Chen Tongbin

Assessing the health risk of heavy metals in vegetables to the general population in Beijing, China

A systematic survey of As, Cd, Cr, Cu, Ni, Pb and Zn concentrations in vegetables from 416 samples (involving 100 varieties) in Beijing was carried out for assessing the potential health risk to local inhabitants. The results indicated that the metal concentrations in vegetables ranged from < 0.001 to 0.479 microg/g fresh weight (fw) (As), < 0.001 to 0.101 microg/g fw (Cd), < 0.001 to 1.04 microg/g fw (Cr), 0.024 to 8.25 microg/g fw (Cu), 0.001 to 1.689 microg/g fw (Ni), < 0.001 to 0.655 microg/g fw (Pb) and 0.01 to 25.6 microg/g fw (Zn), with average concentrations of 0.013, 0.010, 0.023, 0.51, 0.053, 0.046 and 2.55 microg/g fw, respectively. The results showed that the concentrations of As, Cr, Cu, Cd, Pb and Ni in vegetables from open-fields were all significantly higher than those grown in greenhouses. In addition, in local-produced vegetables, all HMs except Zn were significantly higher than those in provincial vegetables. The estimated daily intake (EDI) of As, Cd, Cr, Cu, Ni, Pb and Zn from vegetables was 0.080, 0.062, 0.142, 3.14, 0.327, 0.283 and 15.7 microg/(kg body weight (bw) x d) for adults, respectively. Arsenic was the major risk contributor for inhabitants since the target hazard quotient based on the weighted average concentration (THQw) of arsenic amounted to 44.3% of the total THQ (TTHQ) value according to average vegetable consumption. The TTHQ was lower than 1 for all age groups, indicating that it was still safe for the general population of Beijing to consume vegetables.

Selection of Sugar Cane Varieties with a Low Heavy Metal Accumulation Ability for the Ecological Remediation of Contaminated Farmland

Abstract: How to best use farmland contaminated with low to moderate levels of heavy metals remains a challenge in many parts of the world. Here, we screened sugar cane varieties to identify those with a low ability to accumulate heavy metals and with high tolerance. These trials were conducted in arsenic (As), lead (Pb) and Cadmium (Cd) contaminated farmland in IIuanjiang County, Guangxi Zhuang Autonomous Region, China. We tested seven varieties and found that cultivar Guiyin9 had the highest cane stem yield (187.5 t ha-1) and sugar content (27 t ha-1). The concentrations of As, Pb and Cd in the cane juice of Guiyin9 were all below the maximum limit for contaminants in food. Because Guiyin9 showed low accumulation of the heavy metals tested here and produced a high cane stem yield, this cultivar could be planted as a valuable crop in large areas of southern China contaminated with low to moderate levels of heavy metals.