Recently, in some cities with persistent smog, some residents have chosen to wear masks for protection. Experts remind that there are certain considerations when using masks on hazy days, especially for those who enjoy cycling, who require extra protection.
Lou Qiang, a resident physician in the Department of Respiratory Medicine at the Second Affiliated Hospital of Guiyang College of Traditional Chinese Medicine, told reporters that the main function of a mask is to separate the respiratory organs such as the nasal cavity and mouth from the smog, reducing direct exposure to a certain extent. Wearing a mask on hazy days is necessary, but it must be done properly.
“Ordinary masks have relatively large gaps, allowing tiny particles like PM2.5 to pass through. Moreover, without adsorption layers such as activated carbon, their protective effect is limited. Even if they can block PM2.5, they can’t stop smaller particles,” said Lou Qiang.
Lou Qiang stated that when selecting a mask, the public should pay attention to choosing one made of dense material to block particles to the greatest extent possible. At the same time, it’s important to check whether the mask has an adsorption layer, which can trap particles that penetrate the mask.
The way a mask is worn is not the only consideration—its maintenance should also be taken seriously by the public.
“It is not recommended that the public wash their own masks. Even if you do wash them, it’s best to perform professional disinfection,” said Lou Qiang. “Since high-temperature, high-pressure washing is not feasible in a typical home environment, it’s still advisable to use masks for short periods rather than wash them repeatedly.”
Lou Qiang particularly reminded that people who enjoy cycling need special protection on hazy days. “On smoggy days, air convection is relatively low, and the process of traveling by bicycle, motorcycle, or electric scooter accelerates air flow, which can lead to increased particle absorption in a short time. Therefore, special protection is needed, and it’s best to wear a higher-quality mask,” said Lou Qiang.
Lou Qiang also suggested that since the dust and smoke floating in the air during smoggy weather can easily cause acute upper respiratory infections, acute tracheitis, and pneumonia, people with lung diseases, children—especially those with allergies—should also wear masks when going out on hazy days.