Impact of natural lemongrass and agarwood essential oil diffusion on indoor airborne pollutants: A case study of office environments

This research explores the use of natural-based essential oils to enhance the quality of indoor air (IAQ) in an office environment using an experimental approach. Lemongrass and agarwood essential oils were studied for their potential to contribute to a healthier and sustainable indoor environment due to their antibacterial properties. The essential oil droplets were released using an Ultrasonic Diffuser, and air quality measurements were taken before and after the diffusion of essential oils. The concentration of airborne bioaerosols, VOCs, PM, and other physical parameters were monitored throughout the sampling period. Lemongrass essential oil significantly reduced the total bacterial and fungal count by 74.19% and 76.34% respectively, while agarwood only significantly reduced the total fungal count by 55.20%. This study found that physical parameters such as air velocity and relative humidity have a substantial impact on the efficiency of essential oil diffusion. With a correlation of more than 47%, lemongrass diffusion showed substantial relationships between air velocity and VOC, PM₁₀, and PM_2.5. Diffusion of agarwood showed strong correlations of more than 57% between relative humidity and VOC, TSP, PM₁₀, and PM_2.5. Temperature, as controlled by air conditioning, did not affect diffusion. The study adds to our understanding of the antibacterial and antifungal activities of lemongrass and agarwood essential oils. Diffusing essential oils, particularly lemongrass, improved IAQ as the total microbial count was able to be reduced without impacting other parameters, demonstrating a practical and efficient improvement. The beneficial effect on IAQ highlights the potential of essential oil diffusion for healthier indoor environments, hence helping the promotion of good IAQ following safety and health regulations.