Diurnal variability of ground level and nitrogen dioxide during festive holidays in Kelantan, Malaysia

Ground level ozone (O3) is a noxious secondary air pollutant known to affect human health and the environment adversely. Its photochemical reactions greatly depend on anthropogenic emission that controls their production and accumulation. The impact of several significant festive celebrations in Kota Bharu Malaysia onto O3 was critically investigated in this study. Two years secondary continuous air monitoring data (2013-2014) in Kota Bharu were divided into festive and non-festive holidays according to the specific date of the celebrations and analysed using descriptive statistics, box and whisker plot, time series plot and diurnal plot. The comparisons of diurnal variation of these pollutants during festive and non-festive holidays were analysed using independent sample t-test. The diurnal patterns of ozone during festive and non-festive holidays were showing a consistent trend with slightly different magnitude. The minimum ozone level was observed at nighttime (started from 6 p.m. onwards), and before sunrise, meanwhile, the maximum level of ozone concentration was at noontime (12 p.m. to 2 p.m.). There are no apparent differences between O3 concentrations prior, during and post-festive holidays and changes in human activities are insignificantly influence O3 diurnal variations in Kota Bharu.