MIGRATION AND DEGRADATION OF PYRETHROID RESIDUES AMONG PERISHABLE FOODS, SOIL, AND WATER

Abstract

This dissertation focuses on the migration, accumulation, and phytotoxicity of PYs among the environmental media and mung bean sprouts (Part Ⅰ) and the detection and reduction mechanisms of PYs in seafood (Part Ⅱ). In Part Ⅰ, the double-exponential decline model and the exponential rise to maximum model were suitable to predict PY reduction and accumulation in growth media. Growing conditions influenced the accumulation patterns of PYs. Exposure to PYs at the early stage of the plant's life cycle caused phytotoxicity. In Part Ⅱ, by using the proposed analytical method, we found a negligible risk of PY exposure via seafood consumption in Singapore. Moreover, NaCl solution and the synergistic effect of frozen storage (8 weeks) and grilling significantly reduced PYs in fish. This reduction occurred through C-C bond cleavage, dehalogenation, and double bond cleavage. This dissertation provided useful information to ensure the safety of food production and consumption from PY contamination.