 Hi! Welcome to Oizom Academy. Let's begin with all you need to know about PM 2.5. Particulate matter is not a single air pollutant but refers to a complex mixture of solids and aerosols of varying shape, size and chemical composition. They are composed of various chemical species like organic compounds, inorganic ions, metallic compounds, elementary carbon, etc. They are either directly emitted from a source or are formed through the chemical reactions of other air pollutants like NOx, SOx, VOCs in the atmosphere. As the impact of particulate matter exposure on human health directly depends on the size of particles, they are classified by their diameter for air quality regulatory purposes. The particles with a diameter of 2.5 micron or less are collectively known as PM 2.5. Sources of PM 2.5 include windblown dust from open land, soil erosion, pollen, spores, mold, dirt, forest fires, burning fossil fuels, vehicle emissions, power supply, industrial combustion, metal production, etc. Once released, they stay in the air for a few days or weeks and can travel hundreds of miles before settling down. PM 2.5 particles are more than 100 times thinner than a human hair and can penetrate deeper into the human respiratory tract when inhaled. They induce tissue damage and lung inflammation and may lead to the premature death. Initially, PM 2.5 causes irritation in the eyes, nose, throat, permanent respiratory diseases such as asthma and chronic bronchitis, heart disease and reduces lung function growth in children. An increase in PM 2.5 has been linked to an increase in deaths due to viruses such as novel coronavirus disease COVID-19. Harvard University in one of its studies has claimed that an increase in the PM 2.5 values by 1 microgram per cubic meter corresponded to an 8-person increase in the COVID-19 deaths. PM 2.5 alters the absorption and scattering of light in the atmosphere affecting visibility. They majorly contribute to smog formation. Settling of PM 2.5 can adversely impact the plant, soil and water ecosystems. The metal and organic compounds reduce plant growth while the deposition of PM 2.5 into water bodies affects its quality and clarity. Real-time monitoring of PM 2.5 levels helps in calculating air quality index to deliver health advisories as well as formulating an action plan to meet standards. Different working principles for monitoring particulate matter of all sizes in the ambient environment are gravimetric, TOEM, beta attenuation and laser scattering. OISOM's PM sensor works on the active sampling method of laser scattering that counts particulate matter using a highly accurate laser beam. OISOM's dust droid is an online particulate monitoring system that measures the concentration of various particulate sizes ranging from 1 micron to 100 microns such as PM 1, PM 2.5, PM 10 and PM 100 in the ambient air. Dust droid can be used for dust monitoring in areas with dust laden activities like construction, mining, quarrying, ports, metallurgical processes and many more. Real-time particulate matter monitoring using dust droid can assist in dust separation automation. For instance, to activate suppressants at the location once the threshold is breached. I hope you now know all about PM 2.5. For any questions or suggestions, please contact us. Thank you and happy learning.