Several states have reported finding Iodine-131 in surface water (e.g., lakes, rivers, and reservoirs) and rain water. What does this mean for the public’s health?
Highly sensitive radiation monitors operated by EPA and others have detected very low levels of radioactive material in the air in the United States. These levels are consistent with estimated releases from the damaged nuclear reactors.
These findings were expected, given the sensitivity of our monitors and the fact that radioactive material is known to travel in the atmosphere. Federal, state, and local authorities will continue to monitor levels.
Will contaminated rainwater hurt me? Is it okay for my kids to play in the rain?
The very low levels of radioactive material currently being measured in surface water and rain water are far below those of public health concern.
Is it okay for my pet to drink the rainwater?
Drinking rainwater contaminated with radioactive material at the levels currently being detected is unlikely to harm your pet.
Since contaminated rain may have fallen in my area, is it okay to eat food from my garden or use rain water to irrigate it?
Yes. Keep in mind that it is always a good idea to wash food from your garden before you eat it.
Are there any groups of people that should be especially sensitive to radiation?
Infants, pregnant women and women who are breastfeeding are particularly sensitive to radiation. However, levels being measured now are still many times below the risk for even these groups, even for people who drink rainwater. Drinking water levels are many times below this. At this time, there is no need to take extra precautions with regard to drinking water.
Is it okay to take a shower or bath? Swim in a pool? In a river or lake?
Showering, bathing, or swimming in water with the amount of radioactive material that is currently being measured will not harm your health.
Should I drink bottled water instead of tap water?
At this time, there is no reason to switch to bottled water. State and local authorities will provide information for your community if this situation changes.
Should I be testing my water?
At this time, there is no need to take extra precautions with regard to drinking water.
States and the federal government routinely conduct water monitoring for safety and are working to ensure that drinking water does not pose a health risk to people in the US.
Is this likely to be a long-term problem?
Given the uncertainty related to the nuclear reactors in Japan, we don’t know how levels of radiation currently seen in surface water and rain water will change in the immediate time period. However, we do know that Iodine-131 disappears relatively quickly in the environment.
Who can I contact for the best information about my community?
The best source of information about your community is your local drinking water program or department, or your state environmental protection division or program.
Content source: Radiation Studies Branch (RSB), Division of Environmental Hazards and Health Effects (EHHE), National Center for Environmental Health (NCEH), Coordinating Center for Environmental Health and Injury Prevention (CCEHIP)
UPDATE (Apr 7) -TEPCO Completes Nitrogen Injection At Unit 1
An operation to reduce the risk of a hydrogen explosion at the crisis-hit Fukushima Daiichi atomic power station’s No. 1 reactor by injecting it with nitrogen has gone smoothly, the plant’s operator Tokyo Electric Power Co. said Thursday. Pressure in the reactor’s containment vessel has risen as expected, indicating the success of the operation.
In its operation to prevent a hydrogen explosion at the No. 1 reactor, TEPCO plans to insert nearly 6,000 cubic meters of nitrogen, an inert gas, into the reactor over six days and estimates that about 200 cubic meters were injected between 1:30 a.m. and 9:50 a.m. Thursday.
The firm and the government’s Nuclear and Industrial Safety Agency said they believe chances are slim that another hydrogen explosion will occur immediately or that high volumes of radioactive substances will be emitted following the nitrogen injection operation. – Kyodo News (April 7)
UPDATE – Nuclear and Industrial Safety Agency – Seismic Damage Information (the 74th Release)
The Nuclear and Industrial Safety Agency stated that at Units 1 through 4 at Fukushima Daiichi NPS , “White smoke was confirmed to generate continuously.” Reported on April 6.
TEPCO Press Release (Apr 6) – Measures Taken To Prevent Explosion
Injection of Nitrogen to Reactor Containment Vessel of Fukushima Daiichi Nuclear Power Station Unit 1
“Regarding Fukushima Daiichi Nuclear Power Station Unit 1, taking into account the possibility of hydrogen accumulating inside, we have been considering encapsulation of hydrogen by injecting nitrogen to the reactor containment vessel.
Today, we received an order from minister of economy, trade and industry to report on matter such as necessity of encapsulating nitrogen, method for implementation, and impact assessment of safety.
Accordingly, we have compiled related matters and reported to minister of economy, trade and industry today. The report was approved after the deliberation in the Ministry of Economy, Trade and Industry.
Based on the report, we will begin injecting nitrogen to the reactor containment vessel of Unit 1 today, around 10:30pm”. END
Update [Apr.9] – TEPCO announced 0n 4_9 that they would perform an additional operation to inject nitrogen gas into the containment vessel of the Number 1 reactor to prevent a possible hydrogen explosion, TEPCO plans to increase the purity of nitrogen gas from 98 percent to 99.98 percent.
UPDATE – TEPCO Press Release (April 4) – Seawater at Unit-2 7.5 Million Times Limit
The FDA announced on March, 30 that results from a screening sample taken March 25 from Spokane, Wash. detected 0.8 pCi/L of iodine-131, which is more than 5,000 times lower than the Derived Intervention Level (DIL) set by the U.S. Food and Drug Administration.
In light of that and the eventual elevation of levels as the Fukushima reactor continues to spew radioactive materials into the atmosphere, I have compiled the information below. This information will be updated as events warrant. Check the end of this article for updates and new links.
Internal exposure by ingestion of radioactive iodine (I-131 ) occurs when persons eat food that is contaminated with the fallout. The oral pathway is the main route of internal I-131 exposure for people. Milk is the major source of internal exposure. I-131 is radioactive, has an 8.03 day half-life, and emits beta and gamma radiation.
The thyroid gland is the critical organ for I-131 exposure. Essentially all of the iodine entering the body quickly becomes systemic (EPA 1988), with approximately 30% depositing in the thyroid. Dietary intake of iodine before exposure is important because a relative iodine deficiency increases the thyroid uptake of I-131.
After cow’s graze on grass that has been contaminated by radioactive fallout, glands in the cow’s udder concentrate the radioactive iodine and release it into the milk. Goat’s milk and sheep’s milk contain approximately 10 times the concentration of radioiodine found in cow’s milk.
After exposure, the most critical dietary information needed is the amount and type of milk and milk products consumed, their I-131 concentrations, and the time they were consumed relative to the time of the release.
Inhalation, especially near releases of I-131 in the absence of rain, is another route of internal exposure. However, doses to humans from inhalation and from ingestion of plants, animals, or water are usually small in comparison. Figure 1 shows the exposure pathways of I-131 from the environment to humans.
FDA RADIOACTIVE CONTAMINATION OF HUMAN
FOOD AND ANIMAL FEEDS GUIDELINES
“A temporary embargo to prevent the introduction into commerce of food from a contaminated area should be considered when the amount of contamination equals or exceeds the DILs or when the presence of contamination is confirmed, but the concentrations are not yet known. The temporary embargo would continue until measurements confirm that concentrations are below the DILs.
Normal food production and processing procedures that could reduce the amount of radioactive contamination in or on the food could be simple, (such as holding to allow for radioactive decay, or removal of surface contamination by brushing, washing, or peeling) or could be complex. The blending of contaminated food with uncontaminated food is not permitted because this is a violation of the Federal Food, Drug and Cosmetic Act (FDA 1991).”
Natural Sources of Iodine
Normally, your body stores between 20 to 30 mg of iodine, most of which is kept in the thyroid gland. While iodine deficiency was a problem in the early 20th century, the inclusion of iodine in iodized salt has nearly eradicated the problem. Also, because it is often added to animal feed, iodine is passed onto humans through cow’s milk.
Iodine-131 may not be the only concern in the future if the slightly heavier and longer-lasting isotopes experienced after Chernobyl make it across the Pacific. The food monitoring results from FDA and others following the Chernobyl accident support the conclusion that I-131, Sr-90, Cs-134 and Cs-137 are the principal radio-nuclides that contribute to radiation dose by ingestion following a nuclear reactor accident, but that Ru-103 and Ru-l06 also should be included.
LATEST EPA RADNET MILK INFO:
Radiation from Japan has been detected in drinking water in 13 more American cities, and for the first time cesium-137 has been found in American milk—in Montpelier, Vermont, according to data released by the Environmental Protection Agency late Friday. The sample contained 1.9 picoCuries per liter of cesium-137, which is under EPA’s 3.0 picoCuries per liter standard.
Milk samples from Phoenix and Los Angeles contained iodine-131 at levels roughly equal to the maximum contaminant level permitted by EPA, the data shows. The Phoenix sample contained 3.2 picoCuries per liter of iodine-131. The Los Angeles sample contained 2.9.
The EPA maximum contaminant level is 3.0, but this is a conservative standard designed to minimize exposure over a lifetime, so EPA does not consider these levels to pose a health threat.
Airborne contamination continues to cross the western states, the new data shows, and Boise has seen the highest concentrations of radioactive isotopes in rain so far.
A rainwater sample collected in Boise on March 27 contained 390 picocures per liter of iodine-131, plus 41 of cesium-134 and 36 of cesium-137. EPA released this result for the first time yesterday. Typically several days pass between sample collection and data release because of the time required to collect, transport and analyze the samples.