About 1,300 deaths and 2,500 cases of cancer could be caused worldwide by last year’s nuclear accident in Japan, U.S. researchers concluded.

Most of the cases would occur in Japan, the research team at Stanford University said, contradicting previous claims that Japan’s nuclear crisis will not result in serious health effects.

Only extremely small effects will be felt outside Japan, mainly in mainland Asia and North America. In the U.S., for example, only 0 to 12 deaths and 0 to 30 cancer cases may be recorded in relation to radiation from the Japanese accident.

The study should “serve to manage the fear in other countries that the disaster had an extensive global reach,” one of the authors said.

The scientists used a global atmospheric model to calculate how the radioactive material released by the Fukushima plant is transported. Their study was published in the Energy and Environmental Science journal, on July 17.