1) The document describes an IOT-based system to monitor environmental pollution using sensors for air quality, noise, temperature, humidity, and light.
2) The system uses an Arduino Uno board connected to sensors and an ESP8266 WiFi module to transmit sensor data to the cloud.
3) The sensors measure levels of carbon monoxide, noise, temperature, humidity, and light. The data is transmitted wirelessly via the ESP8266 module and stored in the cloud for monitoring on smartphones and computers.