Status, Sources and Variations of Air Pollutants in the Cox'S Bazar Tourist City of Bangladesh

Abstract

Urban and coastal tourist environments are increasingly exposed to complex air‐pollution mixtures, yet systematic investigations in such settings remain limited in Bangladesh. This study was conducted in nine (09) strategic locations of Cox`s Bazar tourist city of Bangladesh to know the status, sources and daily variations of major gaseous air pollutants (CO, CO 2 , CH 4 , SO 2 , NO 2 , O 3 , and Cl 2 ) including PM 2.5 and PM 10 . A sensor‐based instrument Aeroqual Series 500 was used to investigate the air quality. Measurements were conducted thrice daily: morning, noon, and evening to apprehend diurnal variations of air pollutants. PM 2 . 5 concentrations varied from 42 to 362 µg m − 3 , while PM 10 ranged from 42 to 333 µg m − 3 , with elevated levels observed in traffic‐dominated and construction‐intensive areas, indicating strong influences from vehicular emissions and resuspended road dust. Sulfur dioxide (SO 2 ) exhibited exceptionally high concentrations (10–66 ppb), suggesting combined contributions from local combustion sources and coastal influences, including emissions associated with marine transport and fishing activities. Carbon monoxide (CO) ranged from 0.1 to 6.97 ppm, and nitrogen dioxide (NO 2 ) varied between 19 and 49 ppb, reflecting the impact of traffic‐related emissions. Ozone (O 3 ) showed moderate ambient concentrations (1–200 ppb); however, source apportionment results indicate that O 3 represents a key component of a secondary photochemical factor in the positive matrix factorization (PMF) analysis, highlighting its role in atmospheric oxidation processes rather than dominance in terms of mass concentration. PMF analysis identified major source categories related to vehicular emissions, secondary photochemical reactions, and marine‐influenced activities. Overall, the findings demonstrate that air quality in Cox's Bazar is governed by the interaction of traffic emissions, coastal atmospheric dynamics, and tourism‐related human activities, underscoring the need for targeted emission control in tourist hotspots, improved management of construction‐related dust, and evaluation of fuel quality used in marine transport to protect public health and support sustainable tourism development.