Heavy metals in soils and crops in Vietnam

摘要

In a reconnaissance soil geochemical and plant survey undertaken to study the heavy metal distribution and uptake by major food crops in Vietnam, 400 soils were analysed for C, and As, CA, Co, Cr, Cu, Hg, Ni, Pb and Zn using reverse aqua regia digestion, together with 300 plant samples using nitric acid digestion. Regression analysis between the edible plant part and aqua regia soluble soil metal concentrations indicated a positive relationship between soil Hg in Hg in morning glory (R<'2>=0.452, P<0.002), and many others also displaying positive relationships. Principal component analysis (PCA) of soils undertaken on the geographically distinct southern, central highland and central coastal plains regions, and northern regions, showed distinct regional variation in metal concentrations in soil.