Concentrations and Toxicological Pattern of Landfill Gases towards Risk Cancer-A Review

Landfill is known as the simplest municipal solid waste (MSW) disposal method over years ago because of economical value in operating. However, the gas released by the degradation of waste from the landfill harassed human and environmental. Most research has detected gas compounds in ambient air of landfill which is known as volatile organic compounds (VOCs). Research has founded that several landfill gases (LFG) might be potential to risk cancer. The concentration of LFG in ambient air were influenced by many factors such as waste composition, the age of the landfill, moisture content, temperature, the wind direction and speed. Therefore, it gives the variation of LFG concentration in ambient air at different points of mapping. The large fractions of the total hazardous air pollutions (HAPs) components present in LFG are BTEX (benzene, toluene, ethylbenzene and xylenes), alkanes, organochlorides and terpenes. Over 13 of the HAPs founded in LFG have inhalation-cancer risk which are 1,1,2,2-tetrachloroethane, ethylidene dichloride, thylene dichloride, benzene, carbon tetrachloride, chloroform, dichlorobenzene, methylene dichloride, ethylene dibromide, tetrachloroethylene, trichloroethene, vinyl chloride and polychlorinated dibenzo-p-dioxin. Findings show that raw LFG is approximately 24 times more carcinogenic to human health rather than LFG combustion exhaust. As a conclusion, this paper presents systematic and comprehensive approach to determine the variation of VOC concentration in ambient air that has enabled to develop the toxicological pattern which is useful in evaluating the risk cancer in landfill industry area.