ABSTRACT
Objective To explore the effect of open storage and peeling on the fluorine content of dried com in order to provide a scientific basis for prevention and treatment of coal-combustion fluorosis. Methods In October 2006, 34 samples of freshly dried and 3-month old dried com were sampled in Zhenxiong county, Zhaotong city, Yunnan province. Fluorine content in corn was determined by combustion-hydrolysis-ion selective electrode method. Results The average fluorine content of freshly dried corn by coal-combustion was (4.29 ±1.87)mg/kg,and increased to (6.64±2.64)mg/kg after they had been openly stored for three months and the average content increased by 54.74%. But if corn was peeled off, their fluorine content decreased to (5.03±2.04)mg/kg at a rate of 24.25%. The amount of fluorine absorbed by the skin of corn was more than other parts of com during corn desiccation. Conclusions The inhabitants in coal-combustion fluorosis areas ingest less fluorine through dry com if they eat the peeled corn and take measures to keep it airtight and moisture-proof during storage thus reducing the harm of coal-combustion fluorosis.
ABSTRACT
Objective To assess the fluorine (F), arsenic (As) and selenium (Se) levels in hair of residents from the fluorosis area of Zhaotong and provide reference basis for the evaluation of the health status of populations in fluorosis areas as well as the prevention and control of fluorosis in Zhaotong. Methods Sixty-five hair samples were collected in fluorosis areas(Zhenxiong, Weixin County), including. 41 samples from 6 endemic townships and 24 samples from a non-endemic township. Fluorine content in hair was determined by combustion- hydrolysis-ion selective electrode method. Arsenic and selenium contents in hair were determined by atom- fluorescence method. Results The average contents of hair fluorine, arsenic and selenium contents were (15.1807±15.2397), (2.1806±1.9601), (2.3162±2.4535)mg/kg in the 41 patients with fluorosis and were (18.7703±17.1067), 0.3283±0.2466), (1.2805±0.6970) mg/kg in the 24 inhabitants (control). The difference of fluorine content in hair between patients in fluorosis and control inhabitants was not statistically significant (P 0.05), but the difference in arsenic and selenium content was statistically significant (P<0.05). Conclusions Mild arsenic pollution exists in Zhaotong fluorosis areas, which aggravates the prevalence of fluorosis. Food roasted with blended coal contains high fluorine. Meanwhile it may bring in the supplement of selenium for the inhabitants in Zhaotong fluorosis areas.