Dioxins in remediation workers

A survey was conducted on workers involved in the remediation of a large, chemically contaminated site in Sydney, Australia. Workers were monitored for chlorinated dioxin and furan congeners in blood lipids over a two year period. Baseline levels of blood dioxins in workers starting at the site were similar to background dioxin levels in Australians (below 10 pg/g blood lipids). An action level of double the background levels (20 pg/g blood lipids) was used as an occupational health limit. As time progressed, blood lipid levels in workers increased, with the most likely source being exposure while working at the site. While levels of most congeners remain relatively even, most striking was the proportion of tetrachloro-congeners in exposed workers, which increased steadily. Worker exposure was above the action level in a small number of workers; these workers were transferred to other projects where the potential for dioxin exposure was absent. The role of congener profiling in occupational biological monitoring may provide additional information on workplace exposure to dioxins and related compounds.