Pollution and Health Risk Assessment of Perchlorate in Tea of China

High-performance liquid chromatography-tandem mass spectrometry was used to determine the contents of perchlorate in 279 tea samples in 15 provinces in the central,eastern,and western regions of China. The four-step method recommended by the US EPA was used to analyze the perchlorate contamination of tea samples in different regions for health risk assessment. The results showed that the total detection rate was 98.6%,the contents varied from ND(Not detected)to 1.6466 mg/kg,the median value was 0.1138 mg/kg,the detected perchlorate excess rates(≥ 0.75 mg/kg)was 3.9%. Regional results showed that the median value of tea in each region was 0.2006,0.1151,0.0675 mg/kg in the middle,east,and west,respectively. The perchlorate contamination of tea showed a significant middle-high-west low situation(P<0.05).The median values of each kind of tea were 0.0920 mg/kg in black tea,0.0618 mg/kg in dark tea,0.1453 mg/kg in green tea,0.1183 mg/kg in oolong tea,and 0.0920 mg/kg in white tea. According to the results of health risk assessment,the HQ value of tea perchlorate in Henan,Hubei,Hunan provinces of central region and Guangdong province of eastern region were all greater than 1,and the HQ value of tea in the western region was less than 1,which showed that the health risks of perchlorate contamination in tea in Henan,Hunan,Hubei provinces of central region and Guangdong province of eastern region should be taken seriously. Based on the results of the health risk assessment,it was suggested that the maximum residue limit(MRL)of perchlorate in tea in China could be set to 1.15 mg/kg.