Abstract
Neonicotinoids and fipronil are globally used insecticides for agriculture including rice farms. To reduce the cost of production, most laying duck farms in Thailand are free grazing systems and these ducks are commonly raised on paddy fields. Free grazing ducks are extensively related to paddy field environments. However, the information on levels of these insecticides in paddy fields linked to residues in ducks and eggs are still lacking in Thailand. Therefore, the objectives and methods in this preliminary study are as follows; (1) to evaluate the accumulation levels of neonicotinoids, fipronil, and their metabolites in paddy fields and residues in ducks and egg ducks, these substances and their metabolites in soil, rice, eggs and blood of ducks will be extracted and analyzed using a liquid chromatography with tandem mass spectrometry (LC-MS/MS). (2) To estimate the exposure and potential toxicity of these pesticides for egg duck consumption in humans, the estimated daily intake of these chemicals will be calculated and compared to the international reference levels. In addition, (3) to investigate the metabolism capacity of neonicotinoids and fipronils in ducks, the in vitro biotransformation will be conducted using duck liver microsome containing cytochrome P450 enzyme. The results of this study will effectively provide the information on environmental levels and metabolic capacity of these insecticides in ducks that might relate to our understanding of the potential toxicological effects in humans and other avian.
