Appeared in:
- Vall-E-Vents, the San Fernanado Valley Sierra Club Newsletter, Jan-Feb., 2006.
Plastics – an Unhealthy Habit?
(#6 of the Plastic Plague Series)
Sarah S. Mosko, Ph.D.
The endocrine disruptor bisphenol A is used in the synthesis of some wildly popular polycarbonate water bottles. Photo from ourstolenfuture.org
Plastics are lightweight, flexible, durable and can be molded into just about anything. They fill our toy chests, refrigerators, medicine cabinets and desk tops. Since the explosion of consumer plastics in the 1950s, we have come to rely on them to get us through our busy lives. But, there is a dark side to plastics as well, and it has to do with our health.
Plastics can pose threats to human health at all stages in their life cycle, with specific risks varying with the type of plastic.
During synthesis from petroleum or natural gas, toxic chemicals are used which can be released into the air and water supply. For example, vinyl chloride (a known carcinogen) is used to make polyvinyl chloride or PVC plastics, and a chemical called perfluorooctanaote (PFOA) used in the production of plastic-coated non-stick cookware is also carcinogenic. Furthermore, an assortment of “additives” are often needed to lend particular characteristics to a product.
Many items, like computer housings and hair dryers, require flame retardants because plastics are highly flammable. A family of brominated flame retardants are used most extensively, two of which recently were eliminated from the U.S. market because fetal exposure impairs normal development. The chief one still in use, called “deca,” is currently under scrutiny for similar health concerns. As flame retardants are not chemically bonded to the plastic polymer, but rather just “mixed in,” they are free to migrate out during routine use. Likewise, many products require plasticizers called phthalates to make them soft and flexible, and they are also not chemically bonded. Pliable PVC items, such as some soft children’s toys, as well as blood bags and medical tubing, can be up to 40% by weight phthalates. Pre-natal exposure to some phthalates causes male reproductive tract abnormalities (e.g. malformed testes, infertility) in lab animals. Preliminary data suggest this might hold true for humans as well.
Similarly, a preliminary study has linked pre-natal exposure to a chemical building block of polycarbonate plastics (e.g. 5-gal water jugs) to recurrent miscarriage in humans. That chemical is called bisphenol-A or BPA. BPA, phthalates and brominated flame retardants are all known “endocrine disruptors,” meaning they mimic or block the action of our naturally occurring sex hormones estrogen and testosterone.
That some plastic constituents leach out is not just a hypothetical concern. Migration from food packaging and water bottles into the contents has been documented in a number of scientific studies, and leaching continues when plastics are littered or land-filled. Human exposure to plastic toxins is now essentially universal with a wealth of research showing widespread contamination of human tissues with BPA, phthalates, flame retardants and chemicals from non-stick cookware. Exposure stems not only from direct contact with plastics, but also from the ubiquitous pollution of our air, water, soil and house dust. Youngsters tend to have the highest contaminant levels, perhaps because they commonly mouth objects and spend more time indoors on the ground.
So how do you know if you are at risk in some way? You don’t. Scientists are just now trying to sort out the impact of the host of industrial chemicals accumulating in our bodies in recent decades. Definitive answers may be a long ways off. What is clear, however, is that fetuses are most vulnerable in general to environmental toxins, so we need to start thinking about how our consumer choices could be affecting them. Does this mean you should throw out everything of plastic in your life? That is probably not feasible, unless perhaps you plan on moving to an Artic igloo. But I, for one, have decided to kick the plastic habit and opt for alternatives like glass, aluminum, steel, cardboard and cloth whenever I can.
I remember, almost nostalgically now, a time before plastics played center stage in our lives. For health’s sake, I have decided I can live with a lot less of it.
Boogie Green 