Delimitation of arsenic-contaminated groundwater using risk-based indicator approaches around blackfoot disease hyperendemic areas of southern Taiwan
Resource
Environmental Monitoring and Assessment 134 (1-3): 293-304
Journal
Environmental Monitoring and Assessment
Journal Volume
134
Journal Issue
1-3
Pages
293-304
Date Issued
2007
Author(s)
Abstract
This work determined scopes of arsenic(As)-contaminated groundwater using risk-based indicator classification approaches in blackfoot disease hyperendemic areas of southern Taiwan. Indicator kriging was first used to establish a conditional cumulative distribution function at each cell. Three approaches - the p-quantile estimate, the E-type estimate and the minimization of the expected loss - were then adopted to delimit contaminated regions for a regulated standard of As concentrations in groundwater. According to a risk assessment model established in our previous research, the standard was set to 250 μg/l for aquacultural use, corresponding to the 77.1th percentile of observed concentrations. Misclassification risks and uncertainty were examined for the classification approaches. The analyzed results reveal that contaminated areas are the largest using the 0.771-quantile estimate, whereas they are the smallest using the minimization of the expected loss. Proportions of credible polluted areas with low risks to false positives maintain a constant, 12.9-13.2%, for the classification approaches. To reduce a great impact on human health, As-polluted groundwater should be strictly prohibited to cultivate fish in credible polluted zones and monitored persistently in polluted zones with high risks to false positives. ? Springer Science+Business Media B.V. 2007.
Subjects
Blackfoot disease; Indicator kriging; Misclassification; Risk; Uncertainty
Other Subjects
Arsenic; Environmental impact; Health hazards; Mathematical models; Risk assessment; Blackfoot disease; Cumulative distribution function; Indicator kriging; Misclassification; Groundwater pollution; arsenic; ground water; arsenic; concentration (composition); groundwater pollution; kriging; risk assessment; uncertainty analysis; water quality; aquaculture; article; blackfoot disease; classification; controlled study; endemic disease; health status; risk assessment; standard; statistical model; Taiwan; uncertainty; water contamination; Arsenic; Arsenic Poisoning; Endemic Diseases; Humans; Models, Statistical; Risk Assessment; Taiwan; Water Pollutants, Chemical; Water Supply; Asia; Eurasia; Far East; Taiwan
Type
journal article
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