CPCB explains why AQI readings in India are capped at 500

Central Pollution Control Board (CPCB) issued a clarification after several people questioned why India's AQI readings are limited to 500. "The upper limit of 500 represents the highest level of health concern. Therefore, an AQI of 500 or above indicates almost the same health risk," CPCB said. "Extrapolation of the index wouldn't alter the assigned health impact category," it added.