Several nuclear reactors in Japan were damaged in the aftermath of the powerful earthquake which struck on March 11th. While at the moment, none of these reactors has released enough radiation to pose a health risk, the reality of risk is far from over.
Recent studies have indicated that airborne pollution from China drifts along tradewinds and settles in North America, as exemplified in this article. A website devoted to this phenomenom graphically illustrates this movement based on a dust storm in 1998 which drifted from China to the Pacific Coast of the United States in a matter of 6 days.
And 6 days is important. The most harmful elements of the fallout of a nuclear power plant disaster are isotopes of Iodine and Cesium. According to a New York Times article, these radioactive isotopes have a half life of 8 days for iodine, and 30 years for cesium (half life is the time it takes for half of the atoms to become non-radioactive). Radioactive iodine concentrates in the thyroid gland and can lead to thyroid disorders and cancer. Cesium is more dangerous in the long term due to its half-life, but these risks are far less predictable.
The risk is that any potential fallout could drift across the Pacific Ocean and end up in the United States, most likely concentrated on the northern Pacific Coast, depending upon weather conditions.
Should you be worried?
Most likely not. First, the reactors are not a danger to even the residents of Japan at the present time. According to the latest news from the Associated Press, no reactor is leaking radioactive materials which pose a health risk, and the reactors are being repaired.
And even if any of the reactors do explode and do spread radiactive material into the air, it has to reach the United States. According to one site, radiation from Chernobyl, the worst nuclear power plant disaster in history, drifted less than 1000 miles from the site, whereas the distance from Japan to the US Coast, according to Google Maps, is 2756 miles as the kayak floats (no kidding, search driving directions from Seattle to Japan!)
Additionally, the radiation has to be in high enough concentrations when it reaches the US to do any harm. Across such a distance, the possibility of radiation being dispersed into concentrations that are no longer dangerous is almost a given. Of course, we don’t know for sure. There are a number of factors that remain unknown and thus, the possibility exists that dangerous radiation could affect Americans.
And are there any mechanisms in place to monitor this situation? One set of answers could come from a satellite designed to monitor pollution from east Asia to North America, TERRA, as described by geology.com in this article. This NASA satellite tracks airborne particles, and has the potential to be able to track radiation. In an email response to my inquiry, Dr. Marc Imhoff Project Scientist for the TERRA satellite project at NASA, indicated that TERRA can be utilized to track potentially radioactive plumes, and will if needed.
But the last and best way to monitor the danger is by direct monitoring of radiation. If fallout drifts across the ocean, it must be measured here in the United States to determine the dangers posed, if any. Certainly if fallout does affect the US, we would be alerted.
Is there anything you can do to protect yourself? Yes. If any of the reactors do release radioactive material into the air, you might consider purchasing some potassium iodide capsules. These protect you from both idodine and cesium by essentially flooding your body with the non-radioactive versions (cesium mimicks potassium as far as the body is concerned.) You can also make sure you use iodized salt, or drink some red wine, which also protects the thyroid gland from radiation.
The bottom line is that there is no cause for panic or alarm. But knowing how to protect yourself in case the worst does happen and radiation drifts onto US soil is the best, and probably only thing, you need to do.
Wilkening et. al. Trans-Pacific Air Pollution Science Magazine
Transportation of East Asia Dust Pall across the Pacific Center for Air Pollution Impact and Trend Analysis
William J. Broad Danger Posed by Radioactivity in Japan Hard to Assess New York Times
Talmadge and Yamaguchi Japan races to prevent nuke reactor meltdowns Associated Press
Robert Martin et. al. Chernobyl Global Radiation Patterns
Satellite Measures Pollution From East Asia to North America geology.com
NASA: TERRA (EOS AM-1) NASA