Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are industrial additives of emerging environmental concern. However, the bioaccumulation, biomagnification, and spatial distribution of these contaminants in the Great Lakes of North America are unknown. The present study addresses these knowledge gaps by reporting SDPAs and BZT-UVs in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), and their food web in the Great Lakes for the first time. Herring gull eggs showed much higher detection frequency and concentrations of target SDPAs and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) than that of the whole body fish homogenate. For herring gull eggs, the samples from upper Great Lakes contained significantly greater levels of SDPAs than those eggs from lower lakes, possibly due to the differences in terrestrial food in diet. Interestingly, the predominant SDPAs in herring gull eggs were dinonyl- (C9C9) and monononyl-diphenylamine (C9) which were previously shown to be less bioaccumulative than other SDPAs in fish. In contrast, dioctyl-diphenylamine (C8C8) was the major SDPA in lake trout, and biodilution of C8C8 was observed in a Lake Superior lake trout food web. Such variations in herring gull eggs and fish indicate the differences in accumulation and elimination pathways of SDPAs and BZT-UVs and require further elucidation of these mechanisms.

No abstract

The Biliuhe reservoir, which is one of the most important water sources in Dalian, is the "source of life" of Dalian. To explore the characteristics of heavy metal pollution in Biliuhe reservoir, the potential ecological risk of these heavy metal elements were evaluated by two methods, i.e. geo-accumulation index and potential ecological risk index, and the risk values of heavy metals in sediment were predicted one year later in the future by grey forecasting model GM (1, 1) and RBF neural network. The comprehensive assessment results showed that the pollution level in the reservoir was slight, Hg was the primary element with higher ecological risk while Cu was secondary. The forecasting results indicated that the predicted risk value of Hg was higher than others. The results were discussed in order to provide the theoretical basis for the management of the reservoir in the future. The models will be used widely in the field of ecological risk assessment of heavy metals in sediment, due to the simplification and maneuverability of them.