Officials clad in protective gear scan a man for radiation near the quake-damaged Fukushima Daiichi nuclear power plant on Wednesday. (Gregory Bull / AP)

The U.S. Postal Inspection Service, which investigates mail-related crimes, and U.S. Customs and Border Protection are establishing procedures to detect and analyze any items that may contain harmful levels of radiation. CBP routinely screens mail for radiation.

“Currently, there have been no items detected that would be deemed hazardous,” according to a statement by the inspection service. “American citizens should feel comfortable with these security measures that ensure the safety and security of their mail.”

(Hawaiian news outlets reported late Wednesday that USPS had begun checking mail for radiation levels after mail sent to San Francisco and New York showed elevated levels of radiation. Sources did not immediately independently confirm those reports.)

Japan is still accepting international mail, but USPS warned Wednesday that deliveries to and from parts of the country may face delays in the coming weeks the historic 9.0-magnitude earthquake.

The Japanese postal system is generally regarded as one of the world’s most advanced and sells some goods and services not directly-related to the mail. U.S. postal officials often cite it as a model for what USPS could become if lawmakers ever allowed post offices to sell non-mail products.

The Postal Service handles about 40 percent of the world’s mail volume, about five times more than the Japanese service, according to postal experts.

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