[Abiotic and biotic transformation of persistent organochlorine compounds in the environment]

Abstract

The presence of persistent organochlorine compounds in the environment is defined as being of anthropogenic origin. They are the result of intentional production (pesticides, solvents, dielectric and hydraulic fluids, flame retardants etc.) as well as they are produced as unintentional by-products from many processes (incineration, pulp and paper production, use and production of chlorinated aromatic chemicals and PVC). Nowadays, they are recognized as one of the major classes of the contaminants in the environment because of their wide distribution and a high capacity to bioaccumulate in organisms--especially in higher levels of the trophic food chain. They have been also claimed to cause adverse effects on organisms and human. In the paper, the main classes of chlorinated hydrocarbons are presented, including pesticides, polychlorinated biphenyls and dioxins. The proposed degradative pathways--abiotic (photolysis, hydrolysis) as well as biotic (biotransformation by microorganisms and higher organisms, including human) are reviewed on the basis of current literature.