1. Many studies have shown that toothbrushes, especially those stored in bathrooms, can be heavily contaminated with various microorganisms.
Source: The effect of the toothbrush covers and the presence of toilet in the environment on bacterial growth on toothbrushes
Source: Microbial Contamination of Toothbrushes
2. UV-C is a strong disinfectant against bacteria, effectively damaging their DNA and causing cell death. The combination of UV-A with photocatalysts can improve its effectiveness.
Source: Effect of single and combined exposures to UV-C and UV-A LEDs on the inactivation of Klebsiella pneumoniae and Escherichia coli in water disinfection
Source: Decontamination Potential of Ultraviolet Type C Radiation in Water Treatment Systems: Targeting Microbial Inactivation