The study compared air quality in Ahmedabad, India, using two different index systems. They found that the Composite Air Quality Index (CAQI) better reflects the pollution levels in the city compared to the National Air Quality Index (NAQI). The research showed that particulate matter (PM10 and PM2.5) are the main pollutants in Ahmedabad, especially during winter. The CAQI is more effective at estimating the population's exposure to pollutants when multiple pollutants exceed safety standards at the same time.