Zw. Zhang et al., CONTENTS OF POLLUTANT AND NUTRIENT ELEMENTS IN RICE AND WHEAT GROWN ON THE NEIGHBORING FIELDS, Biological trace element research, 57(1), 1997, pp. 39-50
Because of recent agricultural policy to suppress rice production, a r
ather rare situation occurred in one prefecture in Japan that rice and
winter wheat were grown in fields neighboring each other, rice being
grown from May to October, and wheat from November to June of the next
year. Grains of such rice and wheat were analyzed for cadmium (Cd) an
d lead (Pb) by atomic absorption spectrometry, and eight nutrient mine
rals by inductively coupled plasma emission spectrometry. Concentratio
ns of nutrient minerals were higher in wheat grains than in unpolished
rice grains (without husk), and similar trends were observed also for
Cd and Pb. Flour obtained by milling of the wheat grains had signific
antly less Cd and nutrient minerals than the mother grains, and such r
eduction was also observed by treatment of unpolished rice to polished
grain. Pb concentration was also reduced by the polishing of rice. Pb
in wheat flour appeared to be higher than that in whole grain. Compar
isons between the final edible forms of the two cereals showed that K
and Cu were higher in polished rice than in wheat flour and that such
may also be the case for Cd, whereas the reverse was the case for Ca a
nd Fe, and possibly for Pb.