Only experts were allowed to speak on technical subjects at official meetings of the Athens Citizens' Assembly. On matters of policy, which required value judgment, however, anyone could speak even when it was clear that they had never been taught either policy or judgment. Socrates discusses this in Plato's dialogue Protagoras. Things have changed dramatically in two millennia.

Recently, Toronto City council, not Metro Toronto, engaged itself in a debacle which involved a complex combination of epidemiology and chemistry. A plethora of non-technical people vigorously supported a motion to totally ban the use of Polyvinyl Chloride (PVC) pipe throughout the city. Only after a heated debate did the city dismiss the proposal. During the debate there was more nonsense spouted than in an evening at Yuk Yuks.

The city, of course, has no business getting into such complex issues at all. We have a Federal Health Department, a Federal Environment Ministry and at least 20 provincial ministries of health and environment with the responsibility, and knowledge, to deal with these complex issues. It is as if the Town of Aurora (pop. 30,000), rather well known in equestrian circles, were to impose its own protocols and standards to regulate equine breeding throughout Canada. Toronto City council ultimately showed horse sense by voting against the proposal.

At a much earlier public debate to discuss a total ban on the production of vinyl, an expert from the PVC industry, Fred Krause, outlined epidemiological studies of the manufacture and use of PVC. He presented his case with eloquence, backed up with substantial scientific data. The total volume of dioxin from all PVC manufacture in North America, he said, was only five grams.

His youthful opponent, Charlie Cray from Greenpeace, took to the podium later. He was charismatic and equally persuasive. He, too, used numbers impressively, and convincingly, claiming that the manufacture of PVC produced dangerous levels of dioxins and the entire production of PVC should be banned completely. Cracks in his arguments emerged when he cited Minamata, Japan, and Seveso, Italy¹ as places where there had been dioxin 'disasters'.

When the meeting was thrown open to the floor for general debate, I pointed out that it had been the release of mercury, a heavy metal, not dioxin, that had caused the casualties in Minamata when discharges from a factory entered the marine food chain as highly toxic methylmercury. To confuse a lethal heavy metal with a quite different organic compound did not incite confidence in his argument. As for the Seveso 'disaster' in Italy, I cited academics who had studied the issue and found not one single human death from the Seveso explosion which exposed people to TCDD. The effect on human health was limited to 187 cases of chloracne. This was discussed at a WHO conference in Rome, Italy².

Tumultuous arguments erupted at Toronto's elegant City Hall when attempts to ban vinyl pipe were debated. Pipe tapping, in foreground, was a more practical contest of wills. Photo - ES&E/TD.

Somewhat embarrassed at getting two disasters wrong in as many minutes, Mr. Cray switched to the long term effects of dioxins. He said that some mummies discovered in South America, were found to have low levels of dioxin in their remains. Today's humans, he stressed dramatically, now had vastly higher levels of dioxins in their bodies.

To me this conjured up an interesting scenario. I posited to him that the South American Indians of that day, would probably have had life expectancies in the mid thirties, whereas industrialized countries have pushed life spans into the 70s. Innocently, I suggested that his attempts to link health and anthropology might even suggest that dioxins were actually therapeutic.

He had talked about dioxin as an extremely toxicsingle entity yet there are some 200 types of dioxins, of which only 13 isomers are considered to be toxic. Isomer 2, 3, 7, 8 - TCDD is often referred to as the most toxic chemical in the world, so dioxins are not to be treated lightly. However, to talk about dioxins in such wide generalities, when the seriousness of the issue demanded scientific specifics, diluted the thrust of his argument.

This led to a discussion on PCBs. Now the news media have great trouble, confusing PVCs with PCBs (which has not slowed their breathless coverage of the complex issues for several years). When I mentioned that, over 25 years ago, Canadians were world leaders in using PCBs as fuel in rotary kilns during the manufacture of cement, Mr. Cray said he opposed the use of any hazfuel.

I argued that the high temperatures and long combustion residence times in kilns, plus the fact that the limestone used in rotary cement kilns acts as a scrubber, resulted in PCB destruction rates in the order of 99.9999 percent, required by regulators. Contrary to media generated hysteria, there is no evidence that PCBs have killed a single human being. Moreover, the PCB epidemiology was from studies on workers who had daily skin contact for up to four decades, not from studies on laboratory rats and mice, I said.

But he repeated his opposition to any hazfuels being used. But is not coal a hazfuel with its high levels of SO₂, PAHs and heavy metals? Benzene, toluene, xylene are highly toxic chemicals present in gasoline, so what exactly is a hazfuel, I asked? Coal is not only an expensive fuel, but it also produces acid rain as well as a radioactive residual in the clinker. Many wastes, including PCBs, when they are not safely combusted to make products such as cement, have cost hundreds of millions simply to be expensively incinerated, without the valuable heat being recovered and utilized. But what is toxic?

The question was raised over four centuries ago. Paracelsus, a medieval physician, astutely noted: All things are poison; there are none which are not; it is the dose which constitutes the difference between a poison and a remedy. Paracelsus ironically was the activist of his day. Although accused by many of his contemporaries of charlatanism, Paracelsus profoundly influenced the development of medicine. In 1526 he was appointed professor of medicine and surgery at the University of Basel, but was forced to resign from this position because of his heterodox teachings. He provoked resentment in faculty members and died in 1541 of injuries after being pushed by a servant from an upper-storey window of the house of a physician whom he had offended. Worthy of note _ while his activism did indeed change the face of medical science, his activism was based on science, not stunts.

Now epidemiology is a complex area of study which is gradually revealing new and hitherto unimagined dangers from chemicals. There are disturbing indications that some synthetic chemicals may mimic hormones such as estrogen and progesterone, and tamper with our endocrine systems. These are issues posing real challenges to environmental scientists today.

Science is an unmatched quest to discover truths in a systematic, unemotional manner, one variable at a time, using strict protocols, with findings subjected to rigorous peer review and challenges. This makes science and engineering ill suited in the battle for public opinion where the arena is more appropriate for a circus than serious intellectual debate. While individual scientists are often wrong in their conclusions, vigorous scholarship ultimately will correct the errors. For example, barely 30 years ago, few scientists would admit that there was once only one great continent, Gondwanaland, which split up and bumped, slurped and slithered across the oceans creating great mountain ranges and new continents over eons of time. Dr. Ken Hare says there was an earlier 'shadow' landmass known as Pangaea. Dr. Hare, a former Director of the Institute for Environmental Studies at the University of Toronto, told me that Continental Drift theories were thought of as heresies when he was a student at King's College, London.

But it was systematic research, academic debate and peer review which changed the way we think of our planet. Yes, it was scientists who denied evidence of Continental Drift; that X-rays could see through human tissue³. The medical elders of the day denied the early germ theories and many other advances. But the scientific method, used around the world, relentlessly brought forth new data through peer review and debate which transformed what was once unthinkable into accepted reality. This is how we must decide what is hazardous and what must be banned, not by the stand-up comedies which sometimes masquerade as debates in Toronto's elegant City Hall. There was simply no need for council to behave this way; after all, Yuk Yuks is just a few blocks north of City Hall.

1. Seveso, Italy was the site of an explosion at a trichlophenol factory in 1976, in which livestock and people were exposed to TCDD. It caused 187 cases of chloracne, but apparently no statistically significant increase in the rate of embryotoxic or teratogenic damage in children born of women exposed to the fallout, compared to worldwide averages.
2. I gave a presentation at this 1982 WHO conference in Rome, on how political policies can be shaped by media coverage.
3. In 1900, Lord Kelvin, the physicist for whom a temperature unit is named, said X-rays were a hoax, five years after Roentgen discovered the phenomenon.