United States

Sources of significant background radiation in the United States are (1) terrestrial sources, such as granite and certain other types of rocks; (2) radon and its progeny from the decay of thorium, uranium and other radionuclides; and (3) cosmic radiation - which doubles each 6,000 feet in altitude in the temperate latitudes. Several of the Rocky Mountain states, particularly Idaho, Colorado and New Mexico, have higher than normal levels of each of these categories, combined to make a significant difference between these states and others, especially the Gulf Coast states of Louisiana, Mississippi and Alabama.

We'll take a look at the cancer rates in these areas (American Cancer Society 1998 data) and compare them with background sources. The Linear No-Threshold (LNT) theory would predict an increase in cancer; the hormesis model forecasts a decrease in cancer - and other diseases or conditions affected by immune competence - as the radiation levels increase in the hormetic range. You be the judge.

Jagger investigated the average background exposures and cancer death rates among the 5.84 million people living in Idaho, Colorado and New Mexico, compared with the same factors for the 10.83 million residents of Louisiana, Mississippi and Alabama. His results are shown in Figure 25. While the study does not examine the large number of confounding factors that could possibly influence the data, it does illustrate a trend diametrically opposite to the LNT and is strongly indicative of hormesis. [Jagger, H. Natural background radiation and cancer death in Rocky Mountain states and Gulf Coast states. Health Physics, 75(4), 1998.]

Source for Figure 25: Background Radiation vs. Cancer Rate: Jagger, H. Natural background radiation and cancer death in Rocky Mountain states and Gulf Coast states. Health Physics, 75(4), 1998. Cancer data from the American Cancer Society, 1998.

If you are unaccustomed to reading graphical data, please note that Figures 25 and 26 show two different parameters - radiation dose and cancer rate - for two different geographical areas. The scale on the left side of the graph relates to the bar graphs, while the right-hand values pertain to the cancer deaths per 100,000 persons, as shown by the data points and connecting trend line. What is intended to be shown is the increase in cancer rate (as evidenced by the upward sloping line) compared with the decrease in background radiation indicated by the magnitude of the bar graphs.

A 1994 study by Cohen compares the average radon level and lung cancer rate in the Rocky Mountain states with that in the Gulf Coast states. Radon data come from state agencies, the EPA, and University of Pittsburgh researchers; cancer data are from the American Cancer Society. [Cohen, B. Dose-response relationship for radiation carcinogenesis in the low-dose region. Int. Arch. Occupational Environmental Health, 66, 1994.]

Source for Figure 26: Residential Radon vs. Lung Cancer Rate: Cohen, B. Dose-response relationship for radiation carcinogenesis in the low-dose region. Int. Arch. Occupational Environmental Health, 66, 1994.

Were the data, plotted in Figure 26, to show that lung cancer increased with increasing radon levels, one would have to concede as very likely that the higher residential radon levels were a cause of cancer. Since the evidence shows the exact opposite, one might expect our regulatory agencies to take note and consider revising their policies accordingly. Unfortunately, they apparently don't think they should be bothered with such trivial matters as evidence. "It is the radiation protector's task to protect people from radiation, regardless of whether the radiation has bionegative or biopositive effects."

Craig and Seideman studied the rate of leukemia and lymphocytic lymphoma versus altitude in the United States. [Craig, L. and Seidman, H. Leukemia and lymphoma mortality in relation to cosmic radiation. Blood, 17, 1961.] This, of course, should be a "no brainer" - everyone knows that leukemia is caused by radiation. Since there is about a 4,000 foot difference between the low data points and the high point - and thus a near doubling in cosmic radiation - we will no doubt find, in Figure 27, a doubling of radiation-sensitive cancers like leukemia, right?

Source for Figure 27: Leukemia and Lymphocytic Lymphoma vs. Altitude (U.S.): Craig, L, and Seidman, H. Leukemia and lymphoma mortality in relation to cosmic radiation. Blood, 17, 1961.

Oops. Something is obviously wrong here. I guess it's back to the old drawing board again for the LNTers. Really, this does go on and on. Allow me to mention a few of the more interesting cases - without the plots, since I suspect you're starting to tire of graphs and charts.