May 5 is Children’s Day, a Japanese national holiday that celebrates the happiness of childhood. This year, it will fall under a dark, radioactive shadow.
Japanese children in the path of radioactive plumes from the crippled nuclear reactors at the Fukushima Dai-Ichi power station are likely to suffer health problems that a recent government action will only exacerbate.
On April 19, the Japanese government sharply ramped up its radiation exposure limit to 2,000 millirem per year (20 mSv/y) for schools and playgrounds in Fukushima prefecture. Japanese children are now permitted to be exposed to an hourly dose rate 165 times above normal background radiation and 133 times more than levels the U.S. Environmental Protection Agency allows for the American public. Japanese school children will be allowed to be exposed to same level recommended by the International Commission on Radiation Protection for nuclear workers. Unlike workers, however, children won’t have a choice as to whether they can be so exposed.
This decision callously puts thousands of children in harm’s way.
Experts consider children to be 10 to 20 times more vulnerable to contracting cancer from exposure to ionizing radiation than adults. This is because as they grow, their dividing cells are more easily damaged — allowing cancer cells to form. Routine fetal X-rays have ceased worldwide for this reason. Cancer remains a leading cause of death by disease for children in the United States.
On April 12, the Japanese government announced that the nuclear crisis in Fukushima was as severe as the 1986 Chernobyl accident. Within weeks of the 9.0 earthquake and tsunami, the four ruined reactors at the Dai-Ichi power station released enormous quantities of radiation into the atmosphere.
According to the Daily Youmiri, Japan’s Nuclear and Industrial Safety Agency (NISA) announced that between 10 and 17 million curies (270,000- 360,000 TBq) of radioactive materials were released to the atmosphere before early April, a great deal more than previous official estimates.
Even though atmospheric releases blew mostly out to sea and appear to have declined dramatically, NISA reports that Fukushima’s nuclear ruins are discharging about 4,200 curies of iodine-131 and cesium-137 per day into the air (154 TBq). This is nearly 320,000 times more than d radiation the now de-commissioned Connecticut Yankee nuclear power plant released over a year. NISA’s estimate is likely to be the low end, given the numerous sources of unmeasured and unfiltered leaks into the environment amidst the four wrecked reactors. On April 27, Bloomberg News reported that radiation readings at the Dai-Ichi nuclear power station have risen to the highest levels since the earthquake.
With a half-life of 8.5 days, iodine-131 is rapidly absorbed in dairy products and in the human thyroid, particularly those of children. Cesium-137 has a half-life of 30 years and gives off potentially dangerous external radiation. It concentrates in various foods and is absorbed throughout the human body. Unlike iodine-131, which decays to a level considered safe after about three months, cesium-137 can pose risks for several hundred years.
Measurements taken at 1,600 nursery schools, kindergartens, and middle school playgrounds in early April indicate that children are regularly getting high radiation doses. Radiation levels one meter above the ground indicate that children at hundreds of schools received exposures 43- 200 times above background. And this is outside of the “exclusionary zone” around the Dai-Ichi reactors, where locals have been evacuated. Japan’s Ministry of Education and Science has limited outdoor activities at 13 schools in the cities of Fukushima, Date, and Koriyama Cities.
Although the extent of long-term contamination is not yet fully known, disturbing evidence is emerging. Data collected 40 kilometers from the Fukushima’s nuclear accident show cumulative levels as high as 9.5 rems (95 mSv) — nearly five times the international annual occupational dose. Soil beyond the 30-kilometer evacuation zone shows cesium-137 levels at 2,200 kBq per square meter — 67 percent greater than that requiring evacuation near Chernobyl.
Three-fourths of the monitored schools in Fukushima had radioactivity levels so high that human entry shouldn’t be allowed, even though students began a new semester on April 5.