The application of organic fertilizer could be accompanied by potential hazards to soil and humans caused by trace metals. A wide survey of organic fertilizers was carried out in northern China. A total of 117 organic fertilizer samples were collected to analyze the concentrations of seven trace metals. Simulation models were used to estimate the trace metal accumulation risk in soil and non-carcinogenic and carcinogenic risks to the human body. The concentrations of trace metals varied widely (Cr: 2.74–151.15; Ni: 2.94–49.35; Cu: 0.76–378.32; Zn: 0.50–1748.01; As: 1.54–23.96; Cd: 2.74–151.15; and Pb: 1.60–151.09 mg·kg⁻¹). Chinese organic fertilizer standard limits were exceeded by0.85% for Cr, 5.98% for As, 1.71% for Cd, and 4.27% for Pb. Monte Carlo simulations showed that repeated application of organic fertilizer likely significantly increased the concentrations of Zn, Cd, and As in soil compared with the soil background levels according to the Soil Environmental Quality Standards of China. As and Cr pose high risks to human health, especially as carcinogenic risk factors with a skin exposure pathway. Reducing the content of Cr, Cu, Zn, As, and Cd in organic fertilizer would be of great significance for minimizing the damage caused by trace metals.

Improving the rural living environment is of great significance in enhancing the life quality of rural residents and promoting rural sustainable development. The Chinese government initiated a nationwide three-year action in 2018, followed by a five-year campaign starting in 2021, to improve the rural living environment. Despite these efforts, comprehensive assessment covering multiple facets of the rural living environment at the national level remained scarce. A novel evaluation method was proposed in this study that included seven aspects and nineteen indicators, applied AHP for weighting, and PLS-SEM to analyze the relationships between variables. Then, the completion of key tasks of rural living environment improvement in 37 counties, which were incentivized by the State Council on account of its excellent governance results, was comprehensively investigated and evaluated. The assessment of key tasks in the 37 incentivized counties revealed high completion in rural household solid waste disposal, domestic sewage treatment, and toilet improvement. However, the level of the rural living environment was uneven among different regions, and the progress varied in different key tasks. The funds input had a greater impact on the comprehensive level of rural living environment than social and economic factors. Accordingly, the government should provide more targeted financial and policy support to underdeveloped areas. And priority should be given to the sewage treatment and sanitation, especially in rural and remote areas. Furthermore, local governments should diversify funding sources to ensure the sustainability of rural living environment development. These findings provide a theoretical basis for developing policies and specific plans to address the challenges of financial investment and rural living environment management in China and other developing countries and regions worldwide.