Effects of atmospheric sulphur dioxide and particulate matter concentrations on emergency room admissions due to asthma in Ankara.

Recent studies have associated short-term exposure to respirable particulate matter (PM(10)) and sulphur dioxide (SO(2)) with peak flow decrements, increased symptoms of respiratory irritation, increased use of asthma medications, and increased admission and hospitalization for asthma. To further delineate the association between SO(2), PM(10) exposure and asthmatic response, we compiled daily records of asthma emergency room visits from our hospital and data of meteorological conditions, SO(2) and PM(10) concentrations in Ankara area. Weekly averages of daily counts of emergency room visits for asthma were significantly associated with average weekly SO(2) and PM(10) exposure on previous week (r= 0.328, p= 0.017 and r= 0.355, p= 0.009 respectively). Admission to emergency room for asthma count was also negatively correlated with ambient temperature (r= -0.496, p= 0.0001) and strong wind existence (X(2)= 3.930, p= 0.047) on previous days. It was also positively correlated with ambient relative humidity (r= 0.531, p= 0.0001). We observed that numbers of emergency visits due to asthma were higher in winter months, April and September. In winter and early spring period there was concordance between asthma emergency admissions with air pollutants levels. During this period ambient temperatures were low as well. There were two discordance points in monthly variation of air pollution and asthma visits. We thought that first asthma visits peak was related to allergic pollens during April and second peak was due to opening of schools and increasing of respiratory infections for this reason during September. The general pattern of our results confirms that even low levels of air pollution encountered in Ankara are linked to short-term increases in the number of people visiting emergency department for asthma.