National Breast Cancer Month and the Precautionary Principle
One of the things you have to love about the Left is the never-ending supply of conspiracy theories. Sure right wingers have their share of conspiracy theories too, but rarely do they have the same sort of panache. In a recent column Russell Mokhiber and Robert Weissman outlined one such conspiracy — namely that large corporations have simultaneously created an epidemic of breast cancer and then turn around and try to drum up support for finding a cure with whitewashed events like National Breast Cancer Month.
Mokhiber and Weissman are taken with Breast Cancer Action, and advocates group convinced that environmental factors are responsible for the epidemic of breast cancer, even though their own propaganda concedes that the only known environmental contributor to breast cancer is ionizing radiation (i.e. women exposed to ionizing radiation have significantly higher risks of developing breast cancer). BCA wants more emphasis on studying what they think are the environmental causes of breast cancer. As Mokhiber and Weissman summarize the current state of affairs, however,
This is not exactly the agenda of the cancer establishment, which is hostile to the idea that environmental causation is a significant part of the story of the rising incidence of breast cancer in the United States.
The first time I heard this particular conspiracy theory was in a Molly Ivins op-ed column, and my reaction now is the same then — how can thinking adults swallow this hogwash?
First of all, is there an epidemic of breast cancer? No. Reported cases of breast cancer have certainly increased over the past 3 or 4 decades, but this is due largely to two external factors. The first is the widespread use of mammograms and other tools which have increased detection.
The other factor is simply that women are living longer than ever before. Breast cancer is a disease that overwhelmingly strikes older women. Seventy-five percent of all breast cancer cases occur in women over 50 years of age. More women today live past 50 then ever before, and they live longer once they hit 50. With average life expectancy for women approaching 80 years in the United States, far more women spend far more of their life at ages when breast cancer is most likely to occur. Do the math — something would be wrong if the number of cases of breast cancer wasn’t increasing.
Which doesn’t rule out the possibility of environmental causes, but when you look at the studies that have been done on breast cancer what stands out is precisely the complete failure to find any environmental causation for breast cancer. Alcohol consumption, obesity, herbicides, estrogen compounds, and a whole host of other factors have been examined and as BCA is forced to concede, so far breast cancer seems to occur largely independently of environmental factors.
BCA claims, for example, that “There is strong evidence that estrogen plays a part in the development of some cases of breast cancer,” but in fact there is little evidence of that. First of all, it should be kept in mind that the action of environmental estrogens such as from pesticide residue exert an extremely weak effect compared to the high levels of estrogen that women are exposed to thanks to the processes in their own bodies and from other natural sources. According to Texas A & M toxicologist Stephen Safe, for example, a typical glass of wine carries about 1,000 times as much active plant estrogen as chemical estrogens that a typical person would be exposed to in a single day.
Two human made estrogen-like compounds that some people believe are responsible for cancer, especially breast cancer, are DDT and PCB. Yet the largest study ever of the effect of these compounds and breast cancer was unable to find any link between the two. Using blood samples taken as part of an enormous epidemiological study of nurses (with almost 33,000 nurses giving blood samples), Harvard epidemiologist David Hunter compared blood samples taken from 240 women in the study who subsequently developed breast cancer and compared them with a control group of 240 women with similar lifestyles who didn’t develop breast cancer. After measuring the levels of DDT and PCB in the experimental and control groups, Hunter found no correlation between DDT/PCB levels and breast cancer rates.
DDT and PCB have to be two of the most common artificial estrogen-like compounds in the world. If they are not contributing to breast cancer, it’s hard to imagine what other chemicals are.
Don’t worry though — the folks at BCA aren’t going to let the complete lack of evidence stop them. In fact the lack of evidence actually is considered a positive thing because it lets them bring in the so-called precautionary principle. Here’s how Mokhiber and Weissman sum up this bit of sophistry,
First, [BCA's Barbara Brenner said] cancer prevention efforts must embrace the precautionary principle — the idea that when an activity raises threats of harm to human health or the environment, precautionary measures should be taken in the absence of scientific certainty.
I don’t want to mince any words — the precautionary principle makes absolutely no sense, largely because there are very few things for which scientific certainty is available. If the precautionary principle were taken literally a great deal of activity that occurs in contemporary civilizations would have to go out the door.
For example, it has been studied pretty extensively and it is probably the case that the computer monitor I am using right now will not raise my cancer, but in fact there is some degree of scientific uncertainty on this matter — at least among environmentalists. Are we going to ban CRTs based on the precautionary principle?
This is not an idle issue. Several years ago the town where I grew up in had some environmental activists very angry at the state electrical utility. Again, the scientific evidence indicates that it is very unlikely that electrical power lines contribute to cancer, but there is some scientific uncertainty. Shouldn’t we spend tens of millions of dollars more, the activists wanted to know, to bury the power lines in the ground and take the precautionary route? (Most precautionary principle claims, you will usually find, completely ignore the problem of opportunity costs or attempt to evaluate the potential costs associated with say banning a useful product because of a completely unknown risk).
The precautionary principle could also be extended far and wide. After literally thousands of studies, there is still no good scientific answer to the question of whether or not violent movies, comic books, video games, books or images contribute to real world violence. So in the face of such scientific uncertainty, shouldn’t we just ban such entertainment to be safe?
On both philosophical and factual grounds, the sort of claims advanced by Mokhiber, Weissman and BCA simply don’t hold up. Certainly corporations should not have a license to poison the water and the air, but on the other hand deciding whether or not certain activities are dangerous must be grounded in solid scientific principles not on unsound scare tactics and fuzzy thinking.
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