Appeared in Southern Sierran, February 2006
Plastics Damaging to Health: fetuses and children particularly at risk
by Sarah S. Mosko, Ph.D.
Plastics can pose threats to human health at all stages in our life cycles, with specific risks varying with the type of plastic.
In the process of converting petroleum or natural gas into plastic, toxic chemicals can be released into the air and water supply. For example, vinyl chloride, a known carcinogen, is used to make polyvinyl chloride (PVC) plastics. A chemical called perfluorooctanaote (PFOA) used in the production of plastic-coated non-stick cookware is also carcinogenic.
An assortment of “additives” is often needed to lend particular characteristics to a product. Many items, like computer casings 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 other, called deca, is still in use and currently under scrutiny for similar health concerns. Since flame retardants are mixed with, but not chemically bonded to the plastic polymer, they are free to migrate out of the plastic during routine use.
Many products require plasticizers called phthalates to make them soft and flexible; these also are not chemically bonded to the plastic. Pliable PVC items, like some soft children’s toys as well as blood bags and medical tubing, can be up to 40 percent phthalates by weight. Pre-natal exposure to some phthalates causes male reproductive tract abnormalities, like malformed testes and infertility in lab animals. Preliminary data suggest this might hold true for humans as well.
Pre-natal exposure to a chemical building block of polycarbonate plastics, like 5-gal water jugs, has been linked to recurrent miscarriage in humans, according to a preliminary study. 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 of chemicals from food packaging and water bottles into the contents of the packaging 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 put objects in their mouths and spend more time indoors on the ground than adults do.
So how do you know if you’re at risk in some way? You don’t. Scientists are just now trying to sort out the impacts of the host of industrial chemicals that has been accumulating in our bodies in recent decades. Definitive answers may be a long way off. What is clear, however, is that fetuses are most vulnerable in general to environmental toxins. 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’ve decided I can live with a lot less of it.