Using the dioxin receptor–calux in vitro bioassay to screen marine harbor sediments for compounds with a dioxin‐like mode of action

Abstract

The presence of dioxin-like compounds in sediments from harbors and reference sites along the Dutch coast was investigated using the dioxin receptor-chemically activated luciferase gene expression (DR-CALUX) bioassay. The DR-CALUX response varied between 0.2 and 136 ng/kg dry weight expressed in units of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalency quotients (TEQ). The highest CALUX-TEQ values (> 50 ng TEQ/kg dry wt) were found in sediments from the center of the Port of Rotterdam and from the North Sea canal near Amsterdam. The DR-CALUX activity of harbor sediments was classified by setting guideline values. None of the 257 harbor sediment samples investigated exceeded the maximum value of 1,000 ng TEQ/ kg, while 94% of the samples fail the target value of 2 ng TEQ/kg. Threshold values (25 and 50 ng TEQ/kg) are intended as pass/ fail criteria for offshore disposal of dredged material and were exceeded in 12 and 3% of the samples, respectively. DR-CALUX response did not always match with contamination of polychlorinated biphenyls (PCBs) as determined in bulk sediments (sigma7-PCB ranging from < 1 to 456 microg/kg dry wt). Concentrations of planar PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated-dibenzofuranes (PCDFs), polybrominated biphenyls (PBBs), and polybrominated-diphenylethers (PBDEs) were determined in 20 selected sediment extracts. On average, PCDD/Fs explained 50% of the DR-CALUX activity and planar PCBs 6%. Further research is needed to elucidate the unexplained part of the DR-CALUX response. The DR-CALUX is a highly sensitive and reproducible bioassay that can usefully complement standard PCB analysis, improving the hazard assessment of the disposal of dredged material in the North Sea.

Aryl hydrocarbon receptor (AhR) inducers and estrogen receptor (ER) activities in surface sediments of Three Gorges Reservoir, China evaluated with in vitro cell bioassays

“…There were no great differences between the EROD values among the ten sediment samples, indicating that AhR agonists were distributed rather homogeneously in TGR from Wanzhou to the great dam. The determined EROD TCDD EQ (bio-TEQ) amounts in the present study are comparable with ERODinducing potentials of sediments reported by some other studies, including sediments collected from harbors along the Dutch coast ranging from 0.2 to 136 pg TCDD EQ g −1 dw (Stronkhorst et al 2002) and from Osaka Bay, Japan with 3.7 to 140 pg TCDD g −1 dw (Takigami et al 2005) tested with H4IIE-luc hepatoma cell line after 24 h of exposure, as well as sediments collected from Wenyu River, China with 15 to 64 pg TCDD g −1 tested with H4IIE hepatoma cell line after 72 h of exposure (Luo et al 2009) and from Yeongil Bay, Korea ranging from 2.8 to 320 pg TCDD g −1 dw tested with H4IIE-luc hepatoma cell line after 72 h of exposure (Koh et al 2006). On the other hand, the EROD bio-TEQ amounts reported in our study are higher than those reported in sediments from west coast of South Korea with non-detectable to 11 pg TCDD g −1 dw and north coast of Bohai Sea, China with nondetectable to 28 pg TCDD g −1 dw (Hong et al 2012) and sediments from Meiliang Bay, Lake Taihu before the ecological remediation project ranging from 17.8 to 38.5 pg TCDD g −1 dw (Qiao et al 2009) which were all tested with H4IIE rat hepatoma cells after 72 h of exposure.…”

The Distribution of the MusselMytilusSpecies Along the Norwegian Coast

“…In past years, ER-Luc, YES and YAS have been routinely used to determine (anti) estrogenic or (anti) androgenic activity in complex field samples including extracts of water, production water, suspended particulate matter, sediment and fish bile (Garcia-Reyero et al, 2001;Murk et al, 2002;Legler et al, 2002aLegler et al, , 2002bThange et al, 2000;Houtman et al, 2004;Thomas et al, 2006;Johnston et al, 2007). The methods for conducting ER-Luc, YES and YAS are fully described and validated in the scientific literature (see table below).…”

“…Any risk will be relative to the exposure assumed in the derivation of the guideline and the exposure likely in the actual situation. In some international guidelines concerning the regulation of dioxins, sediments are divided pragmatically into 'clean' and polluted locations on the basis of existing measurements of in vitro bioassays, as with the DR-Luc/DR-CALUX (Stronkhorst et al, 2002). The expected serious chronic effect levels are the average maximum found at locations assumed to be 'clean'.…”

“…The expected serious chronic effect levels are the average maximum found at locations assumed to be 'clean'. For example, DR-CALUX measurements showed in Dutch surface sediments (Stronkhorst et al, 2002;Klamer et al, 2005) from major Dutch "clean" offshore sites up to 70 miles offshore, with values at three offshore sites below 10 pg g -1 (6.9 and 8 respectively). Based on this a background response level has been derived of <10 pg TEQ g -1 dry wt.…”

“…A number of papers have been published describing the validation of the DR-Luc bioassay and describing the correlation between DR-Luc and HRGCMS derived 2,3,7,8-TCDD TEQs (Van den Berg et al, 1998;Stronkhorst et al, 2002;Besselink et al, 2003;Van Loco et al, 2004). It has been shown that frequent participation in interlaboratory exercises improves performance (De Boer et al, 1996;Besselink et al, 2004), but there remains a need for QA to be established as routine within international programmes such as BEQUALM.…”