Christian Khalil
Lebanese American University, Lebanon
Title: Characterization, cytotoxicity and genotoxicity of landfill leachates: A comparative assessment between landfills throughout Lebanon
Biography
Biography: Christian Khalil
Abstract
Statement of the Problem: Lebanon has been witnessing a waste crisis in the last few years due to the closure of a main landfill in Naameh as it exceeded storage capacity. The municipal waste crisis was years in the making because of the absence of a clear national municipal waste minimization, recycling and disposal strategies with the preferred option being landfills throughout the country. The disposition of municipal, medical, industrial and all wastes into landfills helped in short term waste disposal but created a new challenge in the form of leachates. The purpose of this study was to assess the toxicological and health impacts of leachates exposure by investigating a number of regulated and unregulated landfills scattered throughout the country.
Methodology & Theoretical Orientation: The study consisted of sampling leachates from numerous sites scattered throughout the country. Some of the leachates at some sites were subjected to biological treatment prior to disposal into the natural environment while in other sites they were disposed without any treatment. The leachates were collected by our team and subjected to chemical characterization using Gas Chromatography-Mass Spectrometry GC/MS and toxicological assessment using cytotoxicity and genotoxicity assays.
Findings: The study indicated significant high concentrations of Cadmium, Chromium, Copper, Aluminum, Manganese, Potassium, Sodium Nickel and Calcium in comparison to a previous study undertaken on the municipal wastes in Lebanon and published data from worldwide landfills. The leachates also posed significant toxicological and genotoxicological risks as identified by the in vitro assays conducted using human derived cells.
Conclusion & Significance: This study provided qualitative and quantitative knowledge of the volatile and semi-volatile compounds in leachates from numerous sites across Lebanon. Molecules related to cosmetics, medicines, pharmaceuticals, agri- food repellents, plastics were reported in the study. A significant toxic and genotoxic risks can be experimentally revealed by the identification of DEHA, Phthalic acid, mono-(2-ethylhexyl) ester and Tributylamine in untreated leachates dumped into the natural environment. Recommendations are made for biological treatment of leachates prior to disposal into the natural environment.