The Health Risk Assessment of Pb and Cr leachated from fly ash monolith landfill
Journal
Journal of Hazardous Materials
Journal Volume
172
Journal Issue
1
Pages
316-323
Date Issued
2009
Author(s)
Abstract
As of 2004, nearly two hundred thousand tons of fly ash monoliths are created each year in Taiwan to confine heavy metals for reducing the leaching quantity by precipitation. However, due to abnormal monolith fracture, poorly liner quality or exceeding usage over designed landfill capacity, serious groundwater pollution of the landfills has been reported. This research focuses on Pb and Cr leaching from monolithic landfill to assess the risk of groundwater pollution in the vicinity. The methodology combines water budget simulations using HELP model with fate and risk simulations using MMSOILS model for 5 kinds of landfill structures and 2 types of leaching models, and calculates the risk distribution over 400 grids in the down gradient direction of groundwater. The results demonstrated that the worst liner quality will cause the largest risk and the most significant exposure pathway is groundwater intake, which accounted for 98% of the total risk. Comparing Pb and Cr concentrations in the groundwater with the drinking water standards, only 14.25% of the total grids are found to be under 0.05 mg/L of Pb, and over 96.5% of the total grids are in the safety range of Cr. It indicates that Pb leaching from fly ash monolithic landfills may cause serious health risks. Without consideration of the parameters uncertainty, the cancer and noncancer risk of Pb with the sanitary landfill method was 4.23E-07 and 0.63, respectively, both under acceptable levels. However, by considering the parameters uncertainty, the non-carcinogenic risk of Pb became 1.43, exceeding the acceptable level. Only under the sealed landfill method was the hazard quotient below 1. It is important to use at least the sealed landfill for fly ash monoliths containing lead to effectively reduce health risks. © 2009 Elsevier B.V. All rights reserved.
Subjects
Fly ash monolith; Health risk assessment; Landfill structure; Sanitary landfill; Uncertainty
Other Subjects
Carcinogenic risk; Cr concentration; Drinking water standards; Exposure pathways; Gradient direction; HELP model; Landfill capacity; Landfill structure; Parameters uncertainties; Risk distribution; Sanitary landfill; Uncertainty; Water budget; Chromium; Fly ash; Groundwater; Groundwater pollution; Health; Hydrogeology; Land fill; Leaching; Lead; Monolithic integrated circuits; Potable water; Risk assessment; Risk management; Sanitation; Simulators; Waste disposal; Water supply; Health risks; chromium; drinking water; ground water; lead; chromium; computer simulation; drinking water; fly ash; groundwater pollution; health risk; landfill; lead; risk assessment; uncertainty analysis; water budget; article; cancer risk; computer simulation; controlled study; environmental impact; fly ash; health hazard; landfill leachate; leaching; pollution transport; risk assessment; risk reduction; water contamination; water pollution; water standard; Carbon; Chromium; Environmental Monitoring; Environmental Pollution; Geologic Sediments; Humans; Industrial Waste; Lead; Models, Statistical; Particulate Matter; Refuse Disposal; Risk Assessment; Soil Pollutants; Taiwan; Water Pollutants, Chemical; Water Purification
Type
journal article