Provenance & quality
80 soil samples, including 40 from cropland, 11 from orchards and 29 from forests, were collected in a typical peri-urban catchment. All soil samples were collected with a stainless hand auger and stored in snap-sealed polypropylene bags. Soil samples were dried in a Christ LD freeze dryer, sieved and milled (except for pH and soil texture determination) by hand to a fine powder in a mortar and pestle. The concentrations of As, Cd, Cr, Cu, Ni, P, Pb, and lead isotope ratios, were determined with the ICP-MS (Thermo Scientific iCAP Q) in direct solution acquisition mode using a Cetac ASX-520 Auto Sampler. The concentrations of Zn, Ca and K were determined with an X-ray fluorescence (Rigaku Nex CG bentchtop XRF).