Q. I was alarmed to read that eating canned soup can raise body levels of BPA. If this is true for canned soups, wouldn't it follow that other canned foods would pose the same problem?

A. Bisphenol A (BPA) is a component in clear hard plastics and the linings of cans. Many canned foods contain BPA that leaches into the food from the lining.

Research published in the Journal of the American Medical Association showed that people who ate canned soup for a week dramatically increased the amount of BPA in their urine (Nov. 23/30, 2011). Because BPA can act like estrogen in the body, this is worrisome.

There is another overlooked source of BPA. A different reader warns: "BPA also coats the paper that many store receipts are printed on. It comes off on hands. Consumers should decline receipts, or handle them with care and wash their hands afterward. Children should never be allowed to handle these receipts." Research has confirmed that register receipts often contain BPA that can be absorbed through the skin (Environmental Health Perspectives online, Jan. 1, 2012).

Q. I am an international flight attendant. I was pleased to read in your column that coffee might be used for asthma in an emergency.

I think we have some kind of asthma medication in our enhanced medical kit, but just in case, I now know we can use coffee as a backup plan.

A. There is some controversy about how effective caffeine is to open airways. A methodical review of the medical literature concluded that it can "improve lung function for up to four hours" (Cochrane Summaries, Oct. 5, 2011). When nothing else is available, a couple of cups of strong coffee might help.

PeoplesPharmacy.com