Bisphenol A, found in everything from baby bottles to the lining of tin cans, could constitute a danger to human life and health, Health Canada reported last week.
Even the dental industry has cause for concern:"Just when they thought they could breathe easy after years of controversy concerning mercury-based fillings, dentists are finding themselves at the centre of a new debate over the safety of the alternatives," writes Carly Weeks in The other place bisphenol A lurks: our teeth .
"An increasing number of dentists are using sealants and fillings that may expose patients to bisphenol A, a chemical the federal government said last week is potentially dangerous and will be banned from use in plastic baby bottles."
Some studies have found detectable levels of BPA in the saliva of patients after they received sealants or fillings, but experts are divided as to whether this low exposure constitutes a health risk."
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The chemical, which studies show acts like the female hormone estrogen, has been linked to early puberty in girls, breast and prostate cancer, and attention deficit and hyperactivity disorderto cancer and infertility in animals.
Dr. Kapil Khatter's answers to select reader questions on BPA are now available and appear at the bottom of this page.
Dr. Khatter is a family physician and environment and health expert who leads chemical-related policy work at Environmental Defence. Dr. Khatter has a master's degree in environmental studies and has sat on a number of working groups tasked with providing expert advice to Health Canada and Environment Canada.
For the past couple of years, Dr. Khatter has been working on the review of Canada's national pollution law, the Canadian Environmental Protection Act, and on the federal government's Chemicals Management Plan.
Dr. Khatter is also a board member of Health Care Without Harm and the President of the Canadian Association of Physicians for the Environment. He has scientific and policy expertise related to the environment and health, with a unique perspective that comes from being a physician.
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Pearl Sefarian, London: Will you please give us some guidance regarding food in tins? Should we throw out what we now have in our cupboards? Are some foods in tins safer than others? I am thinking about acidic foods like tomatoes and tomato sauce, and also about tinned fish, and tinned lentils. What about peanut butter and vinegar which now routinely come in plastic jars with a triangle on the bottom? Is a triangle with the number 7 in it more dangerous than a triangle with the number 2 in it? thank you
Kapil Khatter: Hello Pearl, There is little information about which food cans are safest. The federal government's recent draft assessment found a broad range of bisphenol A levels in various canned food. The highest levels were actually found in canned vegetables and soups, but the number of cans tested has been too small for that to be a reliable guide. It may have as much to do with how the lining is made as with what food is stored inside. A few companies have started to use cans without bisphenol A and hopefully the number will increase.
Plastics with number 2 recycling symbols so far appear to be of less concern. But there is a lack of publicly available information on their potential risks. Polycarbonate food containers labeled with a number 7 (though not all number 7s), and PVC containers with number 3s are the ones that can leach bisphenol A. Laboratory research has raised serious concerns about the safety of the chemical, so avoiding bisphenol A plastics makes sense as a priority.
Ken Ohrn, Vancouver: I understand that roughly 2 million tons of BPA are manufactured each year. It is used in a wide range of products, including water pipes. With such wide usage, how could anyone avoid ingesting it?
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