Acute Oral Toxicities of Three Pesticides Used in Egyptian Rice Farms to Albino Rats

The present study was carried out to determine the acute rat toxicity of three commercial pesticide formulations recommended against rice pests (i.e. Sumithion 50% EC as insecticide, Sayno 50% EC as herbicide and Fuji-one 40% EC as fungicide). All the tested formulations were administered orally to adult male and female albino rats and the median lethal doses (LD50 values) were determined after 24, 48, 72 and 96hours (hrs) post-treatment. The obtained results revealed that the oral LD50 values of aforementioned pesticide formulations on adult male and female rats were (1166.983, 1253.818), (895.698, 966.445) and (966.445, 895.698) mg/Kg body weight (b.w.) after 24 hrs, respectively. Moreover, the 48hrs oral LD50 values of the tested pesticide formulations mentioned above were (1012.383, 1081.599), (721.09, 838.617) and (721.09, 781.164) mg/Kg b.w., respectively. No rat mortality was occurred after 48hrs. Therefore, the LD50 values after 72 and 96 hrs were the same as determined at 48hrs. The obtained results indicated that the male rats were more sensitive to these toxicants than females. Also, the acute toxicities of these commercial pesticide formulations seemed to be more toxic than their reported toxicities which based on active ingredients. It was surprising that, the candidate fungicide and herbicide exhibited higher acute toxicity to rats than the Sumithion insecticide.