March 15, 2011
As authorities work to avoid a full meltdown at the Fukushima Daiichi power plant, where a second explosion occurred this morning and where three of four nuclear reactors are now experiencing severe cooling problems, potentially harmful radiation has already been introduced to the surrounding environment. There’s still a good deal that’s uncertain about how the situation will play out, but here’s where things stand now.
According to Ron Chesser, director of the centre for Environmental Radiation Studies at Texas Tech University, both of those levels are technically safe for humans, who absorb an average of 360 millirems of radiation per year from cosmic rays and manmade sources. Still, three elements in particular – iodine-131, strontium-90 and cesium-137 – are worrisome because they mimic substances found naturally in the body.