Tannery effluent effects on vertebrates: lessons from experimental animals

The bovine leather processing (tanning industries) stands out as a potentially toxic waste-generating activity. The emission of untreated effluents into the environment may cause serious harm to human health and to the environment. The aim of the present studyit to address a literature review in order to identify studies related to the effect ofeffluent exposure on vertebrates by emphasizingthe identification of the so far observed effect types.The main experimental designs were adopted seeking the presentation of an overview on the already performed investigations and the proposition of future research in this field. A systematic literature review was performed through the search for scientific articles in databases such as LILACS- BIREME, MEDLINE/Index Medicus, SciELO, Google Scholar and PubMed. The search comprised studies published from March 1981 to July 2016. Thirty-four (34)articles were analyzed, 58.8% of them assessed the effects of tannery effluents on fish; 2.9%,on amphibians;0%,on reptiles; 2.9%,on birds; and 35.4%,on mammals.The published studies about tannery effluents and their effects on vertebrates were mostly conducted in India and Brazil. With regard to the scientific fields covered by these previous studies, it was observed that several issues/topics were assessed;there waslittle prevalenceof genotoxic, histological, mutagenic, immunological, biochemical and behavioral studies. Accordingly, i) the number of articles involving tannery effluents and their effects on vertebrate animalsremains very small, ii) there is prevalence of studies involving fish and, more recently, mammals, iii) studies involving the reproductive aspects of the species exposed to tannery effluents are rare; iv) further investigations involving tannery effluents are necessary. The exposure of vertebrate organisms must describe the type and composition of the assessed xenobiotic in details in order tohelp adopting methodological procedures in compliance with the local conditions, thus allowing the extrapolation of the experimental data.