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. Another study has reported that