Globally, the generation of municipal solid waste has increased steadily, raising concerns regarding environmental contamination and potential adverse health effects associated with landfill sites. During waste degradation, landfills emit air pollutan...
Globally, the generation of municipal solid waste has increased steadily, raising concerns regarding environmental contamination and potential adverse health effects associated with landfill sites. During waste degradation, landfills emit air pollutants such as volatile organic compounds (VOCs), ammonia, and hydrogen sulfide, while leachate containing organic matter, heavy metals, and inorganic salts may migrate into surrounding soils and aquatic environments. Heavy metals are of particular concern due to their persistence, bioaccumulation potential, and long-term health effects, and VOCs including benzene, toluene, ethylbenzene, and xylene (BTEX) are classified as hazardous air pollutants because of their inhalation toxicity.
Previous studies have predominantly focused on active landfills, assessing contamination in individual environmental media or characterizing landfill gas emissions. As a result, integrated evaluations linking multi-media environmental contamination, human exposure, and health indicators remain limited, particularly for unsanitary landfills. Although leachate leakage and odor complaints may persist after landfill closure, comprehensive post-closure environmental and health impact assessments have been insufficient.
The objective of this study was to evaluate the environmental and health impacts of a closed landfill that had previously operated as an unsanitary mixed-waste disposal site. Multi-media environmental monitoring of air, soil, surface water, and sediment was conducted in surrounding areas, together with characterization of landfill gas and odor emissions. An integrated exposure and risk assessment was performed, and biomonitoring data and self-reported health information from nearby residents were collected to provide a comprehensive assessment.
Concentrations of VOCs and heavy metals were measured in environmental media, ambient odor levels were assessed, urinary biomarkers were analyzed, and disease histories were obtained through structured questionnaires. Concentrations of heavy metals and VOCs in air, soil, and sediment were generally low, with no significant differences between the study and control areas. In contrast, surface water showed locally elevated levels of sodium, potassium, calcium, and total organic carbon, indicating residual leachate influence. Odorous compounds, including ammonia and hydrogen sulfide, exceeded regulatory thresholds at some landfill and residential locations, and hazard quotients exceeded unity at certain sites.
Integrated exposure and risk assessment indicated that overall health risks were low, although dietary exposure contributed substantially to total estimated risk. Biomonitoring results showed low urinary concentrations of heavy metals and VOC metabolites, with no significant associations between environmental exposure levels and internal biomarkers, suggesting limited internal exposure. Health survey results also indicated a low prevalence of cancer and major chronic diseases.
Overall, the closed mixed-waste landfill exerted limited impacts on surrounding environmental media and human exposure. However, localized surface water contamination and odor-related risks require continued management. This study provides integrated scientific evidence to support post-closure landfill management and protection strategies for environmentally vulnerable communities.