Healthy eating vs. radiation exposure from airplane travel

I've already written about how significant the carbon footprint of flying is relative to "green living" activities that we think of as important (http://sciencejon.blogspot.com/2012/08/how-flying-undermines-your-green.html). But I was largely unaware of the health implications of flying.

Apparently the exposure to cosmic radiation from a round-trip cross-country flight in the US is about 4-10 mrem (http://www.epa.gov/radtown/cosmic.html). This is roughly comparable to the dose you get during a chest x-ray (8 mrem, http://www.physics.isu.edu/radinf/risk.htm). While on average in the U.S. we each get a total of about 360 mrem / year, assuming a dose of 7 mrem per flight, a frequent flier who makes the equivalent of a cross-country round trip flight every week for a year would have an extra 364 mrem, meaning that all else being equal they will have double the average person's radiation exposure. This is represents an increased cancer risk roughly similar to smoking 1,075 cigarettes (http://www.physics.isu.edu/radinf/risk.htm).

The good news? Eating fruits and vegetables can help reduce that risk. While there has been a lot of debate over the value of phytonutrients and antioxidants in the diet in general, a recent study looking at cancer in airline pilots found a significant drop in risk associated with increased consumption of fruits and vegetables (especially dark leafy greens). Dr. Michael Greger has a video about this study (and a similar study that found atomic bomb survivors who ate more fruits and vegetables also reduced their risk of cancer relative to survivors who ate less of them):
http://bit.ly/12ldMKU