Air Pollutant Dispersion and Its Health Impacts in Bukit Rambai, Melaka, and Muar, Johor, Malaysia

Introduction: Unsafe air quality values (>100) were recorded in Bukit Rambai, Melaka, and Muar, Johor, located in southern Peninsular Malaysia, during forest fires in Sumatera and Kalimantan, Indonesia. This study analyzes the dispersion of atmospheric pollutants in these areas over a four-year period (2015–2018). Materials and Methods: Descriptive analysis was performed using SPSS. Wind rose, pollutant rose, and calendar plots were generated using R-Programming and the openair package. Secondary data from the Department of Environment’s Air Monitoring Stations at SMK Bukit Rambai, Melaka, and Kolej Vokasional Muar, Johor, from 2015 to 2018 were used. Results and Discussion: Wind Direction and Speed: The predominant wind direction in both areas were from the northeast. Bukit Rambai recorded 60% of wind from North-Northeast (NNE) and East-Northeast (ENE) in 2015, with a slight variation over the years. Muar also showed a similar trend with 59% from NNE and ENE in 2018. Wind speed in Muar was higher than Bukit Rambai, with average speeds of 5.6 m/s (SD = 3.074) in 2015, decreasing to 1.2 m/s (SD = 0.688) in 2018. Bukit Rambai showed a decrease in wind speed from 5.3 m/s (SD = 2.66) in 2015 to 1.7 m/s (SD = 1.11) by 2018. Pollutant Concentrations: Higher concentrations of API and PM10 were observed with northeast winds. The average API levels at Bukit Rambai were 48.41 (SD = 17.89) and 38.34 (SD = 18.07) at Muar. PM10 levels were also higher at Bukit Rambai (45.41 µg/m³, SD = 29.79) compared to Muar (39.42 µg/m³, SD = 26.08). CO levels were higher in Muar (0.76 µg/m³, SD = 0.40) than in Bukit Rambai (0.64 µg/m³, SD = 0.31), while SO2 and NO2 levels were low in both areas. API and Outpatient Visits: Unhealthy API days (>100) occurred mainly between September and October 2015. Bukit Rambai had 37 days of unhealthy API levels, while Muar had 19 days. These high pollution days were linked to increased outpatient visits for respiratory issues. Conclusion: The study highlights that local emissions are the primary source of pollution, but seasonal factors contribute to higher API levels and respiratory issues. The northeast wind plays a significant role in dispersing pollutants, affecting air quality in both regions.