Uncontrolled coal fires are a universal coal mining and post-mining concern. Efforts to extinguish these fires are often unsuccessful and these fires can result in major catastrophes such as the abandonment of the town of Centralia Pennsylvania in the U.S. and displacement of many thousands of villagers in India. The physical threat of these fires, often a result of coal mining, is a serious issue that has taken the lives of people in the U.S., Asia, and Africa. However, an equally though more insidious issue is the long-term health impacts of the emissions of these uncontrolled coal fires. Recent studies in the Jharia region of India has shown that villagers living about one mile from active coal fires reported twice as many health concerns as villagers living about five miles away. Yet, there are many villages in this region and elsewhere where people are living in immediate proximity to these fires. Studies of the gases emitted from these fires and condensates formed from the escaping gases document the mobilization of potentially toxic gases such as benzene, xylene, toluene, methane, carbon monoxide and elements such as As, Se, Hg, F, Pb, Sb. An SEM/EDX study of a small (30mm X 20mm) piece of condensate collected from an active underground coal fire just meters from a village revealed several generations of deposition with at least 30 phases containing ammonia, B, F, Al, Si, S, Cl, Fe, Cu, Zn, As, Se, Br, Mo, Cd, I, Ba, Pb, and Bi. Clearly, more attention should be paid to this post mining catastrophe to minimize the health problems and deaths resulting from these uncontrolled coal fires.

Coal has contributed enormously to the advance of civilization by providing an abundant, inexpensive, and convenient source of energy. Concurrent with its contributions, coal has extracted a high cost in terms of environmental damage and human health impacts. Coal will remain a key component of the global energy mix for decades to come as well as a major source of global pollutants. Despite its high media profile, misconceptions about coal abound, especially with regard to its human health impacts. Coal also provides several excellent examples of how a geologic material and human health intersect in a variety of surprising ways. Unfortunately, the links between coal use and human health are distorted by a great deal of ignorance and misinformation. This paper discusses the facts and fallacies of the direct health impacts caused by coal (1, 2). There are a number of important health issues caused by coal that fall outside the scope of this review. The health impacts of particulates emitted from coal combustion have received substantial attention since the groundbreaking work of Wilson et al. (3), and through the recent discussions by Davis (4) and Freese (5). The indirect health impacts of coals through their contributions to global climate change, respirable particulates, acid rain, and acid mine drainage are also beyond the scope of this review. Greb et al. provide an excellent general overview of the environmental impacts of coal (6). The potential for health impacts caused by exposure to trace elements has received considerable attention for the past quarter of a century. The US Environmental Protection Agency conducted an extensive study of this issue and concluded (7) that, with the possible exception of mercury, there was no compelling evidence of health impacts caused by the emission of trace elements from coal-burning electric generating utilities. Nevertheless, documented examples do exist of health impacts caused by trace elements emitted by coal combustion. Bencko and Symon (8) described hearing problems in children living near a power plant burning high arsenic coal in the former Czechoslovakia. But, perhaps the most significant example of health impacts caused by trace element release from coal use occurs in Guizhou Province, southwest China, where millions of people suffer from dental and skeletal fluorosis and thousands suffer from arsenic poisoning due to mobilization of these elements by burning mineralized coals in unvented or poorly vented stoves (Figs. 1a and b).