Characterization of persistent-bioaccumulative-toxic (PBTs) substances in hazardous waste: Integration of chemical analysis and in vitro fish cells response

Abstract

High-resolution gas chromatography mass spectrometry (HRGC/MS) is the standard method for analyzing dioxin, furan, and polybrominated retardants in hazardous waste. Methods based on biological interactions (ligand–receptor recognition) have begun only recently to be investigated in the context of environmental applications. We have compared dioxin, furan, and polybrominated diphenyl ethers toxicity levels by two analytical approaches: HRGC/MS analysis and a battery of in vitro bioassays with the fish cell line rainbow trout gonad cell line-2 (RTG-2), in nine (liquid and solid) hazardous waste samples. The battery assays included a cytotoxicity neutral red bioassay, a Kenacid blue protein content bioassay, an ethoxyresorufin O-deethylase bioassay, and a β-galactosidase bioassay. A dose-dependent stimulation of enzymatic activities was observed in four of the nine samples, associated to high levels of octachlorodibenzo-p-dioxin (OCDD) and/or polychlorinated biphenyls (PCB) 77 congener. The enzymatic values of the whole samples were higher than the extracts’ values, which indicated that there had to be other effective compounds in the waste samples that could be lost in the extraction-purification process. The outcome of both approaches makes the bioassay useful as a rough estimate for the synergistic or antagonistic effects of polychlorinated dibenzo-p-dioxins (PCDDs)/Fs and dl-PCBs in extracts from the samples, and it can provide preliminary information regarding the characterization procedure in ecological risk.