The Presence of a Chemical Is Not the Same as Presence of Risk

Dr. Schwarcz’s is currently a chemistry professor at McGill University and the Director of McGill University’s Office for Science and Society. He also hosts “The Dr. Joe Show” on Montreal’s CJAD and has appeared on The Discovery Channel, CBC, TV Ontario and other networks. Dr. Schwarcz has received numerous awards for his work, including the American Chemical Society’s Grady-Stack Award for demystifying chemistry and the Canadian Chemical Institute’s “Montreal Medal” recognizing his lifetime contributions to chemistry in Canada. 

“Chemical” is not a dirty word. Nor is it a synonym for “poison” or “toxin.” Chemicals are the basic building blocks of all matter and classifying them as “safe” or “dangerous” is inappropriate. But of course there are safe or dangerous ways of using chemicals. In any case, chemicals are not to be feared or worshipped, they are to be understood. And perhaps the most important point to understand is that the presence of a chemical does not equate to the presence of a risk.

Thanks to our analytical capabilities, we can now routinely detect substances down to the part per trillion (ppt) level. That’s not finding a needle in a haystack; it’s finding a needle in a world full of haystacks. At that level, we can detect a myriad of chemicals should we choose to look for them! And by selectively referencing the scientific literature, the spectra of risk can be readily raised.

On April 10, a group of health and environmental groups launched a national campaign asking ten major retailers to phase out “potentially” toxic products.  Aren’t all products “potentially” toxic? A chemical’s toxicity depends on its concentration in a product and route of exposure, not simply its presence. Most chemicals can be toxic at high enough levels, including such common items as salt, aspirin or vitamins. Should it really be retailers’ job to pull items from their shelves when numerous regulatory agencies around the world, including several in the US, oversee chemical safety and have the authority to remove products when the evidence justifies it?

The problem is that the human body is very complex, and its interaction with the environment is virtually impossible to totally clarify. We are exposed to a vast array of compounds, and how they interact with each other and with the naturally occurring compounds in our body, defies analysis. One can take virtually any single compound, carry out animal studies with varying doses, and find something that can be used to raise alarm.

For example, eat a bowl of chicken soup and hundreds of chemicals will flood your bloodstream, including many (benzene, methanol, etc.) that are potentially “highly toxic.” Although they are not toxic in the dose found in the soup, if you look for them in the urine, you will find them. Nobody bothers to look, because these chemicals are not deemed important; after all they are “natural,” and nobody has a political interest in banning chicken soup. But the story is different when it comes to synthetic compounds, especially those that have been deemed to be “endocrine disruptors,” like bisphenol A (BPA).

A 2011 study by the Silent Spring Institute, a non-profit research organization, is a case in point. Researchers enlisted twenty people who volunteered to have the amount of BPA and phthalates in their urine measured before and after a change in their diet.  And guess what? After three days of avoiding all canned and packaged products, the BPA levels and phthalate levels in the subjects’ urine decreased by roughly 65 and 55% respectively.

But what does a 65% decrease mean if it is a decrease from a number that was tiny in the first place? And the amounts of BPA and phthalates were in fact tiny, much, much lower than any regulatory limits. So what is the big deal about such a decrease?  What the results actually show is that these chemicals are cleared quickly from the body. But fear of these chemicals is not cleared quite so quickly.

Don’t get me wrong. I’m a big proponent of eating fresh, unprocessed foods.  However, remember that chicken soup made with fresh vegetables and organic, free range chicken can still flood the urine with plenty of compounds that could be vilified the same way as BPA or phthalates, if only one cared to make the effort.

But I’m not worried about the chemicals that could be found in my urine from my soup, or the BPA that might be in the plastic container storing my left over soup because I look at numbers. And those numbers tell me that whatever “toxins” may be present are at levels way below what regulatory agencies find acceptable. I know how the scientists at Health CanadaFDA and EPA determine these levels. I know their qualifications and level of expertise. And I know that for chemicals such as BPA, government agencies like the FDA have evaluated all the available research and have concluded that BPA is safe at the low levels found in food.

The problem may not be the “potentially” toxic chemicals that are in products we buy and use every day as much as the zeal with which some individuals and activist groups attempt to convert an association into causation to fit an ideological agenda.  If we were to remove all “potentially” toxic products from the shelves of the stores we shop at—there would be nothing left for us to buy.