Baseline maps of potentially toxic elements in the soils of Garhwal Himalayas, India: Assessment of their eco-environmental and human health risks

Abstract

Geochemical mapping is frequently used to identify the regions of the Planet with critical chemical elements and their natural or anthropogenic sources. In order to understand elements' geochemistry and to identify the area's potentially harmful associations, high-resolution maps of chemical elements, physico-chemical parameters, a noncarcinogenic hazard index, and a potential ecological risk index were modelled with soil samples collected in the Himalaya region. It is the first environmental and geochemical atlas for this region. It was found that natural processes are determining the distribution of the variable in this area. The granulometric features seem to be strongly influenced by land use, with coarser grain sizes in forest soils, contrasting with the finer grain sizes in agricultural soils. The map distribution of the noncarcinogenic hazard index showed that there is an expected hazard for some variables for both children and adults. Potential ecological risk is revealed to be low to moderate. Remediation of contaminated soils is necessary to reduce the associated risks, make the land resource available for agricultural production, enhance food security, and scale down land tenure problems arising from changes in the land use pattern. This study is subsequent implementation of natural-based approaches to system stability in largely unspoilt area.