Are there geogenic relationships for Lithium between geology, geochemical anomalies and low levels of violence in the region of Guanambi, State of Bahia, NE Brazil? / Existem relações geográficas para o Lítio entre geologia, anomalias geoquímicas e baixos níveis de violência na região de Guanambi, Estado da Bahia, NE do Brasil?

Abstract

Lithium has been applied for therapeutic purposes in the treatment of mental health disorders, such as bipolar affective disease, in the prevention of behaviour changes, and may be related, to some extent, to the reduction of suicide and violence. In Brazil, the main occurrences of lithium are found in the east/northeast region. In the Guanambi domains, in south-central Bahia, until recently, there were no references to lithium occurrences. The geology of the region is characterized by the monzo-syenitic batholith of Guanambi and its associated late intrusions (2.05Ga), where important manifestations of a pneumatolithic character are described. There are also evaporitic levels, interspersed with carbonate members of the São Francisco Supergroup (Bambuí Group - 650Ma). The Geological Survey of Brazil (CPRM) carried out an extensive geochemical survey, sampling and analysing water, sediments and soils. The geostatistical treatment and interpretation of these data revealed the existence of lithium anomalies in the Guanambi domains, in sites that spatially overlap the rocks of the Guanambi batholith and the carbonate rocks of the Bambuí Group. According to Atlas da Violência (2019), in Guanambi the homicide rate was 30.8 deaths per 100,000 inhabitants, that is, it is lower than the average homicide rate in Brazil (31.6 deaths per 100,000 inhabitants), or the average rate in Bahia (48.8 deaths per 100,000 inhabitants). The relationships between lithium and health can be addressed by medical geochemistry. This article is relevant to the community of geoscientists and health planners, whose objective is to investigate the hypothesis put forward of the effective relationship between geogenic lithium levels and the homicide rate in these sites in the State of Bahia.