POLYCHLORINATED BIPHENYL, DIBENZODIOXIN, AND DIBENZOFURAN OCCURRENCE IN THE GENERAL ENVIRONMENT IN ITALY

Topsoil and sediment samples from the Italian general environment were assayed for PCBs, PCDDs, and PCDFs. PCB levels appear to range between 6.2 X 10(2) and 1.6 X 10(4) ng/kg in open areas and between 1.2 X 10(2) and 6.8 X 10(2) ng/kg in cave samples. PCDD plus PCDF levels, as TCDD equivalents (TE units), are between 1.0 X 10(-1) and 4.3 ngTE/kg in open areas, and between 5.7 X 10(-2) and 1.2 X 10(-1) ngTE/kg in cave samples. The less chlorinated PCB homologs seem to reach higher relative levels in cave sediments than in the topsoil of open areas, this probably due to a lower dissipation rate. PCDD plus PCDF levels (TE units) versus cumulative PCB levels provide highly significant linear regression in logarithmic coordinates.