PCDD/PCDF on land around an industrial site and identification of source

Following the discovery of elevated levels of PCDD/PCDF in dairy products and in flue gases at a nearby industrial site, the levels and spatial distribution of these compounds on surrounding land were determined through soil monitoring. In mass terms, the levels in soil were excessive relative to the UK background but in terms of toxicity they were less significant. There were positive correlations between wind directions and deposition levels. The relative amounts of the prominent congeners/congener groups in the soil were similar to those in the flue gas but different from those in the background. An incinerator of chemical waste was identified as the likely source of the PCDD/PCDF.