Polychlorinated Biphenyls (PCBs) and Flame Retardants (PBDEs)

Please note that this section contains my personal notes from my readings on this topic.
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PBDEs are a group of compounds used as flame retardants in children’s pajamas, computers, TVs, foam for furniture, upholstery, rugs, draperies, and car interiors.  In most cases, these chemicals impede ignition, and if a fire starts, they hinder the spread of flames, allowing people time to escape.  As products that contain PBDEs age and break down, these chemical mixtures seep into the air.  Like PCBs, flame retardants stick around for a long time, can travel far, and accumulate in the fat and tissue of humans, animals, and fish.

It is difficult to detect the damage PBDEs do to our children’s growing bodies.  Scientific research conducted on rodents has revealed that, like PCBs, PBDEs interfere with the thryoid gland’s ability to send its hormone thyroxine to do its job in promoting a healthy fetal brain.  Because PCBs and PBDEs are structurally and toxicologically similar, scientists anticipate seeing all of the cognitive and health problems now attributed to PCBs.

– The Toxic Sandbox (2007) by Libby McDonald; page 109

From The Toxic Sandbox (2007) by Libby McDonald; pages 99 – 103:

The Bad News

• Although the EPA banned the production of polychlorinated byphenyls (PCBs) in 1977, without a program to effectively remove PCBs from older electrical equipment, landfills, and waterways, these pollutants will persistently creep into our food chain.
• PCBs are not only persistent but they are fat soluble, meaning they can linger for decades in the fatty tissues of virtually every living organism on the planet.
• Because they accumulate in our bodies more quickly than they are excreted, the older we are when we have children, the more PCBs we expose to our babies, both in utero and through our breast milk.
• PCB levels in breast milk decrease as we breast-feed our babies — as our own decades of exposure are taken up by our infants when they consume our breast milk.
• Although PCBs are steadily declining in our fatty tissues, they are rapidly being replaced by what some news reports have called “the next PCB” — chemical compounds called PBDEs, which are found in fire retardants.
• Structurally and toxicologically like their long-ago-banned chemical cousin, PBDEs are also persistent and bioaccumulative.
• Although there have not been a great deal of studies on the effects of PBDEs, scientists believe they harm children, as PCBs do, impairing learning, memory, attention, and behavior.
• Flame retardants in fabrics such as children’s pajamas are volatile, steadily releasing into the air.
• PBDE concentrations in North American women’s breast milk has been measured at seventy-five times higher than levels in the breast milk of European women.

In animal studies, PCBs and PBDEs are linked to:

• Low birth weight
• Decreased intelligence
• Problems with short-term memory
• Attention deficit disorders
• Impaired immune function
• Hypothyroidism
• Various cancers
• Disruption of sex hormones

The Science

Effects of PCBs on Lake Michigan Children

In the early 1980s some women living close to Lake Michigan consumed on average two to three local PCB-tainted fish meals each month while they were pregnant.  At the time, they did not know the fish were tainted with PCBs, nor were they equipped with information about the prenatal effects of PCBs on unborn babies.

In an effort to understand the prenatal exposure to PCBs, the husband and wife team of Drs. Sandra and Joseph Jacobson, psychologists at Wayne State University in Detroit, tested 212 of the children born to Lake Michigan mothers in 1980 and 1981.  To identify lasting effects, they tested these same children eleven years later.

They found that children whose mothers’ PCB levels (measured in blood samples and breast milk) were slightly higher than the general population had elevated rates of “low normal” IQ scores, difficulty with concentration, poor reading comprehension, and short-term memory problems.  Exposure to these chemicals after birth in breast milk did not appear to further harm the children’s mental capabilities.  Some researchers believe this is because breast milk has built-in qualities that protect babies from environmental contaminants.

From The Toxic Sandbox (2007) by Libby McDonald; page 106:

Ninety percent of a child’s PCB intake is through food, with fish accounting for the highest exposure.  Because farmers use fish meal, fish oil, and waste animal fats as food supplements, the beef, pork, chicken, and dairy products we buy may also include a dose of PCBs.  PCBs are so persistent and accumulative that those consumed by our children may actually be passed on to our grandchildren.

Notes in this “File”:

• Protect Your Children From PCBs and PBDEs