Annual emissions of smoke in Dublin city now are ~mparable to the total from the Greater London area, giving an air c~llution potential for serious health effects during unfavourable ~ispersion conditions. Comparisons with other cities, and the lower than expected concentrations at which health effects have been . detected, raise questions as to the accuracy of the monitoring procedures, An underestimation of smoke concentrations, perhaps by a factor of up to 2,5 may be occurring, Further concerns exist about the degree to which the shrinking monitoring network may be representative of exposure conditions. EEC mandatory daily limit values have now been breached frequently for both smoke and sulphur dioxide, Winter median values for the former have also exceeded the standard. Though adverse winters were required for these to occur in the early 1980s, more recently significant breaches have been registered in winters characterised by average dispersion conditions. This is indicative of a continuing increase in emissions to a level at which mortality increases may be anticipated under some climatic circumstances, One such episode is discussed for January 1982 during which smoke concentrations over 1800 ug/m3 were measured and excess deaths totalling 56 were reported in one hospital study. The policy options available to improve air quality are reviewed.