Phytoremediation of Lead: What Works, What Doesn’t

Urban Farm DB summary

Against a backdrop of heightened concern about lead exposure following the lead-contaminated water supply in Flint, Michigan, a review examines prior research on whether sunflowers (Helianthus annuus) can remove lead from urban garden soil through phytoextraction, in which plants draw contaminant metals up into their shoots. Some preliminary studies suggested sunflowers could phytoextract lead, but more extensive research has been disappointing; adding the chelating agent EDTA raises lead's solubility and plant uptake but is expensive and only meaningful combined with other practices such as compost application. Retired USDA scientist Rufus Chaney states that, unlike successful cases such as alpine pennycress extracting cadmium or canola extracting radioactive cesium, no serious study supports significant lead phytoextraction.