The adverse effects of this chemical are in the news again, causing many people to wonder if it shouldn’t be banned outright.
Bisphenol A (BPA) is a chemical commonly used to line food and beverage containers and to harden plastics. It is the chemical Health Canada cited when recommending that we stop using certain hard-plastic water bottles and baby bottles this past spring.
The springtime ban affected only the sale of baby bottles and clear plastic water bottles with bisphenol A in them. However, the chemical is used in many other types of food containers, including cans, and in a very large number of other consumer products such as CDs, dental sealants, carbonless receipt paper, etc. It breaks down most easily when in contact with heat (part of the canning process), with fatty foods such as fish, with acidic foods such as tomatoes or apple juice, and with alcohol. (source)
Health Canada has already assured Canadians that none of the levels of bisphenol A found when testing cans exceed current Health Canada guidelines. However, to many in the scientific community, acceptable exposure rates are controversial. At the same time, many studies observing health effects at significantly lower levels are dismissed by regulating bodies. (source)
This past Wednesday, the Journal of the American Medical Association (JAMA) published an article entitled Association of Urinary Bisphenol A Concentration with Medical Disorders and Laboratory Abnormalities in Adults. This article notes a significant link between the presence of bisphenol A in urine and higher rates of diabetes and cardiovascular disease, two of the fastest-growing diseases in Canada. According to the report’s authors:
Using data representative of the adult U.S. population, we found that higher urinary concentrations of BPA were associated with an increased prevalence of cardiovasular disease, diabetes, and liver-enzyme abnormalities. These findings add to the evidence suggesting adverse effects of low-dose BPA in animals. Independent replication and follow-up studies are needed to confirm these findings and to provide evidence on whether the associations are causal. (source)
The article goes on to explain that the controversy about the risk BPA poses to humans is based on animal testing, and notes that effects are species-specific.
According to the article, the way that BPA gets into our bodies (ingested, absorbed through the skin or breathed in) may have different harmful effects. It raises concerns about the constant low-level exposure that has become prevalent in modern society. There are also concerns about it leaking into the environment.
The time when BPA enters our system is also important, “given that BPA changes the programming of genes during critical periods during the development in fetuses and newborns”. (source) This is because BPA is an endocrine disruptor: low doses can mimic our hormones, possibly causing negative health effects.
How can you recognise products with BPA?
- Many products with bisphenol A in them are identified by the recycling numbers 7, 7PC, or 3PVC.
What alternatives can you use? (source)
- Use glass, stainless steel or porcelain containers, especially for hot food or liquids
- For baby bottles, choose glass or look for hard plastic bottles without bisphenol A. They can be found in health food stores and in some baby stores.
- For preserved goods, opt for glass jars or canned goods that do not have liners containing BPA.
Donna MacLeod for Consumer Health Information Service, Toronto Public Library [read original post]
- Text of the JAMA article Association of Urinary Bisphenol A Concentration with Medical Disorders and Laboratory Abnormalities in Adults (September 17, 2008)
- JAMA article Bisphenol A and Risk of Metabolic Disorders (September 16, 2008)
- Government of Canada Takes Action on Another Chemical of Concern (June 5, 2008)
- Plycarbonate/BPA Global Group (plastics industry) publications: What is Bisphenol A and how is it used? (July 2007) and Bisphenol A and Consumer Safety (undated)
- World Wildlife Fund, Bisphenol A: A Known Endocrine Disruptor (April 2000)
- BPA news from Environmental Health News (RSS feed)
- CBC News, Bisphenol A: FAQ (September 16, 2008)