Research and development of spatial isotopic models applied for forensic tracking in Brazil

• Grant number: 19/08816-6
• Support Opportunities: Research Program on Global Climate Change - PIPE
• Start date: March 01, 2021
• End date: November 30, 2021
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Tiago Borges Kisaka
• Grantee: Tiago Borges Kisaka
• CNAE: Pesquisa e desenvolvimento experimental em ciências físicas e naturais
• Associated researchers: Gabriela Bielefeld Nardoto ; João Paulo Sena Souza ; Luiz Antonio Martinelli ; Marcelo Zacharias Moreira ; Plínio Barbosa de Camargo
• Associated scholarship(s): 21/02606-0 - Research and development of spatial isotopic models applied to forensic tracking in Brazil, BP.PFPMCG.PIPE

Abstract

The objective of this project is the development of spatial isotopic models (Isoscapes) for the Brazilian territory. This applied technology will enable the use of the stable isotope methodology by this project in the solution of environmental, industrial and forensic problems. Isoscapes are spatial models that show the spatial variability of the isotopic ratio of some elements such as carbon (13C: 12C), nitrogen (15N: 14N), oxygen (18O: 16O), deuterium (2H: 1H), in both vector format (e.g., shapefile) and / or grid format (e.g. raster). The main technical challenge of this project is the development of these isoscapes for the Brazilian territory, which depends on a deep knowledge of the isotopic methodology, but also of statistical and computational techniques for the construction of the isotopic landscapes. The main scientific challenge would be the actual use of these isoscapes, that is, to infer the geographic origin of a given material by correlating its isotopic composition to a given geographic area through isoscapes. This correlation is made through statistical models that are also part of the main objectives of this project. For the construction of isoscapes at local and regional scales, the present project will develop a database and, in parallel, will use field collections to fill existing space gaps. With the real isotopic values, geostatistical methods are used after the analysis to construct the isoscapes. A second important step in the use of isoscapes is the calibration between isotopic values obtained by the isoscapes and their expression in a given organic or biological tissue. A classic example of calibration would be the comparison between the isotopic values of water (oxygen and hydrogen) for supplying a given site (source) and the isotopic values of these elements incorporated into some human tissue such as nail or hair (product). The final step, which represents the scientific challenge to be overcome, is isotopic georeferencing. This means "referencing" a sample of unknown origin to possible geographic areas, with isotopic ratios consistent with the isotopic ratios of this sample through isoscopes built by models and algorithms. At the end of phase 1, we expected to i) complete the isotopic database; ii) finalize the isoscopes; iii) present calibration models of the isotopic composition; iv) and geographic attribution models; in addition to v) providing information to guide the commercialization activities of the services that will be offered by the future company. (AU)