Harvard Study Confirms Leaching of Bisphenol-A (BPA) from Polycarbonate Plastic Bottles
Bisphenol-A (BPA) is a chemical commonly used in the manufacture of polycarbonate plastics, and has recently been the subject of profound attention as a result of concern over its effects on human health. The first study of BPA’s effects on humans was published in September 2008 by Iain Lang and colleagues in The Journal of the American Medical Association. In this study, the authors found that high BPA levels were significantly associated with heart disease, diabetes, and abnormally elevated levels of certain liver enzymes1. Research also appears to confirm that BPA exposure during development has carcinogenic effects and produces precursors of breast cancer2, 3.
Human exposure to BPA appears to be associated with the leaching of this chemical from the plastic lining of canned foods and from polycarbonate plastic bottles. Whether ingestion of food or beverages from polycarbonate containers increases BPA concentrations in humans had not been well studied until recently.
A new study published by Harvard researchers in the May 2009 issue of Environmental Health Perspectives confirmed that in their study sample, one week of polycarbonate bottle use increased urinary BPA concentrations by two-thirds4. The study concluded that regular consumption of cold beverages from polycarbonate bottles is associated with a substantial increase in urinary BPA concentrations irrespective of exposure to BPA from other sources.
The full-text manuscript of the Harvard study can be viewed here.
What does this mean for you? In light of results from this latest study, as well as based on results from previous studies, it may be prudent to observe some cautions:
1. All plastic containers are marked with a recycle symbol. Avoid using all food and beverages from containers that have the numbers 3 or 7 listed inside the symbol (unless the plastic indicates that it is BPA-free).
2. Do not heat food/beverages in plastics or expose plastics to hot liquids. Upon heating, BPA leaches out 55 times faster than it does under normal conditions.
3. Epoxy resins containing BPA are used as coatings on the inside of almost all food and beverage cans. Therefore, it is advisable to minimize the use of canned foods.
4. The National Toxicology Panel recommends avoiding microwaving food in plastic containers, putting plastics in the dishwasher, or using harsh detergents, to avoid leaching.
5. STAY ON TOP OF RESEARCH! — This is an evolving field of study, and there may be much more for us to learn. Ignorance often hurts or kills too many. So, stay tuned to this site or keep on top of other authoritative breaking news on this topic.
Notes:
1 Lang IA, Galloway TS, Scarlett A, Henley WE, Depledge M, Wallace RB, Melzer D (2008). Association of Urinary Bisphenol A Concentration With Medical Disorders and Laboratory Abnormalities in Adults. JAMA 300 (300): 1303.
2 Murray TJ, Maffini MV, Ucci AA, Sonnenschein C, Soto AM (2007). Induction of mammary gland ductal hyperplasias and carcinoma in situ following fetal bisphenol A exposure. Reprod. Toxicol. 23 (3): 383–90.
3 Soto AM, Vandenberg LN, Maffini MV, Sonnenschein C (2008). Does breast cancer start in the womb? Basic Clin. Pharmacol. Toxicol. 102 (2): 125–33. Abstract available at: http://www.ncbi.nlm.nih.gov/pubmed/18226065
4 Carwile et al (2009). Use of Polycarbonate Bottles and Urinary Bisphenol A Concentrations. Environ Health Perspect doi:10.1289/ehp.0900604. Full-text available online at: http://www.ehponline.org/members/2009/0900604/0900604.pdf
