This document describes an IoT-based air pollution monitoring system using Arduino. The system monitors air quality using sensors to detect harmful gases like carbon dioxide, smoke, and NOx. It displays the air quality in parts per million on an LCD screen and webpage. When air quality is poor or hazardous, it triggers an alarm. The system aims to easily monitor air pollution and provide alerts to encourage reducing pollution levels. It uses MQ135 and MQ6 sensors to accurately measure pollutants and temperature and humidity sensors.