Officials in Kashiwa city in Japan's Chiba Prefecture said Saturday that they have detected a high level of radioactive cesium in the soil. About 276,000 becquerels of cesium per kilogram of soil was found below the surface following the detection of an abnormal level of airborne radiation earlier in the week.

Officials said they will conduct a full-scale investigation with the Science Ministry on Monday to find the cause of the cesium. It is still not clear if the damaged Fukushima nuclear plant was the source of the radiation.

Radiation hot spots have been spotted in the Tokyo metropolitan area prompting more calls to the Japanese government to carry out radiation decontamination measures. The latest cesium hot spot was discovered by a resident carrying a dosimeter. Earlier in the week, Tokyo's Adachi Ward detected a level of radiation of 3.99 microservierts per hour next to the machinery room of an elementary school pool.

Meanwhile, scientists at the International Pacific Research Center at the University of Hawaii at Manoa have detected debris from the March 11 Japanese tsunami. The Russian ship the STS Pallada spotted the tsunami debris shortly after passing Midway Islands.

"Yesterday, i.e. on September 22, in position 31 [degrees] 42,21 N and 174 [degrees] 45,21 E, we picked up on board the Japanese fishing boat. Radioactivity level - normal, we've measured it with the Geiger counter," wrote Natalia Borodina, information and education mate of the Pallada. "At the approaches to the mentioned position (maybe 10 - 15 minutes before) we also sighted a TV set, fridge and a couple of other home appliances."

The researchers at the University of Hawaii had been working for nearly six months on the computer model that would predict where the tsunami debris might end up. The new sightings have backed up the researchers' computer model exactly. Scientists now predict that the debris will arrive at the main Hawaiian Islands in two years and then hit the West Coast of North America in three years.

The 9.0 earthquake that devastated Japan on March 11 has been an environmental disaster that has far-reaching consequences. The radiation from the crippled Fukushima nuclear power plant will take decades to clean up. Millions of tons of debris have washed into the Pacific.