Plastics
When I first met Mrs. F (long before she officially became Mrs. F), she got me to abandon all of my plastic tupperware food containers due to her insistance that plastic was harmful to one's health. I was a little dubious about this, but she's wise in her knowledge of these things, so I trusted her. And now we've got a kick-butt collection of jars of every size and shape as well as loads of pyrex containers (with plastic lids, unfortunately). Today she pointed me to this news article from the San Francisco Chronicle about a recent study that links chemicals used in plastics with some adverse health effects:

Researchers have reported for the first time that they have found a highly significant link between human exposure to chemicals used in consumer products and adverse changes in the genitals of baby boys. The sons whose mothers' urine contained higher levels of phthalates, a family of compounds used to soften vinyl and other plastics, were more likely to show the physical changes, according to the University of Rochester study released Thursday. A second study, released Wednesday, looked at another chemical, bisphenol A, and found that pregnant lab animals exposed to very low levels of it produced offspring with impaired mammary-gland development. The exposure levels in the study, conducted by researchers at the Tufts University School of Medicine, were 2,000 times lower than the Environment Protection Agency's safe dose for the chemical. The EPA and the National Institutes of Health contributed funds for the studies to learn more about possible ill health effects from these industrial chemicals, which are produced in billions of pounds worldwide. [...] Bisphenol A has been used for decades in tough polycarbonate plastic. Polycarbonate plastic makes up the hard, brittle drinking water bottles, which may be clear or tinted, sold under the name of Nalgene and other brands, as well as baby bottles and tableware. The chemical is also used in dental sealants, medical devices and in the resin lining of most food cans. Phthalates are used in soft vinyl products and some perfumes, shampoos, soaps, makeup, pesticides, pill coatings and paints. Two forms, DBP and DEHP, are listed as reproductive toxicants and carcinogens by the state EPA, and the European Union has banned both in cosmetics. The chemical has been found at low levels in milk, drinking water and household dust.

Hmmm... I think I might give up my Nalgeen bottle. I think I might also be buying some gifts for a few of my young friends at Recycled Bags (brought to my attention from this post at Treehugger, a great enviro-commerce web site).