|Image by Justin Marty|
The study was published in the journal Environmental Health Perspectives and is the first that actually counted the number of toxic chemicals in the bodies of pregnant women. 163 chemicals were studied and 43 of them were found in nearly every one of the 268 women tested.
The researchers also looked at non-pregnant women and found even higher levels for some chemicals, suggesting that pregnant women may be exercising greater precaution in what they eat and use in their homes. Nevertheless, even at the relatively low levels found in the women, many of these chemicals can have serious consequences for their babies, increasing the risk of birth defects, cancer, cognitive impairment and possibly even obesity.
Below is a list of some of the 43 chemicals found in the majority of the women along with their likely sources and potential health consequences:
- Polychlorinated biphenyls (PCBs) used to be used to insulate high voltage transformers Production was banned in the U.S. in 1979. High exposure can cause skin and liver damage, cancer or death. They can also cause cognitive impairment and neurological damage to children. PCBs both inhibit and mimic the female hormone estradiol, contributing to their mutagenic effects.
- Organochlorine pesticides are a group of chemicals used primarily as insecticides, and include chemicals like DDT, which has been banned for decades in the U.S. However, because they break down very slowly in the environment they continue to contaminate our food supply. These chemicals have been linked to cancer, as well as liver, kidney and neurological damage.
- Polybrominated diphenyl ethers are a class of banned flamed retardants that are chemically similar to PCBs. While this class of chemicals has been banned in some states (California, 2006), similar toxic flame retardants continue to be used and are actually required by law as a flame retardant in the foam of furniture and mattresses, and as insulation in electrical devices. Therefore, all Americans are continually exposed to these chemicals, many of which are known carcinogens. They can also leach into the food supply. A study in Canada found them in salmon, beef, cheese and butter. According to the EPA, they can cause thyroid, liver and neurological damage and reduce fertility.
- Bisphenol A is used to line canned foods and to make some plastics and epoxy resins. It is an endocrine disrupter that may cause neurological damage and cause mutations. It is not yet clear what health effects can be attributed to the substance. However, several preliminary studies suggest that it may have negative effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposure levels.
- Phthalates are used to soften plastics, especially PVC, but have also been used as a coating for pills, as lubricants and in eye shadow, nail polish and hairspray. This class of chemicals also causes hormone disruption and has been linked to premature puberty in girls. Some scientists believe there is a link between neonatal phthalate exposure and undescended testis in boys, though link has not yet been confirmed. Phthalates have also been linked to obesity.
- Polycyclic aromatic hydrocarbons are a common class of chemicals found in smoke and are be produced by cigarettes, campfires, barbecues, candles, incense and plug-in air fresheners. Even when women avoid smoking during pregnancy, exposure can still occur from these other sources as well as from the secondhand smoke of friends, family and neighbors. Shockingly, recent research suggests that even third-hand smoke (residues that stick to walls and furniture and slowly desorb over time to enter the ambient air of a room) can persist in building for years after all smoking has ceased. Not surprisingly, third hand smoke also contains a host of toxic and carcinogenic compounds.In one study, researchers examined the homes of smokers who had moved out and that had remained empty for several months before nonsmoking renters moved in. Not only did they find higher levels of third hand smoke on the walls compared with nonsmoking homes, but the new nonsmoking renters had elevated levels of nicotine in their bodies.
|Second Hand Smoke, by hsufehmi|
The good news is that our exposures to many of these substances can be significantly reduced. For example, exposure to Bisphenol A can be minimized by avoiding the use of plastic bottles and aluminum cans made with the substance. And exposure to polycyclic aromatic hydrocarbons can be reduced by avoiding smoke, especially tobacco smoke, but also candles, incense and air fresheners.