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

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.

Determination of phytotoxicity and cytogenotoxicity due to exposure to particles originating from sugarcane burning using test systems Lactuca sativa L. and Allium cepa L

Sugarcane straw burning generates particulate matter with complex composition resulting in atmosphere pollution. Sugarcane straw sugarcane burning particles (PSSB) contain several chemical compounds that were previously identified to be associated with carcinogenic and mutagenic processes. The aim of the present study was to extract PSSB under lab conditions and subsequently determine phyto- and cytogenotoxicity of these particles using Lactuca sativa L. and Allium cepa L. bioassays. Seeds of lettuce var. Cinderela and onion cv. Vale-Ouro IPA-11 were germinated in Petri dishes containing different concentrations of PSSB at 25, 50, 100, 200 or 300 mg/ml as well as control for 72 hr. Seed germination of lettuce was inhibited by PSSB, in a concentration-dependent manner, accompanied by decreased root growth, suggesting phytotoxic effects. Further, reduction of mitotic index and high number of chromosomal alterations in onion of meristematics cells indicated a cytogenotoxic action attributed to PSSB. Although the chemical composition of PSSB in question has not been determined, the phyto- and cytogenotoxic effects may be linked to the possible presence of polycyclic aromatic hydrocarbons (PAHs), which are were identified as the main constituents of particulate matter resulting from burning of sugarcane straw, in addition to exerting adverse biological effects that might result in mutations and cancer. Data demonstrated that the use of plants bioassays might be an important tool for biomonitoring air quality.

Assessment of the mutagenic potential of the water of an urban river by means of two Tradescantia-based test systems

River pollution can be caused by anthropogenic or natural factors. When testing water quality for the presence of toxic substances, higher plants as bioindicators for the genotoxic effects of complex mixtures are effective and appropriate. Hence, in this work the Tradescantia (clone 02) stamen hair mutations (Trad-SHM) and Tradescantia micronuclei (Trad-MCN) were used to determine mutagenic and clastogenic potential of an urban river. A significant increase in the level of all studied endpoints as well as morphological changes, including pink cells (PC) and colorless cells (CC) in stamen hairs, stunted hairs (SH), tetrads with micronuclei (MN) and MN in tetrads of pollen microspores in the Tradescantia was observed compared to the negative control (tap water). As an example riverine system, part of the River Hrazdan (Armenia) flowing through a highly urbanized and industrial area was studied. The positive control (10 mM CrO₃) showed the highest genotoxicity for the SHM assay (PC: 5.1 / 1000, CC: 17.9 / 1000) and for the MCN assay (12 MN / 100 tetrads and 9.4 ± 0.53 tetrads with MN). Genetic responses were analyzed in conjunction with the concentrations of select elements in the riverine water. Reasons for observing such a high level of genetic markers in the riverine water and applicability of the Tradescantia (clone 02) test-systems in environmental risk assessment and biomonitoring are discussed.

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.

Leukocyte profile of the helmeted manakin, Antilophia galeata (Passeriformes: Pipridae) in a Cerrado forest fragment

Changes in the amounts and proportions of leukocytes, known as leucocyte profiles, have been documented for several bird species and have been used to measure stress levels in these animals. The present work ascertained the biological and ecological attributes that influence the leukocyte profile of Antilophia galeata (Lichtenstein, 1823), the helmeted manakin. This species has been deemed useful in ecological studies because it responds to environmental changes. Blood samples drawn from 89 individuals of A. galeata captured in a Cerrado forest fragment were subjected to analysis under optical microscopy to identify and quantify leukocytes and micronuclei. The number of lymphocytes was greater for males, non-reproductive individuals and individuals infected with ticks. None of the leukocyte components differed in relation to age, molting or body condition index. The amount of micronuclei was correlated with values for total leukocytes, H/L ratio, heterophils, basophils and monocytes. The results suggest that reproduction may be an immunosuppressive factor for the species, producing sexual differences in lymphocyte availability. In addition, biomarkers of genotoxic damage (micronuclei) were related to the amount of leukocytes, indicating that individuals may be sensitive to environmental disturbances. Leukocyte profiles can be considered a useful tool for addressing ecological questions that are relevant to the conservation of species in degraded environments.

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).

Assessment of genotoxic effects on elderly populations exposed to high traffic areas: Results for supporting public health surveillance

In urban areas with intense vehicular traffic, particulate matter in suspension, especially the fraction of particles with ultra-fine diameter, has been regarded as the main problem of chronic diseases in susceptible populations, such as the elderly. This study aimed to determine the genotoxic effects of exposure to air pollution evaluating the association between the frequencies of micronuclei (MN) and binucleated (BN) cells in exfoliated oral mucosa cells of elderly population and exposure conditions, considering the influence of traffic and concentration of PM in different aerodynamic diameters. Traffic of passenger vehicles, heavy duty trucks and environmental concentrations of Particulate Matter were measured twice a day during 28 days before biological sampling of oral mucosa from 154 participants living in areas of distinct levels of urban traffic. Data from this study showed that the group of participants living near road traffic exhibited higher MN cell frequency, when compared to the other groups of subjects. In addition, a canonical correlation analysis between environmental and genotoxicity variables analysis revealed that high concentrations of the particulate matter were correlated with intense traffic and the genotoxicity in exfoliated oral cells.

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.

Effect of urbanization on the micronucleus frequency in birds from forest fragments

The urbanization contributes to environment contamination, mainly by the increased vehicle traffic. This intense traffic releases in the air chemical compounds with mutagenic properties that can affect the entire ecosystem. The birds for the flight accumulate air, absorbing gases or particles. The absorption of this polluted air may be causative agent responsible for micronucleus (MN) induction in bird erythrocytes. The quantitative analysis of MN in birds can assists in the monitoring environmental quality of various places. The study aimed to quantify the MN frequency in birds and compare their variation: I) among forest fragments distant from and near to urbanization, II) among species and populations of birds and III) to find if there is a relation between vehicle traffic and MN induction. The capture of the birds took place in four forest fragments in central Brazil (two distant and two near the city) using mist nets. Blood smears were prepared with blood collected from the tarso-metatarsal vein. A total of 354 individuals were analyzed and MN were found in 52% of the individuals analyzed. All sampled birds were identified and resulted to belong to 50 different species, only 4 of which were captured in all the 4 forest fragments. The average MN frequency, regardless of bird species and sampling area, was 1.04/10,000 erythrocytes. From an overall analysis carried out on all birds, the MN frequencies were found to vary among forest fragments distant from and near to urbanization (x² =15.513; p < 0.001) and demonstrated positive correlation between vehicle traffic intensity and the MN frequency (r = 0.988; df=2; p = 0.011). The species of birds presented variation in the amount of MN (x² = 84.64; df=49; p = 0.001). Therefore, a restricted analysis carried out on the 4 species of birds present in all the forest fragments showed that the populations of Antilophia galeata (x² =6.029; p = 0.014), Basileuterus culicivorus (x² =9.53; p = 0.002), Eucometis penicillata (x² =8.067; p = 0.005) and Myiothlypis flaveola (x² =4.771; p = 0.029) showed difference in the MN frequency, when compared between forest fragments distant from and near to cities. The analysis demonstrated that birds living in forest areas near to the city presented higher MN frequency, probably because pollutants generated by urbanization affect birds and that the larger the vehicle traffic the greater the induced MN in the birds.

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 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.

Richness, coverage and concentration of heavy metals in vascular epiphytes along an urbanization gradient

Richness, coverage and concentration of heavy metals in vascular epiphytes were analyzed in isolated trees along an urbanization gradient in Southern Brazil. A total of 20 phorophytes were sampled in the main street of each site. Concentrations of chromium, cadmium, lead, manganese, nickel and zinc were measured in the leaves of Tillandsia recurvata L. using Graphite Furnace Atomic Absorption Spectrophotometry. A decreasing gradient of epiphyte richness and coverage was observed as urbanization increased. Vehicle fleet and demographic density were the parameters most correlated with the reduction of epiphytic diversity. In T. recurvata, significantly higher values of cadmium, lead and zinc were recorded in the most urbanized areas, and were strongly related to the vehicle fleet and to the demographic density in these sites. The results demonstrated that these parameters could be applied to the diagnosis of environmental quality in urban areas, allowing standardized analyses in other regions.

Assessing the spatial pattern of a river water quality in southern Brazil by multivariate analysis of biological and chemical indicators

Abstract This study assessed the genotoxicity and chemical quality of the Rio dos Sinos, southern Brazil. During two years, bimonthly, cuttings of Tradescantia pallida var. purpurea with flower buds were exposed to river water samples from Caraá, Santo Antônio da Patrulha, Taquara and Campo Bom, which are municipalities located in the upper, middle and lower stretches of the Rio dos Sinos basin. Simultaneously, chemical parameters were analyzed, rainfall data were surveyed and negative (distilled water) and positive (0.1% formaldehyde) controls were made. Micronuclei (MCN) frequencies were determined in tetrads of pollen grain mother cells. From the upper stretch toward the lower, there was an increase in the frequency of MCN and in concentrations of chemical parameters. Cadmium, lead, copper, total chromium and zinc were present at the four sites and a concentration gradient was not demonstrated along the river. The multivariate analysis revealed that two principal components exist, which accounted for 62.3% of the observed variances. Although genotoxicity was observed in Santo Antônio da Patrulha, the water presented higher mean values for most of the assessed parameters, in the lower stretch, where urbanization and industrialization are greater. The spatial and temporal pattern of water quality observed reinforces the importance of considering the environmental factors and their effects on organisms in an integrated way in watercourse monitoring programs.

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).

Biomonitoring of genotoxic effects and elemental accumulation derived from air pollution in community urban gardens

Urban gardening is a growing global phenomenon with a positive impact on society. Despite several associated benefits, growing vegetables in urban gardens that are localized in highly polluted areas poses questions about the safety of the produced food. Therefore, the identification of risk factors that result in possible deleterious effects to human health is important for realizing all of the benefits to society. We evaluated the use of two biomonitoring methods in ten urban gardens of Sao Paulo city and one control site: the micronuclei frequencies for early tetrads of Tradescantia pallida (Rose) Hunt. cv. "Purpurea" Boom (hereafter, Trad-MCN) as a short-term indicator of genotoxic response and tree barks to quantify the accumulation of traffic-related chemical elements as a long-term biomarker of air pollution in urban gardens. Mature plants of Tradescantia pallida were exposed in each garden, and their inflorescences were sampled over three months. A random set of 300 early tetrads in 13 to 21 slides per garden were evaluated for micronuclei frequencies. Elemental concentrations in 428 tree barks samples from 107 different trees in the areas surrounding urban gardens were quantified using an energy dispersive X-ray fluorescence spectrometer. The frequency of Trad-MCN has a significant correlation with traffic variables and chemical elements related to road dust and tailpipe emissions deposited in tree barks. Negative associations between Trad-MCN and both the distance through traffic and the presence of vertical obstacles were observed in the community gardens. The Mn/Zn concentrations in tree barks were associated with increased Trad-MCN.

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.

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.

The impact of water pollution on fish species in southeast region of Goiás, Brazil

The rivers from the region of Catalão, Southeast Goiás State, Brazil, are exposed to intense anthropogenic influences including agricultural activities, industry, and urban waste. The aim of this study was to determine the severity of water pollution by conducting an experiment involving in situ biomonitoring of water constituents on genotoxicity in fish inhabiting these sites. The genotoxicity of three sites of the region were analyzed utilizing the micronucleus (MN) test. It was of interest to determine whether there were differences between sampling sites such as urban perimeter, agriculture, and fertilizer industry in control, and monitored species including Astyanax fasciatus, Astyanax altiparanae, and Characidium fasciatum. Data demonstrated that the species at sites 1, 2, and 3 exhibited a marked increase in frequency of MN compared to fish from site 4. Significant elevation in frequency of MN occurred in erythrocytes of A. fasciatus and A. altiparanae at sites 1 and 2. At site 3 higher frequencies of MN were observed in C. fasciatum. MN induction in C. fasciatum was correlated with chromium levels in water and sediment, while A. fasciatum and A. altiparanae showed an association with zinc in water and sediment. Data suggest that benthic and nektonic fish species display different sensitivities in relation to anthropogenic contaminant influences.

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.

Genetic instability in plants associated with vehicular traffic and climatic variables

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

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.

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.

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.