organoarsenic feed additives used in the swine farming in the
CAFO zone. The net accumulation of arsenic in soil (109.5 tonnes)
is less than the estimated input (126 tonnes), probably because
significant fractions of the arsenic species (primarily in the forms
of arsenate and arsenite) had been leached out of the surface soils
by rainwater and irrigation water, which subsequently impacted
local surface water and groundwater. Therefore, the extensive
use of organoarsenic feed additives makes animal wastes a significant
anthropogenic source of arsenic pollution in the CAFO zone.