Predicting ozone levels from climatic parameters and leaf traits of Bel-W3 tobacco variety.

Air pollution has been identified as a major cause of environmental and human health damage. O3 is an oxidative pollutant that causes leaf symptoms in sensitive plants. This study aims to adjust a multilinear model for the monitoring of O3 in subtropical climatic conditions by associating O3 concentrations with measurements of morphological leaf traits in tobacco plants and different environmental variables. The plants were distributed into five areas (residential, urban or industrial) in the southern region of Brazil and exposed during 14 periods, of 14 days each, during the years of 2014 and 2015. The environmental variables and leaf traits during the exposure periods were described by mean, median, standard deviation and minimum and maximum values. Spearman correlation and multiple linear regression analyses were applied on data from exposure periods. Leaf injury index, leaf area, leaf dry mass, temperature, relative humidity, global solar radiation and accumulated rainfall were used in the regression analyses to select the best models for predicting O3 concentrations. Leaf injury characteristically caused by O3 was verified in all areas and periods of plant exposure. Higher values of leaf injury (24.5% and 27.7%) were registered in the 13th and 12th exposure periods during spring and in areas influenced by urban and industrial clutches. The VPD, temperature, global solar radiation and O3 were correlated to leaf injury. Environmental variables [leaf area, leaf dry mass, global solar radiation and accumulated rainfall] and primarily the VPD were fundamental to improve the adjustments done in the bioindicator model (R2 ≥ 0.73). Our research shows that biomonitoring employing the tobacco "Bel-W3" can be improved by measuring morphological leaf traits and meteorological parameters. Additionally, O3 fumigation experiment should be performed with biomonitoring as conducted in this study, which are useful in understanding the role of other environmental factors.

The application of lichens as ecological surrogates of air pollution in the subtropics: a case study in South Brazil.

The use of lichens as ecological surrogates has been an important tool to evaluate the impact of air pollution in both ecosystem and human health but remains underused in the subtropics due to lack of knowledge. Aiming to support the application of lichen as ecological surrogates of the effects of air pollution in the subtropics, we hypothesized that urbanization was an important driver of changes on lichen diversity, composition, and vitality. For that, we quantified several lichen diversity metrics (richness, cover, and community composition) and photobiont vitality in relation to atmospheric pollution or its surrogates (modeled pollutant gases, pollutants in lichen thallus, and land cover). We confirmed that air pollution was a key driver for lichen diversity. Changes in lichen community composition and vitality were very significantly related to air pollution and integrated the effect of multiple stressors (particulate matter, NOx, and Cu), thus being powerful ecological indicators of air pollution in the subtropics.

Tools used to estimate soil quality in coal combustion waste areas.

Soil is a highly complex environmental compartment that has suffered with the contamination of substances of various origins. Among the main activities that affect soil quality are power generation activities that use fossil fuels, such as mineral coal. Environmental protection agencies encourage scientific investigations using tools described in legal devices or standard protocols to evaluate the potential of coal as a pollutant, especially in places that have large reserves of this mineral like the state of Rio Grande do Sul. The aim of this study was to characterize the leached extracts of different soils from an area influenced by coal waste, to classify them according to the guideline values for groundwater described in CONAMA's n. 420/2009, and to estimate the effects of the leachates ingestion in DNA mutation rates. The volume of soil needed to induce a 100% increase in the spontaneous mutation rate varied between 129.3 and 1544.1 mg of soil among the soils studied. Metals such as Mn, Pb, Cd and Ni surpassed the investigation limits for groundwater at least in one soil sample. The results showed that there can be transfer of soil contaminants to groundwater and soil intake in the area could contribute to the increased mutagenic risk.

Toxicogenetic monitoring in urban cities exposed to different airborne contaminants.

Microparticles found in the air may be associated with organic matter that contains several compounds, such as Polycyclic Aromatic Hydrocarbons (PAHs) and nitro-PAHs, and may pose a significant risk to human health, possibly leading to DNA mutations and cancers. This study associated genotoxicity assays for evaluating human exposure with the atmospheric air of two urban areas in southern Brazil, that received different atmospheric contributions. Site 1 was under urban-industrial influence and the other was a non-industrial reference, Site 2. Organic extracts from the airborne particulate matter were tested for mutagenicity via the Salmonella/microsome assay and analyzed for PAH composition. Cells samples of people residing in these two cities were evaluated using the comet and micronucleus assay (MN).Concentrations of the individual PAHs ranged from 0.01 ng/m(3) (benzo[a]anthracene) to 5.08 ng/m(3) (benzo[ghi]perylene). As to mutagenicity analysis of airborne, Site 1 presented all the mutagenic responses, which varied from 3.2±1.22 rev/m(3) (TA98 no S9) to 32.6±2.05 rev/m(3) (TA98, S9), while Site 2 ranged from negative to minimal responses. Site 1 presented a high quantity of nitro and amino derivatives of PAHs, and peaked at 56.0±3.68 rev/µg (YG1024 strain). The two groups presented very low DNA damage levels without intergroup difference. Although Site 1 presented high mutagenic responses in the air samples, high PAH levels, healthy people exposed to this environment did not show significative damage in their genetic material. However, the evaluation of different environmental and genetic damage in such population is necessary to monitor possible damages.

Salmonella mutagenicity assessment of airborne particulate matter collected from urban areas of Rio Grande do Sul State, Brazil, differing in anthropogenic influences and polycyclic aromatic hydrocarbon levels.

Urban areas are both major sources and major targets of air pollution. The atmospheric environment receives diverse chemical substances, including genotoxic agents that may affect human health. The purpose of this study was to evaluate and compare the atmospheric quality in two urban areas in Rio Grande do Sul State (Brazil), under the influence of greater (Site 1) or lesser (Site 2) anthropogenic sources. Polycyclic aromatic hydrocarbons (PAHs) of environmental interest were quantified and the Salmonella/microsome assay was used for the measurement of mutagenicity. Organic compounds extracted from the airborne particulate matter were analyzed by high-performance liquid chromatography (HPLC) to detect PAHs of interest (known or possible carcinogens). The organic extracts were also tested for mutagenic and cytotoxic activity in the Salmonella/microsome assay with strains TA98, TA100, YG1021 and YG1024, with or without S9 activation. At Site 1, benzo[ghi]perylene (BghiP) and indeno[1,2,3-cd]pyrene (IP) were found at higher concentrations and mutagenicity (revertants per µg extract) varied from 1.0±0.25 (TA98, no S9) to 5.2±0.45 (TA98, S9). At Site 2, BghiP and IP were present in larger amounts and the mutagenic responses ranged from 0.6 to 3.7 revertants per µg (both in TA98, S9). The occurrence of BghiP and IP may be related to vehicular emissions. These and the other PAHs studied, as well as the nitro compounds, may contribute to the mutagenicity found in these airborne particles.

Genetic biomonitoring of an urban population exposed to mutagenic airborne pollutants.

Biomonitoring studies have increased as a consequence of risks and effects to human health on exposure to environmental contaminants, mainly air pollutants. Genetic biomarkers are useful tools for the early assessment of exposure to occupational and environmental pollution. The objective of the present study was to investigate genotoxic effects on people residing and/or working downwind from an oil refinery in southern Brazil and the mutagenic activity of airborne particulate matter (PM10). Samples of peripheral blood and buccal mucosa cells were evaluated using the single-cell gel electrophoresis assay (comet assay) and the micronucleus (MN) assay, respectively. PM10 samples were collected in the target site and the organic matter extraced with dichloromethane was assessed for mutagenic activity in the Salmonella/microsome assay. The exposed group (n=37) was compared to a reference group (n=37) of subjects living in an urban area with limited traffic and industrial influence, located far from the main industrial areas. All PM10 organic extracts showed mutagenic positive responses and the effect decreased in the presence of S9 mix indicating that the predominant compounds present were direct-acting mutagens. The responses of YGs strains are consistent with aromatic amines and nitroarenes being present in the PM10 extracts. The group in the area under the influence of the oil refinery (exposed group) showed significantly higher DNA damage in lymphocytes than the reference group. The MN frequencies in buccal mucosa were very low for both groups and no difference between groups was observed. No association was found between age and tobacco smoking habit and level of DNA damages measured by the comet assay. The results indicate that the comet assay was a sensitive tool to detect DNA damage in subjects under the influence of an oil refinery, with marked genotoxic activity in the atmospheric environment.

Aspectos toxológicos do preservativo de madeira CCA (areniato de cobre cromatado): revisão / Toxicological aspects of chromated copper arsenate (CCA) wood preservative: a review

Chromated copper arsenate (CCA) is a chemical mixture consisting of three pesticide compounds (chromium, copper and arsenic) registered as wood preervatives to prevent fungal or microbial decay. CCA is injected into wood by a process that uses high pressure to saturate wood products with the chemical. CCA-treated wood is commonly used for telephone poles, fence posts, playground equipment, decks, walkways, boat docks and home constructions like fences or pool foors. In this study, a review of the literature was performed, involving articles relating to the toxicology of CCA, a preservative wich is responsible for the largest volume of treated wood in the world. This included relevant information concerning occupationa aspects and public health, particularly its use in homes, parks and playgrounds and aquatic environments to which the public has acess. More attention was given to arsenic, as compared to chromium and copper, because it is the most toxic component in the formula, since it has greater leachinh properties, from wood treated with CCA, as compared to chromium, the second most toxic component. For Brazil BIREME-Latin American and Caribbean Center for Information in Health Sciences was consulted. This gathers 114 Brazilian scientific publications. International literature was researched using Pub Med, a service of the American National Library, wich includes MEDLINE. The periodicals Portal of CAPES was also acessed for international publications, as well as the National system of Toxic-Pharmacological Information - SINITOX...

Mutagenicidade do extrato aquoso de Baccharis articulata (Lam. ) Persoon no ensaio Salmonella/Microssoma / Mutagenicity of aquous extracts of Baccharis articulata (Lam. ) Persoon in Salmonella/Microssoma assay

Baccharis articulata (Lam.) Persoon, é uma planta medicinal muito utilizada como chá no sul do Brasil, pelas suas propriedades digestivas e diuréticas. Extratos aquosos desta planta foram testados quanto à presença de atividade mutagênica no ensaio Salmonella/microssoma, ou teste de Ames, em presença e ausência de atividade metabólica hepática de mamíferos in vitro (fração S9). Foram utilizadas as linhagens TA 98, TA 100 e TA 102, que permitem avaliar mutagênese por delocamento do quadro de leitura, substituição de pares de base e danos oxidativos, respectivamente. Foi possível observar atividade mutagênica direta para as linhagens TA 98, TA 100 e TA 102. Em presença de metabolização hepática foi detectado um decréscimo importante do efeito, persistindo a mutagenicidade do tipo deslocamento do quadro de leitura. Portanto os agentes mutagênicos de ação direta, presentes na infusão de B. articulata, foram em parte, inativados pela fração S9. Outros ensaios serão necessários para a confirmação destas propriedades e suas conseqüências para a saúde humana

Mutagenicity of chromium VI using the Salmonella microsuspension bioassay

The mutagenicity and cytotoxicity of hexavalent chromium (K2Cr2O7) were assessed by a Salmonella microsuspension bioassay, in order to define standard mutagenicity dose-response curves for this compound with TA97a, TA98, TA100 and TA102 Salmonella typhimurium strains, in the presence and absence of the exogenous metabolism fraction (S9). All the Salmonella strains tested were more or less efficiently reverted by Cr(VI) in the absence of S9 mix, with the following ranking of sensitivity available with the necessary concentration of potassium dichromate (µg) to double the number of revertant colonies in the negative control: TA98, TA100, TA97a, TA102. After metabolism the number of revertant colonies decreased in all strains studied, but positivity remained for TA97a and TA100 strains or indications of this mutagenicity in the TA98 and TA102 strains. The Salmonella microsuspension bioassay showed response sensitivity to detect mutagenicity induced by K2Cr2O7, was an appropriate assay to study environmental samples in areas which could be contaminated by chromium VI

Genotoxicity of plant extracts

Aqueous extracts of seven species used in Brazilian popular medicine (Achyrocline satureoides, Iodina rhombifolia, Desmodium incanum, Baccharis anomala, Tibouchina asperior, Luehea divaricata, Maytenus ilicifolia) were screened to the presence of mutagenic activity in the Ames test (Salmonella/microsome). Positive results were obtained for A. satureoides, B anomala and L. divaricata with microsomal activation. As shown elsewhere (Vargas et al., 1990) the metabolites of A. satureoides extract also show the capacity to induce prophage and/or SOS response in microscreen phage induction assay and SOS spot chromotest.