[Speciation Characteristics and Bioavailability of Heavy Metals in Oasis Soil Under Pb, Zn Combined Stress].

Pot experiments were conducted on cole (Brassica) grown in oasis soil under combined stress of lead and zinc, to study the effect of heavy metal combined pollution on cole growth as well as the speciation conversion rules and bioavailability. The result showed that the promoting effect on cole growth was shown in the low concentration treatments, especially on stem leaves. With addition of exotic heavy metals, the main speciations of Pb and Zn in the soil transformed from tight-bound to loose-bound forms as compared to the control, and the bioavailability of heavy metals was increased.

[Uptake effect of Cd and Pb by rape under single Cd/Pb and Cd-Pb combined stress].

This paper investigated the effects of single Cd/Pb and Cd-Pb combined pollution of desert grey soils from the oasis regions on the uptake and translocation of Cd and Pb by rape (Brassica campestris L.), and analyzed the interaction between Cd and Pb. The results of pot experiment showed that the concentration of Cd or Pb was promoted when the concentration of Cd in soil was less than 7.

Accumulation and distribution of cadmium and lead in wheat (Triticum aestivum L.) grown in contaminated soils from the oasis, north-west China.

Background: Crops grown in soils contaminated by heavy metals are an important avenue for toxic metals entering the human food chain. The objectives of our study were to investigate the accumulation and distribution of cadmium (Cd) and lead (Pb) in wheat plants cultivated in arid soils spiked with different doses of heavy metal, as well as bioavailability of these metals in the contaminated arid soils from the oasis, north-west China.

Results: The concentrations of Cd in the roots of wheat plants were about 5, 14 and 8 times higher than those in the shoots, shells and grains, respectively.