The mean arsenic concentrations in the agricultural soils from
the CAFO zone and the Pearl River Delta were higher than the background
concentrations in Guangdong Province (10.8 mg kg1) and
China (11.2 mg kg1), suggesting the surface soils from the agricultural
lands in the Pearl River Delta had been polluted by anthropogenic
sources of arsenic. The higher concentrations of arsenic in the
agricultural soils from the CAFO zone compared to those in the
agricultural soils from the Pearl River Delta indicate that animal
wastes from the CAFO had probably contributed to the elevated
levels of arsenic in local soils.