Elementos potencialmente tóxicos em insetos: uma revisão sistemática

Abstract

For a better understanding of the effects caused by potentially toxic elements (PTE) on ecosystems, insects can be used as bioindicators of environmental quality. The objective of this work was to identify the main trends in scientific studies that carried out the determination and/or quantification of PTE in insects, through a systematic review based on 35 selected articles and following search criteria, inclusion and exclusion criteria. Previously established. The frequency in the use of quantitative analysis techniques was evaluated, these being ICP-OES, ICP-MS, AAS, EDX/EDS, SEM/SEM, TEM, titration and complexation, as well as data on opening and digestion of samples using chemical reagents were raised. The group of insects most evaluated was the taxonomic order Hymenoptera, with emphasis on the bees Apis mellifera, followed by the taxonomic order Coleoptera, represented by beetles. Cadmium, copper, lead, zinc and chromium were the most studied elements and there was a preference for using ICP-OES and ICP-MS techniques to determine and quantify these elements, with nitric acid and hydrogen peroxide commonly being used as reagents for opening and sample digestion. The most significant PTE – those found in insect bodies – were copper, cadmium and lead. Most of the articles evaluated made comparisons between types of environments, along a gradient or not, such as between industrial, urban and rural environments; soil covered with native forest and bare/degraded soil; polluted areas and forested areas. Among the polluting sources detected in the studies evaluated, we can mention, for example, vehicle traffic on highways, iron foundry enterprises, coal plants and iron and steel factories. Few studies were verified using bee species other than A. mellifera, as well as evaluating other groups of insects. Urban areas had a higher PTE content, due to anthropogenic sources that emit pollutants. After the research carried out in this work, it was possible to verify that insects are excellent bioindicators of environmental quality. The importance of carrying out research on the topic is highlighted to seek to understand the impacts that these communities suffer from anthropogenic actions, using this data and information to mitigate the negative effects and promote the conservation of different groups of insects and their habitats.