Title: Contemporary relevance of dioxin and dioxin like compound contaminations in residues from recycling of HCH waste

Auteur(s): Weber R ; Behnisch PA ; Brouwer A ; Van Bavel B ; Lindstroem G ; Zennegg M ; Schilling B ; Pauwels A ;  ; 

Year: 2006

Journal: Organohalogen Compounds

Subject(s): dioxin ;  ; 

Summary: 1, 2, 3, 4, 5, 6-Hexachlorocyclohcxane (HCH)A has been one of the most extensively used pesticides. The application of Lindane and technical HCH during the last 5 decades has resulted in environmental contamination with global dimension and Lindane and HCH is presently evaluated by the Persistent Organic Pollutants Review Committee of the Stockholm Convention for inclusion in the POPs lists. HCH is available in two formulations: technical HCH and LindaneB. Generally, technical HCH contains the isomers in the following percentages: á: 55-80%, â: 5-14%, ã: 8-15%, ä: 2-16%, and å: 3-5%. Of these isomers only the gamma isomer bas specific insecticidal properties. In the late 1940s and 50s the Technical HCH mixture as a whole was sprayed in Europe (and other countries). However it was soon discovered that the application of the technical HCH resulted in inedible crops, vegetables and fruits due to the bad smell and taste of same of the HCH isomers. Therefore, some companies started already in the 1950s with the isolation of the active, and in the applied concentration tasteless, gamma isomer and sold it under the trade name Lindane. The other HCH isomers resulting from production remained as by-products and became finally hazardous waste, creating one of the globe's largest hazardous organic waste problem. The production of Lindane is inefficient as for each ton of Lindane 8 - 12 tons of other HCH isomers are produced and therefore between 1.6 to 4.8 million tons have ended mostly as hazardous waste, which were dumped uncontrol1ed at many sites around the world. These sites and the fate of the waste as well as the consequences for humans and the environment have virtually been ignored but need to be addressed. Alternatively, some HCH waste isomers have been recycled by companies to trichlorobenzene and further products (Figure 2). One of these products in the recycling chain was 2,4,5-T, known to contain high PCDD concentrations and resulting in highly PCDD/PCDF contaminated residues from such production (Table I). In the present study, the distillation residue from HCH decomposition to trichlorobenzene (the key residue of HCH recycling) and the residue of 2,5-Dichlor-4-bromphenol production (an intermediate of the Bromophos production and the brominated-cblorinated analogue of 2,4,5- TCP) (Figure 2) were analysed by high resolution GC/MS and bio assay and the contemporary relevance of these residues is discussed. A second aim of this study was to evaluate samples from industrial processes by means of DR CALUX bioassay and to demonstrate the capability of bioassays for TEQ evaluation of products and residues from the chemical industry.