No abstract

Aminomethylphosphonic acid (AMPA) - one of glyphosate’s main metabolites - has been classified as persistent in soils, raising concern regarding the widespread use of glyphosate in agriculture and forestry. Glyphosate may have negative or neutral effects on soil biota, but no information is available on the toxicity of AMPA to soil invertebrates. Therefore our aim was to study the effect of AMPA on mortality and reproduction of the earthworm species Eisenia andrei using standard soil ecotoxicological methods (ISO). Field-relevant concentrations of AMPA had no significant effects on mortality in acute or chronic assays. Except at the highest concentration tested, a significant biomass loss was observed compared to controls in the chronic assay. The number of juveniles and cocoons increased with higher concentrations of AMPA applied, but their mean weights decreased. This mass loss indicates higher sensitivity of juveniles than adults to AMPA. Our results suggest that earthworms coming from parents grown in contaminated soils may have reduced growth, limiting their beneficial roles in key soil ecosystem functions. Nevertheless, further research is needed to better understand the mechanisms underlying the sublethal effects observed here.

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This work aimed at investigating both the tolerance and the phytodegradation potential of Erythrina crista-galli L. in petroleum-contaminated soil. It consisted in analyzing E. crista-galli germination, surviving, growth, and development when cultivated at different contaminant concentrations and pollutant degradation rates. This specimen was selected because it presented a special behavior among others also exposed to petroleum in an accident that occurred in the Araucaria region (south of Brazil), resulting in a four-million-liter oil spill. The experiment was carried out in a greenhouse containing non-contaminated soil (NCS), vegetated contaminated soil (VCS), and non-vegetated contaminated soil (NVCS) at the following petroleum concentrations: 25 g kg(-1) (VCS-25), 50 g kg(-1) (VCS-50), and 75 g kg(-1) (VCS-75). After 60 days, the soil samples were analyzed by gas chromatography. Germination was more and more evident as higher petroleum concentrations were observed. The surviving rates of groups NCS, VCS-25, VCS-50, and VCS-75 were 64%, 70%, 61%, and 96%, respectively. The VCS group growth was reduced when compared to the control group (NCS). The individuals exposed to petroleum pollution presented differences in the anatomic structure of their roots when compared to the NCS group. It was observed that the petroleum degradation rate was higher for VCS group than for NVCS. E. crista-galli is potentially recommended for petroleum-contaminated soils because of its positive association in the presence of contamination.

Medicines and their metabolites have been found as water contaminants at very low concentrations; moreover, there is no extensive toxicological data to determine the risks associated with their occurrence in water resources. The ibuprofen genotoxicity potential to the Oreochromis niloticus fish (Tilapia), due to nanograms per liter exposure, was evaluated using the micronucleus test. Acute (48 h) and sub-chronic assays (10 days) were carried out at 300 ng/L ibuprofen aquatic concentration comparing with the negative control group (without treatment), with eight animals per group. The results were assessed from the average of triplicate analyses. The micronucleus frequency in peripheral blood of fish was determined using a sample size of 3,000 erythrocytes per animal. Significance was defined using t test (p≤0.05). The bioassay results showed a statistically significant increase in the frequency of micronuclei for both exposure times in comparison to the negative control. The micronucleus frequency observed for the sub-chronic tests was higher than the one identified in the acute assays. The observed ibuprofen genotoxic effects demonstrated an aquatic environmental risk of this pharmaceutical, which occurs for the used fish experimental model in lower concentration than previously described for other aquatic organisms.

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Starch nutritional fractions as well as thermal properties and other analysis are essential for food and industrial application. Cassava bagasse is an important agro-industrial residue and its starch content was evaluated using two alternative methods. Thermal characterization and microscopy analyses helped to understand how hydrolysis

Water samples of the Passaúna River, Curitiba/Paraná (Brazil), were analyzed to determine total and thermotolerant coliform counts and Escherichia coli in order to provide information on human impacts on the water supply. Samples were collected and analyzed monthly, from March 2006 to February 2007, at five different locations along the river, and the multiple tube method was used to obtain total and thermotolerant coliform counts. The results varied from 130 MPN/100 mL to 1.6×10 6 MPN/100 mL for total coliforms, while for thermotolerant coliforms the variation was between 40 MPN/100 mL and 5× 10 5 MPN/100 mL. The E. coli strains isolated from the samples were tested with 13 different antibiotics to determine their antibiotic resistance. The isolated strains were constantly sensitive to seven of the 13 antibiotics tested, and resistant to at least one of the other antibiotics. The results indicated that two factors could influence the increased contamination on this river, viz., seasonality parameters and domestic wastewater discharges. The determination of antibiotic resistance indices aimed to provide information on the anthropogenic influence. Only one of the locations investigated was considered critical due to the anthropogenic influence, with significant impacts from irregular domestic wastewater discharges.