Impact of Pollen Counts and Air Pollution Over Hospital Visits for Respiratory Illnesses in North Delhi Region

ABSTRACT

Background. Ambient aeroallergens and organic or inorganic air pollutants are known to cause asthma exacerbation and subsequent asthma-related hospital admissions. Methods. This study was carried out to study the impact of meteorological factors, air pollution, pollens over hospital visits for respiratory illness in north Delhi region from July 2014 to June 2015. Daily monitoring of pollen grains was done on the roof of the multistorey building (height up to 20m) of the Institute. Meteorological factors including temperature, relative humidity, and precipitations were recorded daily. Daily concentrations of nitric dioxide (NO2), particulate matter (PM2.5) and sulphur dioxide (SO2) were also recorded. Number of hospital visits of patients with respiratory illness were assessed in relation to air pollutants (NO2, SO2 and PM2.5) and climate change (temperature, relative humidity and rain). Results. During the study period, 113,462 pollen counts were recorded. Two highest peaks of mean pollen counts were observed in post-monsoon season (October-2014) and in the spring season (March 2015). The maximum and minimum pollen concentration was observed in the month of March 2015 (18818/m3) and August 2014 (4731/m3). Our results showed that pollen numbers significantly correlated with respiratory emergency department patient visits (P=0.037, r=0.604), and temperature and humidity (P=0.711, r=-120, and (P=0.670, r=-0.137), respectively. NO2 significantly correlated with SO2, respiratory emergency department patient visits and new respiratory OPD patients (P=0.017, r=0.670, P=0.031, r=0.622 and P=0.016, r=0.675, respectively). A statistically significant correlation between rainfall and SO2 was observed (P=0.004, r=-0.757) in the present study. Conclusion. Our study suggests that significant increase in pollen concentration and air pollutants in the ambient environment causes respiratory illness.