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

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

Tools for monitoring aquatic environments to identify anthropic effects.

Anthropic activities are directly related to the contamination of aquatic ecosystems owing to the release of numerous chemicals from agricultural and urban waste. These contaminants cause environmental degradation and a decrease in the availability of water quality. The objective of this search was to evaluate the efficiency of physicochemical, chemical, and microbiological tests; extraction of chlorophyll a; and genetic parameters to identify anthropic activities and weather condition effects on the stream water quality and the consequences of its use by the population. The physicochemical parameters were within the limits allowed by the Brazilian law. However, contamination by metals (Cd 0.510 mg L-1, Co 0.405 mg L-1, and Ni 0.316 mg L-1) has been found at various collection points to be more than the allowable values. The antibiotic oxytetracycline was detected in stream water in quantities of up to 89 µg L-1. In relation to microbiological contamination, Escherichia coli and Pseudomonas spp. have been isolated. The averages of chlorophyll a were up to 0.15558 mg cm-2. Genetic tools identified greater number of micronuclei and DNA damage in periods that showed lower rainfall rates and lower amounts of metals. The analysis used for monitoring was efficient to verify the interference that animal breeding and planting of different cultures have caused on that stream. Thus, the continued use of this water for drinking, irrigation of vegetables, and recreational activities makes the population susceptible to contamination by bacteria and creates conditions for the development of genetic alterations in the long run.

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.