Investigation on fluoride content of brick tea

Abstract

Objective \nTo understand the status of fluoride content in brick tea (pressed tea) in China, and conduct health risk assessment according to the situation of drinking brick tea in fluorosis areas. \n \n \nMethods \nTwenty national designated brick tea manufacturers were selected to collect 1 - 5 varieties of brick tea samples of mainstream varieties with large production volume and large sales volume. If low-fluoride brick tea was produced, an additional sample would be collected to determine the fluoride content of tea. The retrospective analysis method was used to collect the monitoring data of brick tea-type fluorosis in the whole country in 2017, and analyze the use of brick tea in the residents of the brick tea-type fluorosis areas in six provinces (regions) of Inner Mongolia, Sichuan, Gansu, Ningxia, Xinjiang and Qinghai. According to the fluoride content of brick tea, combined with daily average consumption data of brick tea in the brick tea-type fluorosis areas, daily average brick tea intake, and hazard quotient of the daily average brick tea fluoride and the standard recommended fluoride intake were calculated. A health risk assessment was conducted based on the hazard quotient (hazard quotient > 1 indicated a health risk). Through the total fluoride intake standard of the Chinese population, the safe consumption of brick tea with different fluoride content was simulated by using the value of the hazard quotient. The tea fluoride was measured by an ion selective electrode method. \n \n \nResults \nA total of 54 samples were collected, of which 49 were brick tea samples and 5 were low-fluoride brick tea samples. The geometric mean of the fluoride content of 49 brick tea samples was 460 mg/kg, the median was 430 mg/kg, and the range was 102 - 1 797 mg/kg. There were 14 samples with a fluoride content < 300 mg/kg, accounting for 28.6%. The average fluoride content of 5 low-fluoride brick teasampleswas 193 mg/kg, ranging from 102 to 290 mg/kg. Forty-nine brick tea samples were distributed in 5 provinces, the fluoride content of brick tea was the lowest in Yunnan, 128 mg/kg; the highest in Hubei, 712 mg/kg. The lowest fluoride content of brick tea in different varieties was Tuo tea, 130 mg/kg, and the highest was Jinjian tea, 745 mg/kg. There were 1 000 households drinking brick tea in the brick tea-type fluorosis areas in 6 provinces, 73.9% (739/1 000) of households drinking the products of the national assigned brick tea manufacturers; a total of 1 000 brick tea samples were collected, and the geometric mean of brick tea fluoride content was 551 mg/kg, and only 17.5% (175/1 000) of brick tea had a fluoride content < 300 mg/kg. Compared with the national standards and the standards of World Health Organization, hazard quotient of agriculture, animal husbandry, semi-pastoral industry, urban residents through the brick tea fluoride was 0.34, 1.38, 0.75, and 0.21, respectively; 0.29, 1.21, 0.66, and 0.19, respectively. Animal husbandry hada health risk through drinking brick tea among them. According to the health standard of total fluoride intake in China, when drinking brick tea with fluoride contents of 300, 430, 460 and 500 mg/kg, the safe consumption of brick tea for school-age children was 2.9, 2.0, 1.9 and 1.8 kg, respectively, and for adult was 4.3, 3.0, 2.8 and 2.6 kg, respectively. \n \n \nConclusions \nBrick tea has high fluoride content, and percent of qualified brick tea is low and few of low-fluoride brick tea are consumed. There is a health risk in the animal husbandry who has a large amount of brick tea. \n \n \nKey words: \nBrick tea;\xa0Fluoride;\xa0Fluorosis;\xa0Health risk assessment