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Health Chats
The Real Truth About Plastics: What you should and shouldn't worry about
Wednesday Dec 08, 2010, 07:30PM - 08:30PM (EST)
1520352?1291076046
Director of McGill University's Office for Science and Society
Are plastic water bottles safe? Should you microwave food in plastic containers? Are baby bottles made with bisphenol A (BPA) safe for your child? Should you have any concerns about buying plastic toys this holiday season? Find out the answer to these questions and more as world-renowned chemist, Joe Schwarcz, PhD, and pediatrician Stacy Stryer, MD, review the latest research in this live health chat. Please join us at 7:30pm ET on Wednesday, December 8, 2010, to ask the experts your questions and learn the facts about plastics safety.
Joe Schwarcz, PhD:
the problem is that it can shatter when dropped and send shards all over...which is why it was replaced with polycarboante in teh first place
Joe Schwarcz, PhD:
but now we can put a plastic protective layer on te outside of the bottle made of PVC...so even if the bottle drops it doesn't break
Joe Schwarcz, PhD:
then all you have to worry about is the kid chewing onthe outside of thebottle and leaching out phthalates...
Joe Schwarcz, PhD:
there's no free lunch...
Ken_PA:
It's good to see you're not an alarmist. But if I leave a bottle of water in the car on a hot summer day, it will taste like plastic. Can you discuss that? Does heat change the whole discussion?
Joe Schwarcz, PhD:
The "plastic" that you are tasting are actually  dimers and trimers of the monomers use dto make the plastic....
Joe Schwarcz, PhD:
I know that now you are sscared
Joe Schwarcz, PhD:
what on earth is he talking about!
Joe Schwarcz, PhD:
taking you back to your introductory organic chemistry...which I hope was not too dreadful
Joe Schwarcz, PhD:
shouldn't have been!
Joe Schwarcz, PhD:
Plastics are made of polymers...meaning taht they are giant molecules made by linking together small units called monomers...much like links in a chain
Joe Schwarcz, PhD:
the final product has no taste or smell...the long molecules are too large to fit into the receptors on smell and taste cells
Joe Schwarcz, PhD:
but there always are some residual small molecules...made of two or three units (dimers and trimers) embedded in the plastic
Joe Schwarcz, PhD:
with heat these will evaporate and you can taste and smell tehm
Joe Schwarcz, PhD:
the amounts are very very small...and there is no evidence of any physiological effect
madtram:
Polycarbonate drink bottles are being sold in health stores as a safe alternative but you are saying that the best evidence indicates that polycarbonates are more susceptible to BPA leaching?
Joe Schwarcz, PhD:
there is some confusion here..polycarbonate bottles are the ones that are implicated in BPA leaching..the alternatives are made of polysulfones or polyesters
katscan:
Some vegetables come in those microwave bags — are they safe to use? What about storing food in ziploc bags? I do that all the time. Am I exposing myself to BPA?? Thanks!
Joe Schwarcz, PhD:
Not a molecule of BPA in sight...
Joe Schwarcz, PhD:
these are made of polyethylene...the same as the shopping bags....hula hoops....
Joe Schwarcz, PhD:
pig balls...
Joe Schwarcz, PhD:
not those pig balls!
Joe Schwarcz, PhD:
the ones that farmer's throw into the pig pens so that the pigs will play with the balls instead of nibbling oneach others' tails and ears
Joe Schwarcz, PhD:
not a canadian thing!
Joe Schwarcz, PhD:
American pigs also like to play with balls
ginger899:
I have heard that some plastics contain chemicals that mimic estrogen. What impact could this have on, say, the possibility of developing breast, uterine, or ovarian cancers?
Joe Schwarcz, PhD:
you are right..we are talking again about BPA and phthalates...they are estrogenic..
Joe Schwarcz, PhD:
but we are exposed to estrogenic compounds all over the place...
Joe Schwarcz, PhD:
soy contains isoflavones which are estrogenic..so do chickpeas...and of course milk!
Joe Schwarcz, PhD:
and if you like red wine...and who doesn't...you are exposed to resveratrol...the chemical that is associated with the "benefits" of red wine
Joe Schwarcz, PhD:
guess what...resveratrol is an estrogen mimic!
Joe Schwarcz, PhD:
nobody seems to talk about that or that the natural estrogens in milk are thousands of time more potent estrogens than BPA