PM2.5 | Respirable Suspended Particulate Matter | RSPM | Particulate Matter Source |OIZOM ACADEMY
Channel: Oizom
Date: 2021-01-06

Read more https://oizom.com/knowledege-bank/particulate-matter-monitoring/

“PM”, Particulate Matter, is not a single pollutant, but refers to a complex mixture of solids and aerosols of varying shape, size, and chemical composition and may contain many chemical species like organic compounds, inorganic ions, metallic compounds, elementary carbon, etc. These atmospheric particles are defined by their diameter for air quality regulatory purposes.

Particulate matter PM2.5 are either directly emitted from a source (primary PM) or are formed through the chemical reactions of gases such as oxides of sulfur (SOx), nitrogen oxides (NOx), organic compounds, etc. in the atmosphere (secondary PM). The natural sources of particulate matter are wind-blown dust from open land, pollen, spores, mold, dirt, soil erosion, and forest fires.  Anthropogenic sources of PM2.5 include:

Burning fossil fuels such as gasoline, oil, diesel or wood, etc. 
Waste burning, agricultural burning, etc.
Emission from motor vehicle exhaust
Emission from energy supply and industrial combustion processes

Health Impact
When inhaled for short periods, PM2.5 (i.e. up to 24-hours) causes irritation to the eyes, nose, throat, and upper respiratory tracts, coughing, sneezing, and shortness of breath. It aggravates already present respiratory diseases such as asthma and can result in premature mortality, acute and chronic bronchitis, other respiratory symptoms, etc. 

Environmental impact
The major environmental impacts of PM2.5 pollution are visibility reduction and smog. Particulate matter, specifically PM2.5 alters the absorption and scattering of light in the atmosphere affecting visibility. Additionally, the settling of the air-borne particles on plants, soil, and water ecosystems have harmful effects on them. The metal and organic compounds reduce plant growth and yield while the deposition of PM into water bodies affects its quality and clarity. 

Possible corrective measures 
The primary step is PM2.5 monitoring to identify the areas with high particulate levels or areas where air quality does not meet the PM2.5 national standards. In addition to this, the following corrective measures can be taken:

Limit outdoor activities and close windows and vents during times of high air pollution.
Avoid keeping your vehicle idle for long. 
Avoid areas with traffic congestions, construction activities, or unpaved roads. Breathing such polluted air daily also leads to health effects in the long run. 
Eliminate the use of the fireplace, wood stove, gas-powered lawn, or garden equipment. 
Also, eliminate open burning of leaves, trash or other materials
Measurement methods
Different working principles for particulate matter monitoring in the ambient environment are Gravimetric, TOEM, Beta Attenuation (BAM), and Laser scattering. 

Laser Scattering – The PM2.5 monitor based on the physical principle of light scattering, also known as optical particle counter (OPC), measures dust particles illuminated by laser light at a 90° angle. The light scattered from each particle is collected at approximately 90° by a mirror and detected by a photo-diode. This signal is then fed into a multi-channel size classifier where a pulse height analyzer is used to classify each pulse that is proportional to the particle size. The counts in the channel corresponding to PM2.5 converts to the concentration of PM2.5.

Oizom’s working principle for PM2.5 monitoring
Oizom’s DUSTROID is an online particulate monitoring system that measures the concentration of various particulate sizes ranging from 1 micron to 100 microns such as PM1, PM2.5, PM10, and PM100 in the ambient air. Our PM sensor works on the principle of laser scattering. The active sampling powered sensor-based air quality monitor DUSTROID is deployed across several cities, campuses, universities. They are also used for drawing actionable insights to tackle the rise in ambient PM2.5 concentrations.

5 reasons why PM2.5 monitoring is important:
PM2.5 is a complex mixture of solid and aerosols with very small size (about 100 times thinner than a human hair) that can easily pass through the nose and throat and penetrate deep into the lungs and cause severe health issues. 
Particulate matter is emitted into the atmosphere from vehicular exhaust, power plants, combustion processes such as the burning of fossil fuels, waste, etc. They are also formed into the atmosphere from various chemical reactions of other air pollutants such as NOx and SOx. 
When inhaled, it irritates the eyes, nose, throat, and the airways and can also lead to aggravation of respiratory diseases leading to premature mortality, acute and chronic bronchitis, other respiratory symptoms, etc.  
PM2.5 monitoring is an efficient way to detect high concentrations of particulate matter and prevent high-level exposures.