Most people have heard of PCBs, and know their bad, but are not aware of what they actually are and why we produce them.
Photo: Molly O’Connor
PCB is an acronym for Polychlorinated Biphenyls. These were compounds produced as far back as the 1920’s and were used for such things as microscope oils, electrical insulators, capacitors, and electrical appliances (such as televisions). They were also sprayed on dirt roads to keep dust down. Much of the environmental contamination came from the disposal of products containing PCBs in landfills and roadside ditches, but some came from the processing facilities as well.
Today, it is believed about 1.5 billion pounds of PCBs have been produced since the 1920’s and can be found in sediment and tissue samples worldwide; this includes human tissue and has been found in the arctic. It is a suspected carcinogen and is known to affect hormone function as well as the development of the immune system.
Production of PCBs was banned in 1979. Though sunlight and microbes can break them down, the process is slow and the compounds can still be detected in the environment.
Photo: Rick O’Connor
In the Pensacola Bay System, it was first noticed in 1969 within shrimp tissue from Escambia Bay. Repeated sampling since 1969 continues to find them. They have been found in oyster tissue within Escambia Bay and East Bay, as well blue crab tissue from Blackwater River and East Bay. They have also been found in sediments from several tributaries of the PBS – such as Indian Bayou, Bayou Chico, and East Bay.
So how much is there and is the seafood safe to eat?
The Florida Department of Health developed advisory limits – these are based on an 8-ounce meal
| PCB concentration (ppb) | FDOH recommended consumption rate (8-ounce meal) | % of PBS samples that had PCBs at this concentration |
| Less than 50 | All you want | 69% |
| 50 – 100 | 1 meal / week | 14% |
| 110 – 500 | 1 meal / month | 12% |
| Greater than 500 | Do not eat at all | 3% |
The most recent studies indicates that mullet in the upper Escambia River may have high levels of PCBs within their tissues. Concentrations of these compounds are much lower in the lower parts of the PBS and in the East Bay area.
So what can we do?
Monitor the most recent information on seafood safety by visiting www.myescambia.com/our-services/natural-resources-management/marine-resources/seafood-safety.
Dispose of electronic waste (e-waste) responsibly. ECUA has an e-waste disposal site at their landfill. Please take your e-waste to this location and do not discard on the side of the road.
Reference
Lewis, M.J., J.T. Kirschenfeld, T. Goodhart. 2016. Environmental Quality of the Pensacola Bay System: Retrospective Review for Future Resource Management and Rehabilitation. U.S. Environmental Protection Agency. Gulf Breeze FL. EPA/600/R-16/169.
NOAA. (2017). What are PCBs? NOAA website. https://oceanservice.noaa.gov/facts/pcbs.html.
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