Wearing masks in large crowds, especially during festivals like Salah (also known as Eid al-Fitr or Eid ul-Fitr), is significant for several reasons:

1. *Prevention of infectious diseases*: Masks help prevent the spread of airborne illnesses like COVID-19, influenza, and other respiratory infections that can easily transmit in crowded areas.
2. *Protection of vulnerable individuals*: Masks help safeguard people with compromised immune systems, such as the elderly, young children, and those with pre-existing medical conditions, who are more susceptible to illnesses.
3. *Reduced transmission of airborne pathogens*: Masks can reduce the transmission of airborne pathogens, including viruses and bacteria, that can cause a range of illnesses.