eng Science and Education Publishing Applied Ecology and Environmental Sciences 2328-3920 2022-08-01 10 8 498 502 10.12691/aees-10-8-1 AEES20221081 article Sumithra P 350455@msuniv.ac.in 1 Loganathan A 1 Deneshkumar V 1 Department of Statistics, Manonmaniam Sundaranar University, Abishekapatti, Tirunelveli-627012, India The rising industrial revolution, urbanization and increasing human activities are the some of the primary reasons for increasing air pollution. Increasing air pollution adversely affects human health, agricultural production, wild animals. It is also an underlying cause for climate changes and these ultimately culminate in economic losses. Analysis of air quality index (AQI) can help to make recommendations to restrict outdoor air exposure and plan for demand on the healthcare system during periods of higher pollution. This study examines the stochastic behaviour of the AQI in Chennai city. Probabilities have been computed transitions among various states of AQI. Furthermore, steady state probability and mean first passage time have been evaluated. http://pubs.sciepub.com/aees/10/8/1/aees-10-8-1.pdf Markov Chain mean first passage time transition probability matrix AQI