Bioaccessiblity features of particulate bound toxic elements: Review of extraction approaches, concentrations and health risks

Abstract For a better and accurate risk assessment of metal toxicity, the concentration of the bioaccessible fraction (BAF) is more relevant than the total metal concentration. This review describes different extraction methods with different leaching agents for various chemical forms of elements such as As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in ambient particulate matter (APM). Several leaching agents simulating the human body fluids have been developed to determine the bioaccessible metal fractions in APM. This study aims to enhance the knowledge of the bioaccessible concentrations and its impact on human health, documented for different locations worldwide. Furthermore, this study disclosed that confined observations have been found concerning the application and evolution of standard methods for the estimation of biologically relevant elements in ambient particulate matter. This review also revealed that human body simulated fluids like lung and gastric fluids, on comparing to water, provide more realistic values of bioaccessible fractions of potentially toxic elements (PTEs) in assessing human health risks.