It Might Get Messy

All diseases are matters of chance. At the level of fundamental epidemiology, chains of probabilities determine the behavior of diseases in a population. In simple terms, the chance that you’ll encounter the disease organism (or other cause, such as chemical exposure) and the chance that you’ll receive a critical dose (sufficient microbes or molecules to cause illness) define your likelihood of getting sick. Consider two basic examples. Bubonic plague is endemic in ground squirrel populations throughout southwestern U.S. When I walk through a patch of brush pockmarked with ground squirrel burrows, I have a certain chance of encountering plague bacillus (primarily by having a flea leave its squirrel and jump on to me and take a meal), and then a certain chance that the flea will inject enough bacteria cells to trigger the disease. For a second chemical exposure example, when I hike in woods of the Patuxent Preserve, there is a chance I will step near a copperhead snake, and then a chance that the snake will bite me and inject enough venom to make me sick (mostly by digesting the tissues of whatever limb the snake bites). 

Similar probabilities pertain to cancer. With this addition: for many cancers, there is a nonzero chance of spontaneous appearance. Otherwise, there is a chance that some environmental exposure (like smoking) will trigger one or more cells to mutate into a tumor, and then a chance that your immune system will fail to deal with it, and then you’re off and running in cancer land. 

My cancers—of the tongue, throat, palate, and parotid gland—are classic smoker’s cancers. Except I’ve never smoked. I have, however, abused my oral cavity. Heavy and longstanding consumption of alcoholic beverages, heavy use of alcohol-based mouthwash, and heavy use (from my teens to my 30s) of epinephrine inhalers for asthma could all have contributed to cellular malfunction leading to tumor formation. 

Or, it could be that none of the above had a thing to do with it, and that my tumors began with spontaneous mutations of cells in place. According to the American Cancer Society (http://www.cancer.org/cancer/cancerbasics/lifetime-probability-of-developing-or-dying-from-cancer) men in the U.S. have about a 1 in 2 (or 50%) chance of developing serious cancer in their lifetime. Women are about 1 in 3 (33%). 

Think of what this means statistically. For a specific environmental exposure to cause an increase in cancer, it occurs in the context of a 33% of developing cancer in any case. The probability is 0.33. For many kinds of risk assessment, USEPA applies a threshold of 1 additional cancer in 10,000 to 1,000,000 exposures as an “acceptable” risk limit. That pushes those additional cancers pretty far out on the probability scale. 1 in 10,000 means a 0.3301 chance, 1in a million is 0.33001. Not much of an increase in the context of overall cancer rates.

Think of this the next time you hear of some food additive, pesticide, or chemical “doubling” or “tripling” cancer rates. In most cases, this means the probabilities increase from 0.3301 to 0.3303, or 0.33001 to 0.33003. These are not big increases. In fact, in epidemiological studies (where actual cancer occurrence, rather than predicted cancer “risk”, is the measure) such “doubling” or “tripling” of cancer rates is likely to be undetectable because of normal statistical variance in the test populations. That is, the 0.33 cancer rate is an average, with statistical variation that might be 10%, 20%, even 100%, of the average. Under these circumstances, detecting increased cancers from use of a chemical like methylethyldeath (MED) in food or cosmetic products is not possible. The putative “doubling” of cancers due to MED is simply an arithmetical artifact of the risk model. It is not something that could be detected even if it occurs, because with a third of people getting serious cancers anyway, doubling or tripling the rate out in the fourth or fifth decimal place is a trivial increase. 

Now, you are asking why I am subjecting you to this technical harangue. It is because there are important choices to be made regarding how we manage our environment. The resources of money, time, and technical expertise that can be applied to environmental management are finite. If we choose to spend resources reducing exposure to methylethyldeath, we must take resources away from other environmental management activities. Such as assuring sufficient potable water, air free of breathable particulate pollution, sustainable soil quality, and protection from infectious diseases. Environmental management is a “zero sum game”. There is a finite pot of money on the table, and if MED “wins” some of that money, other players (clean water, clean air, infectious disease) “lose” money. 

As a society, human beings must make rational choices when investing in environmental management. Reducing smoking rates and eating a healthy diet both can reduce real-world cancer cases enormously. More than enough to be measurable in epidemiologic studies. And more, in most cases, than MED compounds like alar on apples (remember that?) or nitrates in lunch meat products. 

To come back to my case, beverage alcohol is a powerful carcinogen. The probability of cancers additional to baseline are high enough to be easily measured in epidemiology studies. There is a good chance I gave myself cancer by choosing to drink heavily for decades. But there is also a chance I would have contracted these same cancers had I been a teetotaler without chronic mouth infections (the latter explain my heavy use of mouthwash) and without asthma. There is no way to tell—it’s a matter of chance. 

Anyway, I am continuing to heal and strengthen. I get in a walk to the point of being tired nearly every day now. Assuming I remain cancer-free and continue to have time to devote to recovery, I may achieve something akin to a decent quality of life. 

And, on my walks this week, I got a few decent photos. The first one up—the garter snake eating the enormous toad—entertained me for more than half an hour in the woods. That’s how long it took the snake to immobilize and ingest the toad. And all I could think of while I watched was that the toad was pissed off at himself for making a right instead of a left at the nearby hawthorn bush. Because that left would have reduced his chances of running into the garter snake!

Photos follow. I thank you all most deeply for being here. I can’t emphasize enough how important you have been for my war with cancers. Pat yourselves on the back and have a glass of good wine……