Municipal solid waste management health risk assessment from air emissions for China by applying life cycle analysis

This study is to quantify and objectively evaluate the extent of environmental health risks from three waste treatment options suggested by the national municipal solid waste management enhancing strategy (No [2011] 9 of the State Council, promulgated on 19 April 2011), which includes sanitary landfill, waste-to-energy incineration and compost, together with the material recovery facility through a case study in Zhangqiu City of China. It addresses potential chronic health risks from air emissions to residential receptors in the impacted area. It combines field survey, analogue survey, design documents and life cycle inventory methods in defining the source strength of chemicals of potential concern. The modelling of life cycle inventory and air dispersion is via integrated waste management(IWM)-2 and Screening Air Dispersion Model (Version 3.0) (SCREEN3). The health risk assessment is in accordance with United States Environmental Protection Agency guidance Risk Assessment Guidance for Superfund (RAGS), Volume I: Human Health Evaluation Manual (Part F, Supplemental Guidance for Inhalation Risk Assessment). The exposure concentration is based on long-term exposure to the maximum ground level contaminant in air under the 'reasonable worst situation' emissions and then directly compared with reference for concentration and unit risk factor/cancer slope factor derived from the national air quality standard (for a conventional pollutant) and toxicological studies (for a specific pollutant). Results from this study suggest that the option of compost with material recovery facility treatment may pose less negative health impacts than other options; the sensitivity analysis shows that the landfill integrated waste management collection rate has a great influence on the impact results. Further investigation is needed to validate or challenge the findings of this study.