Five of the six biggest container shippers are maintaining routes to Tokyo and Yokohama after the U.S. Navy said radiation on vessels from the leaking Fukushima Dai-Ichi nuclear plant can be scrubbed off with soap and water.

A.P Moeller-Maersk A/S, Mediterranean Shipping Co. and CMA CGM SA, the top three, are still serving Japan’s two busiest container ports, 2 1/2 weeks after an earthquake and tsunami damaged the Fukushima plant, 220 kilometers (135 miles) to the north. Among the top six shippers, only Hapag-Lloyd AG, the No. 4, is diverting vessels to docks in the south of the country.

The Japanese government is allowing ships to sail as close as 30 kilometers to the stricken reactors, and the International Maritime Organization, a United Nations agency, says operations in and out of Japan can continue as normal, with levels of radiation presenting no medical basis for imposing restrictions.

“These are extremely low levels and are easily cleaned off,” Commander Jeff Davis, a spokesman for Seventh Fleet, which is helping with recovery efforts, said by yesterday by telephone. “Even if they weren’t, they still wouldn’t rise to the level where they would cause any harm to human health.”

Tokyo port, which accounted for 22 percent of Japanese container throughput last year, according to market researcher Alphaliner, has tried to ease fears through steps including posting information about radiation readings. Levels were safe as of March 27, according to the Transport Ministry’s website.

Sales of radiation-detection devices to companies shipping cargoes to and from Japan have increased, U.K.-based safety- equipment supplier International Mining & Marine Ltd. said.

Source:  Bloomberg.