A monitoring station samples air at a particular location. Its instruments report specific pollutants over defined periods; calibration, maintenance and data validation matter. One station is not a measurement of every neighbourhood or of personal exposure. Always check the original monitoring source and the units and averaging window.
Beyond PM2.5 and PM10, India's National AQI framework includes nitrogen dioxide, sulphur dioxide, carbon monoxide, ozone and ammonia. AQI is an index, not the concentration of any one gas. Pollutants may have different sources and measurement units. This Observatory does not calculate an approximate AQI by averaging pollutant values.
Weather affects how pollution accumulates and disperses. Wind can transport pollution, rain can remove some particles, and atmospheric mixing changes how emissions spread. Emissions and weather both vary by season and geography. A change in a station's recorded value alone does not identify a cause or demonstrate policy impact.
Use a station's history and accessible data table to examine recorded points, missing periods and comparable measurement windows. Do not turn gaps into zeroes or compare unlike units. For health information, follow the WHO source and the Health page; this explainer is general background, not medical advice.