Japan Raises Radiation Dose Safety Limit for Nuclear Emergency Workers

Even in the best case scenario available at this point, all workers at Fukushima 1 and 2 battling to save the lives of others must have already suffered great harm to their health, and the harm is about to become greater. — Ed.

Japan’s Ministry of Health, Labor, and Welfare has determined that the existing national safety standard that limits radiation dose makes it impossible to extract enough work time from the workers employed to cool down the nuclear reactors at the Fukushima 1 Nuclear Power Plant.  The ministry has decided that, in the event of emergency, the safety limit is to be 250 millisieverts, 2.5 times the previous limit.

At Fukushima 1, the level of radiation is 400 millisieverts per hour.  The previous limit of 100 millisieverts means that workers can work for only 15 minutes; the new limit of 250 millisieverts means that they can work for 30 minutes.

The ministry explained that “this is an emergency measure, taken in response to the Prime Minister’s request, to prevent this nuclear disaster from escalating.”

Radiation’s effects on health are measured in sieverts.  Though individual differences exist, a higher dose than 250 millisieverts is known to cause a temporary decrease of white blood cells and other acute symptoms.  Regarding that problem, the ministry says that it has duly consulted experts about effects on the workers, noting that “the international standard is a limit of 500 millisieverts, and there is no clear medical evidence for acute health problems below 250 millisieverts.”

The text above combines and translates information from an article published by NHK (16 March 2011, 01:26) and an article published by Nikkei (15 March 2011, 23:48).  Translation by Yoshie Furuhashi (@yoshiefuruhashi | yoshie.furuhashi [at] gmail.com).

var idcomments_acct = ‘c90a61ed51fd7b64001f1361a7a71191’;
var idcomments_post_id;
var idcomments_post_url;

| Print