The always-brilliant Dr. Joe Schwarcz, Ph.D., a professor of chemistry (among other things) at McGill University in Montreal, has hit another one out of the park as can be discerned from his latest Dr. Joe column in the Montreal Gazette.
Dr. Schwarcz is one of the great skeptics and rebutters of junk-science scares, especially those based on the often-intentional misinterpretation of chemistry. This time he takes on the hot button issue of PCBs.
Polychlorinated biphenyls (PCBs) were commonly used in electrical insulation because of their chemical inertness and other desirable properties. But the class chemicals became notorious as an early EPA Superfund target for being dumped in the Hudson River for about 30 years by General Electric, beginning in 1947. That is the issue that usually elicits a response from most people that would be more appropriate for Sarin nerve gas. But Dr. Joe takes issue with this in his own inimitable way.
He is quite convinced that the real PCB story is not at all what we have been told.
[W]hen it comes to the science, the risk posed by the stored chemicals as well as the toxicity of PCBs, in my view, was exaggerated, generating an unwarranted degree of public anxiety. One got the impression that a cache of nerve gas had been discovered as headlines screamed about toxic time bombs, apparently ready to explode. In fact, PCBs are not the devil incarnate.
This is hardly news to our Dispatch readers. ACSH s Dr. Josh Bloom says, There is a thriving cottage industry based on keeping people scared and in the dark about the real risk of chemicals. And, boy, does it work. Between certain self-serving environmental groups, California s schizophrenic Proposition 65, and completely inaccurate news reporting, just about everyone is scared of everything. And please believe that a huge amount of money is being made by taking advantage of these fears the green products and organic food mega-industries being the main beneficiaries.
Following the old, but true adage, The Dose Makes the Poison, Dr. Schwarcz notes that while there have been some documented adverse effects from PCB exposure in the past, this has no bearing on life today: If we assume that humans react similarly to rats, a daily dose of some 8 mg per kg of body weight would be required to possibly cause a problem. This is about 500,000 times greater than what the average person is exposed to on a daily basis. Still, the hint from human occupational exposure and the animal data were enough to classify PCBs as probable human carcinogens.
You can read Joe s commentary in the Montreal Gazette here.
And you can read our own publications entitled What s the Story? PCBs here.