Urban Rivers as Pollutant Sinks and Sources: a Public Health Concern for Recreational River Users?

Although the area of urban river sediment quality has received increasing attention over the last 10 years, the presence of contaminated sediments in urban rivers and the potential risk to public health it poses has yet to be rigorously addressed within the urban river restoration context. This is an issue of particular concern at the current time, as the opening-up of urban rivers is being strongly promoted by many legislative and non-legislative bodies as a multi-benefit approach to tackling a range of urban challenges; from decreasing the risk of flooding to increasing the quality-of-life in urbanised areas. This paper brings together these two contrasting concepts; urban rivers as pollutant sinks and sources (presentation of data on urban river sediment quality) and urban rivers as sites of flood alleviation, amenity, recreation and wildlife value (review of the drivers and initiatives behind the increasing implementation of urban river rehabilitation schemes). In light of this combined assessment, the urgent need for a risk assessment of restored urban river sites to establish whether the presence of contaminated sediments poses a risk to public health is strongly recommended. Should such a risk be demonstrated, a tiered approach to supporting the identification and pro-active management of these risks is proposed as a way to inform and enable, rather than to prevent, the safe and appropriate use of the increasing number of urban river restoration schemes being implemented.