No-one should take KI at this time
The US Embassy Japan indicates that its staffing level has increased by 30 percent because employees from across the US government have volunteered to come help at the mission. About 96 US government employees from outside of Japan have reportedly volunteered and are in the country to help provide assistance around the clock. In addition, the Department of Energy has 36 personnel and 12 Nuclear Regulatory Commission staff in Japan to focus on the nuclear plant incident. The authorized departure that was recently ordered only affected dependents of US personnel at limited posts in Japan, and all employees assigned in country are still there.
In its Fact Sheet dated March 22, 8:30 a.m. JST, the US Embassy was also careful to explain that the voluntary departure of dependents was taken "out of an abundance of caution" and that staffing level at the mission is larger now than it was prior to the earthquake.
Departure of Embassy Family Members: Given the extraordinary circumstances, the State Department and Department of Defense (DOD) on March 16 authorized the voluntary departure of eligible family members and non-emergency DOD civilians from Tokyo, Nagoya, Yokohama and the prefectures of Aichi, Chiba, Fukushima, Gunma, Ibaraki, Iwate, Kanagawa, Miyagi, Nagano, Niigata, Saitama, Shizouka, Tochigi, Yamagata, and Yamanashi. Separately, voluntary departure was authorized for eligible family members at Misawa AB (Aomori Prefecture). We took this step out of an abundance of caution, and in order to enable U.S. government officials and the uniformed military to concentrate on the tasks at hand. Our employees remain in country, and we are absolutely open for business – in fact, the number of people working at the Embassy now is much larger than before the earthquake due to the number of experts who have arrived from the United States to augment our operations in these difficult times. We look forward to our dependents returning to Japan once the situation has eased.Its updated Travel Warning for Japan dated March 21, the embassy also announced it has provided Potassium Iodide (KI) as a precautionary measure for United States Government personnel and dependents residing in certain districts but that "No-one should take KI at this time."
This Travel Warning replaces the Travel Warning dated March 18, 2011, in response to the situation at the Fukushima Daiichi Nuclear Power Plant, the United States Nuclear Regulatory Commission (NRC), the Department of Energy, and other technical experts in the U.S. Government have reviewed the scientific and technical information they have collected from assets in country, as well as what the Government of Japan has disseminated. Consistent with the NRC guidelines that would apply to such a situation in the United States, we are recommending, as a precaution, that U.S. citizens within 50 miles (80 kilometers) of the Fukushima Daiichi Nuclear Power Plant evacuate the area or to take shelter indoors if safe evacuation is not practical.
On March 21, 2011, consistent with NRC guidelines that apply to such a situation in the United States, the U.S. Government is making available Potassium Iodide (KI) as a precautionary measure for United States Government personnel and dependents residing within Nagoya (Aichi Prefecture), Tokyo (Tokyo Capital Region), Yokohama (Kanagawa Prefecture), and the prefectures of Akita, Aomori, Chiba, Fukushima, Gunma, Ibaraki, Iwate, Miyagi, Nagano, Niigata, Saitama, Shizouka, Tochigi, Yamagata, and Yamanashi. The KI should only be consumed after specific instruction from the United States Government. While there is no indication that it will become advisable to take KI, out of an abundance of caution the United States Government is making it available to its personnel and family members to be used only upon direction if a change in circumstances were to warrant. No-one should take KI at this time. In the event of a radiological release, sheltering in place or departing the affected area remain the primary means of protection.
CDC: Potassium Iodide (KI) | Key Facts
- You should only take potassium idodide (KI) on the advice of emergency management officials, public health officials, or your doctor.
- There are health risks associated with taking KI.
Following a radiological or nuclear event, radioactive iodine may be released into the air and then be breathed into the lungs. Radioactive iodine may also contaminate the local food supply and get into the body through food or through drink. When radioactive materials get into the body through breathing, eating, or drinking, we say that “internal contamination” has occurred. In the case of internal contamination with radioactive iodine, the thyroid gland quickly absorbs this chemical. Radioactive iodine absorbed by the thyroid can then injure the gland. Because non-radioactive KI acts to block radioactive iodine from being taken into the thyroid gland, it can help protect this gland from injury.
What KI cannot do?
Knowing what KI cannot do is also important. KI cannot prevent radioactive iodine from entering the body. KI can protect only the thyroid from radioactive iodine, not other parts of the body. KI cannot reverse the health effects caused by radioactive iodine once damage to the thyroid has occurred. KI cannotprotect the body from radioactive elements other than radioactive iodine—if radioactive iodine is not present, taking KI is not protective.
How does KI work?
The thyroid gland cannot tell the difference between stable and radioactive iodine and will absorb both. KI works by blocking radioactive iodine from entering the thyroid. When a person takes KI, the stable iodine in the medicine gets absorbed by the thyroid. Because KI contains so much stable iodine, the thyroid gland becomes “full” and cannot absorb any more iodine—either stable or radioactive—for the next 24 hours.
Iodized table salt also contains iodine; iodized table salt contains enough iodine to keep most people healthy under normal conditions. However, table salt does not contain enough iodine to block radioactive iodine from getting into your thyroid gland. You should not use table salt as a substitute for KI.
Read more here.