Occurrence and ecotoxicological effects of fires at municipal solid waste landfills

Surface and sub-surface fire in municipal solid waste landfills (including dumpsites) is a complex and intricate phenomenon, whose frequency is expected to increase due to climate change. Partial or incomplete combustion of landfill waste at low temperatures during fires leads to generation of toxic compounds, including hydrocarbons, particulate matter and hazardous gases, which contaminate the surrounding geoenvironment and ultimately pose severe health hazards to living entities. Under these circumstances, it is the need of the hour to understand the (i) occurrence mechanisms of landfill fires, (ii) waste properties and operational conditions that may favour landfill fires and (iii) strengths and limitations of the available detection techniques in order to provide recommendations to detect such incidences at an early stage and plan emergency measures. Hence, the present review article critically assimilates the literature on landfill fires and discusses the (a) conditions under which the initiation and sustenance of landfill fires take place, (b) ecotoxicological (geoenvironmental) hazards of landfill fires, both in short- and long-term and (c) detection techniques for an early warning system. Finally, a discussion on the coupled multi-physics interactions undergoing in the waste matrix during landfill fires is presented in this manuscript, which is crucial to mastering this subject.