Lowering the pH leads to the disaggregation of NiO and ZnO nanoparticles and modifies the mutagenic response.

In a changing environmental scenario, acid rain can have a significant impact on aquatic ecosystems. Acidification is known to produce corrosion in metals, hence increasing their harmful effects on the environment, organisms and human health. The prevalent use of metallic nanoparticles (NPs) in everyday products raises concerns regarding exposure and nanotoxicity even in these acidified conditions. We thus report on the cytotoxic and genotoxic potential of nickel oxide (NiO-NP) and zinc oxide (ZnO-NP) NPs when suspended in aqueous media in light of pH variations (7.5 and 5). A modified microsuspension method of the Salmonella/microsome assay was adopted, and strains (TA97a, TA98, TA100, TA102) were exposed to NPs (10-1280 µg/plate) with and without a metabolization fraction. The acidic condition favored disaggregation and caused a decrease in NPs size. Mutagenicity was observed in all samples and different strains, with greater DNA base pair substitution damage (TA100 and TA102), but extrinsic conditions (pH) suggest different action mechanisms of NiO-NP and ZnO-NP on genetic content. Mutagenic activity was found to increase upon metabolic activation (TA98, TA100, and TA102) demonstrating the bioactivity of NiO-NP and ZnO-NP in relation to metabolites generated by the mammalian p450 system in vitro. Modifications in the Salmonella assay methodology increased cell exposure time. The observed responses recommend this modified assay as one of the methodologies of choice for nanoecotoxicological evaluation. These findings emphasize the significance of incorporating the environmental context when evaluating the toxicity of metal-based NPs.

A comprehensive overview of genotoxicity and mutagenicity associated with outdoor air pollution exposure in Brazil.

This review examined the mutagenicity and genotoxicity associated with exposure to outdoor air pollutants in Brazil. A search was performed on the Web of Science database using a combination of keywords that resulted in 134 articles. After applying exclusion criteria, a total of 75 articles were obtained. The articles were classified into three categories: (1) studies with plants and animals, (2) in vitro studies, and (3) human biomonitoring. The investigations were conducted in 11 of 27 Brazilian states with the highest prevalence in the southeast and south regions. Only 5 investigations focused on the effects of burning biomass on the quality of outdoor air. Plants, especially Tradescantia pallida, were the main air pollution biomonitoring tool. When available, a significant association between levels of air pollutants and genetic damage was described. Among the in vitro studies, Salmonella/microsome is the most used test to evaluate mutagenesis of outdoor air in Brazil (n = 26). Human biomonitoring studies were the least frequent category (n = 18). Most of the investigations utilized micronucleus bioassay, in oral mucosa cells (n = 15) and lymphocytes (n = 5), and the comet assay (n = 6). The analysis in this study points to the existence of gaps in genotoxicity studies and our findings indicate that future studies need to address the variety of potential sources of pollution existing in Brazil. In addition to extent of the impacts, consideration should be given to the enormous Brazilian biodiversity, as well as the determination of the role of socioeconomic inequality of the population in the observed outcomes.

Health impacts of PM2.5-bound metals and PAHs in a medium-sized Brazilian city.

Rio Grande is a medium-sized industrial city located in the extreme south of Brazil, and previous studies in this city have shown contamination by metal(loids) and polycyclic aromatic hydrocarbons (PAHs) in water, soil, and sediment and in the atmosphere. In Brazil, the incorporation of PM2.5 monitoring in environmental legislation is recent (2018) and, like other developing countries, the number of studies is still small. This study aimed to investigate the levels of PM2.5 in the industrial and urban area of Rio Grande, to determine the concentration of metal(loid)s As, Cd, Cu, and Pb and of 16 PAHs in the samples of PM2.5, to perform the health risk assessment for these contaminants and the health impact assessment for two possible scenarios of reduction of PM2.5 levels. Our main findings regarding the PM2.5 samples include the following: (1) The levels of this pollutant in the city of Rio Grande were higher than those allowed in current Brazilian legislation, in both the industrial and urban areas; (2) the existence of non-carcinogenic and carcinogenic risks for metals present in all samples; (3) the absence of carcinogenic risk for the assessed PAHs; and (4) the reduction scenarios proposed pointed to a reduction of up to 22 deaths annually in conjunction with reductions in health-related expenditures. Thus, these results may serve as a basis for the development of public health policies aimed at improving air quality, jointly assisting health surveillance and directing future studies towards a better intrinsic approach to the problem.

Ecotoxicological evaluation of fruit extracts from yerba mate progenies (Ilex paraguariensis a St-Hil.): a natural biopesticide.

This study evaluated the biocidal activity of aqueous fruit extracts from Ilex paraguariensis progenies at different ripening stages in two ecotoxicity assays using Pomacea canaliculata juveniles and Danio rerio larvae. Mutagenicity was verified by the Salmonella/microsome assay (TA 98 and TA 100) in the presence and absence of hepatic metabolism in vitro. The results showed that the snails were more sensitive than the larvae to the P.1 progeny extracts in all three evaluated ripening stages. P.3 progeny extracts were the most toxic to Danio rerio larvae after 96 hours of exposure. The toxicity results indicate that the progenies' selection influenced the metabolic contents present in the fruits in all ripening stages over time, indicating high molluscicidal activity for the P.1 progeny. In the Salmonella/microsome assays, the semi-ripe and ripe extracts from progenies P.1 and P.3 showed mainly base pair substitution mutation in assays with metabolism, but at higher doses than the toxic concentrations detected for Danio rerio or Pomacea canaliculata. Therefore, the toxicological investigation of the progenies' extracts can be interesting, given the selection of plant materials influenced the response of the bioassays.

Integrated study of genotoxicity biomarkers in schoolchildren and inhalable particles in areas under petrochemical influence.

This study aimed to evaluate genotoxicity effects of inhalable particulate matter from areas influenced by a petrochemical complex on exposed children population. Peripheral blood and buccal mucosa exfoliated cells were collected from 54 children (5-12 years) at two public schools, 2.5 Km (Site NW) and 35 km (Site NWII) from the main industrial emission source. These areas lie in the first wind direction from a petrochemical complex. Blood samples were used to Comet Assay (CA) evaluating the tail intensity and to the cytokinesis-block micronucleus cytome assay (CBMN-cyt), assessing the frequency of micronucleus (MN), nuclear buds (NBUDs) and nucleoplasmic bridges (NPBs). Buccal micronucleus cytome assay (BMCyt) was used to detect MN and nuclear abnormalities. Mutagenicity of particulate matter (PM) organic extracts from these two sites, besides from one in the second wind direction (NE) was evaluated by Salmonella/microsome assay, microsuspension method, strains TA98, YG1021 and YG1024 with and without metabolic activation (S9). The site closest to the petrochemical complex (NW) presented worse air quality, evidenced by greater PM mutagenicity and more toxic PAHs profile (ΣTEQ). Also, Tail intensity was significantly higher at this site (10.65 ± 0.78) compared to site NWII (6.73 ± 0.92). MN frequencies in CBMN-cyt did not differ among groups, but was significantly higher than an external reference site. NBUDs were significantly higher at site NWII. BMCyt showed no difference among the groups for MNs and NBUDs. Site NWII showed higher frequencies of karyorrhexis and karyolysis. All samples, even within the PM limits, presented genotoxic potential. Results showed that the children are exposed to a mixture of contaminants from different sources, and that the proximity of the petrochemical industry gives a cause of concern. Actions must be taken to identify and reduce emissions and hazardous effects, since air quality standards are not enough to ensure the exposed population health.

Bioremediation of soils contaminated by PAHs: Mutagenicity as a tool to validate environmental quality.

Bioremediation can be used as one of the decontamination techniques for areas contamined by polycyclic aromatic hydrocarbons (PAHs). However the effective biodegradation of these compounds must take into account the possible toxic and mutagenic effects that might persist. In this study the mutagenic potential of soil samples from an area contaminated by wood preservatives was evaluated. The area had already been submitted to a simulated bioremediation process in a microcosm, using two different inoculums (1 and 2), and comparing them to the decay of PAHs. Organic extracts were prepared before and after bioremediation, where the 16 PAHs considered a priority by USEPA were analyzed and tested using the Salmonella/microsome assay. The extracts were analyzed in strains TA98, TA97a and TA100 (+S9mix/-S9mix), YG1041 and YG1042. Considering Inoculum 1 only as bioaugmented and Inoculum 2 also stimulated and enriched, the concentrations of PAHs and mutagenic effect were different. The former identified a greater reduction of mutagenesis and a smaller decrease of PAHs while the latter showed greater mutagenic power even associated with the greatest reduction of PAHS. The possible generation of degradation byproducts with high mutagenic power after a partial biodegradation process can be considered. In strains YG1041 and YG 1042 the mutagenesis values before bioremediation were 747 and 567 rev/g soil, respectively. Although the efficiency of bioremediation was observed, the associated damage indicates that the analysis of contaminants and their relationship with mutagenic effects are a fundamental stage for the effective evaluation of the risks and efficiency of bioremediation processes.

Air quality assessment in different urban areas from Rio Grande do Sul state, Brazil, using lichen transplants.

Based on the need to monitor air pollution and on the importance of doing it with biological organisms, the present work had as main objective to assess air quality in urban areas through lichen transplants. Besides, we also tested whether there were differences among the studied sites, aiming to point out the main pollution characteristics of the areas. The monitoring was carried out in seven cities, which varied from mainly rural to mainly industrial, in Rio Grande do Sul, southern Brazil. The foliose lichen Parmotrema tinctorum was used as the biomonitor species. Physiological tests and contents of sulphur and heavy metals were measured in the lichen thalli. Other pollutants assessed through air samplers were available for some cities, and modeled concentrations of fine particulate matter and nitrogen oxides for all sites. The effect of air pollution negatively reflected on the physiology parameters of the lichen and the concentration of all heavy metals increased after exposure, especially in the industrial sites. We generated a profile of air pollutants and pointed out that Charqueadas and Esteio had the worst air quality. Since they have high demographic densities, the results are of great public health concern and could be guidelines for future studies.

Soil mutagenicity - Effects of acidification and organic pollutants in urban/industrial areas.

This study aimed to analyze (i) the effect of different acid extractions, simulating changes in the background pH of rain on the availability of soil mutagenic compounds, (ii) the presence of organic compounds in soil and (iii) evaluation of the effects of soil sieving on the samples mutagenicity. Surface soil samples were collected at urban and industrial areas and assessed as total grain size composition (Total Soil) and in sieved fraction <0.5 mm (Soil <0.5 mm), through acid extracts with pH simulating those found in local rainfall. Metals were quantified in extracts and soils in natura. Organic extracts were analyzed for PAH content. Salmonella/microsome mutagenicity assay (TA98 strain) was used, in the presence/absence of exogenous metabolism. Nitro-sensitive strains YG1021 and YG1024 were used in the organic extracts. Results showed different mutagenic responses in total soils and in soil <0.5 mm. Soil extraction at pH 3.6 presented higher toxicity, greater variety and concentration of metals. Extraction at pH 5.3 improved mutagenic detection. Thus, local rainfall may be an environmental contamination route, with additional risk of releasing toxic substances during acid precipitation events.

Assessment of sediment mutagenicity in areas under the influence of a contaminated site undergoing a remediation process.

Soil contamination enters aquatic ecosystems affecting sediment quality. The region studied is the Taquari River, Brazil, close to a site contaminated by wood preservatives, with a runoff route into the river. The first stage of the remediation process (In this article, the terms intervention and remediation have been used with slightly different meanings. We consider intervention to be the first phase of the remediation process, which aims to remove active sources) was an intervention to remove the main active sources. The Salmonella/microsome assay and polycyclic aromatic hydrocarbons (PAHs) were used to assess sediment quality in organic extracts during different intervention phases. The strains used were TA98, TA97a, and TA100 with and without S9mix (±S9). The results indicated the presence of pro-mutagens at site Ta010 (closest to the contaminated site) in all samplings, and the highest result occurred before intervention for TA100 + S9 (1,672 ± 215.9 rev/g). These values decreased during (83 ± 23.6 rev/g) and after this process (403 ± 105.9 rev/g), although the PAHs concentrations increased. Samples from this site presented PAHs with a carcinogenic potential during the assessed periods. After intervention, Ta006 (4 km downstream from Ta010) showed the most significant mutagenesis for TA100 + S9 (764 ± 230.2 rev/g) and, although the total PAHs values were lower, the species considered carcinogenic had higher concentrations. Mutagenesis predicted values of PAHs confirmed that carcinogenic species were predominantly detected by TA100, and the other PAHs by TA97a strains. Marked contaminant release to the river was observed, mainly in Ta010 at different periods. Mutagenicity and PAHs values in an internal stream, upstream from Ta010, showed a dispersion route of these agents. Thus, contamination in Ta010 and possible contribution to Ta006, after intervention, provides a warning regarding environmental quality in the region. Environ. Mol. Mutagen. 59:625-638, 2018. © 2018 Wiley Periodicals, Inc.

Genotoxicity biomarkers for airborne particulate matter (PM2.5) in an area under petrochemical influence.

The effects of fine inhalable particles (PM2.5) were evaluated in an area under the influence of a petrochemical industry, investigating the sensitivity of different genotoxicity biomarkers. Organic extracts were obtained from PM2.5 samples at two sites, positioned in the first and second preferential wind direction in the area. The extracts were evaluated with Salmonella/microsome assay, microsuspension method, strains TA98, YG1021 and YG1024. The mammalian metabolization fraction (S9) was used to evaluate metabolite mutagenicity. The Comet Assay (CA) and Micronuclei Test were used in a Chinese hamster lung cell line (V79). All extracts showed mutagenicity in Salmonella, and nitrogenated compounds were strongly present. Genotoxicity were found in CA in almost all extracts and the micronuclei induction at the Site in the first (Autumn 1, Winter 1), and in the second (Spring 2) wind direction. V79 showed cytotoxicity in all samples. The three biomarkers were concordant in characterization Site NO with worse quality, compatible with the greater pollutants dispersion in the first wind direction. All PM2.5 concentrations were lower than those recommended by air quality standards but genotoxic effects were detected in all samples, corroborating that these standards are inadequate as quality indicators. The Salmonella/microsome assay proved sensitive to PM2.5 mutagenicity, with an outstanding influence of nitroarenes and aromatic amines. Analyses using CA and the micronucleus test broadened the levels of response that involve different damage induction mechanisms. Results show that the complex PM2.5 composition can provoke various genotoxic effects and the use of different bioassays is essential to understand its effects.

Evaluation of area contaminated by wood treatment activities: Genetic markers in the environment and in the child population.

Wood preservation activities and related compounds are a problem since these areas have major environmental contamination liabilities which compromise the health of the surrounding population and the integrity of ecological processes. The present study evaluated an area influenced by soil contamination arising from the activities of a deactivated wood treatment plant. The presence and effect of mutagenic compounds in environmental samples were used as markers of exposure together with the evaluation biomarkers of genetic damage in children. Organic extracts from samples of public source water and from fine atmospheric particulate matter (PM2.5) were evaluated for mutagenic potential using the Salmonella/microsome assay. Children living in the area surrounding the plant were analyzed for genetic damage assessed by the comet assay in lymphocytes and micronucleus test (MN) in lymphocytes and oral mucosa and compared to a group living in an area outside the preferential quadrant of atmospheric dispersion and in opposition to the drainage at the site. The mutagenic effect and PAHs concentrations found were similar to studies that evaluated intensely occupied urban areas and those under industrial influence. The MN frequencies in lymphocytes and binucleated cells in the oral mucosa were significantly higher in the risk group. No significant differences were observed in the other genetic damage biomarkers evaluated. The presence of pollutants with a mutagenic and carcinogenic effect on the PM2.5 and the increased in some biomarkers indicate that the population is potentially exposed to substances capable of causing adverse health effects and atmospheric airborne is a possible exposure route.

Characterization of an area of reference for inhalable particulate matter (PM2.5) associated with genetic biomonitoring in children.

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% (25.89-64.71 µg/m3) events above WHO limit value (25 µg/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.

Attic dust assessment near a wood treatment plant: past air pollution and potential exposure.

The wood treatment process uses substances that generate hazardous compounds that may contaminate environmental compartments. In the present study, an area under influence of a deactivated wood treatment plant was investigated to evaluate past air pollution and to try to understand local air dispersion. Attic dust samples were collected from eight residences around the plant and from two residences outside this area, as reference samples. The presence of copper, chromium, arsenic, pentachlorophenol, sixteen priority polycyclic aromatic hydrocarbons and mutagenic activity using Salmonella/microsome assay was evaluated. The residences close to the entrance to the plant were the most affected, according to potentially toxic elements analysis. The PCP concentration was 0.49 mg/kg and the total PAHs content ranged from 0.40 to 13.31 µg/g with greater dispersion than potentially toxic elements. The highest mutagenesis values were 15,905 and 10,399 revertants/g of dust in the absence and presence of S9 mix (mammalian metabolic activation), respectively. Samples in which the total PAHs concentration was less than 2 µg/g no mutagenic effects were observed, including the residences in the reference area. The contribution of PAHs to mutagenesis was 10 percent, indicating that other compounds may contribute to the mutagenic effect. These results suggest that the population was or is potentially exposed to substances with strong effects on health.

Comparative genotoxicity of airborne particulate matter (PM2.5) using Salmonella, plants and mammalian cells.

This study compared genotoxicity in bacteria, plants and cell cultures in areas at risk of exposure to airborne pollution. Genotoxicity of moderately polar organic extracts of PM2.5 from areas with urban airborne pollution (Site 1) and urban-industrial pollution (Site 2) was evaluated using microsuspension assays in Salmonella/microsome, micronucleus test with Tradescantia pallida (Trad-MN) with acute exposure, and in V79 (V79-MN) cells, Comet assay in V79 and human lymphocyte, besides Trad-MN in situ at Site 1. In the Salmonella/microsome assay all samples presented frameshift mutagenic activity (-/+S9), most intense at Site 2 (rev/m(3)). The presence of nitro-PAHs and hydroxylamines in PM2.5 was shown by positive mutagenic responses with YG1021 and YG1024. In tests with Trad-MN, no significant genotoxic responses were found (MN %). In V79-MN a genotoxic response was not found. The Comet assay damages were found in the DNA at Site 1 in both cell systems. Non-detection of genotoxicity with Trad-MN at sites or in environmental samples from polluted areas detected using other biomarkers suggests the need for careful evaluation when biomonitoring genotoxic compounds using plants. The microsuspension assay in Salmonella/microsome was sensitive to detect and identify different classes of airborne mutagenic compounds present in fine particulate matter in Porto Alegre city, showing that monitoring air quality with PM2.5 using this methodology is relevant.

Toxic effects of the ingestion of water-soluble elements found in soil under the atmospheric influence of an industrial complex.

In this study, we investigated the toxic effects of water-soluble elements from a contaminated soil via gavage in a single dose, simulating a geophagy event. The contaminated soil was collected in a field located in an industrial complex, and the control soil was collected in a reference area. Metabolic and behavioral parameters in Wistar male rats were measured after 24 and 96 h of gavage. After 96 h, the major organs were weighed, blood was collected to check hematological parameters, the bone marrow was taken for the micronucleus test, and the liver was used for evaluating the total antioxidant capacity, lipoperoxidation and protein carbonylation. Animals exposed to contaminated soil presented a few significant alterations by comparison with control animals: TBARS and protein carbonyl levels increased, the relative weight of the kidneys increased, metabolic parameters (body weight gain, food intake, water consumption, urine and feces production) depressed and there was behavioral alteration. These findings suggest that soils impacted by atmospheric contaminants can affect the organism physiological status jeopardizing the health of populations living in industrial areas. Finally, this study reassures that ingestion of potentially contaminated soils, even for short periods of time, can cause health risks.

Mutagenicity of particulate matter fractions in areas under the impact of urban and industrial activities.

Organisms in the environment are exposed to a mixture of pollutants. Therefore the purpose of this study was to analyze the mutagenicity of organic and inorganic responses in two fractions of particulates (TSP and PM2.5) and extracts (organic and aqueous). The mutagenicity of organic and aqueous particulate matter extracts from urban-industrial and urban-residential areas was evaluated by Salmonella/microsome assay, through the microsuspension method, using strain TA98 with and without liver metabolization. Additionally, strains YG1021 and YG1024 (nitro-sensitive) were used for organic extracts. Aqueous extracts presented negative responses for mutagenesis and cytotoxicity was detected in 50% of the samples. In these extracts the presence of potential bioavailable metals was identified. All organic extracts presented mutagens with a higher potential associated with PM2.5. This study presents a first characterization of PM2.5 in Brazil, through the Salmonella/microsome assay. The evaluation strategy detected the anthropic influence of groups of compounds characteristically found in urban and industrial areas, even in samples with PM values in accordance with quality standards. Thus, the use of a genotoxic approach in areas under different anthropic influences will favor the adoption of preventive measures in the health/environment relation.

Soil mutagenicity as a strategy to evaluate environmental and health risks in a contaminated area.

Soil can be a storage place and source of pollutants for interfacial environments. This study looked at a site contaminated with wood preservatives as a source of mutagens, defined routes and extent of the dispersion of these contaminants by particle remobilization and atmospheric deposition, considering an evaluation of risk to human health by quantifying mutagenic risk. Soil sampling sites were chosen at gradually increasing distances (150, 500 and 1700m) from SI (industrial area pool) and indoor dust (pool in an area at risk at 385m and at 1700m). Mutagenesis was evaluated in the Salmonella/microsome assay, TA98, TA97a and TA100 strains with and without S9 mix, YGs strains 1041, 1042 and 1024 for nitrocompounds. Acid extracts were analyzed to define the effects of metals and organics for polycyclic aromatic hydrocarbons (PAHs) and nitroderivates, besides concentrations of these compounds and pentachlorophenol (PCP). Risk to human health was obtained from the relation between the quantified potential of mutagenic risk and estimated soil ingestion for children according to USEPA. Metal concentrations showed a gradient of responses with As, Cr and Cu (total metal) or Cr and Cu (fraction available) higher for SI. However, mutagenic effects of the mixtures did not show this grading. Site SR1700, without a response, was characterized as a reference. In organic extracts, the mutagenesis responses showed the mobility of these compounds from the source. In the surrounding area, a smaller pattern similar to SI was observed at SR150, and at the other sites elevated values of direct mutagenesis at SR500 and diminished effects at SR1700. Tests with YG strains indicated that nitrated compounds have a significant effect on the direct mutagenesis found, except SR500. The investigation of indoor dust in the surrounding area enabled confirmation of the particle resuspension route and atmospheric deposition, showing responses in mutagenicity biomarkers, PAH concentrations and PCP dosage similar to SI. The range of values obtained, considering the soil masses needed to induce mutagenicity was 0.02 to 0.33g, indicating a high risk associated with human populations exposed, since these values found surpass the standard estimate of 200mg/day of rate of soil ingestion for children according to USEPA. The study showed that it is essential to evaluate the extent of contamination from the soil to delimit remedial measures and avoid damage to the ecological balance and to human health.

Use of bioindicators to evaluate air quality and genotoxic compounds in an urban environment in Southern Brazil.

Biological indicators are widely used to monitor genotic compounds and air quality in urban environments. Parmotrema tinctorum and Teloschistes exilis have been used to verify the presence of pollutants and analyze morphophysiological alterations in the thallus of species caused by their action. Species were exposed for seven months, in an urban area, in southern Brazil. Mutagenicity and cytotoxicity of PM10 organic extracts were assessed in the Salmonella/microsome assay at two stations. High concentrations of S, Pb, Cr, Zn and Hg were registered in the last period of exposure and more significant morphophysiological damages were verified in the lichens. Generally a higher mutagenic activity is observed in organic extracts of airborne particulate matter during the first months and in the third period of exposure of lichens. In addition, nitro compounds was detected through nitro-sensitive strains. Lichens and mutagenic biomarkers enabled the evaluation of air quality and the presence of environmentally-aggressive compounds.

Runoff of genotoxic compounds in river basin sediment under the influence of contaminated soils.

Contaminated sites must be analyzed as a source of hazardous compounds in the ecosystem. Contaminant mobility in the environment may affect sources of surface and groundwater, elevating potential risks. This study looked at the genotoxic potential of samples from a contaminated site on the banks of the Taquari River, RS, Brazil, where potential environmental problems had been identified (pentachlorophenol, creosote and hydrosalt CCA). Samplers were installed at the site to investigate the drainage material (water and particulate soil matter) collected after significant rainfall events. Organic extracts of this drained material, sediment river samples of the Taquari River (interstitial water and sediment organic extracts) were evaluated by the Salmonella/microsome assay to detect mutagenicity and by Allium cepa bioassays (interstitial water and whole sediment samples) to detect chromosomal alterations. Positive mutagenicity results in the Salmonella/microsome assay of the material exported from the area indicate that contaminant mixtures may have drained into the Taquari River. This was confirmed by the similarity of mutagenic responses (frameshift indirect mutagens) of organic extracts from soil and river sediment exported from the main area under the influence of the contaminated site. The Allium cepa test showed significant results of cytotoxicity, mutagenic index and chromosome aberration in the area under the same influence. However, it also showed the same similarity in positive results at an upstream site, which probably meant different contaminants. Chemical compounds such as PAHs, PCF and chromium, copper and arsenic were present in the runoff of pollutants characteristically found in the area. The strategy employed using the Salmonella/microsome assay to evaluate effects of complex contaminant mixtures, together with information about the main groups of compounds present, allowed the detection of pollutant dispersion routes from the contaminated site to the Taquari River sediment.