Legionella.

Legionella bacteria are transmitted to the lungs of human beings through a process called aerosilization. The most common devices that have been found to transmit the bacteria are air conditioning cooling towers; however, there are many other devices that can transmit the bacteria such as: shower heads, pipes, heat exchange bumpers, whirlpools, humidifiers, respiratory therapy devices, and grocery store misters. The bacteria especially favor the average relative humidity level of sixty-five percent. This is because the humidity enables the bacteria to live for longer periods of time in an airborne environment. In this type of humid environment larger droplets can also evaporate forming smaller ones which are more favorable to the bacteria since smaller droplets can penetrate deep into the lungs without being easily expelled.