Arsenic species in broiler (Gallus gallus domesticus) litter, soils, maize (Zea mays L.), and groundwater from litter-amended fields

Manure and bedding material (litter) generated by the broiler industry (Gallus gallus domesticus) often contain high levels of arsenic (As) when organoarsenical roxarsone and p-arsanilic acid are included in feed to combat disease and improve weight gain of the birds. This study was conducted to determine As levels and species in litter from three major broiler producing companies, and As levels in soils, corn tissue (Zea mays L.), and groundwater in fields where litter was applied. Total As in litter from the three different integrators ranged between <1 and 44mgkg^-1. Between 15 and 20% of total As in litter consisted of mostly of arsenate, with smaller amounts of roxarsone and several transformation products that were extractable with phosphate buffer. Soils amended with litter had higher levels of bioavailable As (extractable with Mehlich 3 solution and taken up by corn leaves). Arsenic concentrations in plant tissue and groundwater, however, were below the World Health Organization thresholds, which was attributed to strong sorption/precipitation of arsenate in Fe- and Al-rich soils. Ecological impacts of amending soils with As-laden litter depend on the As species in the litter, and chemical and physical properties of soil that strongly affect As mobility and bioavailability in the environment.