Development & application of Conceptual Framework Model (CFM) for environmental risk assessment of contaminated lands.

Abstract

Dumping sites are the most common types of contaminated lands as they pollute the environment. Environmental management of contaminated sites cannot be delivered effectively and efficiently without robust holistic & integrated risk assessment. Previous studies reveal the absence of a risk assessment model that holistically integrates all essential factors progressively and categorically. The study aimed to develop a holistic & integrated Conceptual Framework Model (CFM) for environmental risk assessment and to apply developed CFM on real-world existing Mahmood Booti Open Dumping Site (MBODS). CFM developed in this study had three main tiers i.e., baseline study, hazard identification & exposure assessment, and risk estimation. For the application of CFM, baseline data were collected and assessed. Water, leachate & soil samples were collected within 1000 m across the site and analyzed for physio-chemical parameters and heavy metals to estimate risk. Results of applied CFM depicted that Physico-chemical analysis of leachate, water, and soil revealed significant pollution levels. Heavy metal analysis exhibited that Ni, Pb, Mn, and Cr levels exceeded the allowable limits of the “World Health Organization” in leachate, water, and soil samples. It also revealed the existence of metals at the source (dumping site itself), pathway, and receptor of the dumping site. Eir value for Ni, Pb and Cd from the study area manifested a serious probable risk to ecological integrities. Results for PERI from dumpsite demonstrated a serious ecological risk. It can be concluded that although Mahmood Booti dumping site has been at post-closure stage, it is a momentous source of hazardous toxic contaminants to the nearby inhabitants. The work presented in this paper may reproduce repeatedly to create site-specific risk assessment models of other contaminated lands in a cost-effective, consistent and cohesive manner. Application of CFM at Mahmood Booti Dumping site described detailed risk assessment which helps further in risk management.