title: Arsenic stability and mobilization in soil at an amenity grassland overlying chemical waste (St. Helens, UK).
abstract: A 6.6 ha grassland, established on a former chemical waste site adjacent to a residential area, contains arsenic (As) in surface soil at concentrations 200 times higher than UK Soil Guideline Values. The site is not recognized as statutory contaminated land, partly on the assumption that mobility of the metalloid presents a negligible threat to human health, groundwater and ecological receptors. Evidence for this is evaluated, based on studies of the effect of organic (green waste compost) and inorganic (iron oxides, lime and phosphate) amendments on As fractionation, mobility, plant uptake and earthworm communities. Arsenic mobility in soil was low but significantly related to dissolved organic matter and phosphate, with immobilization associated with iron oxides. Plant uptake was low and there was little apparent impact on earthworms. The existing vegetation cover reduces re-entrainment of dust-blown particulates and pathways of As exposure via this route. Minimizing risks to receptors requires avoidance of soil exposure, and no compost or phosphate application.
authors.affiliation: School of Biological and Earth Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK.
authors.forename: William
authors.initials: W
authors.lastname: Hartley
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Dickinson
authors.forename: Rafael
authors.initials: R
authors.lastname: Clemente
authors.forename: Christopher
authors.initials: C
authors.lastname: French
authors.forename: Trevor G
authors.initials: TG
authors.lastname: Piearce
authors.forename: Shaun
authors.initials: S
authors.lastname: Sparke
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Lepp
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000032:analysis*; D004739:England; D004784:Environmental Monitoring / Q000379:methods; D052918:Environmental Restoration and Remediation; D006256:Hazardous Waste; D012037:Refuse Disposal; D018570:Risk Assessment / Q000379:methods; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D006256:Hazardous Waste; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D001151:Arsenic