with the exception of Cu in the CAFO zone. In contrast,
it showed strong positive correlations with Cr, Mn, Co, Ni, Cu,
and Zn, but no significant correlations with Cd and Pb in the agricultural
soils in the Pearl River Delta. Although the presence of significant
linear correlations among arsenic and the other common
heavy metals makes it difficult to identify the sources of arsenic,
the different distribution patterns suggests that the sources of
arsenic in the CAFO zone were not identical to those in the agricultural
soils of the Pearl River Delta in general.