PCB's are a major threat to world health yet their hardly dicsussed in terms of major world problems. Lets look at the facts PCB - or PolyChlorinated Biphenyls was a great step forward for industrial chemistry. They were widely marketed in the 1930s onward and have been used as coolants and lubricants in transformers, capacitors, and other electrical equipment because they don't burn easily and are good insulators. Products made before 1977 (in the United States and Europe) that may contain PCBs include old fluorescent lighting fixtures and electrical devices containing PCB capacitors, and old microscope and hydraulic oils. The manufacture of PCBs was stopped in the US in 1977 because of massive evidence that PCBs build up in the environment and can cause harmful health effects. The truth is that PCBs are extremely stable in the environment and do not biodegrade. They are a pollutant without equal. PCBs were used because of their special qualities, such as: " low vapor pressure " EXTREME stability, non-biodegradability " high boiling point: 278 to 415 C " low solubility in water: 20 C, 15 ppb " good solubility in many organic solvents and in lubricants " good thermal conduction " high dielectric constant " high-temperature resistance However, as an environmental pollutant it is unequalled, and it accumulates in animal tissue with resultant pathogenic and teratogenic effects. It is unquestionably carcinogenic, and under certain conditions converts to dioxin, a highly toxic poison. PCBs were used (and are still used) as coolants and lubricants in transformers, capacitors, and other electrical equipment because they don't burn easily and are good insulators. But the transformers (you can see transformers on electrical transmissions poles, or at any generating or electrical transmission location), will "leak" after a time, and the PCBs make their way into the environment. But not only. PCBs will enter the air, water, and soil during their manufacture, use, and disposal. They can enter the environment from accidental spills during the transformers servicing or their transport. PCBs can still be (and are) released to the environment from normal or hazardous waste sites; from the illegal or improper disposal of industrial wastes and consumer products. PCBs commonly enter the environment by the improper burning of old electrical transformers containing PCBs in municipal incinerators Perhaps the worst form of entering the environment is from illegal dumping. In countries like Greece, the Army, Navy and even the Public Power Corporation would dismantle the old transformers and dump the PCBs into the sea, or shallow pits in desolate areas. How many other countries have been also guilty of this activity? There Goes the Sushi! PCBs once into the environment will bind strongly to soil. PCBs exposed to the air can also travel long distances and be deposited in areas far away from the pollution site (polluters seem to know this phenomenon). If dumped in the water, only small amounts of PCBs may become dissolved. The rest usually bind to organic particles and bottom sediments. As a natural process then, the PCBs are ingested by small organisms and fish in water. They are naturally then ingested by other animals that eat these smaller animals as food. Its is an established fact that PCBs accumulate in fish and marine mammals tissue, and reach levels that may be many thousands of times higher than in water. A test on any fish caught in the wild (or farmed for that matter) will show levels of PCBs now, and is proof of contamination of the sea. What Does PCB do to you? Due perhaps to its wide negative political effect, PCB damage is not as studied or reported as it should be. Dioxin (which PCB can revert to) is a highly toxic and poisonous chemical damaging the liver and easily causing death. There are many studies which show that PBCs cause cancer, birth defects, and other debilitating illnesses. Damage to the liver is a given effect. It is in your food chain and cooking will not purge it from the food. It is in vegetables and fish, meat and chicken. And some countries still use it, and some industrialized countries wish to send their old PCB to underdeveloped countries for easy disposal. |
