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.

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 PM1, 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).

Contamination and health risks assessment in a dam in the southeast region of Brazil using ecotoxicological methods.

Concerned with water quality, specialists have resorted to ecotoxicology as a tool to assess suspected contamination, enabling creation of strategies to repair the observed damage. Organisms such as fish and micro crustaceans are widely used in acute tests due to several characteristics in common among them including (1) accessibility of multiple samples, and (2) enhanced sensitivity when exposed to pollutants. Thus, the objective of this investigation was to determine the degree of toxicity at different points of a dam in Coromandel, Minas Gerais, using Artemia salina and Danio rerio as bioindicator organisms. Water was collected at three points of the dam were subsequently used to expose these organisms to different contaminant concentrations. Following exposure mortality and immobility rates were determined and compared to negative control (only distilled water). Results with exposure of A. salina did not present significant pollution affects. However, in the case of D. rerio the mortality frequency, immobility rate and behavioral alterations was increased at point P3; thus, D. rerio demonstrated greater sensitivity than A. salina. The physical-chemical test indicated that there were changes in parameters including biochemical demand of oxygen, dissolved oxygen and total dissolved solids (in sample at points 2 and 3), confirming toxic potential, and evidence of poor water quality at these locations. Therefore, data demonstrated that water from the dam at certain sites is not suitable for human consumption or leisure activities such as swimming that were previously reported to occur in this reservoir by the local community.

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.

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.

Evaluation of the genotoxicity of neurotoxic insecticides using the micronucleus test in Tradescantia pallida.

Neonicotinoids and phenylpyrazoles are classes of neurotoxic insecticides which are able to bind at different ligand sites of neural receptors, leading to the deregulation of insect neural activity and hence resulting in death. The misuse or indiscriminate use of these chemicals is directly associated with several toxicological effects in biota and at different trophic levels. Based on this premise, the aim of the present study was to evaluate and compare the genotoxic capacity of different concentrations of thiamethoxam (TMX), acetamiprid (ACP), imidacloprid (IMI) and fipronil (FP) through the Micronucleus Test in Tradescantia pallida (Trad-MCN). After acclimatization (24 h), T. pallida stems were treated with stablished concentrations of TMX, ACP, IMI and FP for 8 h. Then, the stems of the model organism were submitted to a recovery phase (24 h). The young inflorescences were harvested and fixed in Carnoy solution and, after 24 h, were conserved in ethanol 70% until the analyzes. The obtained anthers were macerated on slides for microscopy, stained with acetic carmine dye and covered with coverslips before analysis by light microscopy. Considering the insecticides, the micronuclei (MN) frequency in plants treated at concentrations of 0.2 and 0.4 g L-1 for TMX, 0.2; 0.4 and 0.8 g L-1 for ACP, 0.1; 0.2; 0.4; 0.8 and 1.6 g L-1 for IMI and 0.2; 0.4; 0.8 and 1.6 g L-1 for FP differed statistically (p < 0.05, Tukey) from the MN frequency of the negative control. All chemicals evaluated revealed genotoxic activity in T. pallida at the highest concentrations.

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.

Ecotoxicological risk assessment of contaminated soil from a complex of ceramic industries using earthworm Eisenia fetida.

The aim of this study was to determine ecotoxicological parameters for biomonitoring of environmental risk of native soils from a ceramic industrial area that had been contaminated with cadmium (Cd) and chromium (Cr) by using the earthworm, Eisenia fetida. Initially, lab tests were conducted to compare earthworm (Eisenia fetida) growth, survival, morphology, behavior, and reproduction rates following exposure to six concentrations of contaminated soil at 0%, 6.25%, 12.5%, 25%, 50%, or 100% mixed in artificial soil and cow dung following a 28-d incubation period. The second experiment consisted of utilizing Eisenia fetida in a predetermined lowest observed effect concentration to measure heavy metals bioaccumulation from superficial soil collected from a ceramic industrial area following a 56-d exposure. Data demonstrated that in the lab earthworms maintained at 6.25% of contaminated soil, exhibited significant increase in mean weight, bioaccumulation of Cd and Cr associated with a significant decrease in the amount of Cd and Cr in the soil. At field testing, similar results that were observed as in the lab as evidenced by rise in mean weight, higher levels of Cd and Cr in the earthworm tissue accompanied by significant fall in soil levels of Cd and Cr. In conclusion, at tested relevant environmental concentrations, the use of Eisenia fetida for assessing ecotoxicological risk arising from contaminated soil due to ceramic industrial pollutant emissions was found to be an effective tool for biomonitoring program.

Biomonitoring birds: the use of a micronuclei test as a tool to assess environmental pollutants on coffee farms in southeast Brazil.

Birds have often played an important role as environmental bioindicators, and different species can be useful due to their bioaccumulating capacity. The micronuclei test is a cytologic technique used for accessing DNA and is a biomarker for damage to DNA. This study analysed the Cerrado avian community, especially the efficiency of the blue-black grassquit (Volatinia jacarina) in responding to pesticide contamination in situ on different-sized coffee farms in southeast Brazil. The micronuclei test was used in erythrocytes of birds. Eighty-two individuals of 21 bird species belonging to 11 families that were found in all study areas were used to evaluate micronuclei (MN) frequency. Two hundred fifty-two MN were counted in every area of study. The MN average count was 3/10,000 erythrocytes, and 17.1% of all bird species exhibited no MN. The average MN was 1.29 ± 0.69 in small farms, 2.59 ± 1.65 in medium farms, and 5.41 ± 1.34 in large farms. Small farms accounted for 14.3% of MN frequency, medium farms 27.8%, and large farms 57.9%. V. jacarina was the most abundant species found and displayed a sensitive response to environmental contamination. Pesticides appear to induce MN formation in a dose-dependent way when farms are analysed according to their area. Therefore, biomonitoring birds remain an efficient means to detect environmental pollutants, especially pesticides. V. jacarina responds as a sensitive biomonitor, showing a dose-dependent response to pesticides used in coffee farms.

Ecotoxicological effects of the insecticide fipronil in Brazilian native stingless bees Melipona scutellaris (Apidae: Meliponini).

Melipona scutellaris Latreille, 1811 (Hymenoptera, Apidae) is a pollinator of various native and cultivated plants. Because of the expansion of agriculture and the need to ensure pest control, the use of insecticides such as fipronil (FP) has increased. This study aimed to evaluate the effects of sublethal doses of FP insecticide on M. scutellaris at different time intervals (6, 12, and 24 h) after exposure, via individually analyzed behavioral biomarkers (locomotor activity, behavioral change) as well as the effect of FP on different brain structures of bees (mushroom bodies, antennal cells, and optic cells), using sub-individual cell biomarkers (heterochromatin dispersion, total nuclear and heterochromatic volume). Forager bees were collected when they were returning to the nest and were exposed to three different concentrations of FP (0.40, 0.040, and 0.0040 ng a.i/bee) by topical application. The results revealed a reduction in the mean velocity, lethargy, motor difficulty, paralysis, and hyperexcitation in all groups of bees treated with FP. A modification of the heterochromatic dispersion pattern and changes in the total volume of the nucleus and heterochromatin were also observed in the mushroom bodies (6, 12, and 24 h of exposure) and antennal lobes (6 and 12 h) of bees exposed to 0.0040 ng a.i/bee (LD50/100). FP is toxic to M. scutellaris and impairs the essential functions required for the foraging activity.

Acute ecotoxicity bioassay using Dendrocephalus brasiliensis: alternative test species for monitoring of contaminants in tropical and subtropical freshwaters.

In International guidelines for standard ecotoxicological bioassays, Daphnia magna is the most applied microcrustacea for assessing toxicity of different pollutants. However, in research realized in tropical and subtropical areas, autochthonous species must be prioritized because they are adapted to the specificities of ecosystems. In this sense, the present study aimed to assess and compare (with D. magna) the sensitivity of the tropical species Dendrocephalus brasiliensis as alternative test species for monitoring of contaminants in tropical and subtropical freshwaters, by carrying out acute toxicity tests with different pollutants. According results, D. brasiliensis presented EC50-48 h values lower than D. magna for all substances tested, indicating higher sensitivity of the tropical organism in relation to the temperate organism. Furthermore, comparing the results obtained with data from other studies, D. brasiliensis is more sensitive to the chemicals tested than D. magna and has similar sensitivity to Pseudosida ramosa and Ceriodaphnia dubia, common species in tropical areas. In view of this, we suggest that D. brasiliensis can be used as alternative test species for monitoring of contaminants in tropical and subtropical freshwaters.

Contamination of soil and the medicinal plant Phyllanthus niruri Linn. with cadmium in ceramic industrial areas.

Phyllanthus niruri is a plant that is used to prevent calcium oxalate crystallisation and to block the stone formation in urolithiasis. Contaminants in the environment can be readily taken up by medicinal plants due to their ability to absorb chemicals into their tissues. If contaminated plants are ingested, they have the potential to negatively affect human and environmental health. The aim of this study was to assess contamination in the soil and the medicinal plant P. niruri by cadmium (Cd) in ceramic industrial areas of Monte Carmelo, Brazil. Soil samples and plant samples (divided in root, shoot and leaves) were collected from a contaminated monitoring site and from a rural area (which was used as a reference site for comparative purposes). The Cd concentrations of the samples were analysed with an atomic absorption spectrometer. P. niruri was found to be sensitive to soil contamination by Cd that was attributed to ceramic industrial emissions. The results revealed that Cd bioaccumulation in the roots and shoots of P. niruri was associated with a significant increase (p < 0.05) in the concentration of active lignan compounds (phyllanthin and hypophyllanthin) in the leaves. The identification of high concentrations of Cd and active lignan compounds suggests a risk of contamination of the site and the risk of a high dose of Cd to people exposed at the site.

Evaluation of toxicity, mutagenicity and carcinogenicity of samples from domestic and industrial sewage.

Physico-chemical and toxicological analyses are of fundamental importance to determine water quality. The objectives of the present study were to evaluate the toxicity, mutagenicity and carcinogenicity of samples from the Mumbuca Stream and the Perdizes River, through both SMART and the wts test, respectively, in somatic cells of Drosophila melanogaster and to quantify the amount of heavy metals and other pollutants, which are indicative of environmental quality. Water samples were collected (M1, M2, P1, P2 and MP) and submitted to physico-chemical analysis, calculating the water quality index for each sampling site. In order to evaluate the toxicity, mutagenicity and carcinogenicity of the samples, third instar larvae descended from the crossing between virgin female wts/TM3, sb1 and mwh/mwh males (wts test) and ST and HB (SMART) crosses were treated with samples from P1, P2, M1, M2 and MP sites. The physico-chemical analysis and the biological assay allowed us to conclude that undetected values for heavy metals and the low frequency of mutant spots (SMART) and epithelial tumor (wts) in treated flies from the Mumbuca Stream and Perdizes River may be due to the reduction of ceramic activities in the municipality. The physico-chemical analyzes identified altered the environmental quality parameters, which directly influenced the survival of D. melanogaster treated with samples of M2 and MP, which according to the WQI were classified as regular and poor environmental quality, respectively. The altered parameters may be due to clandestine domestic sewage sent downstream of the effluent.

Assessment of genotoxic, mutagenic, and recombinogenic potential of water resources in the Paranaíba River basin of Brazil: A case study.

Exposure to certain pollutants induces a series of alterations in deoxyribonucleic acid (DNA) that may result in genotoxic/mutagenic effects in exposed individuals. The present study aimed to monitor genotoxic, mutagenic, and recombinogenic potential and consequently water quality in two streams in the Paranaíba River basin in the state of Minas Gerais, Brazil, using two bioindicator fish (Rhamdia quelen and Geophagus brasiliensis). The micronucleus (MN) test and somatic recombination and mutation test (SMART) were employed to assess DNA damage. The water quality index (WQI) at the reference site control (S1) due to its proximity to the river source was compared to Córrego do Óleo (S2) with respect to chemical parameter levels of biochemical oxygen demand (BOD), dissolved-oxygen rates (DO), and total solid and fecal coliform counts. These chemical parameters were above the permitted limits at Córrego do Óleo (S2). At a third site, Córrego Liso (S3), a poor WQI was detected, attributed to the influence of domestic and industrial activities where BOD, DO, total solid, fecal coliform, total phosphorus, and turbidity rates exceeded premissible limits. The MN frequencies and the numbers of MN per cell (CMN) at sites S2 and S3 were significantly higher than those at S1 in both species. It is of interest that the increased frequency of MN was similar to the positive control cyclophosphamide only at S3, suggesting that the effects of water contaminants were most severe at this site. At sites assessed (S2 and S3), there was a significant rise in somatic mutation and recombination in the wings of Drosophila melanogaster, indicating the presence of trace elements, mainly lead (Pb) and cadmium (Cd), in the effluents in the Paranaíba River basin sites.

Toxicological assessment of spinosad: Implications for integrated control of Aedes aegypti using larvicides and larvivorous fish.

Integration of larvivorous fish and biolarvicides at low concentrations to control of mosquito larvae in field situations may result in a safer and more effective tool. However, the usefulness of integrated approach depends upon survival and ecological fitness of fish employed. Thus, the aim of this study was to examine the genotoxic effects of combining different sublethal concentrations of spinosad, a naturally occurring neurotoxic insecticide, with male adult poecilid larvivorous guppy (Poecilia reticulata) and platy (Xiphophorus maculatus) fish on Aedes larvae mosquitos. Both fish species have been used for biological control of Aedes larvae in Brazil. Sublethal spinosad exposures were predetermined based on CL50-96hr. Nuclear abnormalities (NA) and micronucleus (MN) frequency in gill cells were measured after 14 d of exposure. Behavioral changes were monitored over 96 h. Although genotoxic effects were not markedly different from control, behavioral changes evaluated based upon the no-observable-effect concentration (NOEC) and lowest-observable-effect concentration (LOEC). Adverse effects were noted at concentrations of 12.6 mg/L (NOEC) and 25.3 mg/L (LOEC) spinosad. Therefore, these insecticide concentrations may be considered as being safe to these fish species and have important implications for integrated approach to control Aedes larvae using natural larvicides and larvivorous fish.

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.