Health Chats
The Real Truth About Plastics: What you should and shouldn't worry about
Wednesday Dec 08, 2010, 07:30PM - 08:30PM (EST)
Joe Schwarcz, PhDBlank
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