Free Republic

Japan’s broken nuclear reactors will have no detectable effect on the health of Americans. If it’s not one thing, it’s another as the Japanese nuclear power plant crisis nears the end of its second week. The most recent news is that radioactive elements appear to be leaking out of a couple of the partially melted-down reactors. Tests show that seawater off the plant site has elevated amounts of radioactive iodine, while others have found traces of plutonium isotopes in the soil around the plant sites. Meanwhile, some workers have been exposed to dangerously high levels of radiation as they work...

Japan's unfolding nuclear disaster has introduced Americans to the confusing practice of measuring radiation exposure. According to some stories, the water nearby to the No. 2 Fukushima reactor has a radioactivity level of 1,000 millisieverts per hour. But other articles describe radiation levels in terms of millirem per year. And a few sources have referred to exposure in terms of millirad or nanogray per hour. Why don't all radiation experts just use the same unit? Because some people are afraid to switch to the metric system. As with distance, weight, and temperature, doses of radiation can be expressed in either...