X-rays changes of forearm and shank of residents from areas with different fluoride contents in drinking water in Jilin province / 中国地方病学杂志

ABSTRACT

Objective To understand common X-ray signs of bone and joint of forearm and shank,in order to provide a basis for diagnosis of skeletal fluorosis.Methods A total of 15 villages which were built for more than 50 years in Nongan and Qianan counties of Jilin province were selected and surveyed by quantitative epidemiological methods.These villages had no industrial and coal-burning-borne fluorine pollution; no other high fluoride sources; had not yet changed to low-fluoride drinking water,and had complete and stable historic data of fluoride content in drinking water.Drinking water fluoride content was determined.Inhabitants lived in the local for more than 10 years,between the age of 16-60 were chosen from the villages based on the 11 levels of fluoride content of drinking water from 0.5-7.0 mg/L and these people were divided into 5 age groups16-,21-,31-,41-,51 to 60.In each age group,10-15 individuals were taken by stratified random sampling to do the forearm and shank joint X-ray examination.Drinking water fluoride content between 0.5-1.0 mg/L acted as the low fluoride group(control group),1.5-7.0 mg/L as the high fluoride group and various X-ray findings and the detection rate were observed.Results Three X-ray signs of skeletal fluorosis,joint degenerative change and osteoporosis were observed.Thereinto,joint degenerative change was the most common.In the high fluoride group(31.55％,153/485),the detection rate of joint degenerative change was higher than that of the low fluoride group (21.58％,41/190) and the difference was statistically significant (x2 =6.62,P ＜ 0.05).Seventy two of 675 peoples used by X-ray were detected with skeletal fluorosis,which occurred mainly in the higher intake of high fluoride group (x2 =25.65,P ＜ 0.01).When water fluoride was up to 6.0-7.0 mg/L,the detection rate of endemic skeletal fluorosis was increased to 44.92％(53/118).Regardless of higher or lower of water fluoride and mild or more serious of the state of fluorosis,changes of X-ray signs of bone surroundings happened first; on average with a detection rate of 95.83％ (69/72),the joint change followed by 79.17％ (57/72) and bone substance change the least at 56.94％(41/72),and the difference was statistically significant (x2=9.64,P ＜ 0.01).Regardless of water fluoride high and low,joint of elbow knee and wrist underwent degenerative change.Degenerative change of elbow joint happened first with a detection rate of 17.78％ (120/675),knee joint followed by 15.41％ (104/675),and wrist joint was the least at 7.85％ (53/675).The difference was statistically significant (x2 =30.74,P ＜ 0.01).Elbow degeneration detection rate(21.03％,102/485) in high fluoride group was significantly higher than that of the low fluoride group(9.47％,18/190; x2=12.47,P ＜ 0.01).X-ray examination showed 35 kinds of signs; most signs could be seen in the high fluoride and the low fluoride groups.But the changes of bone around were seen more often in higher fluoride content group than in lower fluoride content group.Conclusions X-ray signs of endemic skeletal fluorosis are complex and diverse.Only after comprehensive analysis,the diagnostic results are accurate and reliable.