Metals and emerging contaminants in groundwater and human health risk assessment.

Groundwaters are normally consumed without previous treatment and therefore the monitoring of contaminants in order to guarantee its safety is necessary. Thus, we aimed to evaluate the groundwater contamination by metals and emerging contaminants, seeking to understand the relationship between their presence in the groundwater and the use and land cover profile of Itaporã and Caarapó. In addition, the contaminant concentrations observed were compared with maximum permitted values (MPV) and/or with calculated water quality criteria (WQC) for human consumption to investigate possible human health risks due to the groundwater intake. We collected one groundwater sample from each of the 12 wells located in Itaporã and 11 wells located in Caarapó. The metals were analyzed using ICP-OES and the emerging contaminants using LC-MS/MS. At least 1 of the 9 metals analyzed was found in each of the samples. In 12 samples, the metal concentrations verified exceeded the MPV or calculated WQC. A risk to human health has been observed for metals Co, Mn, Cr, and Ni. The emerging contaminant concentrations found in some samples were low (ng/L) and probably did not pose health risks, but their presence in the groundwater showed the impact of agriculture and the inadequate disposal of domestic sewage in the wells of both cities.

Influence of Land Use and Cover on Toxicogenetic Potential of Surface Water from Central-West Brazilian Rivers.

The objective of this study was to evaluate toxicogenetic potential of surface water samples from rivers of center-west Brazil and analyze the influence of land use and cover and physicochemical parameters in genetic damage. Samples were collected during winter (June) and summer (November) at sampling sites from Dourados and Brilhante Rivers (Mato Grosso do Sul/Brazil). The toxicogenetic variables, including chromosomal alterations, micronuclei, and mitotic index, were analyzed in meristematic cells of Allium cepa; and micronuclei, nuclear abnormalities, and DNA strand breaks (arbitrary units, AUT) were analyzed in erythrocytes of Astyanax lacustris. The rivers presented physicochemical values outside the Brazilian laws, which can be a characteristic of human pollution (domestic sewage and local agriculture). The results of A. cepa test suggest that the water samples from Dourados and Brilhante rivers exerted significant (p < 0.05) cytotoxic and genotoxic effects, in both periods of collection, especially alterations in mitotic index. In blood cells of A. lacustris, genotoxic effect of the water samples from the rivers also was observed as significant nuclear abnormalities, DNA breaks (UAT), in both sampling periods, compared with the negative control. Spearman correlation analyses revealed that data of land use and cover and physicochemical parameters were statistically correlated with DNA damages in bioassays. This study demonstrates toxicogenetic potential of water samples from Dourados and Brilhante rivers; furthermore, the type of land use and land cover and physicochemical parameters were revealed to have influence on toxicogenetic damage.

From collection to discharge: physical, chemical, and biological analyses for fish farm water quality monitoring.

The use of chemical substances for the management of fish farming activities may compromise the quality of the tank water itself and of water bodies that receive the effluents. As studies that assess the environmental effect caused by pisciculture are scarce, the present study aimed at evaluating the water quality in two fish farms in the region of Grande Dourados, Brazil, from the site of water collection to the site of water disposal. The tools used for this purpose were the analysis of land use and cover and the determination of physical, chemical, and biological parameters of water samples. Maps of land use and cover were created, and water samples were collected at four sampling sites in two fish farms. The Allium cepa test, assays with Astyanax lacustris, and the Salmonella/microsome assay were performed. In addition, physical and chemical parameters were measured and metal and emerging contaminants in the water samples were investigated. The A. lacustris demonstrated the genotoxicity and the Salmonella/microsome assay suggested the mutagenic potential of water samples from the fish farms and indicated higher genotoxicity in the disposal tanks than in the collection tanks of the Brilhante fish farm. However, all the samples at the Dourados fish farm were genotoxic, and mutagenicity was shown to start at the water collection site. With regard to the A. cepa test, there was no statistical difference between the collection sites in both fish farms. Moreover, the observed genetic damage may be associated with the presence of metals and emerging contaminants in the water samples, which suggests that these chemicals have potential genotoxic and mutagenic effects that are related to the type of land use and cover in the area of the region studied. Considering that contaminated waters can potentially disturb the structure and functioning of natural ecosystems, the present study demonstrated the importance of treating fish farm effluent to minimize the negative effect of this activity on water bodies.

Evaluation the urban atmospheric conditions in different cities using comet and micronuclei assay in Tradescantia pallida.

In the present study, genotoxicity and mutagenicity were investigated in Tradescantia pallida exposed to vehicular traffic at different sites in a high-altitude tropical climate. During March, May, July, September, and November 2014, a comet assay and micronucleus bioassays were conducted on young inflorescences and leaves of T. pallida collected from twelve towns in the southern region of Mato Grosso do Sul with different amounts of vehicular traffic. Weather parameters (temperature, relative humidity and rainfall) were measured and vehicles were counted to determine traffic levels in each town. A higher frequency of genotoxic and mutagenic damage was observed in the municipality of Dourados. The highest frequency of genetic damage was observed in September and November according to both assays. Relative humidity and rainfall were inversely proportional to the frequency of genetic damage in T. pallida during the collection period. Based on these results, we conclude that the bioassays are efficient for assessing the effects of vehicular traffic in these towns with respect to weather conditions over time. These bioassays can be applied to identify risk areas, which are determined by climatic conditions and air pollutants released.

Genotoxic and mutagenic effects of passive smoking and urban air pollutants in buccal mucosa cells of children enrolled in public school.

Nuclear abnormalities (micronuclei and meta-nuclear changes) have been used as biomarkers to identify cell damages. As children are more vulnerable to the adverse effects of pollution when compared to adults, assessing genetic damage caused by environmental influences is of great interest. As such, the objective was to determine metanuclear (karyolysis, pycnosis, karyorrhexis, binucleated cells, chromosome bridges and micronuclei) in cells from the oral mucosa of children associated with the school environment, gender, exposure to cigarette smoke and vehicular traffic. Analyses of nuclear abnormalities were performed in exfoliated buccal cells of children from two public schools located in Dourados - MS. The data were analyzed through Kruskal-Wallis test considering a significance level of 5% (p < .05). The results showed that children exposed to cigarette smoke presented higher levels of nuclear abnormalities than children who were not usually exposed to this type of mutagenic and genotoxic agent, suggesting that such contaminants are related to clastogenic and aneugenic effects on DNA. Moreover, female children had higher amounts of nuclear abnormalities when compared to male children. With regards to the school environment, the study results indicated statistical differences in of term chromosomal abnormalities for schools A and B. Thus, it was possible to determine that children exposed to cigarette smoke are susceptible to further genetic damage than unexposed children, and female children may be more susceptible to genotoxic and mutagenic agents. This study contributes to the current knowledge on the mutagenic characteristics of human cells, supporting the adoption of preventive Public Health measures.

Genetic instability in plants associated with vehicular traffic and climatic variables.

To characterize the effect of vehicular traffic on air quality, the micronuclei of Tradescantia pallida tetrads were counted. Young inflorescences of T. pallida (Rose) D.R. Hunt var. purpurea were collected in 2010, 2011, and 2012, from three sites subjected to different intensities of vehicular traffic. The sites were located in the municipality of Dourados, in the State of Mato Grosso do Sul, Brazil. A standardized methodology was used to analyze the Tradescantia micronuclei, in order to evaluate the mutagenic potential of the local air pollutants. Statistical analyses using the Pearson's linear correlation were employed to determine the relationship between relative humidity and temperature, and the average number of micronuclei. In this study, an increase in the average number of passing vehicles was correlated with an increase in the frequency of micronucleus formation. Climatic factors also influenced micronucleus formation, although vehicular traffic remained the most important factor. Thus, the Tradescantia micronuclei assay may be a useful method of assessing air quality.