For adults, HQs and HI in this studies are mostly lower than safe level (=1). HI decreased in the order
of Pb>Cr>Cu>Ni>Cd>Zn. The highest value of Pb (HI=0.132) is much lower than the safe level.
Therefore, the potential health risks for adults can be overlooked. Meanwhile when compared to children,
the health risk for adults is lower. The HI values of these metals for children are 3 or 4 times higher than
those for adults, especially the value of Cr for children are almost 40 times higher than that for adults. The
result means that children faced greater potential health risks from the heavy metals of park dust.
In the main, the values of health risk obtained in this study are in the receivable range, although some
assumptions applied in the models seemed to be to ideal and simple. The results reflected that exposure to
heavy metals in dusts solely would not cause serious health impacts in the study. However, the calculated
risk is affected by a high degree of uncertainty. Despite many uncertainties, human health risk assessment
has proved to be a powerful tool to distinguish heavy metals and exposure routes of most concern in
urban environments. Dust toxics risk assessment program demonstrates the value of a risk-oriented
approach to informing residents/government about the potential risks associated with exposure to
metals[33].