Investigations of the chemical distribution of heavy metals in street dust and its impact on risk assessment for human health, case study of Radom (Poland)
This work investigated the ecological and health hazards caused by heavy metals present in urban street dust of Radom (Poland). The objectives of this study were to improve the estimation of exposure doses of toxic metals based on their distribution patterns in street dusts and to assess the noncarcinogenic health risk for the residents. Zinc (Zn), manganese (Mn), and lead (Pb) were mainly associated with the reducible fraction, copper (Cu) with the oxidizable fraction, and iron (Fe), nickel (Ni), and chromium (Cr) with the residual fraction. The contents of short-term and long-term labile fractions of the metals were used to assess a direct health risk, a potential health risk and an overall human health risk. The level of the overall risk quantified by the cumulative total labile fraction-HI (tlf-HIc): 3.91E-01 (children) and 3.85E-02 (adults) was lower than the safety limit of unity. The metal that contributed the most to the overall health risk was Pb: 34% (children) and 31% (adults), while Zn and Ni had the least contribution (3% and 2% for both children and adults). It was shown that the risk assessment based on the pseudo-total content of metals can overestimate the health risk by nearly two times when compared to the assessments based on the total content of labile fractions.
