title: Brick tea fluoride as a main source of adult fluorosis.
abstract: An epidemiological survey was conducted in Naqu County, Tibet in September 2001 to investigate the manifestations of fluorosis in adults caused by the habitual consumption of brick tea. Profiles were obtained for the total daily fluoride intake, environmental fluoride levels and average urinary fluoride concentration, and a physical examination and a skeletal radiographic study were conducted. One hundred and eleven 30-78-year-old adults were enrolled. It was found that the fluoride level of water sources in Naqu County was 0.10+/-0.03 mg/l; no evidence of fluoride air pollution was found, but the brick tea water processed foods--zamba and buttered tea--had fluoride contents of 4.52+/-0.74 mg/kg and 3.21+/-0.65 mg/l, respectively. The adult daily fluoride intake reached 12 mg, of which 99% originated from the brick tea-containing foods. The positive rate of clinical symptoms by physical examination was 89%; furthermore, 42 of the 111 subjects were diagnosed by X-ray. The positive examination rate was 83%. Although the osteosclerosis-type skeletal fluorosis (overall increased bone matrix density) affected 74%, arthropathy and arthritis affected a significant number of the patients, resulting in functional disability. The results suggest that this brick tea-type fluorosis had even more severe adverse effects on human health compared with both the water-type and coal combustion-type fluorosis that occurred in other areas of China.
authors.affiliation: Tea and Health Laboratory, Xiangya School of Medical Sciences, Central South University, Changsha 410078, Hunan, PR China. caojin@public.cs.hn.cn
authors.forename: Jin
authors.initials: J
authors.lastname: Cao
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jianwei
authors.initials: J
authors.lastname: Liu
authors.forename: Ruoden
authors.initials: R
authors.lastname: Xirao
authors.forename: Sangbu
authors.initials: S
authors.lastname: Danzeng
authors.forename: Dawei
authors.initials: D
authors.lastname: Daji
authors.forename: Yu
authors.initials: Y
authors.lastname: Yan
mesh_terms: D000328:Adult; D000368:Aged; D001847:Bone Diseases / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000453:epidemiology; D002681:China / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D005459:Fluorides / Q000008:administration & dosage / Q000032:analysis / Q000652:urine; D009050:Fluorosis, Dental / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D013662:Tea / Q000009:adverse effects* / Q000737:chemistry; D018609:Tibet / Q000453:epidemiology
chemical_list: D013662:Tea; D005459:Fluorides