Assessing respiratory morbidity through pollution status and meteorological conditions for Delhi

The study focuses on assessing the status of respiratory morbidity in Delhi over a four years period from 2000-2003. An attempt was made to investigate the role of important pollutants (SO(2), NO(2), SPM and RSPM) and various meteorological factors (temperature minimum & maximum, relative humidity at 0830 and 1730 hrs. and wind speed) in being responsible for respiratory admissions on account of COPD, asthma and emphysema. The study showed that winter months had greater exposure risk as pollutants often get trapped in the lower layers of atmosphere resulting in high concentrations. Statistical analysis revealed that two pollutants have significant positive correlation with the number of COPD cases viz., SPM (r = 0.474; p < 0.01) and RSPM (r = 0.353; p < 0.05), while a meteorological factor temperature (minimum) has a significant negative correlation (r = -0.318; p < 0.05) with COPD. Stepwise multiple regression analysis was performed for COPD as dependent variable and R(2) value of 0.33 was obtained indicating that SPM and RH(1730) were able to explain 33 percent variability in COPD. The partial correlation of SPM and RH(1730) on COPD was higher than any other combination and therefore they can be regarded as important contributing variables on COPD.