Soil Antibiotic Pollution and Ecological Risk Assessment in the Pearl River Delta Region, China

Excessive antibiotic use and their release into soils leads to alterations in soil processes, adversely affecting terrestrial organisms and presenting a serious threat to crop growth and productivity. Herein, the spatial patterns and prevalence of 22 typical antibiotics in agricultural soils throughout the Pearl River Delta area of China. In addition, the contamination characteristics and health risks were evaluated by integrating ArcGIS 10.7 spatial analysis, spearman correlation, and Risk Quotient (RQ) modeling. Antibiotics were detected in all the 240 soil samples with the total concentrations ranging from ND to 897 μg·kg⁻¹ dry weight. The concentrations of seven antibiotic classes followed the order: quinolones (21.0 μg/kg) > β-lactams (15.1 μg/kg) > tetracyclines (9.65 μg/kg) > sulfonamides (3.91 μg/kg) > macrolides (0.26 μg/kg) > chloramphenicol (0.18 μg/kg) > lincosamides (0.03 μg/kg). Among the 240 sampling sites, quinolone antibiotics had the highest average contribution rate (41.89%), followed by β-lactams (30.09%), tetracyclines (19.28%), sulfonamides (7.81%), macrolides (0.52%), and chloramphenicol (0.36%), while lincomycin had the lowest contribution rate (0.06%). Spatial distribution demonstrated a significant positive correlation with per capita livestock/poultry product consumption, while 82.5% of sampling sites exhibited medium-high ecological risk primarily linked to livestock, poultry, and aquaculture. Quinolones, β-lactams, and tetracyclines were identified as the dominant ecological risk drivers in current regions. Mitigation requires synergistic measures including regulated veterinary drug use in aquaculture, enhanced manure treatment, and pollution remediation systems. These findings provide a scientific basis for supervising antibiotic pollution in agriculture soil and improving the sustainability and health of soil in the Pearl River Delta.