Dusts

Dusts refer to finely dispersed solid particles produced by weathering, wear, combustion, and other processes. In the air, dust consists of tiny particles that can be suspended for varying times, contributing to air quality and visibility. The term is often used to describe mineral, organic, or metal particles found as airborne matter or settled dust on surfaces.

Sources and composition: Mineral dusts include silica, quartz, feldspar, and clays from soil and rocks; metal dusts include iron, aluminum, and process-generated alloys; organic dusts include pollen and plant fragments, mold spores, and soot. Dust diversity complicates health and environmental effects.

Sizes and health/environmental effects: Particles smaller than 10 micrometers (PM10) can be inhaled; those smaller than 2.5 micrometers (PM2.5) can penetrate deeper into lungs. Exposure is linked to respiratory and cardiovascular disease, irritation, and allergen reactions. Dust can transport pollutants and affect climate by scattering and absorbing light.

Measurement and control: Air quality monitoring uses gravimetric methods and optical devices to estimate PM fractions. Regulatory limits exist for ambient PM2.5 and PM10 in many countries. Control measures include wetting, containment, ventilation, filtration, and housekeeping to minimize dust generation and dispersion.