To date the consensus of Japanese health officials is that the long-term health effects on residents and workers will be yet to be determined, although 1331 elderly people have recently died from "stress-related" illnesses connected to the event. According to the Associated Press areas outside the 20-kilometer evacuation zone receive an annual exposure of 20-50 millisieverts easily approaching the 50 millisievert limit for nuclear workers. A "Sievert", named after Rolf Sievert (a Swedish scientist), is a unit of measurement designated to measure the effects of radiation on biological organisms. Lewis Pepper, an occupational health physician at the Queens College of New York stated in an interview for Discovery News, "It's a low dose", but goes on to say, "There is no safe level. The model which addresses radiation risk and cancer suggests there is no threshold beneath which there is no risk." Heart attacks and pneumonia, caught from living in unclean evacuation shelters, are cited as the main cause the recent stress-related deaths. Eric Niiler of Discovery News writes, "In Japan, radioactive iodine-131 released from the plant dissipated fairly quickly since it has a half-life of only eight days. But cesium-137 -- another particle emitted during the nuclear fuel cycle -- has a 30-year half-life and is likely still in the environment, Pepper said. For people living nearby, "there remains a chronic risk from food exposure, from the vegetables or animals which eat that radiation and which people consume," he said. Cesium collects in the bones and can lead to various forms of leukemia or bone cancers. According to Pepper the ocurrence of these cancers won't be known for years to come. But perhaps worse is the rise in stress-related deaths that experts are noticing in survivors of the disaster, even those who left to start new lives beyond the danger zone." To put it in comparable terms half the amount of people have died from the stress of the event of Fukushima as did in the September 11th, 2001 attacks on New York City, still a huge amount of casualties in proportion to the population of Fukushima (pre-disaster). In a July 6th, 2011 Situation Report (Report No. 35), the World Health Organization reported the following casualties: Total deaths: 15,534 Missing Persons: 7092 Most of the deaths occurred in the Miyagi (9293), Iwate (4575), and Fukushima (1600) prefectures. To complicate matters medical personnel are leaving the area permanently in hordes. According to Kazuhira Maehara, head of the Fukushima prefecture's hospital association in an interview with the Mainichi Daily News, "There are many cases in which medical personnel are moving out of the prefecture even if they want to stay (because of their family member's desire to leave.)" Some estimates point to 152 doctors having quit between March & December of 2011. Three changes in nuclear policy have been brought about by this disaster: Reactors will no longer share emergency exhaust stacks ( a flaw that led to reactor number four to be destroyed) All 104 U.S. reactors will now be required to have back-up diesel generators and pumps. Older U.S. reactors like the one at Fukushima will have to build new vent stacks to prevent the type of explosion that happened in Japan. Read more of Eric Niiles article HERE.