I have my spiels. I have a summer safety spiel about sunscreens and insect repellents. A winter safety spiel about helmets for skiing and not venturing out on thin ice. Then there are the year-round safety spiels. Wear your seat belt. Look both ways. Don't talk to strangers. It's my job to keep kids safe.
Increasingly I find myself having to give environmental safety spiels. Children are uniquely vulnerable to environmental contaminants for a number of reasons. For one thing, infants and young children tend to mouth objects. Children also breathe proportionally more air than adults and are also closer to the ground and so are exposed to more contaminants in soil and dust. Lastly, children's still-developing nervous and endocrine systems may be more at risk.
One group of environmental hazards I've found to be of particular potential risk to children is of plasticizers. Plasticizers are man-made chemicals used in the manufacture of many household plastic products. Two kinds in particular are of concern. Phthalates are chemicals added to poly-vinyl-chloride (PVC) products to make them soft and flexible. Bis-Phenol A or BPA has the opposite effect. It is used to impart hardness to certain kinds of plastics such as polycarbonate.
Phthalates are used in medical devices like intravenous tubing, but also in food packaging and baby toys like rubber ducks, bath books and soft vinyl blocks.
BPA can be found in many baby bottles and sippy cups. BPA is also used in some composites and sealants used in dentistry.
Phthalates are also ubiquitous contaminants in soil, air and dust. One particular phthalate, diethylhexylphthalate or DEHP, is produced at the rate of almost 2 tons per year. Human exposure comes largely from food contaminated during growing, processing or packaging.
So what exactly are the health risks of plasticizers? Both phthalates and BPA are known as endocrine disrupters. They can act like hormones in the body or block the actions of the body's own hormones. There are few studies on the effects of these chemicals on human health, therefore much of our knowledge is extrapolated from animal studies. Rodents exposed to high levels of phthalates in utero had an increased incidence of abnormalities of the male reproductive tract as well as decreased birth weight. In animal studies, BPA exposure was associated with early puberty as well as increased body weight.