Dioxins and furans legacy of lindane manufacture in Sabiñánigo (Spain). The Bailín landfill site case study.

Lindane (γ-hexachlorocyclohexane) manufacture in Spain generated nearly 200,000tonnes of HCH wastes; near 160,000tonnes were originated by the Inquinosa factory located in Sabiñánigo (northern Spain) and were deposited in unlined landfill sites. This study reports for the first time the content of polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/Fs) in non-recycled HCH wastes that had been disposed in the Bailín landfill site in Sabiñánigo. Samples from solid HCH powder residues (white HCH and δ-paste wastes) and the dense non-aqueous phase liquids (DNAPLs), as well as landfill leachates, soil and sediments have been characterized. White HCH wastes exhibited a toxicity of 1488ngWHO-TEQ2005 ·kg-1 (Σ17 PCDD/Fs), while δ-paste wastes presented a noticeable higher toxicity (12,094ngWHO-TEQ2005 ·kg-1 ). Nevertheless, the maximum toxicity value was found for DNAPLs (37,353ngWHO-TEQ2005 ·L-1 ). Dioxins were predominant in the DNAPL waste whereas furans predominated in the landfill leachates, soil and sediments. However, in solid HCH wastes, PCDD and PCDFs contributed in a similar proportion. The PCDD/Fs congener profiles in landfill leachates, soil and sediments do not resemble the PCDD/Fs profiles found for the HCH wastes. These preliminary results will be of paramount importance in order to estimate the total quantities of PCDD/Fs disposed to the landfill site and to assess the potential mobility of PCDD/Fs, especially to groundwater and landfill leachates. Besides, this information is of great value to design periodical monitoring plans to evaluate the presence of PCDD/Fs in the impacted groundwater and leachates and finally, to evaluate the risk of PCDD/Fs for the environment and human health.