Residue Monitoring of Propiconazole in the Rice–Crab Co-Culture Field and its Toxicity and Bioaccumulation to Eriocheir sinensis

Rice–crab co-culture is a high-benefit eco-breeding pattern that has been extensively developed in many regions of China. However, little attention has been paid to the safety of pesticides used to control rice pests in the crab–rice co-culture system. This study monitored the actual residue levels of propiconazole in water and soil of rice–crab co-culture fields and evaluated the acute toxicity, subchronic toxicity, and bioaccumulation of propiconazole to Eriocheir sinensis. We observed that the residue level of propiconazole in paddy soil was higher than that in paddy water within 42-day field monitoring. Propiconazole demonstrated a low acute toxicity (96 h-LC50 > 100 mg/L) to E. sinensis and exhibited no obvious adverse impact on the growth of E. sinensis after exposure to 500 μg/L, which was 10 times the actual residual concentration of propiconazole in the crab–rice co-culture field. The highest bioaccumulation of propiconazole was obtained from gills, followed by the hepatopancreas and meat. These results will contribute to the guidance of scientific utilization of pesticides in the crab–rice co-culture field.