Linking source characterisation and human health risk assessment of metals to rainfall characteristics

Abstract

Metals deposited on urban road surfaces and incorporated in stormwater runoff are discharged into receiving waters, influencing their quality and can pose human health risks. Effective design of stormwater treatment measures is closely dependent on the in-depth understanding of stormwater pollutant sources and the associated health risks. The study discussed in this paper has linked the sources of metals in stormwater runoff and the accompanying human health risk to rainfall characteristics. The study outcomes confirmed that the metal contributions to stormwater runoff from the primary sources were in the order of sea salt > soil > traffic. Although traffic contributes a relatively lower percentage to wash-off, the human health risks posed by traffic sourced metals were relatively much higher. This implies that traffic sources should receive particular attention in treating stormwater. These outcomes have the potential to contribute to enhancing effective source control measures in order to safeguard natural waterways from polluted road wash-off.