Coal-combustion-related chronic fluorine toxication, a specific endemic disease occurring in China, has been causing serious health problems with teeth and bone damage in the Three Gorges region, attributed to the intake of elevated levels of fluoride emitted through domestic combustion of high-fluorine coal, often without stoves or chimneys in the house. However, a recent epidemical study found that fluorosis in coal-combustion-related endemic disease areas in the Three Gorges region was not significantly alleviated. In some specific areas, the population with symptoms of fluorosis (e.g., teeth and bone problems) showed an increasing tendency.
Our recent study found that endemic disease areas showed high cadmium (Cd) concentrations in the environment and in the urine and hair substrates of the local population. We determined high concentrations of Cd in the local black shales (77.3–212.2 ppm), domestic coals (11.5–54.5 ppm), and arable soils (1.07–59.7 ppm), showing obvious geochemical anomalies. The high Cd in the local environment also contributed to high Cd levels in the local human substrates, averaging 6.73 ppm in hair and 5.1 µg/L in urine.
The studies on the toxicological effects of F and Cd on humans demonstrated that patients suffering from F and Cd toxication had similar clinical symptoms, such as yellow macula on teeth and bone damage. However, the symptoms occurred to different extents due to diverse exposures and nutritional conditions. Therefore, we hypothesized that Cd is a hidden health killer affecting the local endemic disease of coal-combustion-related fluorosis. This hypothesis was supported by recent epidemiological findings (2003–2007) that fluorosis in coal-combustion-related endemic disease areas in the Three Gorges region was not significantly alleviated, but the size of epidemic areas tended to overspread.
Tang J, Xiao T, Wang S, Lei J, Zhang M, Gong Y, Li H, Ning Z, He L - "High cadmium concentrations in areas with endemic fluorosis: a serious hidden toxin?" Chemosphere 76(3):300-5 (2009)
https://www.sciencedirect.com/science/a ... 3509003968
The accumulation of Cd in human bodies tends to cause health problems, particularly dental and skeletal damage. However, the presence of these problems in the study area has conventionally been explained solely by fluorosis, and the contribution of Cd was not previously recognized.
In the study area, half of the urine samples had F contents within the normal range for an unexposed population, but all samples revealed Cd levels higher than those in control populations and unexposed populations.
Yan J, Zhong Z, Huang Q, Wang L, Yong K, Zhang M, Luo X, Yan W - "Study on the correlation between the detection rate of dental fluorosis and the content of chemical elements in the soil of the affected areas" Chin J Endemiol 3:303-308 (2013) PFPC Library
"The detection rate of dental fluorosis in children in Fengjie County was positively correlated with the contents of fluorine and cadmium in the surface soil..."