Toxicological aspects and occurrence of polychlorinated biphenyls in food/ Aspectos toxicologicos e ocorrencia dos bifenilos policlorados em alimentos

CBs are synthetic organic compounds that were widely used in industry as dielectric fluids in transformers and capacitors, paints and lubricants hydraulic oils. After being detected in the environment on the end of 60, then they were identified as contaminants in the whole ecosystem, including the air, water, soil, plants, animals, humans and food, which led to its prohibition in 1977, in the United States, and in 1981, in Brasil. Nevertheless, its use is still allowed in our country in old electronics, until its replacement by other free PCB product. This has resulted in several use episodes, inadequate storage and disposal, contaminating the environment, animals, humans and all the food chain. Studies show that these compounds are able to cause significant changes, such as neurotoxicity, endocrine disruption, and immunosuppression, among others. According to the IARC, PCBs are classified in Group 2A (probably carcinogenic to humans), with the exception of PCB 126, which belongs to Group 1 (carcinogenic to humans). Because their high lipophilicity, accumulates in the food chain and, consequently, has been detected often in many kinds of food, which is the main source of human contamination. The aim of this review is to present the mains aspects related to polychlorinated biphenyls in foods, including their characteristics, toxicological aspects and occurrence.