Analysis of monitoring results of drinking-water-borne endemic fluorosis in Liaoning Province from 2011 to 2016

Objective To master the prevalence of drinking-water-borne endemic fluorosis of children in the disease affected areas of Liaoning Province and to understand the effect of water improvement measures in prevention and control of fluorosis. Methods The data of 18 water improvement projects in drinking-water-borne endemic fluorosis areas of Liaoning Province from 2011 to 2016 were collected by retrospective method, and the data of dental fluorosis in children aged 8 to 12 years old were analyzed. The prevalence and detection rate of dental fluorosis in children aged 8 to 12 years old were analyzed. To compare the incidence of dental fluorosis among children from villages with qualified water fluoride and those from villages with unqualified water fluoride. Results From 2011 to 2016, in the annual survey of 18 water engineering projects in 18 monitored villages, normal operating rate was between 94.44% (17/18)-100.00% (18/18), water fluoride qualified rate was between 88.89% (16/18)-100.00% (18/18). In the monitored village, 4 941 children aged 8 to 12 were examined, and the detection rate of dental fluorosis was 9.8% (484/4 941). The dental fluorosis index was 0.19. The detection rate (14.0%, 10.7%, 10.7%, 8.7%, 6.6%, 8.1%) of dental fluorosis was decreasing year by year (χ2trend=24.3,P<0.05). The total detection rate of children's dental fluorosis in monitored villages (8.1%, 356/4 422) with normal operation of water improvement projects and qualified water fluoride was lower than that in monitored villages with excessive water fluoride (24.7%, 128/519, χ2= 145.1, P < 0.05). Conclusion After water improvement measures are implemented in drinking water fluorosis areas of Liaoning Province, the dental fluorosis of children in the affected areas is effectively controlled, but the problem of excessive fluoride in water improvement projects still exists, and the management of water improvement projects should be strengthened in the future. Key words: Drinking; Fluorosis, dental; Improvement of water engineering