Hindawi Publishing Corporation Journal of Environmental and Public Health Volume 2009, Article ID 969764, 7 pages doi:10.1155/2009/969764 Clinical Study Child Skeletal Fluorosis from Indoor Burning of Coal in Southwestern China Xianghui Qin,1 Shouying Wang,1 Maojuan Yu,1 Lei Zhang,2 Xinhua Li,1 Zhen Zuo,1 Xiuhui Zhang,1 and Lihua Wang1 1 Department of Preventive Medicine, Guiyang Medical College, School of Public Health, Guiyang, Guizhou 550004, China 2 Oﬃce of Health Data and Research, Mississippi State Department of Health, P. O. Box 1700, Jackson, MS 39215-1700, USA Correspondence should be addressed to Maojuan Yu, maojuanyu@gmc.edu.cn Received 14 November 2008; Revised 8 March 2009; Accepted 12 August 2009 Recommended by Stuart Batterman Objectives. We assess the prevalence and pathogenic stage of skeletal ﬂuorosis among children and adolescents residing in a severe coal-burning endemic ﬂuorosis area of southwest China. Methods. We used a cross-sectional design. A total of 1,616 students aged between 7 and 16 years in Zhijin County, Guizhou, China in late 2004 were selected via a cluster sampling of all 9-year compulsory education schools to complete the study questionnaire. Any student lived in a household that burned coal, used an open-burning stove, or baked foodstuﬀs over a coal stove was deemed high-risk for skeletal ﬂuorosis. About 23% (370) of students (188 boys, 182 girls) were identiﬁed as high-risk and further examined by X-ray. Results. One-third of the 370 high-risk participants were diagnosed with skeletal ﬂuorosis. Overall prevalence of child skeletal ﬂuorosis due to indoor burning of coal was 7.5%. Children aged 12–16 years were signiﬁcantly more likely to be diagnosed with skeletal ﬂuorosis than children aged 7–11 years (OR = 1.84, 95% CI: 1.17–2.90; P = .0082). Four types of skeletal ﬂuorosis were identiﬁed: constrictive (60.7%), raritas (15.6%), mixed (16.4%), and soft (7.4%). Most diagnosed cases (91%) were mild or moderate in severity. In addition, about 97% of 370 high-risk children were identiﬁed with dental ﬂuorosis. Dental ﬂuorosis was highly correlated with skeletal ﬂuorosis in this study. Conclusions. Skeletal ﬂuorosis among children may contribute to poor health and reduced productivity when they reach adulthood. Further eﬀorts to reduce ﬂuoride exposure among children in southwestern of China where coal is burned indoors are desperately needed. Copyright © 2009 Xianghui Qin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1. Introduction Fluoride has both positive and negative eﬀects on human health. In fact, ﬂuoride has been shown to prevent dental caries mainly through ﬂuoride’s topical action. Conversely, chronic exposure to excessive amounts of ﬂuoride may cause an abnormal condition called skeletal ﬂuorosis. Overexpo- sure to environmental ﬂuoride has caused endemic ﬂuorosis to become a major public health problem in China. Endemic ﬂuorosis is prevalent in 29 provinces, municipalities, or autonomous regions in China and is associated with three types of ﬂuoride exposure: contaminated drinking water, pollution from coal burning, and tea drinking. More than 10 million people in Guizhou Province suﬀer from various forms of ﬂuorosis [1, 2]. In the southwestern province of Guizhou, endemic ﬂuorosis has been attributed to the use of ﬂuoride-rich coal as an indoor fuel source [1–6]. Coal is the main fuel used by the local inhabitants of Zhijin County. Zhijin is a mountainous area where the moist climate requires residents to burn coal stoves year round in order to dry corn, a dietary staple. Similar to other peasants in this region of China, the local inhabitants use open-burning style stoves, without adequate ventilation, to bake food or dry corn hanging over the stove. Fluoride is released from the coal and accumulates in the drying corn, signiﬁcantly increasing the amount of ﬂuoride a family member is exposed to upon consumption [7]. In 1989, Zhengand Huang hypothesized that ﬂuoride absorbed by corn dried over coal-burning stoves was the probable cause of endemic ﬂuorosis in this region [1]. Families also burn coal to heat their homes. Gaseous forms of ﬂuoride, such as hydrogen ﬂuoride (HF) or silicon tetraﬂuoride(SiF4) , and ﬂuoride dust also pollute indoor air in homes and may be inhaled directly or further concentrate in drying foodstuﬀs [8]. Average family coal consumption is