Cortes-Ramirez J, et al. - Researchers identified the International Classification of Diseases (ICD) codes found in studies of morbidity and/or mortality in populations resident or in proximity of coal mining. They also carried out a systematic review to evaluate the methods of these studies. The analysis included twenty-eight epidemiological studies with ecological design from the USA, Europe and China. In populations resident or in proximity of the mining activities, the link between coal mining and a wide spectrum of diseases, particularly cancer and congenital anomalies, was consistently evident. To provide further evidence of the exposure pathways, integration of other research methods such as individual-level and longitudinal studies was considered valid as the studies that have investigated these links were designed to measure exposures at the group level.