What Spreads When You Sneeze

Sneezing expels an airflow and droplets from the respiratory tract, but speed and particle counts vary widely across people and measurement methods. Some review models cite speeds of tens of metres per second, while an experiment tracking 35 sneezes from four volunteers measured mean droplet speeds of 2–5.4 m/s. “Five thousand bacteria” is not a universal count: particles may contain different microbes, and bacterial presence depends on the person’s condition and sampling method. [1–3]