Wireless Sensor Networks (WSN) consists of sensors used for sensing environmental conditions and lots of more applications in world . Air pollution may be a threat to the lifetime of humans. To control the pollution it's necessary to watch the pollutant gases in periodically. Various pollution monitoring systems using sensor network are developed, deployed and tested within the literature. Currently, researchers focus on the concept of The Next Generation Air Pollution Monitoring System  and have achieved significant breakthroughs by utilizing the advance sensing technologies, MicroElectroMechanical Systems (MEMS) and Wireless Sensor Network (WSN). Comprehensive reviews and comparisons among these three sorts of sensor networks were also performed. Last but not least, we discuss the restrictions of the prevailing works and conclude the objectives that we would like to realize in future systems. There are many statistical distributions of measurement noises, parameter test methods, and different nonparameter test methods. Which one is that the most proper solving method for a specific hypothesis testing problem may be a problem to be discussed further. Research Papaers are the summary of current state of understanding on a specific research topic. They analyze or discuss research previously published by scientist and academicians instead of reporting novel research results.