Outcome analysis of surveillance on endemic fluorosis during thr period of 1991 to 2006 in Jilin Province / 中国地方病学杂志

ABSTRACT

Objective To unveil the changes of endemic fluorosis in order to provide the scientific basis for making countermeasure. Methods Seven villages was selected as monitoring points in Qianan County of Jilin Province where drinking water was improved or was going tobe improved. Dental fluorosis was surveyed with Dean method and for urine fluoride content was tested using fluoride ion-selective electrode analysis in 8 - 12 years old children. Clinical skeletal fluorosis was detected in all residents of aged 16 and over in the beginning of the monitor and every 3 years. X-ray films were taken in those over 16 years old at the beginning of the monitor and every 5 years. Results Detectable rate of dental fluorosis was decreased compared with before(Weizi 11.3% to 2.2%, Danzi 16.3% to 12.1%, Houqi 53.7% to 37.5%, Houju 38.6% to 33.3%), and severity was declining, for example, in Dongnanjing, rate of being moderate was dropping from 11.3% to 7.8%, severe rate from 2.8% to 0;in Houqi moderate rate from 16.7% to 0, severe rate from 1.9% to 0;in Houju, moderate rate from 1.4% to 0,severe rate from 1.4% to 0. However, detectable rate of dental fluorosis rose in Dabin from 61.7% to 70.0% and in Dongbin-donju from 52.7% to 71.1% due to increased fluorides in drinking water. Urine fluorides content in 8 - 12 years old children was decreased to normal level(1.5 mg/L) in most of monitoring spots, but in Dabin it still remained at a high level, being 4.03 and 4.57 mg/L before and after respectively. Detectable rate clinical skeletal fluorosis was between 11.1% - 25.7% among those aged 16 and over in 7 monitoring point in 1991 - 2006, however it increased year after year in Dabin (15.9%, 21.6% and 25.7% in 1991, 1993 and 1995). Positive X-ray rate for skeletal fluorosis was decreased from 54.9% to 24.0% in Dabin, from 40.7% to 23.5% in Dongbin-donju and from 28.6% to 20.4% in Dangnanjing. Conclusions Endemic fluorosis has been controlled attributed to improved drinking water and decreased fluorides content in drinking water. Combined methods are needed to decrease to the intake of fluorides to control the diseases.