Environment

We're Hip to the Dangers of Lead and Asbestos in Old Buildings, But We're Only Just Getting Wise to the Risks Posed by PCBs

Schools across the country are loaded with compounds known to cause major skin irritations and hair loss, and we still aren't aware of their full effects.

You probably know that many paints and window caulks manufactured prior to 1978 contain lead. And you may also know that old vinyl plastic floor tiles may contain asbestos. But you might not be aware that these old building materials and many more are also likely to contain highly toxic polychlorinated biphenyls or PCBs.

These PCBs outgas into the air or become part of the dust in old homes and buildings as the paints, caulks and plastic materials degrade with age. And it is likely they will be costing you a good chunk of your tax dollars soon, because they are in many older school buildings all over the country. Experts are already studying the PCB problem in my hometown of New York's schools.

On November 30, 2010, I attended a public meeting in New York City where experts discussed proposed responses to a pilot study of three local schools that showed high levels of PCBs in classroom air and dust. In these particular schools, the primary sources of the PCBs appeared to be leaking fluorescent light ballasts and old deteriorating caulking compounds. The consensus of the panel seemed to be that the city should replace the old lights and caulk in all city schools and the problem would be over.

This is a shortsighted conclusion, considering that PCBs are actually in many, many building materials and products manufactured before 1978. Since PCBs are extremely stable compounds with respect to heat, light and chemical attack, they are perfect for high-temperature applications, plasticizers and fire retardants. Starting in the 1950s, these miracle chemicals were added to just about everything. One list compiled by the EPA in 1999 says that PCBs were used in:

…some wool felt insulating materials, plastics, paint formulations, small rubber parts, adhesive tape, insulating materials used in electrical cabling, fluorescent light ballast potting materials, gaskets in heating, ventilation and air conditioning and other duct systems, caulking, coatings for ceiling tiles, flooring and floor wax/sealants, roofing and siding materials, adhesives, waterproofing compounds, anti-fouling compounds, fire retardant coatings, coal-tar enamel coatings for steel water pipe and underground storage tanks …and any number of other chemicals uses such as additives and plasticizers.*

In my new book, Pick Your Poison, I use the PCBs to illustrate a really cynical use by manufacturers of a principle called "chemical substitution." This is a process of making subtle changes in the molecules of toxic chemicals to render them "new" chemicals which are then considered unregulated. Here's how it works.

The PCBs, or polychlorinated biphenyls are based on a double benzene ring chemical called biphenyl that has 10 different locations on which a chlorine atom could be placed. When more than two sites are occupied with chlorine atoms, it is common to refer to them as polychlorinated biphenyls. Because there are so many locations and combinations of locations at which chlorine can be located, the PCBs are actually a large class of chemicals.

These "miracle" chemicals made all of the products they were added to last longer, look and function better, and resist fire. By the late 1960s, though, it was clear that they lasted just as long in the environment and the PCBs were considered "probable human carcinogens" by the EPA. There is also evidence that they cause adverse effects on the immune, reproductive, nervous, and endocrine systems. People exposed to large amounts of PCBs also showed telltale signs such as hair loss and a peculiar disfiguring type of acne called chloracne.

Industry fought regulation of these chemicals claiming that products made without PCBs would be inferior in quality, fire resistance, durability, and more. However, the hazards of PCBs became more and more firmly established and they were banned in 1977. Clearly, the paints and other products made after 1977 did not suddenly all fail after this date. In fact, the quality of many of these products improved.

One would think that was the end of the PCB story -- but it's not.

First, construction, demolition, and renovation workers today are still exposed to PCBs. The EPA only requires testing of old paints, caulks, and similar materials only for lead, even though the EPA knows these products are just as likely to contain PCBs. And although EPA regulations under the Toxic Substances Control Act (TSCA) stipulate procedures for handling and disposing of PCB-containing waste materials, TSCA does not require that materials such as paints and caulking be tested for PCBs prior to a building's demolition.

Second, the story is not over because industry immediately replaced PCBs with substitutes. Manufacturers simply exchanged the chlorine atoms on the biphenyl molecule for bromine atoms. Bromine and chlorine are brother and sister elements in the chemical world. They have a great many characteristics in common.

So the quality of products did not alter because the polybrominated biphenyls (PBBs) were substituted for PCBs in your paints, plastics and other materials in commerce. And shortly after that, the molecule was altered again by placing an oxygen molecule in between the two benzene rings to create the equally large class of polybrominated biphenyl ethers (PBBEs).

The cynical part of this story is that anyone with half a brain knew there was no reason to believe that the PBBs or the PBBEs were any less toxic than their chlorine-containing siblings. But because there were little or no data on these brominated chemicals, industry had 30 years to use the various substitutes without legal or regulatory repercussions.

And we soon had good human evidence for the toxicity of the PBBs. For a few months in 1973-'74, a Michigan farmer mistook bags of these chemicals for an animal feed additive and the chemicals got into meat, milk and eggs. Even this limited exposure caused some Michigan residents to develop the same skin disorders seen in people exposed to PCBs such as acne and hair loss.

The publicity involved in this incident resulted in cessation of PBB manufacture, but they were never banned. And the PBBEs are still in our products today. The European Union has banned some of these chemicals for use in plastics and other products. But here in the United States, I can be pretty certain that as I write this article, PBBEs are leaching out of the plastic elements of my computer and into the air and dust in my home office right now. And you and I are almost surely carrying some PCBs, PBBs and PBBEs in our bloodstreams.

So the officials at the public meeting in New York City who are considering strategies for removing PCBs ballasts and caulks from our children's schools are only addressing a tiny part of the problem. Instead, they need to look at many more potential sources of PCBs in school building materials, test also for the PBBs, and consider the toxicity of the products we purchase for schools even today.

* Federal Register, vol. 64, pp 69358–69364, December 10, 1999; quote is from p. 69359.

This article is adapted from the forthcoming book,Pick Your Poison, M. Rossol, Wiley & Sons, projected 2011.

Monona Rossol is the author of the forthcoming book, 'Pick Your Poison: Our Mad Dash to Chemical Utopia is Making Lab Rats of Us All' (Wiley Books).