Tradescantia micronucleus bioassay

Assessment of genotoxicity of air pollution in urban areas using an integrated model of passive biomonitoring

Atmospheric pollution is a major public health issue and has become increasingly critical for human health. Urban atmospheric pollution is typically assessed through physicochemical indicators aligned with environmental legislation parameters, providing data on air quality levels. While the effects of pollution on sensitive organisms serve as a warning for public health decision-makers, there remains a need to explore the interpretation of environmental data on pollutants. The use of species adapted to urban environments as sentinels enables continuous and integrated monitoring of environmental pollution implications on biological systems. In this study, we investigated the use of the plant species Tradescantia pallida as a biomonitor to evaluate the genotoxic effects of atmospheric pollution under diverse vehicular traffic conditions. T. pallida was strategically planted at the leading urban intersections in Uberlândia, Brazil. During COVID-19 pandemic lockdowns, we compared indicators such as physical, biological, and traffic data at different intersections in residential and commercial zones. The reduction in vehicular traffic highlighted the sensitivity of plant species to changes in air and soil pollutants. T. pallida showed bioaccumulation of heavy metals Cd and Cr in monitored areas with higher traffic levels. Additionally, we established a multiple linear regression model to estimate genotoxicity using the micronucleus test, with chromium concentration in the soil (X1) and particulate matter (PM) in the atmosphere (X2) identified as the primary independent variables. Our findings provide a comprehensive portrait of the impact of vehicular traffic changes on PM and offer valuable insights for refining parameters and models of Environmental Health Surveillance.

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.

Biomonitoring of air quality in the Bodoquena microregion, Mato Grosso Do Sul: mutagenic and morphoanatomical alterations in Tradescantia pallida (rose) D.R. Hunt var. purpurea

The objective of this study was to assess air quality in relation to vehicular traffic flow in cities located at different elevations in the Bodoquena microregion, state of Mato Grosso do Sul, Brazil. To do so, a micronucleus test was carried out using the TRAD-MCN bioassay on young Tradescantia buds collected from February to November 2018 in seven cities of the microregion with different traffic flow intensities. Meteorological parameters were evaluated, and vehicular traffic was counted to determine traffic flow in each city. With data from the Shuttle Radar Topography Mission (SRTM) and processing in Esri ArcGIS® software version 10.5.1, the regions was mapped based on an Elevation Model. Morphoanatomical analyses were performed according to standard methodology. Measurements were taken of thickness, length and width of tissues and structures, including the upper and lower cuticle, upper and lower epidermis, hypodermis and mesophyll. The greatest traffic flow was found in the cities of Bodoquena, Guia Lopes da Laguna, Jardim, and Porto Murtinho, with the period from 5:00 to 6:00 p.m. showing the highest traffic flow. The greatest frequency of mutagenic alterations was found in the city of Guia Lopes da Laguna, although the results did not differ significantly from Bonito, Caracol, and Jardim. Throughout the biomonitoring, the summer and autumn seasons showed the greatest micronuclei frequencies in all evaluated cities. Variations in the tissue/structure thickness was observed across cities and seasons, but with a decrease in thickness during autumn. In general, the tissues/structures were smaller for the cities of Nioaque and Porto Murtinho, while the anatomical and morphological characteristics of leaf length and thickness showed no differences among cities. We found limited correlation between micronuclei frequency and traffic flow, supporting the hypothesis that although mutagenic alterations are observed in T. pallida, in this microregion the changes are numerically lower when compared to other regions of the state. In light of the genotoxic and morphoanatomical factors assessed herein, the Bodoquena microregion appears to be well preserved in terms of air quality, presenting low micronuclei frequency and a limited reduction in tissues and leaf structures, regardless of the season.

Analysis of genotoxic effects on plants exposed to high traffic volume in urban crossing intersections

A biological assessment of environmental quality was performed using the tropical plant species Tradescantia pallida (Rose) D.R. Hunt. var. purpurea exposed to different levels of air contamination in urban intersections with high volume of vehicle traffic. Air quality (average daily levels of particulate material in the PM_{1, 2.5, 10} fractions) and traffic volume in crossing intersections were monitored for 30 days before the collection of plants. Frequency of micronuclei and pollen abortivity in inflorescences collected at different intersections with gradual levels of traffic volume were evaluated as biomarkers of genotoxicity. In addition, the concentrations of bioaccumulated heavy metals in the leaves of the collected plants were also investigated. The proposed biological assessment model found a positive association between the environmental variables (traffic volume; concentration of particulate material) and biological effects (leaf concentration of Cr and Cd; micronucleus frequencies and pollen abortivity).

Phytotoxicity and phytogenotoxicity of soil and air in the vicinity of a petrochemical plant in Płock (Poland)

Petrochemical industries have been widely recognised as important emission sources of airborne contaminants including heavy metals and polycyclic aromatic hydrocarbons PAHs, which affect the quality of air, soil and vegetation. In this study, our aim was to examine the phytotoxicity and phytogenotoxicity of soils and air in the vicinity of a petrochemical plant, in order to assess the potential threat of such industrial objects for crops and natural vegetation, in the cases when the allowable concentrations of contaminants are not exceeded and the plants in the vicinity visually do not seem to be affected. For phytotoxicity and phytogenotoxicity assessment, the Phytotoxkit and respectively Vicia RTA and TRAD MCN bioassays were used. According to our results, in spite of relatively low content of heavy metals and PAHs (hardly any exceedance of standards), the phytotoxicity and especially phytogenotoxicity of soil samples collected up to 18 km from the refinery were detected by the bioindicators. The phytogenotoxicity of air was also indicated within the distance of up to 12 km. We concluded that to obtain the complete view of the environmental risks in a surveyed area, a combination of chemical analysis of environmental samples with the bioindication methods should be implemented. In addition, setting the acceptable levels of contaminants should involve a more extensive use of bioindication methods (especially genotoxicity assessment).

Micronucleus Assay with Tetrad Cells of Tradescantia

The Tradescantia micronucleus assay has been used since 50 years for the detection of genotoxins (including carcinogens) in the environment. A large database concerning the effects of individual chemicals and complex environmental mixtures (soil, air and waters) has accumulated. In contrast to other mutagenicity test systems, the effects of low concentrations of heavy metals, radionuclides, certain herbicides, pesticides and gaseous mutagens can be detected and it is also possible to conduct in situ biomonitoring studies with plant. The test system has been validated and standardized protocols have been developed for laboratory experiments and for field studies which are described in this chapter.

Genotoxicity and carcinogenicity of ivermectin and amoxicillin in vivo systems

Antiparasitic substances are chemicals used to control or kill endoparasites and ectoparasites. Based on the premise that Ivermectin (IVM) and Amoxicillin (AMX) are commonly considered in parasitic control in mammals, the present study aimed to evaluate the carcinogenic and genotoxic potential of different concentrations of IVM and AMX through the detection of epithelial tumor test in Drosophila melanogaster. Third-instar larvae descending from the cross between wts/TM3, Sb¹ females and mwh/mwh males were treated with different concentrations of IVM (2.9, 5.8, 11.6 and 23.2 x 10^-17 mM) or AMX (1.37, 2.74, 5.48 and 10.9 x 10^-16mM). The results revealed that IVM increased the frequency of epithelial tumor in D. melanogaster considering all evaluated concentrations, while AMX showed no carcinogenic effect. Furthermore, the Micronucleus (MN) test in Tradescantia pallida was used to evaluate the genotoxic effect of IVM and AMX. T. pallida individuals were exposed for 8 hours at different concentrations of IVM (5.71, 11.42, 22.84 and 45.68 x 10^-5mM) or AMX (5.13, 10.26, 20.52 and 41.05 x 10^-3mM). Findings showed an increase in the frequency of micronuclei in T. pallida treated with 11.42, 22.84 and 45.68 x 10^-5mM of IVM. We conclude that chronic exposure to IVM is directly associated with events resulting from genetic instability (genotoxicity and carcinogenicity). On the other hand, AMX was neither carcinogenic nor genotoxic for D. melanogaster and T. pallida.

Assessment of the genotoxic potential of water courses impacted by wastewater treatment effluents using micronucleus assay in plants from the species Tradescantia

Water pollution and the increase in genotoxic consequences in aquatic environments are well documented indicating the necessity and importance of biomonitoring programs. The objective of the present study was to determine the environmental quality of water resources and genotoxic potential of materials present within water samples obtained from the Perdizes River and the Mumbuca Stream, located in a region of discharge of wastewater treatment effluents using Tradescantia micronucleus assay (Trad - MCN). Water samples were collected from different locations up and downstream of the wastewater treatment plant during rainy season and subsequently submitted to physico-chemical analysis and Trad-MCN bioassay. The spatial distribution of the physico-chemical parameters assessed suggested that discharges of wastewater treatment effluents reduced water quality at all sites examined. Further, exposure to wastewater treatment effluents produced genotoxic effects on tetrads of Tradescantia pallida. These results reinforce the sensitivity of the Trad-MCN bioassay and its potential application in water quality monitoring programs concomitant with physicochemical evaluation.

Genotoxic and mutagenic assessment of spinosad using bioassays with Tradescantia pallida and Drosophila melanogaster

Spinosad (SPN) is a naturally-occurring insecticide obtained from the fermentation process of the actinomycete Saccharopolyspora spinosa. Owing to the larvicidal action, the compound has been used in the control of Aedes aegypti. As a new insecticide commercially available in the market, few data are reported on genotoxic effects in non-target organisms. The objective of the present study was to evaluate the mutagenic effect of SPN through the Micronucleus Test in Tradescantia pallida (Trad-MCN) and using the mutation and somatic recombination test in Drosophila melanogaster (SMART). At the Trad-MCN, after acclimatization (24 h), T. pallida stems were submitted to chronic treatment with SPN at concentrations of 0.156; 0.312; 0.625; 1.25 and 2.5 g/L solution for 24 h, followed by a recovery period. In SMART, considering the third stage larvae, offspring resulting from the ST and HB crossing were placed on chronic treatment (48 h) with 0.039; 0.078 and 0.156 μg/mL of SPN solution. No mutagenic effect was observed at any of the evaluated concentrations in SMART. Additionally, SPN is more toxic after metabolism via CYP6A2 (cytochrome P450) in D. melanogaster. However, SPN at the concentrations of 0.625; 1.25 and 2.5 g/L was able to induce high frequency of micronuclei in T. pallida. Under the experimental conditions of T. pallida in the present study, SPN caused genotoxic activity.

Tradescantia as a biomonitor for genotoxicity evaluation of diesel and biodiesel exhaust emissions

Biodiesel, an alternative energy source, is promoted as cleaner and safer than other fuel options due to its reported reduction of particulate and gaseous emissions (CO₂, CO, and total hydrocarbons). However, its volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbon (PAHs) emissions are key to understanding its toxic, mutagenic and carcinogenic risk factors. This research was developed to assess the genotoxic impact of exhaust emissions using biodiesel from animal fat, palm oil and soybean oil blended with diesel (B80). Diluted exhaust gases were analyzed simultaneously for pollutant emissions and for toxicity using an exposure chamber called the BioToxMonitor, where Tradescantia pallida and a KU-20 clone were exposed to exhaust following Trad-MCN and Trad-SH bioassays. The results show differences in the emission compositions and considerable mutagenic potential among the three biodiesels tested, with palm oil biodiesel emissions being the least harmful, based on its low pollutant concentrations and the negative response in the TradSH bioassay. In contrast, the animal fat biodiesel and soybean oil biodiesel emissions were as toxic as the diesel emissions, being positive in both Trad bioassays. This could be related to the PAH and carbonyl concentrations found in the vehicular exhaust. The genotoxicity of diesel emissions was related to PM₁ and the concentrations of both gas and particle PAHs concentrations, which were two times higher compared to the highest concentrations observed for biodiesel. The data suggest that micronucleus assays in Tradescantia pallida are more sensitive for gaseous pollutant exposure. This is the first reported study of biodiesel exhaust biomonitoring in situ and under controlled conditions inside an exposure chamber.

Response of Tradescantia plants to oxidative stress induced by heavy metal pollution of soils from industrial areas

Numerous investigations have demonstrated that even soil in which concentrations of individual elements do not exceed permissible limits can cause harmful effects in living organisms. In the present study, polluted-soil-induced oxidative stress was evaluated using Tradescantia clone 4430, which is widely used for genotoxicity evaluations, employing biochemical (superoxide dismutase (SOD), contents of ascorbic acid (AA), carotenoids (Car), hydrogen peroxide (H₂O₂), chlorophyll (Chl) a/b ratio), and molecular (RAPD and differential display (DD-PCR)) markers after long-term exposure. The activity (staining intensity) of SOD isoforms in Tradescantia leaves was higher in plants grown in all heavy-metal-polluted test soils compared to the control. No direct link between the soil pollution category and the contents of AA, Car, Chl a/b in Tradescantia leaves was revealed, but the concentration of H₂O₂ was shown to be a sensitive biochemical indicator that may appropriately reflect the soil contamination level. Both short-term (treatment of cuttings with H₂O extracts of soil) and long-term (0.5 and 1.0 year) exposure increased MN frequencies, but the coincidence of the MN induction and the soil pollution level was observed only in some cases of long-term exposure. Soil (geno)toxin-induced polymorphism in the RAPD profile was determined with two primers in plants after long-term exposure to soils of an extremely hazard category. Transcript profiling of plants after long-term cultivation in test soils using DD-PCR showed that the majority of differentially expressed transcript-derived fragments (TDFs) were homologous to genes directly or indirectly participating in photosynthesis, the abiotic stress response, and signal transduction cascades.

Evaluation of vehicular pollution using the TRAD-MCN mutagenic bioassay with Tradescantia pallida (Commelinaceae)

Biomonitoring is one of the tools used to assess the mutagenic potential of the atmosphere. In this study, the mutagenicity of Tradescantia pallida, a species of plant largely present in urban environments, was investigated. The objectives of this study was to estimate the mutagenic potential of vehicular flow through the TRAD-MCN bioassay in cities located at different altitudes in the southwest mesoregion of Mato Grosso do Sul, Brazil, to infer possible abiotic agents that may contribute to the effects of atmospheric pollutants, and finally to map the cities with greater risks to the health of the local population. To achieve these objectives, the Tradescantia-micronucleus test was performed on young buds of T. pallida collected between August 2015 and August 2016 in nine cities of Mato Grosso do Sul. These buds were exposed to traffic flows of various intensities. The data collected consisted of measurements of meteorological parameters and vehicular traffic counts for each city. The variables considered were: mean ambient temperature; micronuclei frequency; vehicular flow; altitude; relative humidity; pluviosity. The application of the Trad-MCN bioassay, with the consideration of environmental variables and altitudes, and the use of the Kernel interpolation technique, allowed us to map the areas with significant pollution risks to the population. The highest frequency of exposure to mutagens occurred in the cities with the highest vehicular traffic intensity. The average ambient temperature failed to show a linear association with the frequency of the micronuclei in the samples analyzed (r = 0.11^ns). A positive correlation was observed between micronuclei frequency and vehicular flow, (r = 0.67; p ≤ 0.001%) and between micronuclei frequency and altitude (r = 0.24; p ≤ 0.05). A negative correlation was found between relative humidity and micronuclei frequency (r = -0.19; p ≤ 0.05%). Thus, higher micronuclei frequency tended to be present in locations with low relative humidity and high altitudes and vehicular flow.

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.

Genotoxicity evaluation of two metallic-insecticides using Allium cepa and Tradescantia pallida: A new alternative against leaf-cutting ants

In order to combat leaf-cutting ants, the pesticide sulfluramid used to be the most widely utilized active ingredient. However, its use was banned in 2009 by the Stockholm Convention, although some countries were allowed to continue using it. As an effective alternative to its replacement, researchers developed a metallic-insecticide system, which is a natural product linked to metal complexes. Thus, the aim of this study was to evaluate the ability of these new metallic-insecticides in change the genetic material of non-target organisms. The tests were performed utilizing chromosomal aberrations and micronucleus tests in the Allium cepa test system and the Trad-MCN test in Tradescantia pallida. To better understand the results, one of the components of the formula, 5-methyl-phenanthroline, was also analyzed according to the same parameters. To A. cepa, the results showed that one of the metallic insecticides induced cytotoxicity and genotoxicity at different concentrations, while the other metallic-insecticide showed chromosomal instability only at the highest concentration. The analysis of 5-methyl-phenanthroline revealed that it can be related with the positive results, since genotoxic effects were induced. In the Trad-MCN test, none of the metallic-insecticides showed genotoxic activity, although one of them induced more micronucleus formation.

Integrated monitoring for environmental health impact assessment related to the genotoxic effects of vehicular pollution in Uberlândia, Brazil

The development of parameters to explore the link between air-related diseases and their significant driving forces is an important aim in terms of national economics and public health. In this study, we did an integrated analysis involving multiple environmental health indicators from Uberlândia, Brazil, registered before and during a period when the Brazilian government reduced taxes on new cars in a bid to bolster local manufacturing. In addition, the present study utilized Driving Force-Pressure-State-Exposure-Effect-Action (DPSEEA) frameworks to evaluate correlations in environmental health indicators over 10 years (2004-2013), in which the Brazilian government reduced vehicle production taxes beginning in 2008. Significant correlations in all indicators selected were found from 2008 to 2013, corresponding to the tax reduction on new vehicles. The frequency of micronuclei (MN) was significantly higher in the city center compared to the reference site, with the highest MN levels observed during the period of reduced taxes. Results reinforced the need to adopt air quality monitoring programs in major cities.

Tradescantia as a biomonitor for pesticide genotoxicity evaluation of iprodione, carbaryl, dimethoate and 4,4'-DDE

There is a current tendency to develop and apply environmentally friendly techniques that meet the requirements of green analytical chemistry as an alternative to conventional analytical methods. For toxicity evaluation, these alternatives may be found in bioassays such as Tradescantia. This technique, developed in the 1980s, is highly sensitive to evaluate environmental mutagens, simple and cheap. In this paper, the sensibility of both the Tradescantia micronucleus bioassay (Trad-MCN) and the Tradescantia stamen hair bioassay (Trad-SH) were studied for carbaryl, dimethoate and iprodione, common agricultural and domestic pesticides that are currently used in Chile, which have never been tested with such bioassays. Biomonitor exposures were performed by capillary absorption for each individual pesticide over a wide range of concentrations, from maximum residue limits (trace levels) up to the application dose in agricultural fields. In addition, the organochloride 4,4'-DDE was included but only in the concentration range from 0.01mgL^-1 to 1mgL^-1, mimicking residue concentrations since it is not a commercial product but, rather, the main breakdown product of the persistent organochloride pesticide 4,4-DDT, whose use was discontinued in Chile in the 1980s. The Trad-MCN bioassay revealed a significant increase in micronucleus frequency at the early tetrads of meiotic pollen mother cells of the biomonitor Tradescantia pallida var. purpurea, induced by 4,4'-DDE (for 1mgL^-1), dimethoate (for 40mgL^-1, 200mgL^-1, 400mg/L^-1) and carbaryl (for 889mgL^-1). Iprodione did not generate any significant change at the tested concentration. Meanwhile, the Trad-SH bioassay was carried out by analysis of the phenotype variations of the stamen hair cells of the Tradescantia clone KU-20 for the same pesticides and doses. This bioassay was not sufficiently sensitive for toxicity evaluation of most of the pesticides tested, with exception of dimethoate in low doses (2 and 5mg/L^-1).

The Tradescantia micronucleus assay is a highly sensitive tool for the detection of low levels of radioactivity in environmental samples

Environmental contamination with radioactive materials of geogenic and anthropogenic origin is a global problem. A variety of mutagenicity test procedures has been developed which enable the detection of DNA damage caused by ionizing radiation which plays a key role in the adverse effects caused by radioisotopes. In the present study, we investigated the usefulness of the Tradescantia micronucleus test (the most widely used plant based genotoxicity bioassay) for the detection of genetic damage caused by environmental samples and a human artifact (ceramic plate) which contained radioactive elements. We compared the results obtained with different exposure protocols and found that direct exposure of the inflorescences is more sensitive and that the number of micronuclei can be further increased under "wet" conditions. The lowest dose rate which caused a significant effect was 1.2 μGy/h (10 h). Comparisons with the results obtained with other systems (i.e. with mitotic cells of higher plants, molluscs, insects, fish and human lymphocytes) show that the Tradescantia MN assay is one to three orders of magnitude more sensitive as other models, which are currently available. Taken together, our findings indicate that this method is due to its high sensitivity a unique tool, which can be used for environmental biomonitoring in radiation polluted areas.

Evaluation of herbicides action on plant bioindicators by genetic biomarkers: a review

The use of pesticides has increased worldwide, owing to the demand for products of good quality and to satisfy a growing population. Herbicides represent almost half of the total amount of pesticides used. Although important to the reduction of costs and an increase of productivity, their indiscriminate use, as well as that of the other pesticides, is a global environmental problem, since they affect the living organisms. To evaluate the damage caused by herbicides to the environment, different organisms have been used as bioindicators, especially higher plants, due to several advantages. This is a literature review on herbicidal actions in plant bioindicators, as assessed by genetic biomarkers. Also, the present manuscript aimed to characterize the main organisms (Allium cepa, Vicia faba and Tradescantia spp.) and the most used biomarkers (mitotic index, chromosome aberrations, micronuclei, sister chromatid exchange and mutations). We concluded that herbicides induce cytotoxicity and genotoxicity in the assessed bioindicators. The data corroborate the existing warnings of the risks that the indiscriminate and increasing use of pesticides poses to the environment and its biodiversity.

Chemical and toxicological characterisation of anticancer drugs in hospital and municipal wastewaters from Slovenia and Spain

Anticancer drugs are continuously released into hospital and urban wastewaters, where they, most commonly, undergo conventional treatment in wastewater treatment plants (WWTPs). Wastewaters contain complex mixtures of substances including parent compounds, their metabolites and transformation products (TPs). In this study, samples of hospital effluents and WWTP influents and effluents from Slovenia and Spain were analyzed for twenty-two selected anticancer drugs, their metabolites and transformation products. Acute and chronic toxicity tests were performed on the crustacean Ceriodaphnia dubia, genotoxicity was determined with Tradescantia and Allium cepa micronucleus (MN) assays and in vitro comet assay in zebrafish (Danio rerio) liver cell line (ZFL cells). Sixty of the two hundred-twenty determinations revealed detectable levels of anticancer drug residues. Among the targeted compounds, platinum based were most frequently detected (90%). Furthermore, erlotinib was detected in 80%, cyclophosphamide and tamoxifen in 70% and methotrexate in 60% of the samples. Seven of ten samples were toxic to C. dubia after acute exposure, whereas after chronic exposure all samples reduced reproduction of C. dubia at high sample dilutions. Allium cepa proved insensitive to the potential genotoxicity of the tested samples, while in Tradescantia increased MN frequencies were induced by a hospital effluent and WWTP influents. In ZFL comet assay all but one sample induced a significant increase of DNA strand breaks. Correlations of chemotherapeutics or their TPs were detected for all bioassays except for Allium cepa genotoxicity test, however for each test the highest correlations were found for different substances indicating differential sensitivities of the test organisms.

Impact of common cytostatic drugs on pollen fertility in higher plants

Cytostatic drugs are among the most toxic chemicals which are produced. Many of them cause damage of the genetic material which may affect the fertility of higher organisms. To study the impact of the widely used anticancer drugs [cisplatin (CisPt), etoposide (Et), and 5-fluorouracil (5-FU)] on the reproduction of higher plants, pollen abortion experiments were conducted with species which belong to major plant families, namely with Tradescantia paludosa (Commelinaceae), Arabidopsis thaliana (Brassicaceae), Chelidonium majus (Papaveraceae), and Alisma plantago-aquatica (Alismataceae). All compounds increased the frequencies of abortive grains. The lowest effective doses were in general in a narrow range (i.e., 1 and 10 mg/kg of dry soil). The effects of the individual drugs were similar in T. paludosa, A. plantago-aquatica, and Ch. majus, while A. thaliana was consistently less sensitive. The highest abortion rate was obtained in most experiments with CisPt, followed by 5-FU and Et. Comparisons of the doses which caused effects in the present experiments in the different species with the predicted environment concentrations and with the levels of the cytostatics which were detected in hospital wastewaters show that the realistic environmental concentrations of the drugs are 4-6 orders of magnitude lower. Therefore, it is unlikely that these drugs affect the fertility of higher plants in aquatic and terrestrial ecosystems.

Analyses of combined effects of cytostatic drugs on micronucleus formation in the Tradescantia

Recent experiments showed that 5-fluorouracil (5FU), cisplatin (CDDP), etoposide (ET), and imatinib mesylate (IM), which are currently among the most widely used anticancer drugs, cause damage of the genetic material in higher plants. The aim of the present study was to determine whether mixtures of these drugs cause synergistic or antagonistic effects which may have an impact on their environmental safety. Therefore, the effects of binary mixtures of these anticancer drugs on the induction of micronuclei (MN) which reflect structural and numerical chromosomal aberrations were assessed in Tradescantia tetrads. Synergistic/antagonistic effects were determined by comparison with single exposures that would be equally effective in a reference model of independent action. This comparison was performed at two distinct effect sizes. We found clear evidence for synergisms in combination experiments with IM and antagonism in a high-dose experiment with ET and 5FU. Our findings indicate that IM increases the genotoxic effects of other anticancer drugs. The maximal effects which we found were in the range between 19 and 38 % in the excess of effect sizes predicted under independent action. These effects may have an impact on the overall genotoxic activities of untreated hospital waste waters but not on the environment in general as the predicted environmental concentrations of the studied drugs are several orders of magnitude lower as the levels which are required to cause induction of MN in higher plants.

Impacts of particulate matter pollution on plants: Implications for environmental biomonitoring

Air pollution is one of the serious problems world is facing in recent Anthropocene era of rapid industrialization and urbanization. Specifically particulate matter (PM) pollution represents a threat to both the environment and human health. The changed ambient environment due to the PM pollutant in urban areas has exerted a profound influence on the morphological, biochemical and physiological status of plants and its responses. Taking into account the characteristics of the vegetation (wide distribution, greater contact area etc.) it turns out to be an effective indicator of the overall impact of PM pollution and harmful effects of PM pollution on vegetation have been reviewed in the present paper, covering an extensive span of 1960 to March 2016. The present review critically describes the impact of PM pollution and its constituents (e.g. heavy metals and poly-aromatic hydrocarbons) on the morphological attributes such as leaf area, leaf number, stomata structure, flowering, growth and reproduction as well as biochemical parameters such as pigment content, enzymes, ascorbic acid, protein, sugar and physiological aspect such as pH and Relative water content. Further, the paper provides a brief overview on the impact of PM on biodiversity and climate change. Moreover, the review emphasizes the genotoxic impacts of PM on plants. Finally, on the basis of such studies tolerant plants as potent biomonitors with high Air Pollution Tolerance Index (APTI) and Air Pollution Index (API) can be screened and may be recommended for green belt development.

Biological impact of environmental polycyclic aromatic hydrocarbons (ePAHs) as endocrine disruptors

Polycyclic aromatic hydrocarbons (PAHs) are often detected in the environment and are regarded as endocrine disruptors. We here designated mixtures of PAHs in the environment as environmental PAHs (ePAHs) to discuss their effects collectively, which could be different from the sum of the constituent PAHs. We first summarized the biological impact of environmental PAHs (ePAHs) found in the atmosphere, sediments, soils, and water as a result of human activities, accidents, or natural phenomena. ePAHs are characterized by their sources and forms, followed by their biological effects and social impact, and bioassays that are used to investigate their biological effects. The findings of the bioassays have demonstrated that ePAHs have the ability to affect the endocrine systems of humans and animals. The pathways that mediate cell signaling for the endocrine disruptions induced by ePAHs and PAHs have also been summarized in order to obtain a clearer understanding of the mechanisms responsible for these effects without animal tests; they include specific signaling pathways (MAPK and other signaling pathways), regulatory mechanisms (chromatin/epigenetic regulation, cell cycle/DNA damage control, and cytoskeletal/adhesion regulation), and cell functions (apoptosis, autophagy, immune responses/inflammation, neurological responses, and development/differentiation) induced by specific PAHs, such as benz[a]anthracene, benzo[a]pyrene, benz[l]aceanthrylene, cyclopenta[c,d]pyrene, 7,12-dimethylbenz[a]anthracene, fluoranthene, fluorene, 3-methylcholanthrene, perylene, phenanthrene, and pyrene as well as their derivatives. Estrogen signaling is one of the most studied pathways associated with the endocrine-disrupting activities of PAHs, and involves estrogen receptors and aryl hydrocarbon receptors. However, some of the actions of PAHs are contradictory, complex, and unexplainable. Although several possibilities have been suggested, such as direct interactions between PAHs and receptors and the suppression of their activities through other pathways, the mechanisms underlying the activities of PAHs remain unclear. Thus, standardized assay protocols for pathway-based assessments are considered to be important to overcome these issues.

Genotoxicity of Water Contaminants from the Basin of Lake Sevan, Armenia Evaluated by the Comet Assay in Gibel Carp (Carassius auratus gibelio) and Tradescantia Bioassays

Combination of bioassays and chemical analysis was applied to determine the genotoxic/mutagenic contamination in four different sites of the basin of Lake Sevan in Armenia. Water genotoxicity was evaluated using the single cell gel electrophoresis technique (comet assay) in erythrocytes of gibel carp (Carassius auratus gibelio), Tradescantia micronucleus (Trad-MCN) and Tradescantia stamen hair mutation (Trad-SHM) assays. Significant inter-site differences in the levels of water genotoxicity according to fish and Trad-MCN bioassays have been revealed. Two groups of locations with lower (south-southwest of the village Shorzha and Peninsula of Lake Sevan) and higher (estuaries of Gavaraget and Dzknaget rivers) levels of water genotoxicity were distinguished. Correlation analysis support the hypothesis that the observed genetic alterations in fish and plant may be a manifestation of the effects of water contamination by nitrate ions, Si, Al, Fe, Mn and Cu. Increase of DNA damage in fish also correlated with content of total phosphorus.

Biomonitoring of the environmental genotoxic potential of emissions from a complex of ceramic industries in Monte Carmelo, Minas Gerais, Brazil, using Tradescantia pallida

The micronucleus (MN) test and analysis of heavy metal biological accumulation in Tradescantia pallida (T. pallida) were bioassays used to assess the genotoxic potential of emissions from a complex of ceramic industries into the atmosphere in a city in Brazil that is considered a national reference source for roof tile production. The ceramic industry emission-exposed T. pallida plants were biomonitored during the dry season, in June, July, and August 2013. In addition to the contaminated monitoring site, a reference site in a peri-urban area was utilized, for comparative purposes. Genotoxicity assessments were determined monthly, while heavy metal bioaccumulation was measured at the end of the total exposure period. The MN frequency was significantly greater in T. pallida plants exposed in the ceramic industry emission monitored area compared to the reference site, and highest MN rates were observed in July and August. With respect to heavy metal bioaccumulation in T. pallida leaves, cadmium (Cd) and chromium (Cr) concentrations were significantly higher in plants at the ceramic industry emission monitoring site. Thus, in relation to the parameters assessed, T. pallida was found to be sensitive to atmospheric contamination by heavy metals attributed to ceramic products emissions generated by the ceramic industry, confirming that this plant species may be employed as a reference organism in biomonitoring studies.

Cytotoxic and genotoxic activities of waters and sediments from highway and parking lot runoffs

The genotoxicity of water and sediment samples from stormwater treatment systems and water from urban highway runoff was tested in the Salmonella/microsome assays with Salmonella typhimurium, micronucleus assay (Trad-MN) with plants and with human-derived liver cells (HepG2), or comet assay with HepG2. Cytotoxicity of water samples was studied using either reactive oxygen species (ROS) generation, cell proliferation or dye exclusion assay in HepG2. Concentrations of several contaminants in the tested samples were also measured. Results suggested that urban highway runoff exposed to severe vehicle traffic emissions caused genotoxic effects in comet assay and in Trad-MN assays. Sediments induced either mutagenic effects in strain YG1024 or genotoxic effects in Trad-MN assay. These effects could be due to the presence of nitro-polycyclic aromatic hydrocarbons (NPAHs) which possess carcinogenic and mutagenic properties. Influent and effluents of stormwater treatment systems did not induce genotoxic activity or effects on HepG2 cell viability; however, the influents were able to induce ROS generation and cell proliferation in HepG2 cells. As the methods require a sterile filtration of the water samples, this could have also removed particulate-associated polycyclic aromatic hydrocarbons (PAHs) and resulted in a less pronounced induction of genotoxicity, as would be expected by PAH contamination.

Genotoxic evaluation of the River Paranaíba hydrographic basin in Monte Carmelo, MG, Brazil, by the Tradescantia micronucleus

Pollutants have adverse effects on human health and on other organisms that inhabit or use water resources. The aim of the present study was to assess the environmental quality of three watercourses in Monte Carmelo, MG, Brazil, using the micronucleus test on Tradescantia. For each treatment, 15 plants were exposed to water samples for 24 h. The control group was exposed to formaldehyde (0.2%) and the negative control to Hoagland solution. Subsequently the plants were placed in Hoagland solution for 24 h to recover. Cells were stained with 2% acetic carmine and examined by light microscopy. Three hundred tetrads were analyzed per slide. The frequency of genotoxic alterations was expressed as the number of micronuclei per 100 tetrads, and the groups were compared by ANOVA. At all sample sites for each watercourse significant genotoxicity indices were observed. The results suggest that in the Mumbuca creek, the current situation of effluent discharge should be reconsidered by the municipal environmental authorities. The increase in micronucleus frequency denoted for water samples of the Mumbuca creek, Lambari river and Perdizes river emphasizes the need to adopt environmental vigilance strategies, such as biological monitoring.

Biomonitoring the genotoxic potential of the air on Tradescantia pallida var. purpurea under climatic conditions in the Sinos River basin, Rio Grande do Sul, Brazil

The present study evaluated the genotoxic effects of the atmospheric air on Tradescantia pallida var. purpurea in urban areas with different intensities of vehicular traffic and in riparian forest fragments in the Sinos River Basin (Rio Grande do Sul, Brazil), considering the influence of climatic conditions prevailing in these environments. Bimonthly, from May 2012 to March 2013, cuttings with flower buds were exposed for 8 h in urban and riparian forest environments in the municipalities of Caraá, Taquara and Campo Bom in the upper, middle and lower sections, respectively, of the Sinos River Basin. Simultaneously, negative controls were made and climatic data were recorded. Micronuclei (MCN) frequencies were determined in young tetrads of pollen mother cells and expressed as MCN/100 tetrads. Significantly higher MCN frequencies were observed in buds exposed in urban and riparian forest environments in Taquara (up to 7.23 and 4.80, respectively) and Campo Bom (up to 4.90 and 4.23, respectively) than in buds exposed in Caraá (up to 2.90 and 2.50, respectively), in the majority of samplings, and in relation to the negative control (up to 1.93) in all months. Over the course of the period monitored, there were significant variations in MCN frequencies at all sampling points, with the exception of the urban environment in Caraá. For the urban environments, relation between the MCN frequency, vehicular traffic and mean temperature was observed. For the riparian forest fragments, there was no association between MCN frequency and climatic factors. Tradescantia pallida var. purpurea can be considered a useful tool to point out areas with increased atmospheric pollution, since the exposure of plants under severe climatic conditions is avoided to minimize their negative influence on the formation of micronuclei.

The comet assay in higher terrestrial plant model: Review and evolutionary trends

The comet assay is a sensitive technique for the measurement of DNA damage in individual cells. Although it has been primarily applied to animal cells, its adaptation to higher plant tissues significantly extends the utility of plants for environmental genotoxicity research. The present review focuses on 101 key publications and discusses protocols and evolutionary trends specific to higher plants. General consensus validates the use of the percentage of DNA found in the tail, the alkaline version of the test and root study. The comet protocol has proved its effectiveness and its adaptability for cultivated plant models. Its transposition in wild plants thus appears as a logical evolution. However, certain aspects of the protocol can be improved, namely through the systematic use of positive controls and increasing the number of nuclei read. These optimizations will permit the increase in the performance of this test, namely when interpreting mechanistic and physiological phenomena.

Biomonitoring of water genotoxicity in a Conservation Unit in the Sinos River Basin, Southern Brazil, using the Tradescantia micronucleus bioassay

The Tradescantia micronucleus (Trad-MCN) bioassay was used to investigate genotoxicity of water bodies in the Parque Municipal Henrique Luís Roessler (PMHLR), a conservation unit in the city of Novo Hamburgo, Southern Brazil, from November 2010 to October 2011. Every month, cuttings with young inflorescences of Tradescantia pallida var. purpurea were exposed for 24 hours to water collected at three sites in the park: (S1) head of the main stream; (S2) head of a secondary stream; (S3) a point past the junction of the two water bodies in which S1 and S2 were located. As a negative control, cuttings were exposed to distilled water for 24 h every quarter. Micronuclei (MCN) frequency was determined in young tetrads of pollen mother cells and described as MCN/100 tetrads. Rainfall data were also recorded. In nine months at S1 and S2, and in eleven months at S3, micronuclei frequencies were significantly higher than in quarterly controls, in which frequencies varied from 1.19 to 1.62. During sampling, no significant differences were found in MCN frequencies at S1, which ranged from 2.2 to 3.6. At the other sampling sites, there were significant differences between the months evaluated, and MCN frequencies ranged from 1.3 to 6.5 at S2 and from 2.3 to 5.2 at S3. There were no associations between rainfall and MCN frequencies at the three sampling sites. Tradescantia pallida var. purpurea confirmed genotoxicity in the water bodies of the PMHLR, even at the head of the streams, which suggests that actions should be promoted to control anthropogenic effects in the streams of this conservation unit.

Allium cepa and Tradescantia pallida bioassays to evaluate effects of the insecticide imidacloprid

The indiscriminate use of pesticides has become a serious environmental concern. Of them, imidacloprid (IMI) is one of the most widely used worldwide. In 2010 in Brazil, 1.934 tonnes of IMI were sold and mainly used for sugarcane crops. Several studies have examined the toxicity of IMI as well as its possible ecological effects. However, few studies have examined its toxicity at the genetic level. This is one of the biggest challenges for the scientific community, which is concerned about the impacts of these contaminants on the environment and human health. In this study, we evaluated the effects of IMI above the genetic material in Allium cepa and Tradescantia pallida following exposure to different concentrations of this insecticide. The results demonstrated that the concentrations tested induced chromosomal alterations and increased the frequency of micronuclei. Therefore, IMI in these concentrations was genotoxic to the tested organisms. These factors should be taken into account when applying this pesticide.

Monitoring of volatile and non-volatile urban air genotoxins using bacteria, human cells and plants

Urban air contains many mutagenic pollutants. This research aimed to investigate the presence of mutagens in the air by short-term mutagenicity tests using bacteria, human cells and plants. Inflorescences of Tradescantia were exposed to air in situ for 6h, once a month from January to May, to monitor volatile compounds and micronuclei frequency was computed. On the same days PM10 was collected continuously for 24h. Half of each filter was extracted with organic solvents and studied by means of the Ames test, using Salmonella typhimurium TA98 and TA100 strains, and the comet assay on human leukocytes. A quarter of each filter was extracted with distilled water in which Tradescantia was exposed. PM10 concentration was particularly high in the winter season (> 50 μg/m(3)). In situ exposure of inflorescences to urban air induced a significant increase in micronuclei frequency at all the sites considered, but only in January (p < 0.01). Aqueous extracts collected in January and February induced genotoxic effects in Tradescantia exposed in the laboratory (p < 0.01). Ames test showed that organic extracts of winter urban air were able to induce genetic mutations in S. typhimurium TA98 strain (± S9), but not in TA100 strain, with a revertants/plate number nine times higher than the negative control. Comet assay showed that winter extracts were more toxic and genotoxic than spring extracts. All the mutagenicity tests performed confirmed that urban air in North Italy in winter contains both volatile and non-volatile genotoxic substances able to induce genetic damage in bacteria, human cells and plants.

Acute toxic and genotoxic activities of widely used cytostatic drugs in higher plants: Possible impact on the environment

Cytostatic drugs are highly toxic pharmaceuticals and it was repeatedly postulated that they may cause adverse effects in ecosystems. The acute toxic and genotoxic properties of these drugs have not been adequately investigated in higher plants so far; therefore, we studied the most widely used drugs (5-flurouracil, 5FU; etoposide, Et; cisplatin, CisPt; carboplatin, CaPt; vincristine sulfate, VinS and cyclophosphamide monohydrate, CP) in micronucleus (MN) assays with meiotic pollen tetrad cells of Tradescantia and with root cells from Allium cepa. MNi are formed as a consequence of chromosome breaks and aneuploidy. We monitored also the acute toxic properties of the drugs, i.e. inhibition of cell division (mitotic indices and retardation of root growth) in the latter species. All compounds caused in both indicator plants genotoxic effects. The order of genotoxic potencies expressed as NOELs in µM was CisPt (0.1)≥ Et (0.5)>CP (1.0)>CaPt (10)>5FU (30)>VinS (100) in Tradescantia. A similar order was seen in Allium MN but Et was less active (5.0µM). Four compounds caused alterations of the mitotic indices under the present conditions namely CisPt (0.5), Et (10.0), 5FU (10.0) and VinS (100). Inhibition of root growth decreased in the order CisPt (0.5)>Et (1.0)≥VinS (1.0)>5FU (5.0)>CaPt (33.0)>CP (>1000). Comparisons of the NOELs with the predicted environmental concentrations (PEC) show that the latter values are at least 5 orders of magnitude lower and indicate that it is unlikely that their release in the environment may cause adverse effects in higher plants. However, it is notable that the levels of both platinum compounds and of 5FU in hospital effluents may reach levels which may induce damage of the genetic material.

Assessment of genotoxicity and acute toxic effect of the imatinib mesylate in plant bioassays

Imatinib mesylate (IM) is at present one of the most widely used cytostatic drugs in developed countries but information on its ecotoxicological activities is scarce. This article describes the results of the first investigation in which genotoxic and acute toxic properties of the drug were studied in higher plants. IM was tested in two widely used plant bioassays namely in micronucleus (MN) assays with meiotic tetrad cells of Tradescantia (clone #4430) and in mitotic root tip cells of Allium cepa. Additionally, acute toxic effects (inhibition of cell division and growth of roots) were monitored in the onions. Furthermore, we studied the impact of the drug on the fertility of higher plants in pollen abortion experiments with three wildlife species (Chelidonium majus, Tradescantia palludosa and Arabidopsis thaliana). In MN assays with Tradesacantia a significant effect was seen with doses ⩾10μM; the Allium MN assay was even more sensitive (LOEL⩾1.0μM). A significant decrease of the mitotic indices was detected at levels ⩾10μM in the onions and reduction of root growth with ⩾100μM. In the pollen fertility assays clear effects were observed at doses ⩾147.3mgkg(-1). Data concerning the annual use of the drug in European countries (France, Germany, Slovenia) enable the calculation of the predicted environmental concentration (PEC) values which are in the range between 3.3 and 5.0ngL(-1). Although comparisons with the genotoxic potencies of other commonly used cytostatic drugs and with highly active heavy metal compounds show that IM is an extremely potent genotoxin in higher plants, it is evident that the environmental concentrations are ⩾5 orders of magnitude lower as the levels which are required to cause adverse effects.

Red mud a byproduct of aluminum production contains soluble vanadium that causes genotoxic and cytotoxic effects in higher plants

Red mud (RM) is a byproduct of aluminum production; worldwide between 70 and 120 million tons is produced annually. We analyzed RM which was released in the course of the Kolontar disaster in Hungary into the environment in acute and genotoxicity experiments with plants which are widely used for environmental monitoring. We detected induction of micronuclei which reflect chromosomal damage in tetrads of Tradescantia and in root cells of Allium as well as retardation of root growth with contaminated soils and leachates. Chemical analyses showed that RM contains metals, in particular high concentrations of vanadium. Follow-up experiments indicated that vanadate causes the effects in the plants. This compound causes also in humans DNA damage and positive results were obtained in carcinogenicity studies. Since it was found also in RM from other production sites our findings indicate that its release in the environment is a global problem which should be studied in more detail.

CAPSULE ABSTRACT

Our findings indicate that the red mud causes genotoxic effect in plants probably due to the presence of vanadate which is contained at high concentrations in the residue.

Morphometric differences of Microgramma squamulosa (Kaulf.) de la Sota (Polypodiaceae) leaves in environments with distinct atmospheric air quality

Plants growing in environments with different atmospheric conditions may present changes in the morphometric parameters of their leaves. Microgramma squamulosa (Kaulf.) de la Sota is a neotropical epiphytic fern found in impacted environments. The aims of this study were to quantitatively compare structural characteristics of leaves in areas with different air quality conditions, and to identify morphometric parameters that are potential indicators of the effects of pollution on these plants. Fertile and sterile leaves growing on isolated trees were collected from an urban (Estância Velha) and a rural (Novo Hamburgo) environment, in Rio Grande do Sul, Brazil. For each leaf type, macroscopic and microscopic analyses were performed on 192 samples collected in each environment. The sterile and fertile leaves showed significantly greater thickness of the midrib and greater vascular bundle and leaf blade areas in the rural environment, which is characterized by less air pollution. The thickness of the hypodermis and the stomatal density of the fertile leaves were greater in the urban area, which is characterized by more air pollution. Based on the fact that significant changes were found in the parameters of both types of leaves, which could possibly be related to air pollutants, M. squamulosa may be a potential bioindicator.

Cashew nut roasting: chemical characterization of particulate matter and genotocixity analysis

BACKGROUND

Particulate matter (PM) is potentially harmful to health and related to genotoxic events, an increase in the number of hospitalizations and mortality from respiratory and cardiovascular diseases. The present study conducted the first characterization of elemental composition and polycyclic aromatic hydrocarbon (PAH) analysis of PM, as well as the biomonitoring of genotoxic activity associated to artisanal cashew nut roasting, an important economic and social activity worldwide.

METHODS

The levels of PM2.5 and black carbon were also measured by gravimetric analysis and light reflectance. The elemental composition was determined using X-ray fluorescence spectrometry and PAH analysis was carried out by gas chromatography-mass spectrometry. Genotoxic activity was measured by the Tradescantia pallida micronucleus bioassay (Trad-MCN). Other biomarkers of DNA damage, such as nucleoplasmic bridges and nuclear fragments, were also quantified.

RESULTS

The mean amount of PM2.5 accumulated in the filters (January 2124.2 µg/m(3); May 1022.2 µg/m(3); September 1291.9 µg/m(3)), black carbon (January 363.6 µg/m(3); May 70 µg/m(3); September 69.4 µg/m(3)) and concentrations of Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br and Pb were significantly higher than the non-exposed area. Biomass burning tracers K, Cl, and S were the major inorganic compounds found. Benzo[k]fluoranthene, indene[1,2,3-c,d]pyrene, benzo[ghi]perylene, phenanthrene and benzo[b]fluoranthene were the most abundant PAHs. Mean benzo[a]pyrene-equivalent carcinogenic power values showed a significant cancer risk. The Trad-MCN bioassay revealed an increase in micronucleus frequency, 2-7 times higher than the negative control and significantly higher in all the months analyzed, possibly related to the mutagenic PAHs found.

CONCLUSIONS

This study demonstrated that artisanal cashew nut roasting is a serious occupational problem, with harmful effects on workers׳ health. Those involved in this activity are exposed to higher PM2.5 concentrations and to 12 PAHs considered potentially mutagenic and/or carcinogenic. The Trad-MCN with T. pallida was sensitive and efficient in evaluating the genotoxicity of the components and other nuclear alterations may be used as effective biomarkers of DNA damage.

Cytotoxic and phytotoxic effects of the main chemical components of spent pot-liner: a comparative approach

Spent pot-liner (SPL) is a hazardous solid waste produced by the aluminum industry. Although its composition may vary, fluoride and cyanide salts as well as aluminum are predominant components. A seed-germination and root-elongation test was performed with Lactuca sativa seeds as a test system. SPL induced decrease of seed germination rate and root elongation. The concentration of 26.5g/L SPL was established from a regression curve as the IC50 (inhibition concentration 50%). Through chemical analyses, the concentrations of fluoride, cyanide and aluminum in SPL solutions of 26.5g/L (IC50), 39.75g/L (1.5IC50) and 13.25g/L (0.5IC50) were determined. Further, a cell-cycle test was conducted with root tips of L. sativa exposed to these same SPL solutions. All test chemicals presented toxic effects on meristematic cells of L. sativa. Aluminum was identified as the SPL component mainly responsible for reduction of the mitotic index. Chromosomal alterations resulted from the interactions among the three main chemical components of SPL, without a clear predominantly responsible agent. Induction of condensed nuclei was mainly due to effects of aluminum and fluoride, and may serve as an indicator of induced cell death.

Biomonitoring air quality during and after a public transportation strike in the center of Uberlândia, Minas Gerais, Brazil by Tradescantia micronucleus bioassay

The aim of this study was to address the lack of information concerning the air quality in the city of Uberlândia, Minas Gerais, Brazil. In this study, we conducted an unprecedented experiment involving the in situ biomonitoring of air genotoxicity in the city center during and after a public transportation strike using the Tradescantia micronucleus test. The frequency of micronuclei was significantly higher in the city center compared with the reference site (Mann-Whitney test, p < 0.05), with the highest MN levels being observed during public transport stoppage (Kruskal-Wallis, Dunn p < 0.01). In addition, the multiple linear regression analyses revealed that the low circulation of buses during public transport stoppage and the increase in the concentration of particulate matter from the increased flow of vehicles in the city center during the strike positively influenced the MN frequency. The climatic factors did not change during the biomonitoring period, reflecting the fact that climatic factors did not influence the MN frequency.

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.

Composition and mutagenicity of PAHs associated with urban airborne particles in Córdoba, Argentina

The comet assay and micronucleous test were used to assess the genotoxicity of organic compounds associated with particulate material collected in the city of Córdoba, Argentina. Samples were collected on fiber glass filters and their organic extracts were analyzed by GC-MS. These extracts were used for the comet assay on human lymphocytes and for the MCN test with Tradescantia pallida. The concentrations of polycyclic aromatic hydrocarbons as well as some of their nitro derivates were higher during winter. Their composition suggested that their main emission sources were gasoline and diesel vehicles. We observed genotoxic effects of these organic extracts due to the presence of both direct and indirect acting mutagens. We found a good agreement between the two test systems employed, which encourages the further use of plant bioassays for air pollution monitoring, especially in developing countries, due to their flexibility, low cost and efficiency.

Micronucleus assay with tetrad cells of Tradescantia

The Tradescantia micronucleus assay is being used since almost 50 years for the detection of genotoxins (including carcinogens) in the environment. A large database on the effects of individual compounds and of complex environmental mixtures (soil, air and water) has accumulated. In contrast to other mutagenicity test systems, the effects of low concentrations of heavy metals, radionuclides, certain herbicides and pesticides, and gaseous mutagens can be detected and it is also possible to use the test for in situ biomonitoring studies. The test system has been validated, and standardized protocols have been developed for laboratory experiments and for field studies, which are described in this chapter.

In situ biomonitoring of the genotoxic effects of vehicular pollution in Uberlândia, Brazil, using a Tradescantia micronucleus assay

The growing number of cars in large cities is directly linked to changes in the chemical composition of urban air, which has increasingly high concentrations of potentially genotoxic chemicals. Therefore, discovering and monitoring the risks associated with exposure to atmospheric pollutants is indispensible for preventing environmental and health problems. Because of the lack of reliable data regarding the air quality in the city of Uberlândia, the present study sought to test whether the genotoxic risks in areas with different levels of vehicular traffic can be measured using the Tradescantia micronucleus assay (Trad-MN). Therefore, more than twenty inflorescences were exposed to locations with different amounts of vehicular traffic twice per year from the winter of 2006 to the summer of 2011. The inflorescences were then analysed to determine the micronucleus (MN) frequency. In addition, we sought to determine the influence of factors linked to city climate on the MN frequencies obtained at each monitored location. Our results show that, although low relative humidity positively influenced MN formation in Tradescantia pallida tetrads, the major determining factor for clastogenic events was the level of vehicular traffic at the locations monitored over the five-year study.

Ground and surface water for drinking: a laboratory study on genotoxicity using plant tests

ABSTRACT

Surface waters are increasingly utilized for drinking water because groundwater sources are often polluted. Several monitoring studies have detected the presence of mutagenicity in drinking water, especially from surface sources due to the reaction of natural organic matter with disinfectant. The study aimed to investigate the genotoxic potential of the products of reaction between humic substances, which are naturally present in surface water, and three disinfectants: chlorine dioxide, sodium hypochlorite and peracetic acid. Commercial humic acids dissolved in distilled water at different total organic carbon (TOC) concentrations were studied in order to simulate natural conditions of both ground water (TOC=2.5 mg/L) and surface water (TOC=7.5 mg/L). These solutions were treated with the biocides at a 1:1 molar ratio of C:disinfectant and tested for genotoxicity using the anaphase chromosomal aberration and micronucleus tests in Allium cepa, and the Vicia faba and Tradescantia micronucleus tests. The tests were carried out after different times and with different modes of exposure, and at 1:1 and 1:10 dilutions of disinfected and undisinfected humic acid solutions. A genotoxic effect was found for sodium hypochlorite in all plant tests, at both TOCs considered, while chlorine dioxide gave positive results only with the A.cepa tests. Some positive effects were also detected for PAA (A.cepa and Tradescantia). No relevant differences were found in samples with different TOC values. The significant increase in all genotoxicity end-points induced by all tested disinfectants indicates that a genotoxic potential is exerted even in the presence of organic substances at similar concentrations to those frequently present in drinking water.

Integral assessment of pollution in the Suquía River (Córdoba, Argentina) as a contribution to lotic ecosystem restoration programs

The Suquía River lower-middle basin (Córdoba, Argentina) is subject to a strong anthropic impact because it receives pollutants from different sources (industries, wastewaters, heavy traffic, agricultural land use, etc.) We have assessed the degree of watershed degradation of Suquía River lower-middle sections through the analysis of different ecosystem compartments (air, water, riparian soil, sediments and biota), in order to provide useful data to be considered in future river restoration programs. Four study sites were selected along the river (La Calera city, Córdoba city, Corazón de María village and Río Primero city) which were sampled during the low- and high-water flow periods. We analyzed: a) chemical and physical characteristics of water, sediments, and riparian soil; b) heavy metal content of water and sediments, and c) semi-volatile organic compounds in air. Besides, pollutant bioindicators such as fish assemblages, lichens (Usnea amblyoclada), vascular plants (Tradescantia pallida), and microorganisms (fecal coliform and Escherichia coli) were used to further assess the status of the river. All analyzed ecological compartments were affected by water pollution, particularly, fish assemblages, sediments and riparian soils by heavy metal and coliform bacteria. Moreover, we detected a possible contribution of sulfur and a high pollutant content in air that merit further research about other air-water exchanges. Accordingly, we strongly suggest that an action to restore or remediate the anthropic effect on the Suquía River be extended to all possible compartments along the river.

Genotoxicity of SPL (spent pot lining) as measured by Tradescantia bioassays

Spent Pot Liner (SPL) is a solid waste product generated in the process of aluminum production. Tradescantia micronuclei (Trad-MN) and stamen hair mutation (Trad-SHM) bioassays are very useful tests to assess genotoxicity of environmental pollutants. In the present study, we intended to investigate the genotoxicity of this waste with Tradescantia bioassays using leachates of SPL simulating the natural leachability of SPL in soil. The formation of micronuclei (MN) was found to be concentration dependent. MN frequency enhanced significantly with SPL treatment. In addition, SPL also appeared to increase the percentage of dyads and triads. Trad-SHM assay showed that SPL increases pink mutation events as SPL concentration increases. These results demonstrated that SPL is a cytogenotoxic agent that affects different genetic end-points (induction of micronuclei and point mutations) even at low concentration (2% and 3%).