Thousands of Japanese citizens are dead or missing after last month’s devastating earthquake and tsunami, hundreds of thousands have lost their homes and Japan’s government and power company are still struggling to control three badly damaged nuclear power reactors.

As part of that struggle, authorities have been venting limited amounts of radioactive water into the ocean and radioactive gases into the air, and leaks exacerbated by explosions have spewed radioactive materials. People in Japan are rightly concerned. But, as of now, potential health risks appear to be limited in Japan and virtually nonexistent in the United States.
We stress “as of now.” Operators have still not been able to restore emergency cooling systems for the reactor cores and spent fuel pools. Nuclear fuel could still melt and release huge amounts of radioactive materials. Aftershocks pose a continuing threat. But the radioactive material that has been released so far — deliberately or accidentally — seems too small to pose a present danger.
Top officials from American health agencies said this week that Americans are in no danger from the trace amounts of radiation being detected in this country’s air, water or food supplies. Thomas Frieden, the director of the Centers for Disease Control and Prevention, said emphatically: “There is no threat to health in the U.S. from radiation coming from Japan.”
That means there is no reason for anyone here to take potassium iodide pills or any nostrums being peddled as protective. The Food and Drug Administration is testing food imports from Japan for traces of radiation just to be safe, and the Japanese government is banning or monitoring various food exports before they leave that country.
In Japan, the biggest radiation doses have hit workers within the plant. Beyond the plant boundaries, small amounts of radioactive material have fallen on land, but not enough to be an immediate health hazard. Much bigger amounts of radiation have been detected just off shore, although the levels appear to be diminishing and a major leak has been plugged.
The ocean should disperse and dilute radioactive materials to safe levels. However, a fish caught dozens of miles away from the plant was found to contain high levels of radioactive iodine, showing the potential for radiation to concentrate in marine life. Officials in Japan and around the globe will need to keep monitoring the air and water and the fish supply for many months, if not longer.
(Source: nytimes.com)