The Ministry of Health and Welfare also announced the new guideline (link in Japanese) for 3 types of cancer (stomach, esophagus, colon) for evaluating the application for workers' compensations from radiation workers:
Cumulative radiation exposure of 100 millisieverts or more;
5 years or more from the start of the work and the onset of the disease.
Applying this new guideline, Mr. Masao Yoshida, ex-plant manager of Fukushima I Nuclear Power Plant who developed an esophagus cancer will not qualify. His cumulative radiation exposure is supposed to be 70 millisieverts, and his health check prior to the accident didn't reveal he had a cancer.
From Nikkei Shinbun (9/28/2012):
Ministry of Health and Welfare announces guideline for evaluation of workers' accident compensations when workers develop cancer in the course of radiation work
On September 28, the Ministry of Health and Welfare announced the guideline for evaluation of three types of cancers, stomach, esophagus, and colon, when evaluating the applications for workers' accident compensations by radiation workers at nuclear power plants and medical facilities. The main points in the guideline include 'cumulative radiation exposure of 100 millisieverts and higher', '5 years or more between the start of the work and the onset of the cancer. There was no guideline for these cancers to determine the relationship between the radiation work and the onset of the diseases.
Upon receiving the application from two people who claim they developed cancer because of their work at nuclear power plants, the Ministry's committee compiled the guideline from the past epidemiological studies. One person developed two types of cancer, and submitted the application on December 2009. The other person developed one type of cancer, and submitted the application in February last year. The Ministry hasn't disclosed the name of the cancer or whether the applications have been approved or not.
The Ministry also disclosed that a worker who had worked in the restoration work during the Fukushima I Nuclear Power Plant accident submitted the application for workers' compensation this month, claiming he developed a cancer. According to the Ministry, it is the first time that a worker at Fukushima I Nuclear Power Plant has submitted the application because of cancer after the March 11, 2011 disaster.
In case of workers at nuclear power plants, particularly those workers who hop from one plant to another doing maintenance work, cumulative radiation exposure of 100 millisieverts may not mean much at all, because the official numbers on their radiation worker handbooks may not mean much at all. But when it comes to official compensations, what matters is what's officially on the books, and their claims may be rejected as the "official" numbers may be well below 100 millisieverts.