E. Levei, M. Senila, C. Roman, C, et al.???? , Assessment of aqua regia extractable and plant-available pb content in polluted soil,  Studia Universitatis Babes-Bolyai CHEMIA, 53/3 (2008) 51-56

Title: Assessment of aqua regia extractable and plant-available pb content in polluted soil

Abstract: In this study for monitoring the soil contamination with Pb in the industrially polluted area of Baia Mare, the aqua regia extractable Pb content as well as the plant-available fraction were determined by inductively coupled plasma atomic emission spectrometry, after extraction in HCl-NHO₃ mixture and in buffered DTPA, respectively. The aqua regia extractable Pb content was in the range of 88-2200 mg/kg, exceeding in all cases the alert level (50 mg/kg) and in most cases the intervention level (100 mg/kg) for sensitive soils. The plant-available Pb ranged between 10-292 mg/kg, exceeding in most soil samples the concentration limit of 20 mg/kg DTPA-extractable Pb considered to be the maximum level to avoid human risk. The average percentage of plant-available Pb was 21% showing that considerable amounts of Pb could be absorbed from soil by plants and propagated through the food chain in human organism.

Key words: soil contamination, aqua regia extractable Pb content, plant-available Pb