title: A comparison of TEQ contributions from PCDDs, PCDFs and dioxin-like PCBs in sewage sludges from Catalonia, Spain.
abstract: Eight sewage sludges from rural, urban and industrial wastewater treatment plants (WWTPs) in Catalonia (Spain) were analysed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) to determine the present levels of contamination. A method based on an automated cleanup system followed by an isotope-dilution high-resolution mass spectrometric analysis was employed. Total toxicity equivalent (WHO-TEQ) values were calculated using the toxicity equivalent factors (WHO-TEFs) proposed by WHO for dioxin-like PCBs, PCDDs and PCDFs. The WHO-TEQ(PCDD/F) values for these samples ranged from 4.9 to 20.8 pg/g dry weight (d.w.), with a mean value of 9.3 pg/g d.w., whereas WHO-TEQ(PCB) levels ranged between 1.9 and 6.6 pg/g d.w., with a mean value of 4.2 pg/g d.w. The WHO-TEQ(PCB) contribution varied from 13% to 50%, suggesting that PCB contribution on the toxicity of the samples must be taken into account. Moreover, these contemporary PCDD, PCDF and PCB concentrations were compared with previous data obtained from sewage sludge samples collected during the 80s. Our findings show that contemporary PCDD, PCDF and PCB levels have declined since the 80s.
authors.affiliation: Mass Spectrometry Laboratory, Ecotechnologies Department, IIQAB, CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain. eeeeco@cid.csic.es
authors.forename: E
authors.initials: E
authors.lastname: Eljarrat
authors.forename: J
authors.initials: J
authors.lastname: Caixach
authors.forename: J
authors.initials: J
authors.lastname: Rivera
mesh_terms: D001331:Automation; D001572:Benzofurans / Q000032:analysis*; D002947:Cities; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D007220:Industrial Waste; D013058:Mass Spectrometry; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis*; D012722:Sewage / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013030:Spain; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004785:Environmental Pollutants; D007220:Industrial Waste; D000072317:Polychlorinated Dibenzodioxins; D012722:Sewage; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls