Health risk assessment of 42 pesticide residues in Tieguanyin tea from Fujian, China

The objective of this study was to evaluate the residues of 42 pesticides subject to public concern in Tieguanyin tea produced in Fujian, China. The presence of 42 pesticide residues in 90 Tieguanyin tea samples were determined. A total of 17 pesticides were detected. At least one pesticide residue was detected in 65 samples (72.2%). The detected pesticides imidacloprid, tolfenpyrad, bifenthrin, acetamiprid were found in 55.6%, 33.3%, 18.9% and 16.7% of samples, respectively. Pesticide residues in Tieguanyin tea varied significantly over the seasons and across the production regions. Based on data obtained, the health risks associated with long-term exposure to those pesticides were assessed and risks of detected pesticides were ranked. The hazard quotients (HQs) among the detected pesticides range from 5 x 10(-8)for fenpropathrin to 3 x 10(-4)for imidacloprid. The results demonstrated that despite a high occurrence of pesticide residues in Tieguanyin tea, residue levels observed could not be considered as a serious public health problem. The risk ranking scheme showed dicofol and thiacloprid were considered to pose a medium-risk. The suggestions for 17 detected pesticides used in Tieguanyin tea plantation were made, including those already banned from use in China (dicofol and methomyl), recommended for diminished use (thiacloprid and chlorpyrifos), and permitted use with considering the pre-harvest interval (13 other pesticides).