Analysis of monitoring results of drinking-water fluorosis in Jiangsu Province from 2011 to 2015

Objective To understand the drinking water type fluorosis in Jiangsu Province, dynamically monitor the disease trends, and to evaluate the operation effect of the water project comprehensively. Methods Twenty-six fluorosis districts and counties in Xuzhou, Lianyungang, Suqian, Huaian and Yancheng were selected as the monitoring sites. The change of water improvement engineering and the value of water fluoride were surveyed and tested. There were three different situations of changed water: the water improvement engineering operated normally was the first, the water improvement engineering operated abnormally or water fluorine excesses the standard was the second, and without water improvement was the last. The teeth of children aged 8 to 12 years were checked according to the method of Dean. The skeletal fluorosis of adults was checked according to "Diagnostic Criteria of Endemic Skeletal Fluorosis" (WS 192-2008) by X-ray inspection. Results The normal operation rates of changed water project from 2011 to 2015 were 100.00% (30/30), 85.29% (29/34), 82.50% (33/40), 95.92% (47/49), and 97.83% (45/46), and the excessive rates of water fluorosis for normal operating engineering were 13.33% (4/30), 17.24% (5/29),9.09% (3/33), 14.89% (7/47), and 11.11% (5/45). The dental fluorosis detection rates of children aged 8 to 12 years were 33.68% (194/576), 28.30% (711/2 512), 36.25% (1 577/4 350), 22.06% (837/3 794), and 20.44% (903/4 417) from 2011 to 2015, the differences were statistically significant (χ2= 190.952, P 0.0125). The X-ray detection rates of skeletal fluorosis in adults from 2011-2015 were 17.83% (51/286), 16.61% (49/295), 15.36% (51/332), 10.95% (53/484), and 5.16% (16/310); urinary fluoride range was 0.02-22.0 mg/L; the geometric average was 0.67-4.06 mg/L, there was no statistical significant difference of skeletal fluorosis distribution annually (χ2= 6.060, P > 0.05). Conclusion The general condition of drinking water type fluorosis in Jiangsu Province from 2011 to 2015 is gradually under control, but the engineering operation and water quality improvement still need to be improved; water change project not functioning or with excess fluorine is more harmful to children's teeth. Key words: Drinking water; Fluorosis, Dental; Water-improving project; Trend analysis