It’s the latest evidence that the health and environmental effects of the Fukushima nuclear-power-plant accident will be devastating and long-lasting. After a review of data on the amount of radiation leaked by the damaged plant following the March 11 earthquake and tsunami, Japanese nuclear-safety officials raised their assessment of the crisis to Level 7, the highest ranking on an international scale of nuclear-incident severity–which puts the Fukushima disaster on par with the Chernobyl explosion in 1986
