The concentrations of marker PCBs (28, 52, 101, 118, 138, 153, 180) in fish have been assessed with GC-MS: an average concentration of 540 ng-PCB g(-1) fat (5.02 ng-PCB g(-1) wet weight) was observed. The average concentration of PCDD/Fs, assessed with the CALUX bioassay, amounted to 64 pg-CALUX-TEQ g(-1) fat (0.58 pg-CALUX-TEQ g(-1) wet weight) and that of PCDD/Fs + dioxin-like PCBs amounted to 131 pg-CALUX-TEQ g(-1) fat (1.18 pg-CALUX-TEQ g(-1) wet weight). Results of the PCB congeners analyses show that PCB-153 is the most abundant congener in almost all samples, with also main contributions of the 138- and 180-congeners. For some species such as the sand sole and lemon sole, a fairly constant PCB content, independent of the fat percentage, was observed. For a second group of species such as whelks, cod, and whiting, a positive correlation was observed between their PCB concentration (ng g(-1) fat) and their % of fat. The relationship between marker PCBs and PCDD/Fs concentrations, when plotted on a log scale, fits a straight line (correlation coefficient r = 0.83). With our results on fish and literature data for other food products, intake of marker PCBs and PCDD/Fs could be calculated for the adult population in Belgium (19-60 years old). The Total Daily Intake (TDI) of marker PCBs (ng-PCB day(-1)) ranges between 1690 and 2210. The TDI of PCDD/Fs (pg-CALUX day(-1)) ranges between 80.5 and 122, that of PCDD/Fs + dioxin-like PCBs amounts to 151. When PCDD/Fs in fish are assessed with GC-HRMS, the TDI can be lower. The relative importance of fish regarding marker PCB intake amounts to 15-19%, while regarding PCDD/Fs intake it amounts to 34-51%. Using TDI, the body burden evolution of marker PCBs and PCDD/Fs, with age has been calculated.

No abstract

No abstract

For several decades, Northern Québec has been exploited by mining companies for its mineral resources, yet, research documenting the effects of toxic stress on fish health in subarctic environments remains limited. In this study, one lake directly affected by mining activities in the Schefferville area, two lakes close to mining facilities in the Fermont and Schefferville areas, and one reference lake were sampled for water, sediment and fish. Our results suggest that manganese bioaccumulation induced an oxidative stress in Catostominæ, as demonstrated by the positive relationships between manganese concentrations and catalase activity and 8-hydroxy-2’deoxyguanosine concentrations, as well as the negative relationship with glutathione peroxidase activity (both catalase and glutathione peroxidase activities being biomarkers of antioxidant capacities and 8-hydroxy-2’deoxyguanosine an indicator of DNA oxidative damage). Similarly, selenium bioaccumulation was positively correlated with 8-hydroxy-2’deoxyguanosine concentrations in Salmoninæ. These results suggest a prooxidant role of excess selenium and manganese, and highlight the interspecific variability of fish responses to contaminated areas around historical and current iron ore mining operations.