Fluoride Action Network


GOAL: To understand the characteristics of forearm and crus X-rays of residents from areas with varying concentrations of fluoride in their drinking water, providing evidence for diagnosis of osteofluorosis.

METHOD: Using quantificational epidemiological methods, a total of 15 villages from Qianan and Nonan Counties of Jilin Province were selected as the subjects of the investigations; these villages all had at least 50 years of history, complete records of drinking water fluoride levels for that period with stable levels, no industrial or coal-burning fluoride pollution, no other sources of fluoride, and no low-fluoride drinking water alternatives. Fluoride concentration was determined and the areas were divided into 11 fluoride concentration levels (from 0.5 to 7.0 mg/L), and then from each range subjects ages 16-60 that had lived in the area for at least 10 years were selected.  We considered 5 age ranges with cutoffs at 21, 31, 41, and 51, and a random selection of 10 to 15 subjects was made from each age range and the forearm and crus of was examined by x-ray. The 0.5-1.0 mg/L group were regarded as the low fluoride (control) group, and the 1.5-7.0 mg/L range was considered the high fluoride group; the two groups were compared with respect to various x-ray signs and disease detection rates.

RESULT: The x-ray examination showed  three kinds of changes: osteofluorosis, articular degeneration, and osteoporosis. Of these, articular degeneration was the most common, with the detection rates of the high fluoride group (31.55%, 153/485) higher than the low fluoride group (21.58%, 41/190), a statistically significant difference (x2=6.62,p< 0.01). Among the 675 subjects, 72 were diagnosed with osteofluorosis, with most of them occurring in the high fluoride group (x2=25.65,p< 0.01).When the fluoride concentration reaches 6.0-7.0 mg/L, the detection rate increases markedly, to 44.92% (53/118). Regardless of fluoride concentration or degree of osteofluorosis, the most prevalent x-ray sign was change to the periosteum, reaching 95.83% (69/72), articular changes were second with 79.17%, 57/72), and changes to trabecular patterns were observed least (56.94%,41/72); the differences between the three were statistically significant (x2=9.64, p<0.01). Regardless of fluoride concentration, there was degeneration of the elbow, knee, and wrist joints, the detection rate was highest for the elbow joint (17.78%, 120/675), followed by the knee (15.41%, 104/675), and wrist degeneration was observed the least (7.53%, 53/675), the differences between the three were statistically significant (x2=30.74, p<0.01). The detection rate for articular degeneration of the elbow for the high fluoride group (21.03%, 102/485) was markedly higher than the low fluoride group (9.47%, 18/190, x2=12.47, p<0.01). Of the 35 signs detectable by x-ray examination, most were found in both high and low fluoride groups; periosteal changes were rarely seen in the low fluoride group, and often seen in the high fluoride group.

CONCLUSION: The signs of osteofluorosis in detectable in x-rays are quite varied and complex, when x-rays are used for diagnosis a comprehensive analysis should be carried out based on all the various signs and an overall determination made; only then will a diagnosis be correct and reliable.