According to the scientists, thecloud may exist in Southeast Asia within several days withradionuclide concentrations decreasing with every passing day.
The most powerful radioactive cloud is expected to disperse rapidly on April 9 and 10.
Earlier, MoST said even if the cloud covers Vietnam, the radiationlevel would increase by only 100 times from the previously-detectedlevel. This means that the observed concentration of radiation is atseveral thousands of micro Bq per cubic metre, thousands of times lowerthan the limit stipulated by the Vietnamese standards.
By15:00, April 9, apart from the recognition of the natural radioactiveisotopes, the observation stations in Da Lat and Ninh Thuan alsodiscovered radioactive I-131.
In Ho Chi Minh City , the radioactive isotopes I-131, Cs-134 and Cs-137 were recorded.
"Theradioactive isotopes recorded at the three above-mentioned locationsare at low level, and do not pose a threat to human health and theenvironment," according to the report.
Cs-134 was found inthe pine needle samples (which are often used to indicate radioactivepollution in the atmosphere and vegetation) in addition to the isotopesBe-7, K -40, U-238, Th-232 and Cs-137 but the level of Cs-134 was verylow and does not affect human health./.