An Assessment of Possible Effect of Risk Elements Contained in Soil on Human Organism

Abstract

Physiologicaly Based Bioavailability Extraction Test (PBET) was tested at eight soils differing in their physicochemical properties to assess the potential bioavailability of risk elements (As, Cd, Pb) via ingestion of the soil. The results showed that the simulated human gastrointestinal tract fluid is able to extract heavy metals fixed in soil matrix in considerable portion of the total element content. Significant differences were observed between the extractable element contents with simulated gastric fluid and simulated duodenal fluid. Comparison of PBET method and soil extraction with 0,01 mol l^–1 solution of CaCl₂, the extraction method simulating approximately the plant-available portions of risk elements showed higher mobility of soil elements by using the PBET test, especially in the case of As and Pb. For instance, arsenic belongs to the elements characterized by limited plant-availability and its extractability with 0,01 mol l^{– 1} solution of CaCl₂ did not exceed 1 % of total content whereas the soil extraction with simulated gastric solution reached up to 4 % of total arsenic content. Therefore, potential risk of direct soil ingestion in contaminated areas should be taken into account and investigated in further research.