Toxicity Assessment of Different Formulations of Diazinon to Avian

The short-term risks of pesticides to avian currently are assessed by comparing the LD50 and LC50 determined from the laboratory acute oral toxicity test and dietary toxicity test. This paper assessed the toxicity of different formulations of diazinon to Japanese quail (Co-turnix japonica) and hill partridge (Arborophila brunneopectus). Firstly, a rang- finding test was conducted to determine the dosage levels of diazinon to birds in acute oral toxicity test, and then the definitive test was conducted to determine the LD50 of different birds. Duration of definitive test was 7 days, during test periods, all signs of intoxication, other abnormal behavior and mortality were recorded and reported by dosage level and byday. Based on the results oforal toxicitytest, the toxicitycategoryofdifferent fomulations of diazinon to birds was educed. In dietarytoxicitytest, Japanese quai(l Coturnixjaponica) and 50% diazinon ECwere selected todetermine the LC50.The test period was 8 days, including 5 days of exposure to 50% diazinon EC in the diet (exposure period) followed by at least 3 days of additional observation (post- ex- posure period) while the test birds are receiving an untreated diet. Mortality and abnormal behavior were recorded throughout the test period. Average body weight and food consumption per day were calculated and recorded. Finally the LC50 were determined by statistical analysis. The results showed that the LD50 of diazinon and its two formulations to Japanese quail was 4.61￣13.9 mg·kg-1 body weight, and there were significant toxicity differences between the two formulations and diazinon; while, the LD50 to hill partridge was 22.39￣31.67 mg·kg-1 body weight, and there were no significant toxicity differences between the two formulations and diazinon. 50% diazinon EC showed significantly different avian dietary toxicity to different birds, being high toxicity to Japanese quail with LC50 120 mg·kg-1 fodder and low toxicity to hill partridge with LC50 1 210 mg·kg-1 fodder. 50% diazinon EC for seed treatment and 10% particulate diazinon for dressing in the field could be harmful tobirds.