Quantifying human exposure to selected soil-bound metals using human biomonitoring and physiologically-based pharmacokinetic modelling

Research Problem and Objective Current exposure models used in contaminated land risk assessment are highly conservative. Use of these models may lead to over-estimation of actual exposures, possibly resulting in negative... [ view full abstract ]

Research Problem and Objective
Current exposure models used in contaminated land risk assessment are highly conservative. Use of these models may lead to over-estimation of actual exposures, possibly resulting in negative financial implications from unnecessary remediation. A study is being carried out to improve our understanding of human exposure to selected soil-bound elements (As, Cd, Cr, Pb, Ni) resulting from allotment land-use.

Methods
The research employs physiologically-based pharmacokinetic (PBPK) modelling and biomonitoring to quantify human exposure to these elements. Biomonitoring is being carried out with thirty-six participants across Scotland. Ethical approval was granted by the University of Reading Research Ethics Committee.

Results and Conclusion
Preliminary PBPK models have been developed. The models were used to estimate the distribution and accumulation of the elements in key body organs/compartments, thus indicating the internal body burden. In addition, the PBPK models have been used to predict the concentrations of the elements in blood and urine. Simulating low metal intake (based on soil and allotment produce test results from a pilot study), the predictive models suggest that detection of these elements in participants’ blood and urine would be possible within a given period of time following exposure. This information is being used to plan the biological monitoring and in the subsequent interpretation of test results from biological samples.

Importance of the work
The findings from this study will help improve the existing models used to predict human exposure to soil-bound contaminants, subsequently promoting a more sustainable approach to contaminated land management.