Heavy metals concentration in street dust from residential and industrial areas at mukim Hulu Kinta Perak

Street dust forms due to the interaction of the atmosphere, lithosphere (pedosphere), and anthroposphere and can be regarded as an index of the environmental condition in urban areas because it may affect ecosystems and human health. Therefore, this research aims to determine the amount of heavy metal content and its subsequent risks to human health in 72 street dust samples collected from two locations, i.e., industrial and residential areas in Mukim Hulu Kinta, Perak. The heavy metal concentrations were obtained by wet acid digestion and Atomic Absorption Spectroscopy (AAS) for the assessment of copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb) concentrations. The results showed a high concentration of Zn and the lowest concentration of Cd. The decreasing trend of metal levels of street dust average from the residential and industrial areas is as follows: Zn > Cu > Pb > Cd. Statistical analysis using an independent t-test indicated a significant difference in Pb levels between the residential and industrial areas (p = 0.004. t = -1.562, df = 70). However, no significant differences are noted in the results for Cu, Cd, and Zn levels between the areas. In addition, the geo-accumulation index (Igeo) value has been calculated to assess the contamination of heavy metals, and the result is in the following order: Cd > Zn > Cu > Pb. As the hazard quotients (HQ), indicated that the HQ of Cu, Cd, Zn, and Pb was less than one which is an acceptable limit for humans. Thus, the residential and industrial areas exhibit a safe level of heavy metals in street dust for the population.