An investigation on current situation of coal-burning type endemic fluorosis control and prevention in Ludian County of Yunnan Province / 中华地方病学杂志

ABSTRACT

Objective To investigate the status of coal-burning type endemic fluorosis in Ludian County of Yunnan Province,to evaluate the prevention and control effect.Methods Multi-stage sampling was adopted in 2016.Five townships from Ludian endemic fluorosis areas and 2 villages of each township were randomly selected.The condition (children's dental fluorosis,urinary fluoride,adult skeletal fluorosis),epidemic factors (use of stoves,fluoride content of main household foods,indoor air fluoride content),health education awareness of endemic fluorosis were investigated in the above mentioned villages.Results The dental fluorosis positive rate of children aged 8-12 was 10.14％ (51/503) while a total of 503 children were investigated,the index of dental fluorosis was 0.16,and adult skeletal fluorosis detection rate was 1.92％ (2/104) while a total of 104 adults were investigated.The geometric mean of urinary fluoride content of children was 0.39 mg/L,ranging from 0.02 to 2.54 mg/L.Totally 98,161,and 151 samples of pepper,rice,and corn were detected.The medians of fluoride content were 0.96,0.42,and 0.43 mg/kg,respectively,ranging from 0.26 to 13.46,0.13 to 2.20,and 0.21 to 2.54 mg/kg,respectively,in which the fluorine contents of pepper 48.98％ (48/98) was higher than 1.0 mg/kg.The correct drying rates of both corn and pepper were 100.00％ (201/201),and the correct preservation rates of corn and pepper was 99.50％ (200/201) and 100.00％ (201/201),respectively.The use rate of improved stove,rate of intact stove,correct use rate of intact stove were 100.00％ (201/201),96.02％ (193/201) and 100.00％ (193/193),respectively.The fluoride contents in the indoor air of the families (the fire period was 0.32 μg/m3 and the fire extinguishing period was 1.22 μg/m3) from the areas of fluorosis which had properly used the improved stoves were lower than that of the national hygienic limit content (the one-hour average concentration limit is 20 μg/m3).The knowledge of prevention and control of coal-burning type fluorosis among fifth-grade primary school students and household heads was investigated in 104 and 201 people,respectively,with the awareness rates of 80.77％ (252/312) and 86.23％ (520/603),respectively.Conclusion By implementing the comprehensive prevention and control measures,which mainly focus on the improvement of the stove and the health education,the coal-burning fluorosis in Ludian County has been effectively controlled,and the prevention and control work has achieved remarkable results.