These recommendations are for people in North America as of March 27, 2011.
Radioactive releases from the Fukushima sites have been very high for two weeks, especially on-site. Significant radiation levels continue to be reported in nearby towns. For that reason, NIRS supports the U.S. Nuclear Regulatory Commission's call for a 50-mile evacuation zone around the Fukushima site.
Radiation from the Fukushima accident began arriving in North America on Friday, March 18, 2011. Radiation continues to be released at Fukushima and will continue to arrive in North America for days to come, and perhaps longer. Eventually, slightly elevated radiation levels are likely to occur throughout North America and much of the world.
The radiation levels that will come to North America will not be large enough to cause acute symptoms or immediate health effects.
At this point, we do not believe it will be necessary—or feasible given the expected duration of elevated radiation levels—to take shelter. Nor is evacuation a feasible strategy, since after arriving on North America’s west coast the elevated levels will continue to move to the east. We will post immediately if there is reason to believe that sheltering is necessary.
However, unnecessary exposure to radiation should be avoided when possible. Rain, in particular, can bring radioactive particles to the earth.
If it rains over the next several days, stay out of it if possible. If you get wet, put your clothes in the wash and take a shower.
Leave outerwear and shoes at the door so you don’t track water in your home.
Do not collect rainwater for drinking or later garden use during the period of time when active distribution of radioactivity is happening.
A dust mask does little or nothing for you. A respirator such as used for toxic chemicals will help to reduce exposure, however it is very unlikely that exposures in the US to gases from Japan will be concentrated to the point where a gas mask is needed. If you live near a nuclear power plant, you might want to add one to your emergency kit.
Special note: There is a long historical record of the nuclear industry piggy backing “routine” release of radioactivity to the air and water under the “cloak” of a larger nuclear event. Be aware that if you are near a nuclear facility you are at a higher risk of elevated “routine” exposure even if there is no local accident during this time.
FOOD + WATER
If you have access to well water, you likely do not need to worry about radioactivity in your water until the “recharge” period for your water source has passed – and likely the natural filtering of the Earth will reduce the level of radioactivity.
If you have a municipal water supply, ask your municipality to monitor and report the status of the level of radioactivity in the supply. You can offer that this may seem like an unlikely issue, but it is better to provide MORE information to people than less, and you have a right to know.
Food will be impacted directly in terms of contamination from fallout and indirectly from the food chain. Direct impact primarily applies to areas where radioactive fall-out is concentrated. There was a lot of impact on food production across Europe from the Chernobyl accident. As of today, experts do not yet see this level of release in North America. In other words, when it comes to local food, if there is direct contamination, the source is likely the “routine” radioactivity that is released from the facilities that are already in our communities.
The food chain, and international supply of food complicate the issue of radioactive food. Here are some of the type of foods that are most likely to concentrate radioactivity:
Dairy, meat, fish, eggs, nuts, seeds, oil. Many processed foods contain hidden oils.
IF there are significant amounts of radioactivity that are distributed from Fukushima it will take some time to enter the food that is in the market place – for instance, the grain in the bread in the store today was grown some months ago.
There is no way to know about the food, but in general, this is a good reason to push for real-time monitoring of where the plumes are traveling and to ask your county officials to collect rain samples and make the results known to local residents so that you can make informed choices.
NIRS Southeast Office
Questions and Answers on Radiation
Q1. What is ionizing radiation?
A1. Ionizing radiation is energy that is given off by unstable atoms as they decay.
In a nuclear power reactor core, radioactive uranium atoms split into smaller radioactive atoms (like cesium, strontium, iodines) which give off alpha, beta and gamma radiation. These particles and waves have sufficient energy to cause damage to DNA and cells if they are get into the environment and our bodies.
Q2. How is radiation measured?
A2. Radiation is detected with specialized instruments, such as geiger counters. Different instruments detect the different types of radiation. They count the radioactive emissions (particles and rays from the nucleus of the atom).
1 emission per second is a becquerel (Bq)
37 billion emissions per second equal one Curie (Ci). 1 Ci= 37 Billion Bq
Radiation DOSES are somewhat complicated calculations based on assumptions about the amount, type of radiation, the angle of exposure. Although the effects are different depending on the body mass and gender of the individual exposed, this is not incorporated into the dose calculation.
The units used are Sieverts (Sv) and Rems (r).
A thousandth of a Sievert is a millisievert (mSv);
A thousandth of a Rem is a millirem (mr).
A thousandth of a mSv is a microSievert (uSv);
A thousandth of a millirem is a microrem (ur).
1 Sievert = 100 rems
10 microSieverts = 1 millirem
Q3. IS there a safe level of radiation?
A3. No, there is no safe level of radiation. Every exposure to ionizing radiation increases our risk of cancer. Radiation causes other health problems such as ischemic heart disease, reduced immunity, birth defects and mutations.
Even natural background radiation has health risks, and in some places steps can be taken to minimize exposure, for example to radon.
Children are many times more vulnerable to radiation, as are elders. A National Academy of Sciences report (BEIR-3) found that women are 50% more likely than men to suffer cancer from radiation.
Q4. What are “normal” levels of radiation?
A4. Background levels of radiation vary depending on elevation, location, time, rock formations. For years background has been approximately 80 millirems/year at sea level, not including radon. Government and industry charts estimate that we receive 360 millirems per year including about half of that from radon. Those charts attribute about 60 millirems per year from naturally occurring radiation from the earth and sun.
The US Environmental Protection Agency (in 40 CFR 90) limits members of the public to 25 millirems a year from a nuclear power facility. The US Nuclear Regulatory Commission allows 100 millirems per year. (These are legal levels, not “safe levels.)
We list these for comparison to the millirem numbers that are being estimated from the failing nuclear power reactors and their accompanying irradiated fuel pools.
Q5. How does nuclear power radiation differ from natural background?
A5. The uranium in nuclear power reactors splits to make “fission products” and absorbs neutrons to form “transuranics” that are very biologically active. Some of the radioactive elements formed decay very rapidly (in a few minutes, hours, days); some take hundreds to millions of years. The persistent elements bioaccumulate in the food chain. They give external doses but also can concentrate in bones, muscles and other organs and irradiate from within for as long as they remain radioactive and lodged in the body. The radiation from the sun and from the rocks exposes us from outside. It does not concentrate inside. Radon gas occurs naturally and it can be breathed into the body. Medical radioactivity is generally very short lasting and gives a specific benefit to the patient.