Soil pollution evaluation and health risk assessment of heavy metals around Douroud cement factory, Iran

Abstract

Industrial activates have contaminated the soils around the industries to some pollutants such as heavy metals. Nowadays, among the different industries, cement factories are of major environmental pollutant sources. Therefore, the main objective of this study was to evaluate the soil pollution to heavy metals around Douroud cement factory in terms of geo-accumulation index, pollution index, and integrated pollution index. Also, a health-risk assessment was carried out. Sampling was performed at intervals of 500 m, 1250 m, and 2000 m from the factory site. Soil samplings were taken from the depths of 0–10 cm and 10–20 cm from the top surface. The health-risk assessment regarding soil around the factory was assessed based on the USEPA procedure. The study results showed that the average concentrations of chromium, nickel, copper, lead and zinc in the soil around the cement factory were 115.77 mg/kg, 139.07 mg/kg, 80.47 mg/kg, 56.27 mg/kg, and 135.73 mg/kg, respectively. Also, the results showed that the concentration of the heavy metals in the top soil was significantly higher than subsurface sampling layers. Furthermore, the findings showed that the concentrations of all evaluated heavy metals were higher than the USEPA standard. The pollution index values in the soil around the cement factory were Cu > Pb > Zn > Ni > Cr. Based on this study, the daily intake rate of all the elements by oral ingestion route was higher than the inhalation and dermal contact routes. The hazard quotient values of all metals in all studied sampling points were < 1.