Two profiles (P1 and P2) were established along two lines perpendicular to the direction of the Luan River flow and 200 pore water and sediments samples as well as thirty maize samples, were collected from ten drills in these two profiles. Spatial distribution models of iron, manganese and lead were established using the Simple Kriging method, and the transfer factor (TF) and multi-metal (combined) target hazard quotient (CTHQ) were calculated to assess the potential human health risk of the metals. The results indicate that the maximum TF value was 3245.37 for iron in the sheath, while its min value was 13 for lead in the seeds. Of the ten drills, Sd08 possessed the maximum CTHQ (1.74), while the CTHQ of the other drills was less than the unit, indicating that it is not likely to impact human health. This work indicates that the Luan River and the associated irrigation water have significant effects on the spatial distribution of the three metals in the critical zone (CZ). Iron exhibited greater transfer ability than manganese and lead, however it was mainly concentrated in the roots and sheath of the maize, rather than the seeds. The human health risks of metals are attributed to lead.
Supplementary material: These graphs quantitatively characterize the important parameters for manganese, iron and lead contents in maize. They are available at http://doi.org/10.6084/m9.figshare.c.3828172