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Polychlorinated biphenyls (PCBs) |
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What are polychlorinated biphenyls (PCBs)?
Polychlorinated biphenyls (PBCs) are a group of chlorinated compounds that were manufactured in the United States between 1929 and 1977. PCBs were used predominantly as coolants and lubricants in electrical equipment. The production of PCBs was halted in the United States in 1997 because of evidence of its environmental and human health effects from the manufacture, use and disposal of these chemicals. PCBs were never manufactured in Canada.
Today, PCBs can still be found in certain products made before 1977, such as hydraulic oils, and electrical devices including fluorescent lighting and transformers.
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What are the health concerns associated with PCBs?
The health and environmental concerns of PCBs are a result of their chemical properties. PCBs are very stable and slow to degrade in the environment. They are fat-soluble and can build up in fatty tissues of fish and mammals.
Spills of liquid PCBs could occur due to poor storage, during transportation and poor handling practices during the remediation process. These are of concern primarily because of the long-term effects associated with the accumulation of PCBs in the environment. Fires of PCB substances are of greater concern than spills. This is because the combustion products of PCBs, including dioxins and furans, can be released into the air, where they can be inhaled and/or further dispersed into the environment. Occupational exposures to large amounts of PCBs are associated with acne-like skin conditions and liver damage.
There are also indications that high dietary intake of PCBs can have adverse effects on the development of the foetus and may increase the risk of cancer. Infants born to women who regularly consume fish and wildlife that are contaminated with PCBs have a higher risk of neurobehavioural and immunological problems (i.e., problems associated with the nervous and immune systems).
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How could Toronto residents be exposed to PCBs?
The risk for PCBs exposure in Toronto is very low. Exposure to PCBs is limited to very low levels found in food and the environment. The major risk to Toronto residents from PCBs would be as a result of accidental exposure from spills or fires. Exposure to PCBs in contaminated food may be a concern for people who regularly consume fish and wildlife in their diet.
PCBs may be found in sport fish in local lakes in Ontario. It is recommended that residents, particularly women of childbearing age, including pregnant women and nursing mothers who consume sport fish caught in Ontario lakes refer to The Guide to Eating Ontario Sport Fish for consumption advice. This guide is published every other year by the Ontario Ministry of the Environment in co-operation with the Ministry of Natural Resources as part of the province's Sport Fish Contaminant Monitoring Program.
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How are PCBs regulated in Ontario?
The Ontario Ministry of the Environment (MOE), under Regulations 347 and 362 of the Environmental Protection Act, has the responsibility for regulating, approving and monitoring PCB waste storage sites.
In December 2001, the MOE proposed amendments to Regulation 362 that would require all PCB wastes currently in storage to be destroyed within three years, with accelerated destruction of PCBs being stored at sensitive locations (e.g., schools and hospitals). If endorsed, the amended Regulation will result in the elimination of all registered PCBs in storage in Ontario.
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Where are PCB storage sites located in Toronto?
In Toronto, the number of PCB storage sites has decreased steadily from about 340 sites in 1998 to about 200 in 2001. The Ontario Ministry of the Environment maintains a computerized inventory of all provincially registered PCB waste storage sites with more than 50 litres of PCBs. This list is updated yearly and is available on
CD-ROM. The CD-ROM can be purchased directly from the Environmental Monitoring and Reporting Branch of the Ministry by any member of the public at a cost of $75 (plus tax). To obtain an order form for the CD-ROM, the public can contact:
Ontario Ministry of the Environment
Environmental Monitoring and Reporting Branch
125 Resources Rd.
Etobicoke ON M9P 3V6
Tel: 416-235-6300
Fax: 416-235-6235
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Where can I find more information on PCBs?
Read other reports on PCBs prepared by Toronto Public Health or visit the following Web sites for more information:
Links to sites external to the Toronto Public Health Web site are provided as a convenience and their inclusion does not imply that Toronto Public Health endorses or accepts any responsibility for the content or use of these sites.
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