Answer to Question #12594 Submitted to "Ask the Experts"

I just read where John Wayne, Susan Hayward, and 89 other people developed cancer after filming The Conqueror. The filming location had received radioactive dust from nuclear testing over a hundred miles away, and while filming they stirred up that dust and inhaled it. Supposedly, 91 out of the 220 cast members developed cancer. Also, in the 1960s France conducted atomic bomb testing in the Sahara Desert. Can wind-blown dust particles from this contaminated area still be harmful to humans if inhaled? Right now (2018) large quantities of that Saharan dust are blowing in over South Texas. Should we be wearing masks to filter that dust?

I wanted to answer this question, in part, because (1) I've spent the last 30 years studying the health risks of radioactive fallout, (2) I'm one of very few Americans who has actually been on the French nuclear test site in the Sahara, and (3) I empathize with your inquiry as I am also a native Texan!

First, let me comment on the information you provided about the filming of the The Conqueror with John Wayne. As the film was released in 1956, I can assume it must have been shot in about 1954, apparently, near St. George, Utah, downwind of some of the nuclear tests conducted in Nevada. At that time, about 30 of the eventual 100 atmospheric nuclear tests to be carried out at the Nevada site had been conducted by the time the movie was filmed (see the nuclear weapon archive website). You have cited that 91 of the 220 cast members developed cancer and that radiation exposure from the dust at the filming site was the cause. I agree that 91 cancers of 220 cast members sounds like a lot. It suggests a cancer rate of 91/200 × 100 = 41.3%. But is that abnormally high? Statistics on cancer occurrence in the United States suggest that the lifetime risk of cancer for males is about 39.7% and 36.7% for females, not greatly different than the rates among the cast. As we mature, the odds of dying of cancer increase from about 25% to 50%. Whenever a cancer survey is made among a small group (say, 100 persons or less), there are variations in the observed cancer rates, either larger or smaller. Moreover, it has also been reported that many cast members were heavy smokers, increasing their risk over the average. I believe that given the available information, there is no compelling evidence that the cancer rate among the cast was higher than national rates. Careful study of the types of cancers as well as other factors would be needed to make a more definitive statement.

Now to your question regarding nuclear testing in the Sahara. I'm familiar with French nuclear testing sites in Algeria because in 1999, I was a member of the International Atomic Energy Agency's monitoring team there (see the report of radiological conditions at former French test sites ).

There are two important issues related to your concern. First, the atmospheric nuclear tests in the Sahara (which are the only ones of interest since other tests were underground) were relatively few and relatively small. There were only four in the atmosphere with an explosive yield of about 100 kilotons (equivalent TNT), which was about 10% of the explosive yield of atmospheric nuclear tests in Nevada. The atmospheric tests in the Sahara were conducted in 1960, about 58 years ago. That is important because radioactive decay results in a large decrease in the contamination level.

While I understand that regional news has reported on dust from the Sahara Desert reaching Texas, I would think it would be equally plausible for dust to reach Texas from Nevada, but there has been no concern that I can recall about the radioactive level of Nevada dust in Texas. The factors that serve to protect you from nuclear testing residues, regardless of where dust might have originated, are the long length of time since nuclear testing was conducted and the tremendous dilution in the atmosphere that takes place when dust travels thousands of miles.

I greatly appreciate your concern but as a professional, I believe the dust itself is more of a hazard to the respiratory system than the minute amounts of radioactivity that could be carried. To further ease your mind, you should know that the Environmental Protection Agency routinely monitors the air for radioactivity (seethe EPA RadNet website) and there would be alerts through the local press if there was a radiation hazard detected.

I recommend that, in general, you should protect yourself from excessive dust inhalation as part of good health care, but I do not personally believe there is any significant radiation hazard to you from potentially contaminated dust originating at the French nuclear test sites in the Sahara desert.

Best of health to you.

Steven L. Simon, PhD, FHPS,