On the afternoon of the 15th, the people of Tokyo in Japan learned that Tokyo will begin to be exposed to radiation pollution and have left the urban areas one after another. Parents bring their children back home early. In the morning, the No. 2 and No. 4 units of the Fukushima Daiichi Nuclear Power Plant exploded in succession. The Japanese government acknowledged that the leakage of nuclear power plants was enough to harm human health. Tokyo has also monitored small radioactive substances that emit radiation that exceeds the standard by 20 times. According to data compiled by the Japanese Ministry of Education, Culture, Sports, Science and Technology on the 21st, radiation doses in the four counties in the northeast and the Kanto region have rebounded. However, due to the detection of excessive levels of radioactive substances in raw milk and vegetables produced in various counties, the Japanese government asked the four counties in Fukushima and Ibaraki to limit the listing of agricultural and livestock products. According to data released by the Ministry of Education, Culture, Sports, Science and Technology on the 21st, at 19:00 local time on the 20th, a radiation dose of 0.129 microsieverts per hour was temporarily observed in Yamagata Prefecture, which was the highest value after the accident at the Fukushima Daiichi nuclear power plant. In the monitoring from 17 o'clock on the 20th to 9 o'clock on the 21st, the highest dose of radiation was still in Ibaraki Prefecture, which was 0.493 microsieverts per hour, which was more than twice that of the previous statistics. The observations in Saitama Prefecture and Kanagawa Prefecture were 0.079 microsieverts per hour and 0.073 microsieverts per hour, respectively, all showing slight increases. According to a separate survey conducted by Fukushima Prefecture and Miyagi Prefecture, the radiation dose measured at 19:00 on the 20th in Fukushima City was 8.85 microsieverts per hour, and the value at 9:30 on the 20th in Sendai City was 0.18 microsieverts per hour. Decreased from the previous measurement. The impact of radioactive materials on Japan's environment and food safety continued to attract attention on the 21st. The Ministry of Education, Culture, Sports, Science and Technology said on the 21st that through testing samples of tap water collected from various places on the 20th, it was found that tap water in Ibaraki, Tochigi and Gunma contained radioactive iodine and radioactive cesium, Tokyo and Saitama, Chiba, Kanagawa, Niigata, and Yamanashi. Tap water in the prefecture contains radioactive iodine. Among them, Yamanashi Prefecture was tested for the first time. In addition, on the 21st, Fukushima Prefecture also detected radioactive iodine in the local tap water through a single test, but it was less radioactive than the previous day. The area where tap water detected radioactive substances increased from 9 on the 20th to 10 on the 20th. In Icheon-mura, Fukushima Prefecture, the activity of iodine activity per kilogram of tap water was measured at 965 becquerels, while the iodine activity per kilogram of drinking water set by the Japan Atomic Energy Safety Committee was 300 becquerels. The Japanese Ministry of Health, Labour and Welfare has urged local residents not to drink tap water. However, in the 21st test, the activity of iodine in tap water in Iidamura has dropped to 492 becquerels. Due to the recent rain and snow conditions in the disaster-stricken areas and surrounding areas, radioactive materials leaking into the air from nuclear power plants may fall along with rain and snow. The Ministry of Economy, Trade and Industry of Japan’s Atomic Energy Security Agency said on the 21st that residents around the radius of 20 km to 30 km of a nuclear power plant would be showered if they go out and get wet after showering. The used rain gear should be placed in a plastic bag and placed outside the house. However, the agency said that even if the radiation dose in rainwater is higher than usual, it will not affect health. The above measures are just in case. The neighboring countries and regions have also continued to closely monitor the spread of radioactive contaminants in Japan. Russian local media reported on the 21st that the Russian Defense Ministry has used six aircraft to monitor air radiation levels in the Russian Far East. The monitoring scope includes Primorsky Krai, Kamchatka Krai, Khabarovsk Krai and Sakhalin. As of the morning of the 21st, the radiation levels in the Far East regions are still in the normal range, and there are no radiation violations recorded in the 610 major fixed and mobile day/night monitoring stations in the Far East. A number of incidents of overdose of raw milk and vegetable radioactive substances were detected in recent days in Fukushima Prefecture and the surrounding area. The Japanese government’s Atomic Energy Countermeasures Headquarters headed by Prime Minister Naoto Kan was requested by the “Special Measures for Atomic Energy Countermeasures†on the 21st. In the four prefectures of Shima, Ibaraki, Tochigi, and Gunma, spinach and a kind of mustard were restricted, and raw milk in Fukushima Prefecture was also restricted. The Japanese Institute of Radiological Medicine said in this regard that due to the implementation of the restrictions on listing, excessive food will not be circulated in the market, so it will have no effect on consumers. If you are still not confident, cleaning, peeling, and discarding the leaves on the outside can help reduce the potential impact of radioactive materials. The Ministry of Health, Labor, and Welfare also said that after about 8 days, half of radioactive iodine will decay. In addition, it is a water-soluble substance, so cleaning is very effective. In view of the excessive radioactive material content of agricultural and livestock products, the Minister of Agriculture, Forestry, and Fisheries of Japan Lu Yeh-Dohiko said at a press conference on the 21st that it will cooperate with the Ministry of the Environment and other departments to investigate whether the soil of drylands and paddy fields is contaminated by radioactive substances.