Analysis and assessment of soil environmental quality of some farmlands in Beijing

Forty-five surface soil samples in the farmland were collected from Beijing and analyzed for the concentrations of Cu, Pb, Cd, Cr, As, Hg, HCHs, and DDTs. The results of statistical analysis indicated that, among heavy metals, the pollution of Cd is the most serious, and then followed by this order Cd > Cu > As > Pb > Cr > Hg. Except Pb and Cr, other heavy metals concentrations exceeded the background levels in the area. Only in one place, the concentration of Cd exceeded the critical value of national soil quality standard. DDTs were the main pollution of Organochlorine pesticides. The comprehensive assessment shows that the soil environmental quality of farmland in Beijing is quite clean and safe for meeting the requirement of developing metropolitan modern agriculture.