Taxonomy of factors which influence heavy metal build-up on urban road surfaces

An Liu,Chandima Gunawardana,Janaka Gunawardena,Prasanna Egodawatta,Godwin A Ayoko,Ashantha Goonetilleke

doi:10.1016/j.jhazmat.2016.02.026

Abstract

Heavy metals build-up on urban road surfaces is a complex process and influenced by a diverse range of factors. Although numerous research studies have been conducted in the area of heavy metals build-up, limited research has been undertaken to rank these factors in terms of their influence on the build-up process. This results in limitations in the identification of the most critical factor/s for accurately estimating heavy metal loads and for designing effective stormwater treatment measures. The research study undertook an in-depth analysis of the factors which influence heavy metals build-up based on data generated from a number of different geographical locations around the world. Traffic volume was found to be the highest ranked factor in terms of influencing heavy metals build-up while land use was ranked the second. Proximity to arterial roads, antecedent dry days and road surface roughness has a relatively lower ranking. Furthermore, the study outcomes advances the conceptual understanding of heavy metals build-up based on the finding that with increasing traffic volume, total heavy metal build-up load increases while the variability decreases. The outcomes from this research study are expected to contribute to more accurate estimation of heavy metals build-up loads leading to more effective stormwater treatment design.

Highlights

Heavy metals deposited on urban roads, which are primarily attached to road dust, is of particular concern in the urban water environment since stormwater runoff transport these pollutants to receiving waters, degrading water quality [1,2]
Since the heavy metals are attached to road dust, the total dust loads per unit area (g/m2) is given
This research study ranked factors in terms of their influence on heavy metals build-up by using data generated from a number of different geographical locations around the world

Summary

Introduction

Heavy metals deposited (build-up) on urban roads, which are primarily attached to road dust, is of particular concern in the urban water environment since stormwater runoff transport these pollutants to receiving waters, degrading water quality [1,2]. Due to their high toxicity [3,4], accurate estimation of heavy metal loads is essential for the design of effective stormwater treatment strategies. Few research studies have undertaken a comprehensive analysis of these factors and their role in heavy metals build-up. It is difficult to investigate a wide range of influential factors during an individual research

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