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.

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.

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.

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.