Pyrethroid residue concentrations and associated consumer health risks in fresh vegetables from Khon Kaen markets, Thailand

Abstract

Background: Increased concerns over the potential health impacts on consumers from widespread pyrethroid use in agriculture have necessitated the implementation of maximum residue limits (MRLs) on food products. In Thailand, while such regulations exist, their enforcement remains incomplete.  The study aims to monitor pyrethroid contamination in Khon Kaen market vegetables and evaluate the risks posed to human health. Method: A total of 100 samples representing ten different fresh vegetable types were collected from May to July 2024. Pyrethroid residues in vegetables collected from both structured and unstructured markets in Khon Kaen, Thailand, were analyzed using gas chromatography (GC) with a micro electron capture detector (μECD). Health risks for both short-term and long-term exposure were calculated by combining the detected pyrethroid residue levels with estimated dietary intake data, utilizing a relevant database. Results: Samples of Chinese kale contained the highest levels of lambda-cyhalothrin detected at 0.71 mg/kg and bifenthrin at 0.70 mg/kg. The structured markets within Muang District had a high prevalence of detectable residues from pyrethroid groups. An evaluation of the short-term (sHI) and long-term (cHQ) health risks associated with the consumption of these vegetables indicates potential health risks exceeding acceptable thresholds, particularly among children. Conclusion: This investigation reveals pyrethroid contamination in vegetables from the Khon Kaen province markets in Thailand. It is vital to reduce contamination to ensure food security as well as educate consumers about this contamination to increase their food safety. Keywords: Pyrethroids, Pesticides, Maximum Residue Limits, Vegetables, Insecticide residues, Health risk assessment