Halldin CN, et al. – Characterization was pursued of the utility of ‘other symbols’ in the radiographic features, in the National Institute for Occupational Safety and Health–administered Coal Workers’ Health Surveillance Program (CWHSP) participants. The radiographic features of importance as part of routine chest radiographic surveillance were elucidated. Though these symbols were not diagnostic they could be used to elucidate the features related to dust exposure. Emphysema was among the most commonly identified radiographic features in the study cohort. It was linked to respirable dust exposure. A comparison could be performed with other dust exposed populations.