The Occurrence and Distribution of Neonicotinoids in Sediments, Soil, and Other Environmental Media in China: A Review

Neonicotinoids (NEOs) have emerged as viable alternatives to conventional organophosphate pesticides and are widely used in agriculture, horticulture, and household applications. However, the increasing frequency and concentration of NEOs detected in water, sediments, soil, and other environmental media have raised significant concerns about their threats to ecosystems and public health globally. This review paper compiles and integrates key findings from previous studies to analyze the overall occurrence and distribution trends of NEOs in sediments, soil, and other environmental media in China from 2019 to 2024, which has updated and analyzed new data and advanced the knowledge that the previous literature disclosed. The main findings of this work were that over the past decades, NEOs have been consistently detected in sediments, soils, and other environmental media at concentrations ranging from 1 to 10 ng g−1 dw. Acetamiprid (ACE), imidacloprid (IMI), clothianidin (CLO), and thiamethoxam (THM) are the most frequently detected NEOs in sediments and soil. It was found from this work that the threshold concentration of NEOs in soil is very limited, and there are no official acceptable toxic levels of NEOs in soil/water/sediments. Only few countries have conducted the work, at the initial phase, on regulating NEOs and have established their regulatory threshold levels. The associated ecological risks and levels of human exposure in soil have been evaluated, revealing that imidacloprid and thiamethoxam present higher risks for long-term environmental contamination due to their relatively higher concentrations. In contrast, acetamiprid, clothianidin, dinotefuran, and thiacloprid exhibited lower environmental persistence, potentially posing lower ecological risks. These trends imply the need for more focused monitoring and regulatory efforts for compounds like imidacloprid, which exhibit higher concentrations in environmental media. Despite these findings, the contamination of NEOs in sediments and soils is still considered to receive insufficient attention, particularly in northern and western China. Furthermore, the presence of NEOs in other environmental media, including indoor dust, wheat grains, vegetables, and teas, warrants further investigation and concern.