Evaluation of the effect of municipal waste compost in reducing lead accumulation in animal diet and organs

Background and Public concern over the effects of environmental pollutants on human health has intensified, prompting heightened scrutiny of toxic substances in human and animal diets over recent decades. This study aims to assess the impact of municipal waste compost on diminishing lead (Pb) concentrations in the diets and organs of grazing ruminants.  In a controlled greenhouse experiment, compost was incorporated into naturally Pb-contaminated soil at four concentrations: 0%, 1%, 3%, and 5% (w/w). Stipa arabica plants were cultivated over six months. Subsequently, the Pb content in soil and plants was measured using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The daily Pb intake by cattle and sheep and its accumulation in their organs were then calculated using food chain models. These findings were evaluated against EU standards for animal product quality, focusing on animal health and human food safety.  The study identified the 1% compost addition as the most effective concentration, reducing Pb intake by 65% in cows and 60% in sheep, aligning with permissible health standards. Lead accumulation in the organs followed the pattern of kidneys > liver > muscle tissue, with a 64.77% decrease observed upon compost application. The Pb levels in all tested organs were lowered to safe thresholds concerning animal health. Moreover, Pb concentrations in meat fell below the standard limits, ensuring food safety for human consumption.  Municipal waste compost, as an organic amendment, can significantly lower lead concentrations in the diets and tissues of grazing animals, ensuring levels remain within acceptable limits.