Polychlorinated naphthalenes: an environmental update.

Polychlorinated naphthalenes (PCNs; CNs) form a complex mixture of up to 75 congeners containing from one to eight chlorine atoms per naphthalene molecule. Chloronaphthalenes are widespread global environmental pollutants which accumulate in biota. All chloronaphthalenes are planar compounds and can contribute to the aryl hydrocarbon (Ah) receptor-mediated mechanism of toxicity with a combination of various 2,3,7,8-tetrachlorodibenzo-p-dioxin like toxic responses. There are three known main sources of environmental pollution with PCNs: technical PCN formulations, technical polychlorinated biphenyl formulations, and thermal and other processes in the presence of chlorine. The purpose of this paper is to briefly review the most recent data on environmental pollution, chemistry, analysis, sources, formation, persistence, toxicity and behavior of PCNs.