Cash register and credit card receipts are a likely source of BPA exposure

Prior posts have noted the controversy surrounding BPA, and the enormous evidence that it poses a significant threat to human health. As noted in prior posts, research has been demonstrating that BPA is an estrogen-mimic that leaches out of polycarbonate plastics, resins used to line most food cans, and dental sealants; besides impacting gonads, there is also some evidence that BPA may make individuals more likely to develop cancer in the future. Most of the concern has focused on the use of BPA in various plastics, and the leaching of BPA from these plastics into liquids contained in the bottles, tubing, and cans. Now, cash register and credit card receipts have been identified as a potential route of exposure.
 
 
Some carbonless copy papers (now used for most credit card receipts) and the thermal imaging papers that are spit out by most modern cash registers, rely on BPA. Manufacturers coat a powdery layer of BPA onto one side of a piece of paper together with an invisible ink. When heat or pressure is applied, the ink and BPA would merge to yield color.
 
 
When reviewing the potential for harm from BPA in polycarbonate bottles, the quantities described as the leaching of nanogram quantities. In contrast, the average cash register receipt that uses the BPA technology [and not all of them do] apparently has 60 to 100 milligrams of free BPA. Free-BPA is not bound into a polymer, like the BPA in polycarbonates; in contrast, it represents individual molecules of BPA that are loose and, one might say, ready for uptake. Ironically, this may mean that in the urban environment the largest source of human exposure to BPA is in the form of credit card and cash register receipts.
 
 
Once on the fingers, BPA can be transferred to foods. Additionally, researchers note that some hormones (like estrogen in certain birth-control formulations) are delivered through the skin by controlled-release patches. Thus, researchers are justifiably concerned that estrogen mimics like BPA might similarly enter the body through the skin. The particular route is not a certainty at present. BPA and real estrogen do not have the same structure, so their permeability might vary. Additionally, there are all kinds of materials in the skin that might selectively degrade or alter this hormone imposter as it passes through. At present, no one knows.
 
 
The data on this issue has not yet been published in a pier-reviewed journal. However, media stories on the research can be found at http://www.usnews.com/money/blogs/fresh-greens/2009/10/08/bisphenol-a-another-reason-you-dont-need-your-receipt and http://www.newsinferno.com/archives/13299.