System and method for reducing microorganisms

A system for reducing microorganisms, the system comprising:

• a light assembly operable to emit at least two of:
• a first blue light at a first peak wavelength of 400-410 nm with a full width half maximum of at most 25 nm, the first peak having a first time averaged intensity I1, to target a first photoreactive component of the microorganisms;
• a second blue light at a second peak wavelength of 440-464 nm with a full width half maximum of at most 25 nm, the second peak having a second time averaged intensity I2, to target a second photoreactive component of the microorganisms;
• a third blue light at a third peak wavelength of 465-490 nm with a full width half maximum of at most 25 nm, the third peak having a third time averaged intensity I3, to target a third photoreactive component of the microorganisms;
• and
• a processor communicably coupled to the light assembly to control the time averaged intensities of the blue lights emitted by the light assembly such that if two blue lights are used, the time averaged intensity of one blue light is between 0.67 and 1.33times the time averaged intensity of another blue light;
• and if three blue lights are used, the time averaged intensity of any one blue light is between 0.76 and 1.24 times the time averaged intensity of the time averaged intensity of both the other blue lights.