Health risk assessment of toxic trace metals in private car dusts from Pretoria, South Africa

Concentration of trace metals from car dust have not been examined from private cars in South Africa. The present study investigated the concentrations of trace metals from selected car dust from three car washing centres in Pretoria, South Africa. Different private cars were selected at three prominent car washing centres in Pretoria, South Africa. Dust samples were collected from these cars and analysed for trace metal concentrations using ICP-MS. The highest mean concentrations for the trace metals were recorded for Mn (862.9 ± 14.65 µg/g). The concentrations of Mn, Zn, Cu and Cr were the highest from all the dust samples. A positive correlation was also noticed for elements such as Pb and Cu, Cu and Zn, Mn and Pb, Cr and Pb and Mn and Cu suggesting a common source for these elements. The geo-accumulation revealed extreme contamination for trace metals Cr, Ni and Zn with values greater than 7. The carcinogenic and non-carcinogenic risk calculated showed that the exposure route was in the order: ingestion > dermal absorption > inhalation. Both the non-carcinogenic and carcinogenic risk calculated for the drivers are less than 1. However, continuous ingestion with an increase in the concentration of these metals may pose serious carcinogenic risk over time. It will therefore be necessary for future research to investigate the relationship between the trace metals in blood of these drivers.