Sunday, April 3, 2011

BPA, a widely used chemical I try to avoid.



I first became aware about Bisphenol-A (BPA) some time ago when I heard recommendations to avoid plastic baby bottles made with BPA. Then, I noticed that companies like Nalgene started offering clear plastic drinking bottles BPA free. Recently, I became aware that some food companies have been choosing to eliminate BPA from their aluminum can liners. I started wondering about BPA and whether I should be concerned.

It turns out that BPA is found in many products we use everyday, including aluminum cans, plastic water bottles, and even cash register receipts (where it is used to coat the thermal paper used for printing). It is used to make polycarbonate plastic and epoxy resins. These products are meant to harden plastic and coat things, but the BPA content may be of concern.

BPA is a synthetic estrogen and even trace amounts have been shown to disrupt hormones in the endocrine system. The body's balance of hormones is delicate and any external disruption can cause a wide variety of problems. BPA has been linked to chromosomal damage, reproductive system abnormalities (erectile disfunction and severely reduced sex drive, among others), impaired brain and neurological functions, cardiovascular system damage, adult-onset diabetes, early puberty, obesity, asthma, cancer, and even resistance to chemotherapy. Those last two are a terrible combination -- gives you a disease (cancer) and prevents a potential treatment from working at the same time.

BPA based plastics break down readily, especially when heated or washed with strong detergents.  Heating plastic baby bottles, dishes, or food storage containers in a microwave or washing them in a dishwasher causes more BPA to be released. Furthermore, BPA is readily absorbed through the skin, so when you accept a cash register receipt that is coated with BPA you will not be able to help absorbing some of this chemical.

Unfortunately, as with many chemicals, the risks of BPA are not well understood. The most concerning evidence about BPA is linked to the effects on infants and young children and so I particularly recommend that you be aware of these issues with infant formula, baby bottles and other foods given to children. The evidence for adults is less clear, but it stands to reason that something that has dangers for children may also pose risks for adults; we're all humans, after all.  I think it is prudent that pregnant women, and even women of childbearing age, consider avoiding BPA whenever possible. We would all probably do well to adhere to the precautionary principle and avoid BPA whenever possible, unless and until more evidence clarifies the issue.



If you think you have avoided exposure, think again. The U.S. Centers for Disease Control and Prevention (CDC) has found detectable levels of BPA in the urine of 93 percent of Americans tested over the age of six. The EWG (Environmental Working Group) has been investigating BPA and has published some concerning data.  In one study, EWG found that BPA had leached from epoxy can linings into more than half the canned foods, beverages, and canned liquid infant formula randomly purchased and tested at supermarkets around the country. Furthermore, EWG found high levels of BPA on 40 percent of receipts sampled from major U.S. businesses and services, including outlets of McDonald's, CVS, KFC, Whole Foods, WalMart, Safeway and the U.S. Postal Service.

My suggestions concerning BPA:
  • Avoid canned food if you are not sure that the can lining is BPA free. Particularly avoid canned foods for infants and children as even canned baby formulas have been found to leach BPA. Use glass baby bottles, drink bottles, and food storage containers. Glass is chemically inert and probably the safest type of container you can use. Even the lids used on glass containers may contain BPA, so be sure to check with the manufacturer about any metal part used in a container.
  • Avoid polycarbonate, especially for children's food and drinks. Avoid plastic bottles, plastic food storage containers, and particularly plastic baby bottles. This plastic is usually marked with the recycling code #7 or the letters “PC”. Plastics with the recycling labels #1, #2, and #4 on the bottom are better choices because they do not contain BPA. Soft and cloudy plastics also do not contain BPA (e.g. Nalgene produces a cloudy colored, soft water bottle that is BPA free).   
  • Avoid heating plastic bottles or containers in the microwave unless you know they are BPA free (Personally, I avoid heating plastic containers even if they are BPA free, as I am not comfortable with what else we may find out is leaching from plastic during the heating process).
  • Avoid metal water bottles or thermoses with liners, as the liner may contain BPA. Choose refillable stainless steel water bottles without a liner.
  • Use BPA free plastic containers only when you really need them (for example, when taking a packed lunch), and be cautious about heating the container.
  • Avoid handling your store register receipts unless you are certain that they are not coated with BPA. You can usually feel the difference, as BPA coated receipts feel slippery and different from ordinary paper.  Ask the person at the cash register to place the receipt directly in your bag or refuse the receipt altogether. ( I try to only handle these receipts if I need to return an item) 
  • Support companies that are making the investment in removing BPA from their products.  It is more costly for them to do this, so consumer support will dictate how fast this transition takes place.

Finally, since avoiding BPA also means avoiding many plastics, I think we all get a secondary benefit from avoiding this potentially toxic chemical. Plastics, while often recyclable, nonetheless are harmful to the environment for many reasons. The entire life cycle of plastics from the raw materials (petroleum and petrochemicals), to their inevitable escape into our oceans is fraught with problems. Anytime we can avoid them, we are helping not just ourselves, but the planet as a whole.

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For more information about:
Companies providing BPA free cans: http://www.treehugger.com/files/2010/03/7-bpa-free-canned-foods.php
BPA in canned goods: http://www.ewg.org/reports/bisphenola
BPA in store receipts: http://www.ewg.org/bpa-in-store-receipts
BPA skin penetration: http://www.ewg.org/news/science-news-skin-no-barrier-bpa
History and Timeline about BPA: http://www.ewg.org/reports/bpatimeline
A review of the science about BPA from STATS at George Mason University: http://stats.org/stories/2008/why_journ_failing_plastics_may6_08.html
Factsheet on BPA from NSF International: http://www.nsf.org/consumer/newsroom/pdf/FACT_SHEET_ON_BPA.pdf
For a good overview of the problem with plastics: http://5gyres.org/


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Researched and written by Dr. Rebecca Malamed, M.D. with assistance from Mr. Malcolm Potter.

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