Analytical approaches and criteria to define environmental contamination from an accidental polychlorobiphenyl (PCB) spillage

On December 7, 1988, 1400 kg of a PCB‐based dielectric fluid mixture from a power transformer were accidentally spilled over stretches of two paved roads in southern Italy. After the accident, analysis of residual fluid left in the transformer revealed the presence of polychlorinated dibenzodioxins and dibenzofurans at a concentration of 1.4 μg/g (expressed as 2,3,7,8‐tetrachlorodibenzodioxin “toxicity equivalents"). The analytical strategy and criteria adopted during the emergency phase to identify areas with different chemical contamination and risk levels are described.