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The main objective of this article is to analyze global trends in the use of methods to assess the contamination of heavy metals (MP) associated with urban road sediment (SV). A systematic literature review was carried out between the years 1995-2018. A citation frequency index was used to establish an order of importance for the detected categories. The results show the following order of importance for the categories detected: metallic enrichment (87.0%) > health risk (55.8%) > environmental risk (35.1%). The global preference methods for each of the categories are the geoaccumulation index (55.8%), hazard quotient (50.6%), and the ecological risk index (31.2%), respectively. These preferences are possibly conditioned by the local existence of information on background concentrations of MP, daily inhalation doses of particles associated with SV, toxicity factors due to ingestion/dermal contact with MP, and emission factors of SV particles. The most relevant MP are Pb (97.4%), Cu (93.5%), and Zn (89,6%). However, Cr-Cd-As are also highlighted for their high ecological and carcinogenic risk. [ABSTRACT FROM AUTHOR]

Isolation and culture of microorganisms with capacity to degrade environmental pollutants are important for implementing bioremediation plans. This study is an evaluation of the yeast extract effect on both the microbial capacity to assimilate the organo-phosphorous pesticide methyl parathion and the isolation processes of microorganisms useful for degrading this pesticide. Microorganisms evaluated were obtained from fresh soil historically fumigate with this pesticide. Trials were conducted with defined solid means enriched with methyl parathion (0-60 mg L-1) and yeast extract (0-0.5 g L-1). It was found that microorganisms were able to assimilate up to 5 mg L-1 methyl parathion with no yeast extract, without evidence of toxic effects. Assimilation capacity increased 10 mg L-1 in cultures enriched with 0.5 mg L-1 yeast extract. Yeast extract in doses used did not affect the isolation of microorganisms. However, isolation through direct culture in means enriched with methyl parathion as the only source of carbon was difficult due to the addition of organic matter of soil, which allowed the growth of resistant strains with no pesticide degrading capacity. [ABSTRACT FROM AUTHOR]

In order to evaluate the effect of inorganic nutrient addition (phosphorus or commercial fertilizer) over the microbial degradation capacity present in a solid matrix contaminated with chlorpyrifos, malathion and methyl parathion, microcosms assays were held under controlled conditions of light, moisture and temperature for 30 days. Results showed that even though three treatments microorganisms were able to degrade the three organophosphorus pesticides, microorganisms of phosphorus-enrichment treatment were less efficient to degrade Chlorpyrifos and Methyl Parathion than microorganisms of Fertilizer-enrichment treatment. A direct relation between mineralization and microbial pesticides degradation capacity was not observed. The microbial activity was not affected by the presence of organophosphorus pesticides. [ABSTRACT FROM AUTHOR]