Heavy Metal(loid)s Accumulation and Human Health Risk Assessment in Wheat After Long-Term Application of Various Urban and Rural Organic Fertilizers

Abstract

Composting urban and rural wastes into organic fertilizers for land application is considered the best way to dispose of and recycle waste resources. However, there are some concerns about the long-term effects of applying various organic fertilizers on environment and health risks derived from heavy metal(loid)s (HMs). A 15-year field experiment was conducted to evaluate the effects of continuous application of chicken manure compost (CM), sewage sludge compost (SSC), and domestic waste compost (DWC) for wheat on the accumulation, transfer, and health risks of HMs. The results revealed that, compared with control, continuous application of CM raised the concentrations of cadmium (Cd), chromium (Cr), copper (Cu), and zinc (Zn) in topsoil; SSC facilitated Cd, Cr, Mercury (Hg), arsenic (As), Cu, and Zn accumulation; and DWC elevated the levels of Cd, Cr, Hg, lead (Pb), and Zn. The HMs concentrations in wheat grain were almost unaffected by the application of the organic fertilizers except for Hg and Pb concentrations. However, the HMs concentrations in both soil and wheat grain remained far below the limits of regulation in China. The long-term application of organic fertilizers did not cause additional noncarcinogenic and carcinogenic risks.

Keywords: Heavy Metals, Human Health Risk, Wheat consumption, soil pollution, Urban and rural organic fertilizers