The production of PCBs was prohibited in developed countries during the 1970s and 80s. More than 20 years have passed, but problems still remain because proper treatment of PCB wastes and products has not been pursued. The PCBs remaining at this moment can be divided into 3 groups: 1) PCBs still in use; 2) stored PCBs; and, 3) PCBs in locations that are unknown due to inaccurate management. All of these are sources of trouble.

The production of PCBs is prohibited in many countries, but some products that were produced and distributed before the prohibition are still in use while they remain functional. Their continued use creates risks of environmental pollution.

Equipment that contains PCBs is used in open applications or in closed systems. Open application means that the product is always exposed to the environment directly. PCBs are easily released into the environment, and cause immediate and serious problems. Products in open application include sealing materials between concrete walls and windows or doors, which are used as heating insulation or water leakage prevention. A Swedish scientist reported that PCBs in sealant evaporate in small amounts and contaminate room air. When a building using this form of insulation is torn down, the disposal of such waste material becomes a problem. It is necessary to treat this material as a PCB contaminant.

Is there a problem when PCBs are used in a closed system, tightly sealed, and considered to be not leaking? Yes. On the presumption that PCBs will not leak from containers, closed-system equipment containing PCBs, such as transformers and capacitors, are still being used. PCB use is permitted until theses products are taken out of service, but their continued use causes many problems.

Photo:Center for Marine Environmental Studies (CMES), Ehime University

One problem is the frequent occurrence of accidents. It is too late to change these products when worn out. In Europe, fire and explosion accidents of transformers and stabilizers have been reported. After twenty or thirty years, equipment becomes old and can explode unexpectedly. In Japan, as well, explosions of capacitors used with fluorescent lights have been reported recently; PCBs showered over students' heads in schools. To avoid such accidents, we should immediately stop using equipment that contains PCBs, and not wait until problems arise.

There are other problems caused by using closed-system equipment. Though called "closed system," such equipment is not perfectly sealed and PCBs may leak out of tiny gaps in fittings (Refer to this page). We should stop the use of such equipment as soon as possible, and replace it with new products.

Expired and discarded PCB equipment should be treated properly, by carefully extracting toxic materials. These materials should be treated as soon as possible, but we cannot treat them unless we have proper facilities. Without disposal capacity, we are forced to store these products. When there are few facilities for handling such materials, as is the case in Japan, all discarded PCBs must be stored. This is not only costly but is very risky.

Just storing PCBs pollutes the environment. Watanabe (1996) examined the air in a storeroom of expired stabilizers in Thailand, and reported that higher concentrations of PCBs were detected in air near the stabilizers than in air 5 meters distant. When the stabilizers were taken away, concentrations of pollutants diminished by half. This result very strongly suggests that the PCBs in the stabilizers were the source of the air pollution. PCBs in storage appear to leak out little by little.

When storage periods are prolonged, owners may change, there may be inaccurate management due to bankruptcy or termination of business, or the stored products may end up missing or causing an accident.

How is PCB equipment treated when lost? We can easily assume that such equipment is not treated properly. It may be handled in the same way as non-toxic equipment, thereby polluting the environment. Or, it may be abandoned in waste treatment plants. There is also the possibility that such equipment may be illegally exported to developing countries where there is no information, nor strict control of PCBs. Unfortunately, we do not have reliable information on missing PCB products. Once lost, we are helpless to take action.

Clearly, we should not allow more PCB wastes to become lost. We must carry out thorough control of PCBs, and we must check the labels and the oil itself to confirm that no PCBs remain in disposed equipment. Instead of simply storing these dangerous products, we must mount an effort to treat them properly.