Residues, Drivers, and Health Implications of Herbicides in Typical Black Soil Regions of China: Soil-Crop System Linkage and Targeted Human Risk.

Abstract

The widespread use of herbicides is essential for weed control and crop productivity but has led to the accumulation of residues in soil and crops, posing potential risks to ecosystems and human health. This study systematically investigated herbicide residues in croplands of China's typical black soil regions, focusing on the soil-crop-human health continuum. Through regional-scale, multi-media surveys, 54 herbicides (including degradants) were detected in soil and 21 herbicides (including degradants) in crop grains, with the mean concentrations of 257 μg kg-1 and 1.54 μg kg-1, respectively. Soil properties and crop types significantly influenced herbicide residue levels and patterns. Ecological risk assessments revealed that eight herbicides posed high ecological risks (RQ>1), while six herbicides exhibited bioaccumulation potential (BCF>1) between soil and crop grains. Human health risk assessment further indicated non-negligible non-carcinogenic risks associated with fomesafen residues in rice grains for both adults and children (NCR>1×10-4), suggesting that long-term consumption of rice may lead to adverse non-cancer health effects. Based on these findings, integrated risk management strategies were proposed to mitigate herbicide residue hazards in soils and crops, ensuring the safe and sustainable use of black soils and protection of public health. This research highlights the need for targeted mitigation and management measures to reduce herbicide inputs and minimize ecological and human health risks in intensive agricultural systems. The results provide critical baseline data and scientific insights for the risk management of herbicide residues in black soil agricultural ecosystems, and also offer a reference framework for balancing agricultural productivity and environmental and human health protection in intensive agricultural production regions worldwide.