In 1968, more than a thousand people in Yusho, Japan became sick after eating food cooked in PCB contaminated oil. This was the first time in nearly 40 years that PCBs were even considered to have toxic effects on humans. Since that incident, there have been disagreements over the health effects from PCBs. The one thing experts can agree on is that PCBs can be found almost anywhere.
PCBs were first manufactured in 1929 and quickly became regarded as an industry favorite due to their nonflammability, chemical stability and electrical insulating properties. PCBs were used in hundreds of industrial and commercial applications including electrical, heat transfer and hydraulic equipment. PCBs also were used as plasticizers in paints, plastics and rubber products, in pigments, dyes and carbonless copy paper.