According to World Health Organisation figures, 30% of all cancer deaths, 20% of all coronary heart diseases and strokes and 80% of all chronic obstructive pulmonary disease are caused by cigarette smoking. In accordance with the recommendations of the Tobacco Free Policy Review Group Report the Irish government has introduced a smoking ban in all workplaces with the exception of prisons and psychiatric hospitals. This study measured the levels of benzene and 1,3-butadiene in air, two known carcinogens and environmental tobacco smoke (ETS) markers, in pubs both before and after the smoking ban was introduced. The results of the study have quantified the significant gross differences in pre and post ban exposure levels. The International Commission on Radiological Protection (ICRP), Human Respiratory Tract model for Radiological Protection has then been adopted to assess the amounts of these pollutants typically absorbed in the nose, throat and lungs of the workers and patrons of pubs in Ireland before and after the smoking ban. This has revealed a reduction in the average dose of benzene and 1,3-butadiene of 91% and 95% respectively for a typical three hour exposure in Irish pub.