Pollution is certainly not the new thing in today's world. Calculating pollution in urban areas can efficiently promote better planning and encourage better use of transport which may lead to bring huge social and economic benefits. Based on the Wireless Sensor Network (WSN) technique, the authors' investigates the pollution of different areas in metropolitan cities. They design the architecture of WSN based pollution monitoring system which collects pollution range from different areas and send the collected information to server. Wireless sensors used to calculate the percentage of harmful gases present in the air which is useful to avoid different health related issues in that particular area by using data mining.