The Interaction Of Fluoride And Cadmium In Agricultural Soil-crop Systems And Health Risk Assessment In Baiyin Urban Region

Baiyin city is a non-ferrous metal smelting base in northwest China.The untreatedindustrial sewage and domestic wastewater had been dumped into Dongdagou and Xidagou streams and used for irrigation water for farmland by the local resident.Thus,the agricultural soil and crops had accumulated large amoumts of F and heavy metals.The interaction of F and Cd in agricultural soil-crop systems may affect their accumulation in crops and fractionation distribution in soil,and then negatively affect human health.The pot-culture experiment and field survey were conducted to measure the concentrations of F and Cd in the different part of crops and soil.In addition,the changes of the fractionation distribution of F and Cd in soil were discussed under the stresses of single F/Cd or F-Cd.In order to identify the potential health risk regarding F and Cd contamination in soil and crops,the health risk assessment based on F and Cd contamination in soil and grains was measured.This reseaech may serve as a basic understanding for the interaction of F and Cd in soil-crop systems and provide a suggestion for environmental management.The main results in this research as the follows:?1?The wastewater irrigation since 1950s had led to soil F and heavy metals contamination,and the contaminated soil may have potential noncarcinogenic and carcinogenic effects on the local resident.Further,the wastewater irrigation may also result in the decreases of soil pH,Fe,Mg,and CaCO₃.?2?Wheat and maize grains were contaminated by F and Cd,and wheat grains contamination may lead to a high noncarcinogenic health risk for the local resident.?3?Soil F application increased the contents of Cd in exchangeable,carbonate and Fe-Mn oxyhydroxides fractions,which increased Cd accumulation in oilseed rape.?4?Soil Cd application decreased the content of F in water soluble fraction,which suppressed F accumulation in oilseed rape.?5?F and heavy metals more easily accumulated in the roots and leaves of wheat plant,and in the roots,leaves and stalk3 of maize plant.Additionally,the aboveground parts of wheat and maize plants should not be used for feed purpose for some livestock.