Chemical
fertilizers are overwhelmingly used on agricultural lands in the
Pearl River Delta. In contrast, animal wastes are the predominant
form of fertilizers used in the CAFO zone due to their ready availability
and the short transportation distance required. The correlation
between the contents of arsenic and organic carbon in the
surface soils from the CAFO zone suggests that the fertilization of
agricultural lands with animal wastes was a likely source of arsenic
in the surface soils.