ABSTRACT Air quality monitoring program was conducted for three years in transit of South Bangladesh called Bhandaria Upazila (Location: Nadmulla area) under Pirojpur district. The research was continued in the years 2019, 2020 & 2021. The air quality was measured in respect of CO, SO2, NOx and PM concentration in that particular area using Gas Analyzers (model: Handheld 3016). The wind direction of those sites was also monitored during monitoring the greenhouse gases emission. Finally, the analyzed data was combined, presented as a table and to add in the manuscript. The analytical results on concentration of GHGs (CO, SO2, NOx, PM10 and PM2.5) explored that the CO concentrations gradually decreased within the study period. The estimated AQI values of CO were below 50, which confirmed the green condition in respect of ambient air quality standards for Bangladesh, WHO guideline and US standard. The NOx concentrations were within the limit of 19-45.00 µg/m3 which also confirmed the green state. The conc. of SO2 was similar (<10.00 µg/m3) within the study period, which proved the pertaining the minimum sources for SO2 emission in the study area. The concentrations of PM10 has exceeded the green level and reached 85.00µg/m3, though the concentration of PM2.5 is being decreased but still the AQI values also exceeded the green level.

Key words: Greenhouse gases, measurements, coastal area, Pirojpr district

Introduction Rising atmospheric concentrations of greenhouse gases (GHGs), in particular carbon dioxide (CO2), threaten have serious impacts on food production, natural ecosystems and human health across the next 100 years. Industrialized and rapidly industrializing countries are the most important sources of greenhouse gases. However, the biggest impacts will be felt by people in developing countries, especially those in low-lying coastal areas and marginal agricultural areas. Air pollution has emerged as humanity’s most critical problem in recent decades. Globally, most urban areas face serious air quality problems due to over-increasing populations, combined with land use change and increased car traffic. Vehicle exhaust is estimated to contribute more than 45-55% of total pollution from all sources. Now, this complex pollution problem is not only limited to big cities, but it remains a problem in Himalayan tourist places and urban places all year round which can cause health problems for many people (Singh et al., 2007). Human activities since the beginning of the Industrial Revolution (around 1750) have led to a 45% increase in atmospheric carbon dioxide concentration, from 280 ppm in 1750 to 415 ppm in 2019. This increase has occurred despite the fact that more than half of the emissions have been absorbed of various natural “sinks” involved in the carbon cycle (ESRL, 2008). During the industrial era, human activities added greenhouse gases to the atmosphere, primarily through the combustion of fossil fuels and deforestation (IPCC AR4 WG1, 2007). Global warming is the direct consequences of GHs. Climate change due to global warming and its negative consequence on environment and agro ecosystem is a serious concern of global community of recent age. It is considered as one of the most serious threats to the environment with its potential negative impacts on food security, agriculture, fisheries, human health, biodiversity, water and other natural resources. In Bangladesh, we have evidences of increased frequency of floods, changing rainfall patterns, more frequent droughts and salinity intrusion. An increasing number of evidence in recent years has clearly established the fact that anthropogenic climate change is a reality (SRDI, 2010). The coastal region is the habitat for 40 million people and they are very much vulnerable to the natural disaster along with an area of about 720 km coastline. They cannot lead a happy and peaceful life since frequent natural disasters tend to