image via GreenSage.com A chemical in certain plastics, bisphenol
A (BPA), is leaching into our urine if we drink or eat from certain
plastic bottles or containers. BPA has already been linked to
diabetes and cardiovascular disease, but the Harvard School of Public
Health (HSPH) is calling for additional research on BPA and breast
cancer, reproductive health, and on BPA's effects on infants and
children using these containers.
The HSPH research participants were 77 Harvard volunteer college students. At the start of the study, students were told not to drink anything out of plastic, only stainless steel or glass, and just to drink their normal amount of liquids that way; it was a kind of BPA detox. After a week, their urine samples came back low for BPA.
But the following week, the students were each given two polycarbonate plastic drinking containers and told to drink their normal amounts of cold fluids from these bottles; no heat was to be applied to the bottles, through the dishwasher, microwave, or hot liquids.
The urine tests following the week of drinking from plastic showed BPA concentrations up 69 percent. They were that high, even though no hot liquids were consumed from the bottles, nor were the bottles heated. Leaching of BPA is predicted to be even higher when heat is present, as when baby bottles are heated.
Polycarbonates are hard plastics and are very clear, even though they may be color-tinted. Many baby bottles, sippy cups, food containers, and drinking glasses for the home are made with polycarbonate; they resemble the clarity of glass, but are not breakable. They may be marked "non-leaching," but leaching is still possible, especially if they are heated.
Some polycarbonate producers have already agreed not to use BPA in their bottles but, as a consumer, you should be seeing that information on the label or the packaging. "PC" is usually written on the bottoms of containers or the number "7." Though not all "7" containers are made with BPA, if you are not sure, don't use them.
Plastics with recycling labels "1," "2," or "4" do not contain BPA and they would be better choices. They may be made of polyamine, polypropylene, or polyethylene. Use glass or metal containers, but make sure that metal containers do not have a liner of plastic, like a travel coffee cup; it's likely to contain BPA. Also beware of food cans that have plastic liners.
The HSPH study, Use of Polycarbonate Bottles and Urinary
Bisphenol A Concentrations appears on the website of the journal Environmental Health Perspectives.
Sources: HSPH via RDMag.com, Living the Science, Environmental Working Group