Respiratory Health Effects of Air Pollution in Delhi and its Neighboring Areas, India

In this paper we examine the overall effects of a series of new air quality regulations that have differentially affected air quality in Delhi relative to its outlying areas. Air pollution data, collected at 113 sites (spread across Delhi and its neighboring areas) from July-December 2003, were used to compute localized measures of air pollution within and outside the boundaries of data. In addition a socio-economic and respiratory health survey was administered in 1576 households. This survey collected time use, residence histories, demographic information and direct measures of lung function with 3989 subjects. Geographic information systems were used to link air pollution and respiratory health data. Using resident histories in combination with secondary data to impute cumulative exposure prior to the interventions, the effects of recent air quality measures on lung function were then evaluated. The analysis suggests that the interventions results in a significant improvement in respiratory health. As might be expected, effects are the strongest among those individuals who spend a disproportionate share of their time out of doors.