Dr Barry Noller is overseeing a Lead Pathways Study being undertaken by the Centre for Mined Land Rehabilitation at the University of Queensland.143 The study was commissioned by Xstrata, which mines zinc, lead, silver and copper in its Mount Isa mines in western Queensland. Mount Isa attracted media attention in 2010 over concerns that many children were being exposed to excessive amounts of lead from the mine.144 State Government testing indicated generally elevated lead levels in Mount Isa children. In February 2011 local mother Sharlene Body lodged a AUD$1 million compensation claim against Xstrata, the Mount Isa City Council and the Queensland State Government on behalf of her son, who is alleged to have registered blood lead levels more than three times the World Health’s Organization’s recommended minimum. As part of its efforts to better inform the community, the local council posted information on its website and published a simple brochure. Parents were advised to cover any areas of bare earth in yards with lawn or planting, or as a last resort, concrete, to help minimise dust, and therefore airborne lead particles. It seemed to me to be a good opportunity to explore phytoremediation options. Australian studies have shown the success of native species such as Lomandra longifolia and Poa labillardieri in trace metal accumulation of soil-borne lead.145 My landscape imagination ran away, visualising the backyards, public parks and street edges of Mount Isa planted with robust native plants that not only suited the climate and increased amenity, but were working to reduce contamination and improve the health of residents. Quickly, Dr Noller relegated such thoughts to the realm of uneducated fancy. There are no known ‘hyperaccumulator’ plants for lead. It is not a contaminant that can be treated with phytoremediation, and is best treated by adding apatite calcium phosphate to modify the soil.146
Phytoremediation of a former service station in Ronnde, Denmark using Salix. (Lcl via Wikimedia)
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