Point source identification using a simple permutation test: A case study of elevated PCDD/F levels in ambient air and soil and their relation to the distance to a local municipal solid waste incinerator
Journal
Stochastic Environmental Research and Risk Assessment
Journal Volume
26
Journal Issue
2
Pages
225-233
Date Issued
2012
Author(s)
Abstract
A point source for environmental pollution may be identified by the spatial association of samples collected in the vicinity of the emission source. In this study, we used a simple permutation test to explore the spatial correlations between the ambient air and soil polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) congener profile concentrations and their distances to a municipal solid waste incinerator (MSWI) in northern Taiwan. Kendall's τ was applied for the correlation between the PCDD/F concentrations of a total of 9 airborne and 12 soil sampling sites and their distances to the incinerator. The results showed that the correlation was highly negatively associated for soil PCDD/Fs (τ = -0. 515, p-value = 0. 011) and was marginal for airborne PCDD/Fs (τ = -0. 667, p-value = 0. 055), conditional on the seasonal wind attributions. For the 17 individual congener profiles, most of the air and soil samples had a negative association, with 7 and 10 reaching statistical significance (p-value < 0. 05) or borderline significance (0. 05 < p-value < 0. 10), respectively. The permutation test provides a simple and robust statistical method for the identification of a potential pollution source from a limited sample size. Our analytical results show that dioxin emissions from the investigated MSWI had a definite environmental impact on the surrounding area. © 2011 Springer-Verlag.
Publisher
Springer New York LLC
Type
journal article