Polychlorinated Biphenyls (PCBs): Closing the book on PCBs; problem solved.1 Feb 2011
This should be a short blog since PCBs were banned from production in 1979 and must be long gone from the environment. It seems like PCBs have gone the way of acid rain, hole in the ozone, Dodo bird, and that cute little kiwi bird on your can of shoe polish. Oh sure, there might be some PCBs behind a barbed wire fence someplace, but we can move on, right?
Last summer on a bike trip through Black Moshannon State Forest in Central Pennsylvania I noticed a 6” x 6” sign on a telephone pole that read, “Caution Contains PCBs.” It got me thinking; was that sign from 30 years ago? What is the state of PCBs in the environment today? My 30 second search of PCBs for this area turned up a 2011 public health advisory for fish consumption due to mercury and PCB contamination.1 The Agency for Toxic Substances and Disease Registry (ATSDR) have summarized the health implications for PCB exposure and have found that there are “significant health consequences” associated with large amounts of fish consumption. Other findings: developmental deficits and neurological problems in children whose mothers ate PCB contaminated fish.2
The sign on that bike trip listed “40CFR761,” the Code of Federal Regulations (CFR) which has a variety of exemptions to PCB restrictions. Equipment containing liquid PCBs may still be maintained as long as they are enclosed. Some of the exemptions include electromagnets, capacitors and transformers. Solid forms of PCB-containing products also have use exceptions to the rules. One notable example is carbonless copy paper. Use authorizations may be given for products under 50ppm; such products would include: adhesives, caulk, coatings, grease, paint, rubber, gaskets, and sealants, to name a few. 3 The rules take into account that any process that involves carbon, chlorine and heat may produce PCBs.
Back to that bike ride; the sign is explained in 40CFR761.40 p.572 where a transformer on a utility pole that contains greater than 50ppm of PCBs must be clearly marked on that pole. PCBs are still used and inadvertently manufactured today. 4
The EPA is currently reassessing these regulations and plans to have updates to the CFR by April 2013. 5 While this class of compounds has not been manufactured in large quantities in 30 years their use continues and their persistence assures that they will be in the environment for a long time.