Dust

Dust is a collection of fine solid particles that are suspended in air or settle on surfaces. It is common in both indoor and outdoor environments, and particle sizes range from coarse to fine. Of particular concern are particles smaller than 10 micrometers (PM10) and especially those under 2.5 micrometers (PM2.5), which can be inhaled deep into the lungs.

The composition of dust varies widely and can include mineral dust from soil, plant and animal fibers, skin flakes, textile fibers, pollen, microbes, combustion byproducts, soot, volcanic ash, and microplastics. Indoor dust often contains allergens such as dust mite bodies and feces, pet dander, and mold spores, alongside everyday debris from activities and furnishings.

Dust sources include natural processes like windblown soil and pollen, as well as human activities such as cooking, smoking, heating, and outdoor pollution that settles indoors. Dust can act as a medium for chemical reactions on its surface and can transport nutrients and contaminants between environments.

Health effects are most pronounced with inhalation of fine dust, which is linked to respiratory irritation, asthma symptoms, and cardiovascular issues, particularly for PM2.5. Allergic reactions may arise from dust mites, mold, and pollen. Dust also affects environmental quality by reducing visibility, settling on surfaces, and influencing climate through light scattering and heat absorption; deposited dust can deliver nutrients to ecosystems.

Management and measurement involve monitoring PM2.5 and PM10 levels and reducing exposure through filtration (for example, HEPA filters), ventilation, humidity control, and regular cleaning. Minimizing dust sources and employing damp cleaning can help reduce accumulation and allergen levels.