Toxin BPA Contaminates Plastic Beverage Containers
By Michael Ross
This article was published by PristinePlanet.com Newsletter, issue #8, 2005-06-10.
As if the problem of chlorine, lead, pesticides, and other toxins in our municipal water is not enough, there is growing concern with the plastic containers from which we drink that water, as well as other beverages. Specifically, scientific studies indicate that most plastics leach various pollutants into the fluids stored in and dispensed from the water bottles and other containers made from those plastics.
For instance, there is a brewing controversy over one such toxic substance, bisphenol A (BPA), a chemical utilized in the manufacturing of clear, hard plastics such as those found in food-storage containers, baby bottles, and the lining of soda cans. BPA is released from such plastics when they are washed, heated, or exposed to acidic substances — such as citrus fruit juices and soda — and simply from the aging of the plastic. In turn, the BPA contaminates the contained food with which it comes in contact.
Health experts know that sex hormones, even in tiny amounts, can have dramatic effects upon human beings. Unfortunately, BPA imitates the sex hormone estradiol. This has prompted scientists to test the substance upon laboratory rats and mice. As a result, they have discovered that even low doses of BPA can cause hyperactivity, increased formation of fat, early onset of puberty, abnormal sexual behavior, disruption to normal reproductive cycles, and structural damage to the brain.
But how significant is the usage of BPA? Given that 6 billion tons of the chemical are produced every year, and then used to make these everyday beverage containers and other items, it is little wonder that researchers are actively investigating the effects of BPA on living organisms exposed to it. Furthermore, BPA is used not just as the building block for polycarbonate plastic, but also in the manufacture of epoxy resins and other plastics.
Astonishingly, these results have been known for many years. In a peer-reviewed and comprehensive study published on 13 April 2005 in Environmental Health Perspectives, Frederick S. vom Saal and Claude Hughes of the University of Missouri noted that there have been 115 published studies on the low-dose effects of BPA. Of these published studies, 94 reported deleterious effects on the mice and rats tested, while only 21 studies found no damage. It is rather telling that of the 11 studies funded by chemical companies, not one found any adverse effects from BPA. (Of course, this could just be a coincidence.) Of the studies conducted by scientists not associated with chemical manufacturers, over 90 percent discovered ill effects from BPA.
But as consumers in a free market, we have choices. The types and levels of pollutants released by plastic containers, depend upon the acidity of the liquid and any damage to the plastic, such as aging, heat, cold, and direct sunlight. Another major factor is the type of plastic. For example, high-density polyethylene, designated "#2 HDPE", is soft and opaque, and typically used for 2.5-gallon water bottles. The plastics industry and government deem #2 HDPE safe, while many health researchers argue that it is one of the most common culprits of water toxicity from plastic. Some sources advise people to instead opt for polyethylene terephthalate (#1 PETE) or polycarbonate (#7), which are harder.
But rigidity alone is no guarantee of safety. Lexan polycarbonate resin was developed by General Electric in 1953, and is now widely used in products ranging from baby bottles to bulletproof windows. Because it is hard and durable, and does not acquire or impart any odors or flavors, it quickly became a favorite for water bottles and other beverage containers. Sadly, it has been shown that plastics made using polycarbonate resin can leach BPA. In 1998, Dr. Patricia Hunt of Case Western University discovered that Lexan-based plastics contaminate liquids with BPA, which can reduce sperm count and interfere with normal prostate and breast tissue development. She documented that such leaching can occur even as a result of normal usage at room temperature, as well as exposure to cleaning agents and heat. These results were published in 2003 by the journal Current Biology.
Clearly, BPA is a widespread and worrisome pollutant that we are still being exposed to, despite mounting evidence of its toxicity. Unless something is done about it, then scientists could reconfirm the dangers using another 90 studies, and yet we would still be exposed to BPA.
Copyright © 2005 Michael J. Ross. All rights reserved.