An investigation of coal-burning-borne endemic fluorosis followed comprehensive control in Guizhou

Abstract

Objective To observe the effects of comprehensive prevention and control measures through the trend change analysis of the prevalence of dental fluorosis of children and urinary fluoride in Guizhou. Methods Three villages were selected in each county from Qianxi, Pu'an and Renhuai, in 2009, 2011 and 2013. Dental fluorosis of all children aged 8-12 were examined using the reference Diagnosis of Dental Fluorosis (WS/T 208-2011); 50 children were selected randomly from each village to detect urinary fluoride content according to the reference Determination of Fluoride in Urine-ion Selective Electrode Method (WS/T 89-1996). Results The detectable rates of dental fluorosis of children aged 8-12 from Qianxi, Pu'an and Renhuai were 53.20% (490/921), 89.97% (547/608) and 51.73% (629/1 216), respectively, in 2009, 46.68% (281/602), 63.60% (332/522) and 43.84% (530/1 209), respectively, in 2011 and 34.04% (256/752), 14.29% (80/560) and 26.97% (243/901), respectively, in 2013, and the detection rate in each county was reduced year by year (χ2 = 60.46, 674.96, 125.95, all P < 0.01). In 2009, 3 counties' urinary fluoride levels of children aged 8-12 were (1.21 ± 1.29), (0.89 ± 0.80) and (1.00 ± 0.59) mg/L, respectively, which were significantly higher than those of 2013 [(0.94 ± 0.52), (0.68 ± 0.26) and (0.87 ± 0.33) mg/L,t = 3.743, 4.778, 3.743, all P < 0.01]. Conclusions The dental fluorosis prevalence and urinary fluorine content of children aged 8-12 are falling obviously through comprehensive prevention and control measures. The target to control and eliminating the disease of endemic fluorosis is not reached. It should be continue to strengthen management after comprehensive prevention and control measures. Key words: Fluorosis; Coal; Dental, fluorosis; Urine