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 = 0.11ns). 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.

This study aimed to assess the micronuclei formation in Tradescantia pallida var. purpurea through active and passive biomonitoring of air genotoxicity and its relation with abiotic environmental factors, and to analyze the concentrations of trace elements in flower buds and leaves, in order to determine the importance of these parameters to atmospheric quality monitoring. For 2 years, active biomonitoring was conducted with exposure of cuttings with flower buds at three sites in the metropolitan area of Porto Alegre in southern Brazil, and indoor (negative control). For passive biomonitoring, flower buds were collected from beds at the same sites. Meteorological and vehicular traffic data were recorded during the exposures. The micronuclei (MCN) frequencies obtained by active and passive biomonitoring for Canoas, Esteio, and São Leopoldo (respectively means of 5.44, 5.34, 4.17 and of 3.01, 2.47, 2.72) were significantly higher than those of the negative control. Furthermore, the sensitivity of the flower buds used for active biomonitoring was greater compared to those used for the passive biomonitoring, which was evidenced by significantly higher MCN frequencies. The multivariate analysis indicated two main components responsible for 74.58 % of the variances observed, and pointed to a strong relation between micronuclei frequency from active biomonitoring and vehicular traffic. Temperature and relative air humidity did not relate with the formation of micronuclei in both biomonitoring systems. Flower buds proved to be efficient bioaccumulators of trace elements, as they accumulated concentrations of up to three times more than the leaves.

Bioaccumulation of five heavy metals (Cd, Cu, Mn, Pb, and Zn) in six plant organs (panicle, leaf, stem, root, rhizome, and bud) of the emergent and perennial plant species, Miscanthus sacchariflorus, were investigated to estimate the plant’s potential for accumulating heavy metals in the wetlands of Dongting Lake. We found the highest Cd concentrations in the panicles and leaves; while the highest Cu and Mn were observed in the roots, the highest Pb in the panicles, and the highest Zn in the panicles and buds. In contrast, the lowest Cd concentrations were detected in the stem, roots, and buds; the lowest Cu concentrations in the leaves and stems; the lowest Mn concentrations in the panicles, rhizomes, and buds; the lowest Pb concentrations in the stems; and the lowest Zn concentrations in the leaves, stems, and rhizomes. Mean Cu concentration in the plant showed a positive regression coefficient with plot elevation, soil organic matter content, and soil Cu concentration, whereas it showed a negative regression coefficient with soil moisture and electrolyte leakage. Mean Mn concentration showed positive and negative regression coefficients with soil organic matter and soil moisture, respectively. Mean Pb concentration exhibited positive regression coefficient with plot elevation and soil total P concentration, and Zn concentration showed a positive regression coefficient with soil available P and total P concentrations. However, there was no significant regression coefficient between mean Cd concentration in the plant and the investigated environmental parameters. Stems and roots were the main organs involved in heavy metal accumulation from the environment. The mean quantities of heavy metals accumulated in the plant tissues were 2.2 mg Cd, 86.7 mg Cu, 290.3 mg Mn, 15.9 mg Pb, and 307 mg Zn per square meter. In the Dongting Lake wetlands, 0.7 × 10³ kg Cd, 22.9 × 10³ kg Cu, 77.5 × 10³ kg Mn, 3.1 × 10³ kg Pb, and 95.9 × 10³ kg Zn per year were accumulated by aboveground organs and removed from the lake through harvesting for paper manufacture.

Regarding the rapid progress in the production and consumption of nanobased products, this research considered the behavior of Melissa officinalis toward zinc oxide nanoparticles (nZnO), nanoelemental selenium (nSe), and bulk counterparts. Seedlings were irrigated with nutrient solution containing different doses of nZnO (0, 100, and 300 mg l⁻¹) and/or nSe (0, 10, and 50 mg l⁻¹). The supplements made changes in growth and morphological indexes in both shoot and roots. The mixed treatments of nSe10 and nZnO led to a drastic increase in biomass, activation of lateral buds, and stimulations in the development of lateral roots. However, the nSe50 reduced plants’ growth (45.5%) and caused severe toxicity which was basically lower than the bulk. Furthermore, the nSe and nZnO improved K, Fe, and Zn concentrations in leaves and roots, except for seedlings exposed to nSe50 or BSe50. Moreover, the nSe and nZnO supplementations in a dose-dependent manner caused changes in leaf non-protein thiols (mean = 77%), leaf ascorbate content (mean = 65%), and soluble phenols in roots (mean = 28%) and leaves (mean = 61%). In addition, exposure to nZnO and/or nSe drastically induced the expression of rosmarinic acid synthase (RAS) and Hydroxy phenyl pyruvate reductase (HPPR) genes. Besides, the nSe, nZnO, or bulk counterparts influenced the activities of nitrate reductase in leaves and peroxidase in roots, depending on dose factor and compound form. The comparative physiological and molecular evidence on phytotoxicity and potential advantages of nSe, nZnO, and their bulk counterparts were served as a theoretical basis to be exploited in food, agricultural, and pharmaceutical industries.

The aim of this study was to assess possible genotoxic effects on floriculturists in a region of the state of Rio Grande do Sul, in the south of Brazil, using the micronucleus test (MN) and comet assay. Thirty-seven floriculturists and 37 individuals not exposed to pesticides participated in the study. The micronucleus test was performed with epithelial cells of the oral mucosa. In the microscopic analysis, 2000 cells were evaluated per subject, verifying the frequency of MN and the frequency of other nuclear abnormalities (nuclear buds, binucleated cells, and karyorrhexis). For the comet assay in the peripheral blood lymphocytes, 100 cells were classified in five classes, according to the migration of DNA fragments, thereby generating the frequency of damaged cells and the damage index. There was no difference between the exposed and control groups in the frequencies of MN and other nuclear abnormalities in the epithelial cells of the oral mucosa. However, the comet assay showed that both the frequency of DNA damaged cells and the damage index were significantly greater in the exposed group. The results therefore indicate that floriculturists are exposed to mixtures of pesticides with genotoxic potential.

The cytogenetic toxicity of rhodamine B on root tip cells of Allium cepa was investigated. A. cepa were cultured in water (negative control), 10 ppm methyl methanesulfonate (positive control), and three concentrations of rhodamine B (200, 100, and 50 ppm) for 7 days. Rhodamine B inhibited mitotic activity; increased nuclear anomalies, including micronuclei, nuclear buds, and bridged nuclei; and induced oxidative stress in A. cepa root tissues. Furthermore, a substantial amount of long nucleoplasmic bridges were entangled together, and some nuclei were simultaneously linked to several other nuclei and to nuclear buds with nucleoplasmic bridges in rhodamine B-treated cells. In conclusion, rhodamine B induced cytogenetic effects in A. cepa root tip cells, which suggests that the A. cepa root is an ideal model system for detecting cellular interactions.

In this paper, we present the results of mercury concentration in soils, buds and leaves of maple (Acer platanoides—Ap) and linden (Tilia platyphyllos—Tp) collected in four periods of the growing season of trees, i.e. in April (IV), June (VI), August (VIII) and November (IX) in 2013, from the area of Poznań city (Poland). The highest average concentration of mercury for 88 samples was determined in soils and it equaled 65.8 ± 41.7 ng g⁻¹ (range 14.5–238.9 ng g⁻¹); lower average concentration was found in Ap samples (n = 66): 55.4 ± 18.1 ng g⁻¹ (range 26.5–106.9 ng g⁻¹); in Tp samples 50.4 ± 15.8 ng g⁻¹ (range 23.1–88.7 ng g⁻¹) and in 22 samples of Tp buds 40.8 ± 22.7 ng g⁻¹ (range 12.4–98.7 ng g⁻¹) and Ap buds 28.2 ± 13.6 ng g⁻¹ (range 8.0–59.5 ng g⁻¹). Based on the obtained results, it was observed that the highest concentration of mercury in soils occurred in the centre of Poznań city (95.5 ± 39.1 ng g⁻¹), and it was two times higher than the concentration of mercury in other parts of the city. Similar dependencies were not observed for the leaf samples of Ap and Tp. It was found that mercury concentrations in the soil and leaves of maple and linden were different depending on the period of the growing season (April to November). Mercury content in the examined samples was higher in the first two research periods (April IV, June VI), and then, in the following periods, the accumulation of mercury decreased both in soil and leaf samples of the two tree species. There was no correlation found between mercury concentration in leaves and mercury concentration in soils during the four research periods (April–November). When considering the transfer coefficient, it was observed that the main source of mercury in leaves is the mercury coming from the atmosphere.