Seasonal Patterns and Trends of Air Pollution in the Upper Northern Thailand from 2004 to 2018

The seasonal patterns and trends of air pollutants can be used in assessments quality, facilitating authorities’ decisions on policies for monitoring managing. objective this study was to investigate the upper northern Thailand (UNT) from 2004 2018. hourly pollutant concentration data including carbon monoxide (CO), nitrogen dioxide (NO2), oxide (NOx), sulfur (SO2), ozone (O3), particulate matter ≤ 10 µm (PM10) recorded 6 stations UNT were obtained Pollution Control Department, Ministry Natural Resources Environment Thailand. Cubic splines assess pollutants. Linear regression estimate average increase concentrations at each station. results exhibited CO, NOx, NO2, O3 PM10, all while SO2 only one station Lampang Chiangmai. these rose during August September reached peak levels March. In past 15 years, overall had significantly increased, by 0.015 ppm, 0.012 ppb ppb, respectively. contrast, NOx PM10 decreased –0.010 –0.008 –0.011 µg m–3, provide information authorities setting up proper measures control mitigate quality impacts especially dry season.