Roughly a year ago one of the first studies showing that BPA, the known estrognic plastic used to make polycarbonate bottles, leached into liquids under extreme conditions of heating and rigorous washing was published to much fanfare. The study raised a serious issue, although it seemed that unless you were routinely heating your liquids in a well washed bottle (huh? wash my water bottle? In the dishwater?) – a problem clearly relevant to new parents, but not so to folks like me who were done reproducing – ridding the household of all polycarbonate wasn’t a high priority. While I did replace the kid's bottles with the now suspect PET bottles (more on that one later) the old polycarbs still went to the tennis courts and up Mount Toby with me. I just couldn’t justify adding more plastic so the recycle or waste cycle so as long as I had it, I used it. Same with the gem-colored polycarb juice glasses we’ve used for years.
Well, as usual with chemicals we’re just getting to know more intimately than we’d like, there's always one more study that makes us wonder if "we've" really done our best when it comes to using chemicals wisely. This time it's a new study published in Environmental Health Perspectives by researchers at the Harvard School of Public Health which reports that BPA molecules really don’t need all that much coaxing to be released from bottle to water. In fact, just regular use, filling them up with cold liquids and drinking was enough to raise concentrations of BPA in the urine of polycarb bottle using Harvard students.
After one week of drinking all their cold beverages from Nalgene Lexan bottles (could you fill this bottle rather than that beer stein please?), and peeing into a cup during the designated hours of 5-8PM, students increased their pre-polycarb urine concentrations by 69%. In other words – you get a little BPA with your water even if you don’t heat it up and abuse the bottle.
Given that the very young (newborns and infants) tend to retain their BPA a bit longer (because their metabolic system which clears chemicals like BPA is less active than adults) this study, one of the first to show that normal use of polycarb means exposure to BPA, should give pause to any parent still using the old polycarb baby bottles. It’s certainly enough to push me to take those pretty gem-colored juice glasses and relegate them to the craft cabinet.
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3 comments:
Is a 69% increase necessarily something to get excited about? If you raise the level from 1.2 to 2.0 MIRCOgrams, is that really an issue? What level is the level of concern? If the level of concern is 10, who cares if we go up 69% from 1.2?
And - who drinks beer, in a bar, from their own water bottle? What would happen if we had realistic exposure data? If we're worried about baby bottles, then check the levels in baby formula that's been in the bottle, and check the BPA in baby urine.
Hi Joe, thank you for your comments. You are correct that exposure and dose matter. There have already been studies with baby bottles - and yes they do leach BPA, and the older more "used" (or washed) the bottle is, the more BPA leaches out.
The point of the beer remark was just that students were directed to drink all their cold beverages from the bottles (I made an assumption here -that twenty-somethings don't exist on just milk and water.) While it's true this was a worst case scenario - as you point out - who drinks all the time from polycarb?
However, that said, to get back to concentrations, while what leaches out may be low, I think our understanding of the potential impacts of the chemical is lacking. We know it is estrogenic - but don't always understand the subtle impacts of xenoestrogens such as BPA. We also know that we're exposed to a lot of different estrogens, both naturally occurring and from products like polycarbonate. How our bodies handle all these chemicals in combination is unclear. Often in this case, as we understand more - the "levels of concern" tend to drop over time as well.
When that is the case (there are insufficient data, the chemical is known to cause problems in higher concentrations, and we know there is exposure particularly to the youngest and most vulnerable) AND it is a chemical that can fairly easily be removed from consumer goods (it already has been removed from bottles and there are alternatives like glass) or reduced from our diet - then at least in our home, it makes sense to switch.
For more check out: http://www.sciencenews.org/view/generic/id/36488/title/Plastics_chemical_linked_to_heart_disease,_diabetes
I've been listening to the recent news on BPA and, as someone who used plastic baby bottles with both kids (12 and 8 years ago now), it is very disheartening.
Anyway, I came across your blog via your book on scientists and motherhood, via my research on American women scientists (I'm a historian). I love your perspective and easy-to-digest overviews of the issues!
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