Assessment of heavy metal pollution in the soil of a construction and demolition waste landfill

Abstract

Construction industry has a significant effect on the environment and human health. In developing countries including Iran, the waste generated through construction and demolition is disposed in landfills, posing further harms to the environment by increasing the amounts of heavy metals (HMs). In order to tackle the mentioned issue, the first step is to assess the landfill soil’s contamination and risk. To date, no study has examined the status of heavy metal pollution and risk assessment of construction and demolition waste (CDW) landfills in Shiraz, Iran, although a large amount of CDW is disposed in this city. In order to fulfil the mentioned gap within the body of knowledge, a novel study was conducted in which a case study CDW landfill within Shiraz, Iran, was investigated carefully. 420 samples were collected, which was followed by various types of assessment techniques including geo-accumulation index, pollution load index, enrichment factor, and potential ecological risk assessment. The results obtained from pollution assessment methods illustrated considerable levels of contamination within the landfill, with Cd as the main contaminant (PLI value of 14.15, and significant enrichment for 92.7% of the collected samples). Risk assessment also showed a high-level risk of HMs for 84.16% of the samples extracted from the landfill soil, and the most prominent contributors were Cd and Pb with average ecological risks of 712.2 and 57, respectively. The results of this study can have a great impact on future policies and strategies regarding the disposal of CDW in Shiraz, Iran.