Aerosols

Definition

A colloidal suspension of fine solid particles or liquid droplets dispersed in a gas, typically air. In biological contexts, aerosols are distinguished from larger, rapidly settling suspensions by particle diameters generally below 1 μm, though practical usage often extends to larger droplets that remain airborne long enough to be inhaled, contact surfaces, or travel atmospheric distances. The term properly denotes the particle-gas mixture, not the particulate matter alone.

Etymology

Example

Female gypsy moths (Lymantria dispar) release sex pheromone as an aerosol plume; males navigate upwind through turbulent filaments of the odor-laden air to locate calling females, demonstrating how aerosol dynamics shape mate-finding behavior in insects.

Synonyms

• aerial suspension
• airborne particulate

Related Terms

• pheromone plume
• olfactory orientation
• particulate matter
• bioaerosol
• vector-borne transmission
• respiratory spiracle

Usage Notes

Distinguish 'aerosol' (the mixture) from 'aerosol particles' (the suspended material). In medical and veterinary entomology, 'bioaerosols' specifically carry living organisms or biological materials such as fungal spores, allergenic proteins, or arthropod-borne pathogens. Contrast with 'spray' (larger droplets with shorter airborne residence) and 'dust' (dry particulates, often with different dispersal properties). Specialists may use 'aerosol' loosely for any airborne suspension, but precise usage reserves it for thermodynamically stable or slowly settling dispersions.