Physicochemical and ecotoxicological based assessment of bottom sediments from the Luján River basin, Buenos Aires, Argentina

Abstract

The physicochemical analysis of bottom sediments of the Lujan River was done on samples from 14 sites situated along its course and covered grain size and organic matter, total N and P, sulfides, heavy metals, organochlorine, and pyrethroid pesticides. In addition, acute 10-day whole-sediment laboratory toxicity tests were carried with each sample, using the native amphipod Hyalella curvispina as test organism. In order to correlate both types of results, data were assessed by multivariate analysis, including principal component analysis (PCA). The physicochemical profile of samples resulted similar along the river course, though several anomalous data were registered in the middle course of the river, mainly in samples taken downstream a large industrial complex; with a few exceptions in upper basin sites characterized by the dominance of agricultural activities, the pesticides concentration were consistently below the analytical detection limits. Almost 50% of the samples induced adverse effects on the amphipod when testing sublethal and lethal end points. The toxicity of the samples in terms of survival rate was extremely high in two sites, in particular in samples taken downstream the Pilar industrial complex. The integration of a selection of physicochemical and toxicological parameters of the sediments by PCA allowed discriminating areas of the river basin according the type and intensity of their particular pollution condition.

Global occurrence of pyrethroid insecticides in sediment and the associated toxicological effects on benthic invertebrates: An overview

“…Pyrethroid residues are an emerging threat to aquatic ecosystems globally, due to their frequent detection at high concentrations in sediments from agricultural and non-agricultural however, little information have been reported on sediment residues of pyrethroids in these countries [117][118]. In addition, studies have concentrated on certain areas within countries.…”

Pesticide impact study in the peri-urban horticultural area of Gran La Plata, Argentina

“…A subsample of the homogenized sediment was separated in a 200 mL container for pesticide residue analysis and stored at − 20°C until the analysis. The subsample for the toxicity bioassay was preserved at 4°C in darkness until its use (Peluso et al, 2013a(Peluso et al, , 2013b. Dry weight was measured at 105°C until constant mass, and organic matter content was determined by calcination at 550°C (loss on ignition) (APHA, 1998).…”

“…Standardized whole-sediment toxicity tests were performed using the amphipod Hyalella curvispina as the test organism, following USEPA (2000) protocol recommendations for Hyalella azteca with modifications. In recent years, this amphipod species has been used as a test organism in ecotoxicological assessments (Peluso et al, 2011(Peluso et al, , 2013a(Peluso et al, , 2013b. Test organisms were obtained by sieving cultures maintained in dechlorinated tap water in our laboratory.…”

“…Since bottom sediments provide nutrients and habitat for a wide variety of benthic organisms, sediment quality evaluation becomes relevant for the protection of aquatic life (Paixão et al, 2011). Wholesediment toxicity tests provide a good methodology to assess the bioavailability of pollutants to these organisms (Hintzen et al, 2009) and allow for the evaluation of interaction effects resulting from the complex mixture of components in sediments (Peluso et al, 2013a(Peluso et al, , 2013b. In this sense, amphipods are model species for this type of toxicity bioassay (USEPA, 2000).…”

New Records of Pathogenic Bacteria from Urban Rivers in Argentina

“…Many investigations [3,10,11] indicate that the Matanza-Riachuelo River is one of the most polluted courses in South America, showing extremely high levels of undesirable chemical substances. Bacterial amounts also demonstrated an unacceptable water quality, but previous references did not emphasized on taxonomic species level.…”