PM2.5 (PM₂.₅)
Fine Particulate Matter (≤ 2.5 µm)
Microscopic inhalable airborne particles capable of deep cardiovascular and pulmonary penetration.
What is PM2.5 (Fine Particulate Matter (≤ 2.5 µm))?
Particulate Matter 2.5 (PM2.5) consists of microscopic solid particles and liquid droplets suspended in the air with an aerodynamic diameter of 2.5 micrometers or less — approximately 3% the diameter of a human hair. Due to their ultra-fine size, PM2.5 particles remain airborne indefinitely, bypass the upper respiratory defenses (nasal passages and cilia), penetrate deep into lung alveoli, and can enter the systemic bloodstream.
- •Cooking with gas burners, frying, and grilling oils
- •Tobacco smoke, incense sticks, and scented candles
- •Unvented space heaters and wood-burning fireplaces
- •Resuspension from movement across carpets and upholstered fabrics
- •Infiltration of outdoor traffic and industrial smog through HVAC dampers
- •Internal combustion engine vehicular exhaust (soot and sulfate condensates)
- •Coal, oil, and biomass-fired power generation and industrial facilities
- •Agricultural crop residue burning and dust storms
- •Wildfires, forest fires, and construction site aggregate processing
Health Effects of PM2.5
- •Eye, nose, throat, and mucosal membrane irritation
- •Coughing, wheezing, and acute shortness of breath
- •Triggering of severe asthma flare-ups and acute bronchitis
- •Temporary reduction in pulmonary lung capacity
- •Chronic obstructive pulmonary disease (COPD) progression
- •Atherosclerosis, coronary heart disease, and increased risk of myocardial infarction
- •Impaired cognitive function and elevated risk of neurodegenerative decline
- •Systemic vascular inflammation and reduced life expectancy
Concentration Levels & Safety Guidelines
Standardized thresholds to identify when active ventilation and air filtration intervention is required.
Air quality is considered satisfactory, and air pollution poses little or no risk.
Acceptable quality; however, very sensitive individuals may experience slight respiratory irritation.
Members of sensitive groups may experience health effects; general public is less likely to be affected.
Everyone may begin to experience health effects; serious health risks for high-risk individuals.
| Organization | Guideline Limit | Exposure Timeframe |
|---|---|---|
| World Health Organization (WHO) | 5 µg/m³ | Annual Mean Target |
| World Health Organization (WHO) | 15 µg/m³ | 24-Hour Mean Target |
| US EPA NAAQS | 9.0 µg/m³ | Annual Primary Standard |
| US EPA NAAQS | 35.0 µg/m³ | 24-Hour Primary Standard |
How DLE Measures PM2.5
High-precision laser diodes illuminate an active sensing cavity. As airborne particles transit through the focused optical chamber, they scatter laser light. High-speed photodiodes convert the scattered pulses into electrical signals, binning individual particles into discrete aerodynamic diameters to compute real-time mass concentration.
Wall-mounted and duct-integrated multi-channel particulate sensing hardware.
Explore SystemHigh-CADR filtration units engineered to capture 99.97% of airborne PM2.5 and ultrafine particles.
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