Airborne particles vary greatly in size, and each size range has different origins, health impacts, and benefits when detected.

Large particles greater than 10 micrometers (µm) — such as coarse dust, pollen, and mold spores — are mostly trapped in the nose and throat. While they generally do not penetrate deep into the lungs, they can still cause irritation, allergic reactions, and discomfort. Detecting these particles is useful for allergy forecasting, controlling dust in industrial sites, and monitoring agricultural or construction activities.

PM₁₀ (particles with diameters of 10 µm or smaller) are small enough to be inhaled into the upper respiratory tract. They typically come from road dust, industrial emissions, pollen, and mold. Long-term exposure can aggravate asthma, bronchitis, and other respiratory conditions. Monitoring PM₁₀ helps ensure compliance with air quality regulations and workplace safety standards.

PM₂.₅ (particles with diameters of 2.5 µm or smaller) are fine particles generated mainly by combustion sources such as car exhaust, power plants, and smoke from fires. They can penetrate deep into the lungs and even enter the bloodstream, contributing to cardiovascular and lung diseases. Detecting PM₂.₅ is critical for public health warnings, reducing exposure during pollution peaks, and developing pollution-reduction policies.

PM₁ (particles 1 µm or smaller) are ultrafine particles often produced by combustion engines, certain industrial processes, and chemical reactions in the atmosphere. Because of their extremely small size, they can reach the deepest part of the lungs — the alveoli — and pass into the bloodstream, potentially affecting the heart, brain, and other organs. Monitoring PM₁ allows for early detection of harmful pollution from traffic and industrial hotspots.

Nanoparticles (smaller than 0.1 µm or 100 nanometers) are found in diesel exhaust, welding fumes, and engineered nanomaterials. They can cross biological barriers and cause oxidative stress and inflammation at the cellular level. Their detection is particularly important for protecting workers in nanotechnology, metallurgy, and electronics manufacturing.