Sampling alkalies river

Fig. 2 Location of the lower Ebro River catchment, zebra mussel, crayfish, and fish species sampling sites in the Flix dam area. Samples were taken at several stations in the four areas (RF = control site upstream WR = wildlife reserve HS = hot spot or chlor-alkali plant, and MD = meander). Positions of dams (black bars) and overflow dams (grey bars) are indicated to illustrate the mutual isolation of aquatic organisms sampled...

Fig. 3 Map with the sampling sites in the Cinca River, upstream (SI) and downstream (S2) of the chlor-alkali plant of Monzon showing THg levels. Adapted from [65]...

A second risk zone corresponds to Monzon (17,042 inhabitants), a highly industrialized city in the middle Cinca River. Its industrial activity has caused the historical release of organic and inorganic compounds to the river coming from chlor-alkali industry, from production and utilization of solvents and organochlo-rine pesticides, and from the use of brominated flame retardants in the production processes. Very high concentrations of mercury have been recorded for sediment and fish samples in the downstream of Monzon [2-4]. 

This section of the Ebro River is under the direct impact of the Flix chlor-alkali plant and of its residue sediments. Contamination of Hg and OCs is maximal in these sediments, and there is evidence that it leaks downstream as far as at least to Xerta, 37 km away Flix ([8, 9], Fig. 4a, d). Fish populations in Flix show poorer condition and fecundity than their counterparts sampled in Riba-roja or the Delta [38]. In addition, HSI and CF in carps showed good correlation (positive and negative, respectively) with OC burden (Fig. 4c). These data indicate that the pollution by Flix residues and, specifically, by OCs, affects the growth and health status of fish from the low Ebro River. 

The river sediment was collected from a bank located at 500-700 m of the merging point of the river Toce and Lago Maggiore (Italy). The sample is typical for an anaerobic situation in rivers with prolonged industrial activity (chlorine-alkali plant). It was treated in the same manner as the lake sediment. 

Are these mercury values for Cranberry Lake streams high or low They a2 e similar to levels reported for Lake Windemere (12 -29 ng/1) by Gardner (1978) and the unpublished work of Harris (1971). on the Oswegatchie River (17 - 72 ng/1) but sonewhat lower than Onondaga Lake, near Syracuse, New York contaminated by chlor-alkali plant residues. Buller s synoptic survey (1972) of mercury in surface waters of the Adirondack Mountain region yielded no samples above 500 ng/1 total mercury and 100 ng/1 soluble mercury. 

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