Geochemical phases of soil and the bioaccessibility of some elements in soils and vegetables from boron mines.

The bioaccessibility of some elements (As, B, Cd, Cu, Fe, Mn, Ni and Zn) in soils and vegetables was determined using the physiologically based extraction test. An investigation of the geochemical phases of soils through sequential extraction methods followed by ICP-MS detection was also undertaken. Samples were collected from Iskele, Begendikler and Yolbasi villages in the Bigadic region and Yildiz village in the Susurluk region of Balikesir province, Turkey. All of these villages are close to boron mines. Principal component analysis and correlation analysis demonstrated the interrelationship between the bioaccessibility values of these elements in the gastric and intestinal extracts of soils as well as the plant samples grown in those soils and the elements' concentrations in the different soil fractions. From the bioaccessible concentrations of the elements in the intestinal phases, it was shown that the amounts of As, B, Cu, Mn and Ni in some plant samples were higher than the recommended and tolerable values for human consumption. The bioaccessibilty of these elements in the soils and plants were statistically related with the concentrations of these elements in the labile phases of the soil. The methodology adopted here would be applicable to determining interactions between elements and soil fractions and the interrelationships between bioaccessibility data and soil fractions for any soil samples.