Tuesday, 1 August 2017

How atomic weapons testing can explain racial differences in US lung cancer rates

The Centers for Disease Control and Prevention has a page showing the different lung cancer rates among races in the United States of America and the one for males is shown below.

It clearly shows that black males have the highest risk of lung cancer followed by white males and then Hispanics (and other groups) having the lowest risk. It is plausible that smoking has caused these cancers by some unknown mechanism and that some other unknown mechanism/s alter the risk according to ethnicity. But I think atomic weapons testing fallout provides a simpler explanation that arguably makes fewer assumptions and the explanation is location.

A few years back I plotted white male lung cancer rates against annual rain fall by US county and found a strong correlation. Radioactive fallout comes down from the atmosphere mostly in rain so we could plausibly expect to see more lung cancer where there is more rain. See chart below.

As can be seen there is indeed more lung cancer where there is more rain for white males.
And for comparison here is male smoking prevalence by US county 1996 and 2012.

If it's written on a cigarette packet - it's probably not true.
(Fredriks law)

The reason why I chose white males is as follows. Black males are more likely to be diagnosed as having lung cancer than white males or Hispanic males . If you know that black people live in  greater numbers in the south east of the US ,  then it would be tempting to assume that this explains the higher levels of lung cancer in that region (the stroke belt). But because I chose white males then this plausible explanation for excess lung cancer deaths in the south east of the US is eliminated.

Black people are more likely to live in the parts of the US that have high rainfall and therefore will have higher exposure to atomic weapons testing radioactive fallout 1945 - 1985.


Hispanic people are more likely to live in the parts of the US that have not so much rainfall and therefore will have lower exposure to atomic weapons testing radioactive fallout 1945 - 1985.

The modern lung cancer epidemic in the US correlates with the period of atomic weapons testing fallout period of 1945 - 1985

Historical cigarette consumption United States of America

We can see from comparing lung cancer rates of Spanish men and Mexican men , any theoretically protective property of being Hispanic against lung cancer risk, clearly does not work very well for Spanish males. This is because Spanish males have a massively higher lung cancer risk compared to Mexican males despite both groups being of the same ethnicity.

Male smoking prevalence in Spain in 2001 was 39% and in Mexico in 1998 it was 51%. So location rather than smoking prevalence or ethnicity seems a stronger factor.

Historic lung cancer trends in both Mexico and Spain correlate reasonably well with the nuclear fallout period 1945 - 1985 (the fallout period is for the world).

Historical cigarette consumption in Spain

But then ...

... Mexico does not have a reputation for having many rainy days.