McGill Alert / Alerte de McGill

Updated: Mon, 07/15/2024 - 16:07

Gradual reopening continues on downtown campus. See Campus Public Safety website for details.

La réouverture graduelle du campus du centre-ville se poursuit. Complément d'information : Direction de la protection et de la prévention.

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Dateline NBC: Endocrine Disruptors

The presence of a chemical is not the same as presence of risk. But when you report results in percentages you can mislead easily. For example your chance of winning the lottery is trivial but if you buy two tickets you increase your chances by 100%. Sounds impressive but it is irrelevant in practical terms. So reducing very low levels of BPA or phthalates in the blood by 100% similarly has no practical significance.

Well…finally the Dateline piece on “hormone disruptors,: for which I was interviewed aired on March 24th. It was not as bad as it could have been, but not as good either. In the end I got 58 seconds clipped out of a 3-hour long interview! They didn't manage to include my comment that reducing extremely low levels to even lower ones has no clinical significance. I even gave an analogy: if you drink a cup of coffee you expect to find caffeine in the urine. If you then abstain it will vanish. Drink again and it's back. So what? All you have shown is exposure which does not equate to risk. The presence of a chemical is not the same as presence of risk. But when you report results in percentages you can mislead easily. For example your chance of winning the lottery is trivial but if you buy two tickets you increase your chances by 100%. Sounds impressive but it is irrelevant in practical terms. So reducing very low levels of BPA or phthalates in the blood by 100% similarly has no practical significance. Furthermore testing the urine is not very meaningful because it indicates what is being eliminated! It is what is left in the blood and tissues that is critical. And with BPA as we know from the recent Teeguarden study, there is virtually nothing detectable in the blood because it is quickly eliminated. As for the mouse studies they talked about, yes there are biological effects at exposures greater than human exposure. But of course the human is not a giant mouse. Rodents have different enzyme systems and metabolize BPA differently.

Unfortunately they gave much more air time to Rick Smith of “Environmental Defense” and his alarmist crony with their implied message that that “hormone disruptors” are undermining our health. I had made it clear that “hormonal activity” and “hormone disruption” are not equivalent. I also pointed out that there are some 11,000 compounds that are known to have endocrine activity and if any one of these were investigated to the same extent as BPA or the phthalates, similar issues would crop up.  I was glad they put in my comments about triclosan, which I really think should not be in soaps or toothpaste, because I was concerned that they would portray me as some sort of apologist for the chemical industry, which of course I am not. Although they didn’t include my discussion about how this was an environmental issue and not an “endocrine disruption issue.” As was to be expected the public was left with the overall impression that there is reason to worry and that Rick is the knight in shining armour who is set to slay the fire breathing dragon, namely the chemical industry. Well, that armour is actually pretty rusty. Anyway, at least I made it onto Dateline. Maybe next time I can get 60 seconds on 60 Minutes. On the positive side, the comments on my personal Facebook page have been overwhelmingly positive. 

You can watch the full documentary here- http://www.nbcnews.com/video/dateline/51320243

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