Polychlorinated Dioxins Research Articles

Sources and Relative Importance of PCDD and PCDF Emissions

Polychlorinated dioxins (PCDD) and dibenzofurans (PCDF) have been identified in technical products and pesticides, most of which are not very widely used today. Other sources are incinerators of various types like MSW incinerators, hazardous waste incinerators and industrial incinerators. PCDDs and PCDFs have also been identified in exhausts from cars running on leaded gasoline with halogenated additives. Background levels of PCDDs and PCDFs have been identified in fish and other aquatic organisms from the Great Lakes and the Baltic Sea, and also in human adipose tissue samples from U.S.A., Canada, Sweden, Japan and Vietnam as well as in samples of breast milk from Sweden, Denmark, West Germany, the Netherlands, Yugoslavia and Vietnam. The isomeric pattern in all these biological samples is very similar. The relative importance of different sources to the general background is difficult to estimate although the contribution of direct inhalation from point sources like MSW incinerators is small.

Measurement of combustion products from liquid PCB waste incinerator

Liquid polychlorinated biphenyls(PCB) waste was burned at 1400°C for 2 seconds, and activated carbon for post gas treatment system were analyzed for determining combustion products. The main products were chlorophenols(CP) and trace amount of polychlorinated dioxins(PCDD) and polychlorinated dibenzofurans(PCDF) were detected.

Remedial measures and disposal practices for wastes containing dioxins and furans

Recent events in Seveso, Italy and in Niagara Falls, New York, Jacksonville, Arkansas, and the State of Missouri regarding polychlorinated dioxins (PCDDs) and a major transformer fire in Binghamton, New York involving polychlorinated biphenyls (PCBs) and polychlorinated furans (PCDFs), have clearly illustrated the need for swift, appropriate, remedial measures to control and contain contaminated areas.The paper discusses alternative approaches that have been or are currently being employed for the destruction or containment of PCDD-, PCB-, or PCDF-contaminated wastes in the United States. Because of the notoriety of these “political wastes”, evaluation of control measures is made more difficult; however, some generally useful conclusions are detailed.

Identification of polychlorinated dibenzofurans in environmental samples

The polychlorinated dibenzofurans (PCDFs) are tricyclic aromatic compounds, which in chemical and toxicological respects are very similar to polychlorinated dioxins (PCDDs). The 2,3,7,8-tetra-, 1,2,3,7,8- and 2,3,4,7,8-penta-CDFs are extremely hazardous compounds, they can be compared with the extremely toxic 2,3,7,8-tetra-CDD (ref. 1). PCDFs have been identified in PCBs at levels of 1–10 p.p.m., the major peaks being 2,3,7,8-tetra- and 2,3,4,7,8-penta-CDF (refs 2–4). A large number of PCDFs and PCDDs occur as contaminants in chlorophenols5–7, and they have also been recognized and identified in fly ash and other incineration products at the p.p.b.–p.p.m. level18–11. In 1968,1,200 people in Japan were poisoned (Yusho disease) by a cooking oil contaminated by PCB12 and more than 50 PCDF isomers13. Liver samples from exposed patients were found to contain a highly reduced number of PCDFs, apparently many isomers were excreted or metabolized14. We report here the identification of a series of PCDF isomers in environmental samples.