Potential human exposure to systemic insecticides via alcoholic beverages: first report on Japanese sakes

Hydrophilic systemic insecticides that translocate within plant tissues have created emerging dietary exposure pathways via alcoholic beverages produced from treated crops. While such insecticides have been detected in wines and beers, their occurrence in sake, a traditional Japanese rice-based beverage, remains unexamined. This study analysed 52 sake samples from five prefectures in Japan for seven neonicotinoids and six metabolites, chlorantraniliprole, ethiprole, sulfoxaflor, and triflumezopyrim using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Risk assessments were evaluated by comparing detected concentrations with red wine data and regulatory limits, and by calculating hazard quotient (HQ) and hazard index (HI) values based on maximum daily intake (MDI) and acceptable daily intake (ADI) implemented in Japan. Systemic insecticides occurred in 88% of samples (maximum 68.2 μg/L), with dinotefuran as the most frequently detected compound. Contamination levels were comparable to Asian red wines but exceeded those reported for EU red wines, which are subject to stricter regulations. Although concentrations were below Japan's tap water limits and contributed <0.2% of Japanese ADIs (HQs, HIs < 1), 81% of samples and eight compounds exceeded EU drinking water thresholds. Given the potential cumulative and synergistic effects, strengthened regulation and monitoring of systemic insecticides in alcoholic beverages including sake are suggested.