Dioxin-Like Polychlorinated Biphenyls at Dilijan Landfills (Republic of Armenia)

Polychlorinated biphenyls (PCBs) are substances of wide distribution, high toxicity, persistence, and ability to long-distance migration. They are characterized by unique properties: temperature stability; high boiling point; non-combustibility; resistance to chemical and physical influences; high dielectric constants. The old and new landfills of Dilijan district (Republic of Armenia) were investigated. Sampling was done at both the old and new landfills and 20 samples of soil were taken for further laboratory analyses. Determination was done on Shimadzu chromatograph equipped with an electron capture detector. Separation of substances was performed on a 60 m glass capillary column with DB-5MS UI. The results of analyses (n=560) were focused on concentrations of dioxin-like PCBs; non-dioxin-like PCBs; and common PCBs. Municipal waste dumps of Dilijan are active sources of PCBs accumulation and spread. In soil samples from both the old and new landfills excess concentrations of PCBs were found in 100% of cases compared to normative level, and the summary concentrations of the latter multiply exceeded the normative level. PCBs-related environmental pollution is of great concern because the emergence and spread of PCBs in nature is not always subject to control and regulation, as the sources of PCBs formation are diverse.