DIOXIN CONCENTRATIONS IN THE BLOOD OF WORKERS AT MUNICIPAL WASTE INCINERATORS

Objectives-increased concentrations of polychlorinated dibenzo-p-dioxi ns (PCDDs) and polychlorinated dibenzofurans (PCDFs) in pooled blood s amples from workers at municipal waste incinerators have been reported . This study was undertaken to confirm these results in individual blo od samples from potentially exposed and unexposed workers at municipal waste incinerators compared with matched unexposed controls and compa red with concentrations in the slag and fly ash from the municipal was te incinerators. Methods-Concentrations of PCDDs and PCDFs were determ ined in the blood of 10 workers from an old municipal waste incinerato r without adequate pollution controls, 11 workers from a newer inciner ator with modern pollution controls, and 25 controls from the general population group matched for age (+/-10 years), sex, and race, and in the slag and fly ash from the older incinerator. Results-Significant i ncreases of certain PCDDs and PCDFs were found in the blood of the wor kers from the older incinerator compared with the controls as follows: octaCDD (1051 (438) v 637 (344), P < 0.001), hexaCDF (52.3 (28.7) v 3 0.2 (18.2), P < 0.01), heptaCDF (43.9 (30.4) v 22.7 (12.4), P < 0.001) , total PCDDs (1262 (484) v 825 (454), P < 0.001), total PCDFs (133.0 (68.1) v 93.7 (36.7), P < 0.05), and total PCDD/Fs (1395 (537) v 918 ( 437), P < 0.001). The workers from the older incinerator with the grea test exposure were found to have the most significant increases of the blood PCDDs and PCDFs, and the pattern of increased PCDD and PCDF con geners in the blood corresponded to the pattern in the incinerator sla g and ash. No significant differences were found between the blood con centrations of the workers at the newer incinerator and the controls. Conclusion-Occupational exposure to slag and fly ash from municipal wa ste incinerators may increase the blood concentrations of PCDDs and PC DFs. Modern pollution control technology in new incinerators may be ab le to minimise potential exposure to slag and fly ash and thus the abs orption of PCDDs and PCDFs from this source.