Air pollution and hospital admissions for chronic obstructive pulmonary disease in Novi Sad

Abstract

Introduction: The study was aimed at establishing the association between the number of daily hospital admissions for chronic obstructive pulmonary disease and daily concentrations of air pollutants in the city of Novi Sad during 2007 - 2009. Material and methods: The research data were based on the daily concentrations of sulfur dioxide (SO 2) and nitrogen dioxide (NO 2) measured in 24h air samples and the daily number of hospital admissions of adults (>18 years of age) for chronic obstructive pulmonary disease (ICD10:J44) on the territory of the city of Novi Sad during the observed period. The applied generalized linear model according to the Poisson regression type included the days of week, month of year, season, mean daily temperature and the relative humidity of air as controlled variables in addition to daily hospital admissions (a dependant variable) and sulfur dioxide and nitrogen dioxide concentrations as independent variables. The final statistical model chosen according to the Akaike criteria was also tested with respect to the different lag structure of air pollutants and meteorological parameters. Results: No statistically significant association was found between the daily number of hospital admissions for chronic obstructive pulmonary disease (n=1001) and daily concentrations of sulfur dioxide and nitrogen dioxide (p>0.05). A statistically significant increase in the daily number of hospital admissions for chronic obstructive pulmonary disease was repeatedly observed after weekends, i.e. on Mondays (OR=2.301; 95% CI:1.813-2.920). With respect to monthly variations, it was found that the risk of increased number of daily hospital admissions for chronic obstructive pulmonary disease was statistically significantly higher (p<0.01) during February (OR=1.695; 95% CI: 1.282-2.242), March (OR=1.612; 95% CI:1.210- 2.149), April (OR=1.703; 95% CI:1.247-2.326) and May (OR=1.809; 95% CI:1.350-2.424) compared to January. According to the applied regression model along with the control of meteorological factors, it was found that each increase in the relative air humidity by 10% on the territory of the city of Novi Sad was statistically significantly associated with the increased number of the hospital admissions for chronic obstructive pulmonary disease by 0.6% (OR=1.006; 95% CI:1.000- 1.011) at lag of three days. Conclusion: The association of the number of hospital admissions of adults for chronic obstructive pulmonary disease was not statistically significant with respect to the determined air quality; however, it was statistically significant with respect to the air humidity, workdays and months of the year.