Health effects of indoor fluoride pollution from coal burning in China.

The combustion of high fluoride-content coal as an energy resource for heating, cooking, and food drying is a major exhaust emission source of suspended particulate matter and fluoride. High concentrations of these pollutants have been observed in indoor air of coal-burning families in some rural areas in China. Because airborne fluoride has serious toxicological properties, fluoride pollution in indoor air and the prevalence of fluorosis have been analyzed in a fluorosis area and a healthy nonfluorosis area in China and in a rural area in Japan. For human health, fluoride in indoor air has not only been directly inhaled by residents but also has been absorbed in stored food such as corn, chilies, and potatoes. In the fluorosis area in China, concentrations of urinary fluoride in the residents have been much higher than in the nonfluorosis area in China and in the rural area in Japan. In the fluorosis area, almost all elementary and junior high school students 10-15 years of age had dental fluorosis. Osteosclerosis in the skeletal fluorosis patients was very serious. Urinary deoxypyridinoline in rural residents in China was much higher than in rural residents in Japan. Data suggest that bone resorption was extremely stimulated in the residents in China and that fluoride may stimulate both bone resorption and bone formation. Because indoor fluoride from combustion of coal is easily absorbed in stored food and because food consumption is a main source of fluoride exposure, it is necessary to reduce airborne fluoride and food contamination to prevent serious fluorosis in China.

Health effects of fluoride pollution caused by coal burning.

Recently a huge amount of fluoride in coal has been released into indoor environments by the combustion of coal and fluoride pollution seems to be increasing in some rural areas in China. Combustion of coal and coal bricks is the primary source of gaseous and aerosol fluoride and these forms of fluoride can easily enter exposed food products and the human respiratory tract. Major human fluoride exposure was caused by consumption of fluoride contaminated food, such as corn, chilies and potatoes. For each diagnostic syndrome of dental fluorosis, a log-normal distribution was observed on the logarithm of urinary fluoride concentration in students in China. Urinary fluoride content was found to be a primary health indicator of the prevalence of dental fluorosis in the community. In the fluorosis areas, osteosclerosis in skeletal fluorosis patients was observed with a high prevalence. A biochemical marker of bone resorption, urinary deoxypyridinoline content was much higher in residents in China than in residents in Japan. It was suggested that bone resorption was stimulated to a greater extent in residents in China and fluoride may stimulate both bone resorption and bone formation. Renal function especially glomerular filtration rate was very sensitive to fluoride exposure. Inorganic phosphate concentrations in urine were significantly lower in the residents in fluorosis areas in China than in non-fluorosis area in China and Japan. Since airborne fluoride from the combustion of coal pollutes extensively both the living environment and food, it is necessary to reduce fluoride pollution caused by coal burning.

Effectiveness of the analysis of craniofacial morphology and pharyngeal airway morphology in the treatment of children with obstructive sleep apnoea syndrome.

OBJECTIVE: In general, no consensus has been reached regarding the diagnostic criteria for obstructive sleep apnoea syndrome (OSAS) in children and the criteria for selecting treatment are inconsistent. Therefore, the craniofacial and pharyngeal airway morphology of OSAS in children who had undergone drug therapy (non-op group) and OSAS in children who had undergone both drug therapy and surgical therapy (adenotonsillectomy) (op group) were compared. The purpose of this study was to examine the effectiveness of craniofacial morphology and pharyngeal airway morphology analysis in the treatment of children with OSAS. METHODS: The craniofacial and pharyngeal airway morphology of the control group, the non-op group and the op group were compared to examine the differences of each group. The comparison used Mann-Whitney's U test. RESULTS: A comparison between the non-op and the op groups showed significant differences in the facial axis, mandibular plane angle, ramus plane to the SN (porion and orbit) point, point Pog (pogonion) to the McNamara line, anteroposterior dysplasia indicator (APDI), D-AD1 [the distance between the posterior nasal spine (PNS) point and the nearest adenoid tissue, measured along the PNS-Ba (basion) point plane], D-AD2 (the distance between the PNS point and the nearest adenoid tissue, measured along a line from the PNS point perpendicular to the S (sella turcica)-Ba point plane), upper pharynx and soft palatal length. The op group showed significantly lower values of APDI than the non-op group, indicating that the op group showed a significant occlusion of class II, and that the mandibular bone was positioned posteriorly relative to the maxillary bone. CONCLUSIONS: The op group showed a significant posterior position and backward rotation of the mandibular bone, stenosis of the nasopharyngeal airway and an elongated soft palate compared with the non-op group, and it was speculated that there was a high probability of the necessity of surgical therapy (adenotonsillectomy) when a morphological factor played a major role as a cause of obstructive sleep apnoea. We recommend craniofacial morphology analysis and pharyngeal airway morphology analysis in the diagnosis and treatment planning of OSAS children.