Polycyclic aromatic hydrocarbons (PAH) are produced by many industrial processes and, according to many studies, the highest exposure levels have been measured in coking plants and foundries. One of the aims of this investigation is to determine whether or not the use of carbon stable isotopic analysis could aid in the identification of the source of PAHs, by the monitoring of these compounds derived from a wide range of coals of different origins.Research Council for Coal and Steel Project REDPAH (RFCS-CT-2005-00005).Peer reviewed