So I've been hearing a lot of talk lately about the possibility that plastic has some pretty bad health effects, but I really hadn't had the chance to read up about it until this month.
So here's the deal: There have been lots of studies that have found that some plastics have bad health effects, but according to the scientific community, there's not quite enough scientific evidence to be sure. Still, based on the research available, it is likely that both plastics #3 and #7 have some pretty nasty health effects.
Polyvinyl Chloride or PVC (Plastic #3)
Scientific research has found that phthalates, which are added to PVC to soften it for certain uses, leech out of PVC into the human body. Unfortunately for us all, studies have also found that PVC may cause side effects such as decreased lung function, increased weight, increased resistance to insulin, low sperm count, and DNA damage to sperm. It has also been found the exposure to phthalates in PVC may negatively effect the reproductive development of infant males, resulting in undescended testes, smaller scrota, and smaller penises.
USES: PVC is used in products such as children's toys, vinyl floors, wallpaper, shower curtains, vinyl bibs, and cosmetics, including lotions, shampoos, and nail polish. It is also used in many medical products including plastic bags for storing blood, plasma and intravenous fluids, feeding, breathing and dialysis tubes, catheters, respiratory masks, and exam gloves.
Polycarbonate (included in plastic #7 category, "Other")
Polycarbonate contains a chemical called bisphenol A that leeches into the foods that it comes in contact with. This chemical is widely known to mimic the human hormone estrogen. At this point, very little research has investigated the effects of Bisphenol A on humans. Based on the limited number of studies that have examined everyday contact with bisphenol A, the chemical may increase the risk of miscarriages and polycystic ovarian syndrome, a condition that can cause infertility, ovarian cysts, and baldness in women.
In animals however, bisphenol A has been widely researched. In the more than 150 studies on the effects of very low doses of bisphenol A in animals, the chemical has been linked to obesity, prostate and mammary gland cancers, early onset of puberty, reproductive-organ defects, reduced sperm counts, altered mammary glands, and difficulty getting pregnant. Scientists also found that low doses of bisphenol A received prenatally had lasting effects throughout an animal's lifespan.
Note that high doses of bisphenol A have not been found to cause significant effects, and that special interests groups have conducted high dose studies that have allowed them to make claims contrary to low dose studies.
USES: Polycarbonate is used in products such as baby bottles, aluminum cans, pop cans, nalgene bottles, generic polycarbonate water bottles, sunglasses, eyeglasses, safety glasses, coffee makers, consumer electronics, laptop computers, CDs, DVDs, and dental sealants. It's also used for many other products including car parts, water filters, textiles, and paper, and is a widely used flame retardant.
To read more about potential negative health effects of PVC and Polycarbonate, visit:
L.A. Times article - Plastic May Not Be So Fantastic for Kids
Salon.com article - Two Words: Bad Plastic