Objective: To investigate the current prevalent status of endemic fluorosis in the floodplain area of the lower Yellow River in Shandong province.
Methods: According to "The National Technical Scheme for Endemic Disease Control in 2008", 16 counties were chosen to carry out the epidemiological survey of endemic fluorosis. Three villages were chosen in each county, to determine the fluoride content of drinking water and to check the dental fluorosis of children aged 8 to 12 year old, the skeletal fluorosis of adults over 16 years of age. Both children and adults were tested for urine fluoride. The content of fluoride in drinking water and urine was determined by F-ion selective electrode while dental fluorosis of children aged 8 to 12 years old was diagnosed by Dean's method and adults skeletal fluorosis by the National Standard for "Diagnosis of endemic skeletal fluorosis" (WS 192-2008).
Results: The investigation was taken place in 26 'improved-water-quality' villages in 16 counties, among which 19 villages had water fluoride content ≤ 1.00 mg/L and accounted for 73.08% (19/26), 7 villages had water fluoride content > 1.00 mg/L and accounted for 26.92% (7/26), with the highest water fluoride content as 3.73 mg/L. In 22 'yet to improve-water quality' villages in 16 counties, 5 villages had water fluoride content ≤ 1.00 mg/L (accounted for 22.73%), 17 villages had water fluoride content > 1.00 mg/L (accounted for 77.27%), with the highest water fluoride content as 3.38 mg/L. The overall rate of dental fluorosis among children aged 8 to 12 years old was 52.18% (1042/1997), with the index of dental fluorosis as 1.17 and the rate of dental damage as 8.01% (160/1997). The urinary fluoride values above 1.40 mg/L were found in 65.00% (845/1300) of children aged 8 to 12 years old, with the highest urinary fluoride concentrations as 18.53 mg/L. The rate of skeletal fluorosis by clinic and X-rays in adults older than 16 years old were 4.35% (1121/25 781) and 11.36% (5/44), respectively. The urinary fluoride values above 1.60 mg/L were found as 63.92% (606/948) in adults older than 16 years old, with the highest urinary fluoride concentrations as 21.35 mg/L.
Conclusion: The status of endemic fluorosis had not been effectively controlled and the situation for endemic fluorosis control was still critical in the floodplain area of the lower Yellow River in Shandong province, suggesting that the preventive approaches on endemic fluorosis control should be strengthened.