The influence of xenobiotics in river sediment on the reproduction and survival of Daphnia magna, 1820, Straus [Influência de xenobióticos no sedimento de rio sobre a reprodução e a sobrevivência de Daphnia magna, 1820, Straus]
Goncalves S.P.,Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler FEPAM |
Lucheta F.,Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler FEPAM |
de Souza V.K.,Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler FEPAM |
Terra N.R.,Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler FEPAM
Acta Limnologica Brasiliensia | Year: 2012
Aim: The Taquari River, a tributary of Guaíba Lake, is a major economic and environmental source for Rio Grande do Sul, a state located in the far south of Brazil; Methods: This study evaluated the interference of sediment from this river in the reproduction and survival of 320 microcrustaceans (80 organisms per site) of the Daphnia magna species. Four sites between the middle course and the river mouth were monitored using eight samples from each site, between June/06 and April/10. Mortality higher than 20% suggested the acute action of the sample on the daphniids, while low reproduction indicated the presence of chronic toxicity. Sometimes an effect on survival was noted, but the number of individuals generated was always low. Semi- static chronic assays (21 day) were developed in 50 mL beakers using sediment and M4 culture medium at a ratio of 1:4 (v:v). Each beakers received a microcrustacean born from lots presenting LC50-24 hours = 0.98 mg K2Cr2O7 ± 0.04 mg totaling ten replicas per sample. The assays were developed under controlled light (16 hours light/day) and temperature (20 °C ± 2 °C) conditions; Results: Duncan test showed a variation in reproduction (p < 0.05) with the presence of chronic toxicity. There was less reproductive activity in 91% of the samples, while for survival the reduction attained 9%. Spearman correlation identified the dependence between the rainfall index and reproduction in one of the samples and was absent when the rainfall index was compared to survival; Conclusions: Taquari River presented episodes of toxicity, and it is necessary to continue studies in the area and to inspect local sources of pollution, as already has been done. Chronic bioassays should be maintained when the purpose is to evaluate environmental quality, since reproduction proved more sensitive than survival.
Silva da Silva C.,Federal University of Rio Grande do Sul |
Silva da Silva C.,Instituto Federal Of Educacao |
Rossato J.M.,Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler FEPAM |
Vaz Rocha J.A.,Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler FEPAM |
Vargas V.M.F.,Federal University of Rio Grande do Sul
Mutation Research - Genetic Toxicology and Environmental Mutagenesis | Year: 2015
Humans are exposed to health-impairing air pollutants, especially children who are more sensitive to cancer-causing toxins. This study described an area of reference for inhalable particulates (PM2.5) by chemical (polycyclic aromatic hydrocarbons) and mutagenic characterization associated with the genetic biomonitoring of children (aged 5-11 years). The area studied was in a small town in Brazil, used as reference in previous studies. Organic matter of PM2.5 (extracted with dichloromethane) was evaluated for mutagenesis in a Salmonella/microsome (microsuspension) assay, in strains measuring frameshift error (TA98, YG1021 and YG1024) and base pair substitution (TA100) of DNA, in the presence and absence of rat liver metabolization fraction (S9). Exposure was studied analyzing a sample of 45 children using comet assay (peripheral blood lymphocytes) and micronucleus (exfoliated buccal mucosa cells). PM2.5 concentration for the period was 9% (25.89-64.71μg/m3) events above WHO limit value (25μg/m3). Mutagenesis responses (revertants/m3) varied from negative (spring) to 8.3±0.69 (autumn) (-S9) and 5.4±0.36 (winter) (+S9), in strain TA98, and for TA100, in spring, from negative to 14.8±4.23 (-S9) and 17.5±2.72 (+S9). YG strain results show mononitroarenes and aromatic amines. Mean biomonitoring values were established for MN, 0.3±0.41 (‰) and for other cell types a variation from 0.6±0.73 (‰), nuclear buds to 57.5±24.92 (‰), karyorrhexis. Comet assay means were 23.1±12.44; 7.3±11.66 and 0.9±2.30 for tail length, intensity and moment, respectively. There was no difference for sex and age for the different parameters. A significant difference in confounding factors was observed for passive smoking and MN induction. PAHs and mutagenesis in the air may be related to local vehicular emissions. These results challenge the definition of areas of reference for air pollution associated with human biomonitoring including the region studied. © 2014 Elsevier B.V.