First Assessment of Metals Contamination in Road Dust and Roadside Soil of Suva City, Fiji

Studies have claimed that road dust and roadside soil are potential banks of pollutants generally in urban areas. Thus, quantifying the concentrations of metals in an urban area is a prerequisite for assessing pollution and their health effects. Hence, this study reports the concentration of the metals, such as Cd, Co, Cr, Ni, Cu, Pb, Zn, and Fe, in the road dust and the roadside soil of Suva City. A total number of 45 road dust and 36 roadside soil samples were collected at 18 different locations around Suva City with potential traffic influence and analysed. The respective metals concentration in the road dust and roadside soil samples of Suva City were Cd (3.7 and 3.1 mg/kg), Co (35.0 and 33.2 mg/kg), Cr (40.0 and 34.0 mg/kg), Ni (54.3 and 32.4 mg/kg), Cu (172.3 and 265.7 mg/kg), Pb (71.0 and 59.3 mg/kg), Zn (685.0 and 507.0 mg/kg), and Fe (41,010.4 and 39,525.5 mg/kg) and showed the decreasing order as Fe > Zn > Cu > Pb > Ni > Cr > Co > Cd and Fe > Zn > Cu > Pb > Cr > Co > Ni > Cd for road dust and roadside soil, respectively. Furthermore, the mean values of the metals surpassed their background levels, except for Fe, whereas the mean values of Cd, Ni, Cu, and Zn have exceeded their permissible limits in road dust. Similarly, Cd, Cu, and Zn have exceeded their permissible limit in roadside soil except for Ni. The geo-accumulation index (I_geo) assessment of Suva City road dust thus indicated nonpolluted to moderate pollution by Ni and Cu and moderate pollution by Zn. The I_geo assessment of the roadside soil showed moderately polluted by Cu and Zn but no pollution from the remaining studied metals. Overall, the study indicated that the sampling locations at an industrial site of Suva City is highly predominated with almost all of the studied metals and is a concern to the general public who live and work within the vicinity of Walu Bay industrial area.