How microbes travel
Bacterial and viral particles spread when someone sneezes or coughs, expelling droplets into the air. These become dispersed by physical disturbances, like wind and water, or other microscopic particles, like dust. As these water and mucous droplets travel, they evaporate and begin to shrink, which can leave behind microbes small enough to be carried on air currents. Inhaling these viral or bacterial particles can spread coughs, colds, influenza, tuberculosis and other infectious agents.