Study on relationship between drinking water endemic fluorosis and urine fluorine in Linyi county, Shanxi province

Abstract

Objective To investigate the prevalence for endemic fluorosis of drinking water type and to discuss the relationship between endemic fluorosis and urinary fluorine in Linyi county, Shanxi province. Methods In 2006, three counties were selected as heavy, medium and control areas according to the distributing feature of the disease. The dental fluorosis in each spots was examined by Dean method. The levels of urinary fluorine were determined by fluorine selective ion electrode. The skeletal fluorosis of adults were examined by X-ray. Results There was evident differences of dental fluorosis and skeletal fluoresis among the heavy and the medium endemic fluorosis and control areas(X~2 = 410.945, P < 0.01 ), the prevalence of dental fluoresis in the medium area and the heavy area were 92.34% (253/274), 90.09% ( 291/323), significantly higher than in the control area[23.27% (64/275), X~2 = 274.927,268.287, all P < 0.01]. The heavy area had the highest rate of the skeletal fluorosis rate [59.75% (141/236) ], the medium area had the middle-level of the skeletal fluorosis rate[24.76%(52/210), X~2 = 183.578, P< 0.01]. Urine fluorine contents in both beavy[ (4.69 ± 0.17)mg/L] and medium areal (4.86 ± 0.13)mg/L] were higher than that in the control areas[ (1.75 ± 0.04)mg/L, H = 411.197, P< 0.01], and there was linear relevance between the different degree of skeletal fluorosis and urine fluorine contents (r = 0.508, P < 0.01). Conclusions The local fluoresis condition of Linyi county in Shanxi province was serious. The degree of skeletal fluorosis is associated with the fluoride content in urine. Key words: Fluoride poisoning; Fluorosis, dental; Osteofluorosis; Urine