there's no reason for people an ocean away to suddenly stock up on potassium iodide. Some key suppliers say they're back-ordered and are getting panicked calls from potential customers.

"Tell them, `Stop, don't do it,'" said Kathryn Higley, director of radiation health physics at Oregon State University.

"There's a lot of mythology about the use of potassium iodide," added Dr. Irwin Redlener, a pediatrician and disaster preparedness specialist at Columbia University. "It's not a radiation antidote in general."

The pill can help prevent radioactive iodine from causing thyroid cancer, for which children are most at risk in a nuclear disaster.

Japan's Nuclear Safety Agency has stored potassium iodide to distribute in case of high radiation exposure, and the U.S. Navy is giving it to military crews exposed to radiation as they help with relief efforts in Japan. But government and independent experts say that Americans have little to fear from any radiation released by the damaged Japanese nuclear plant.

"You just aren't going to have any radiological material that, by the time it traveled those large distances, could present any risk to the American public," said Nuclear Regulatory Commission Chairman Greg Jazcko.

Other governments echoed that warning.

"We do not expect any health risk following the nuclear reactor releases in Japan, nor is the consumption of potassium iodide tablets a necessary precaution," British Columbia's health ministry told the public Tuesday.

In Russia, where memory of the very different Chernobyl disaster 25 years ago is strong, media reports said pharmacies in Vladivostok, a major port just west of Japan, had run out of the pills.

What does this drug do?

Potassium iodide, a salt also known as KI, has just one use: It shields the thyroid from radioactive iodine. It blocks no other type of radiation, and protects no other body part.

The drug, either pill or liquid form, is sold over-the-counter and is considered safe, although some people may experience allergic reactions.

Potassium iodide is most important for children and pregnant women, because a growing thyroid is much more active and more likely to absorb radioactive iodine, said Columbia's Redlener. It should be given within a few hours of radiation exposure — but isn't considered that useful for people over age 40.