Human Health Risk Assessment of Organophosphorus Pesticides in Tea Leaves Harvested from Farm Regions of Gilan Province, Iran

Abstract

Tea holds a special place in Iranian culture, ranking as the most widely consumed beverage after water. A significant portion of Iran’s domestic tea production (approximately 70%) originates from the lush landscapes of Gilan province. The Iranian Tea Research Center (ITRC) claims that Iranian tea is pesticide-free. However, there is a concern that tea farms in the foothills may be exposed to pesticide spraying from nearby citrus gardens. This study aimed to investigate the presence of the 17 organophosphorus pesticides in tea leaf samples collected from tea plantation areas in Gilan province. Sample preparation was carried out using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method, followed by the determination of pesticide concentrations using the gas chromatography (GC) method. To assess the non-carcinogenic risk associated with the consumption of black tea due to pesticide residues, we followed the guidelines provided by the United States Environmental Protection Agency (USEPA). The results were striking, revealing the presence of pesticide residues in all tested samples, raising concerns about the purity of Iranian tea. Notably, the hazard quotient (HQ) for children (<15 years old) exceeded that for adults (>15 years old). Furthermore, spring-harvested tea samples demonstrated higher HQs compared to their autumn counterparts.