Steven Hentges, Ph.D
Wednesday, August 30, 2017

Last week Health Canada released an anticipated report with important new data on exposure of Canadians to a variety of chemicals. It’s important because without knowing how much of which chemicals we’re exposed to, it’s difficult to know whether those chemical exposures are safe or not.
 
After all, dose does matter. If you’re not sure about that, imagine taking a bottle of aspirin next time you have a headache. You will get rid of your headache, and a lot more. In particular you might get rid of your life since two aspirin are safe and effective for the headache but a whole bottle of aspirin could kill you.
 
The Fourth Report on Human Biomonitoring of Environmental Chemicals in Canada provides exposure data on 54 environmental chemicals for more than 2,500 participants throughout Canada. The report is part of an ongoing program that produces biennial reports, this one covering the 2014-2015 time period.
 
The report includes data on exposure to bisphenol A (BPA), which is primarily used to make polycarbonate plastic and epoxy resins. Those materials are widely used in products that make our lives better and safer every day, and our use of those products raises the potential for exposure to trace levels of BPA. The Health Canada report is so important because it tells us just how much BPA Canadians are exposed to. As noted above, the dose does matter.
 
Most likely you didn’t see any of the limited media coverage on the report, and that’s a good thing since it appears the media didn’t actually read the report. Perhaps the most glaring omission from the few media stories is a point so important that Health Canada included it in its short “Backgrounder” on the report.
 
It is important to note that the presence of a chemical in a person’s body does not necessarily mean that it will affect their health.”
 
Of course what we want to know is whether the presence of a chemical in our body will affect our health. The report documents that BPA, in the form of its inactive metabolite, is present in urine, which means exposure did occur.  But what does that data mean for our health?
 
Fortunately for consumers, it’s relatively easy to interpret the data with respect to health. Along with other government bodies, Health Canada has already determined a safe intake level for BPA. And, in a previous study, Health Canada researchers further determined the amount of BPA that would be measured in urine if exposure occurred at the safe intake level. That value is known as the Biomonitoring Equivalent (BE) for BPA.
 
Comparison of the new data with the BE reveals that typical exposure to BPA in Canada is fully 1,000 times below the safe intake level set by Health Canada. The data strongly supports Health Canada’s earlier conclusion that “Bisphenol A does not pose a risk to the general population, including adults, teenagers and children.”
 
It’s not just Canadians who can be confident in the safety of BPA. A recent analysis from a group of researchers in China revealed that exposure to BPA is very low in every one of the 30 countries where it’s been measured. Perhaps the US Food and Drug Administration says it best in a Q&A on its website:  Is BPA safe? Yes.