Transformations, air transport, and human impact of arsenic from poultry litter

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid) is a common feed additive for poultry and swine, acting as a highly effective growth promoter. Most of the roxarsone is excreted unchanged in fecal matter, and most of this waste material is disposed of by application to farm lands as a fertilizer. Previous studies have demonstrated that roxarsone undergoes fairly rapid degradation after field application, or during composting prior to field application, producing a mixture of arsenic compounds that include both inorganic and organic arsenicals, not all of which have yet been identified. The previous studies have focused primarily on how arsenical mixtures are transported through groundwater and runoff water. The present study reports on the transport of both roxarsone and some of its degradation products through the air to impact homes near poultry litter-applied fields, resulting in house dust arsenic levels in 29 tested homes ranging from 10.7-130 mg/kg.