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We all know air pollution. How to choose the appropriate material for wearing masks?

Masks on the market can be divided into cloth masks, N95, surgical masks, activated carbon masks and paper masks, and the suitable time for use is also completely different. What kind of mask do you like to use?

1. Cloth mask or cotton mask: suitable for daily cleaning.

Wang Weisheng, an attending physician in the infection department of Mackay hospital, pointed out that cotton masks have large gaps. These masks are more suitable for cleaning at home and block dust and pollution with large particles, but the effect is not enough to prevent influenza virus.

Wang Weisheng explained that although most influenza viruses can only spread by adhering to droplets with large particles, wearing cloth masks can provide a certain degree of barrier, because the particles of the virus itself are small, in the past, cloth masks could only filter out about 37% of the virus particles in the air (referring to particles above 0 and 3 microns), and the gap between the cloth masks and the face is also large, Therefore, if you are in a hospital or indoor closed space with a high amount of virus, the blocking effect by cloth mask may not be very good.

However, if you only have a cold and are afraid that the droplets of coughing and sneezing will affect others, wearing a cloth mask is still an option to be considered.

2. Activated carbon mask: available for cyclists and cleaning, but its anti air pollution effect is limited.

Masks that emphasize the addition of activated carbon can not resist influenza or serious air pollution. Because the function of activated carbon mask is only used to adsorb volatile organic solvents and impurities in the air. Therefore, it is only suitable for riding motorcycles, spraying organic solvents and painting to prevent odor, oil and other dirt.

Moreover, Wang Weisheng said that after activated carbon adsorbs a certain amount of volatile organic compounds, it can no longer play its role. Therefore, it usually needs to be discarded once in a polluted environment, or the time should not exceed four hours.

3. Mask for medical operation: it can prevent influenza, but it is still not enough to prevent air pollution.

It is commonly used in hospitals and operating rooms. This kind of mask can filter more than 90% of 5 micron particles. When there are respiratory symptoms or influenza is prevalent, it is enough to block the virus hidden in mouth and nose droplets. There are usually three layers of non-woven cloth, usually green, pink or blue.

The functions of the three-tier design are as follows:

■ outer layer: PP water splashing material, which can block the attachment of droplets or blood with disease source.

■ middle layer: special filter screen can block bacteria and dust.

■ inner layer: super soft fine fiber, which can absorb sweat and grease.

However, in order to resist air pollution, the effect of this kind of medical mask is still not enough. Because the particles of PM2 and 5 are less than 2 and 5 microns, the medical mask can not completely filter these fine particles. According to Chen Zhijie, a professor at the Institute of occupational medicine and industrial health at the Public Health College of National Taiwan University, most of these masks are of graphic design and can not fit closely to the face. Suspended particles can still be sucked into the body through the gap. In fact, the protection against PM2 and 5 is only about 30% ~ 80%.

4. American N95 or European ffp1 mask: it can effectively prevent air pollution.

The main function of this kind of mask is to filter suspended particles, which can resist more than 95% of virus particles of more than 0 and 3 microns. The experiment of National Taiwan University Public Health Institute found that it can block 80% ~ 99% and 7% of air pollutants. Moreover, because the three-dimensional shape can be close to the face, the tightness is higher than that of medical and activated carbon masks, and the protective effect is also better. Therefore, if the air quality is too poor, it is best to use this kind of mask.

However, in order to avoid influenza or visit patients in hospitals, it is still recommended to wear general medical masks. Because N95 mask will cause difficulty in breathing due to high airflow impedance, ordinary people should avoid wearing it for a long time. It is also not suitable for poor lung function, pregnant women or people with chronic respiratory diseases and asthma. Therefore, Wang Weisheng said that if the air pollution is serious, it is best to simply avoid going out.

5. Paper masks: only used when other masks cannot be obtained.

It is commonly used in paper masks often issued by hospital vending machines or gifts. The effect of filtering particles is the worst and it is not waterproof. Lack of protection against droplets, saliva, blood and other dirt. Therefore, Wang Weisheng suggested that it should be used only when other masks cannot be obtained and must not be used.

Do not wear wrong iron bars on the front and back, and the waterproof layer shall be outside

It should be noted that the positive and negative effects of masks are much worse, but many people often don't know which side of masks to wear. Wang Weisheng reminded that the difference between the front and back of medical masks depends not on the color, but on the material. The waterproof layer should be on the outside, and the cloth surface layer should be close to the mouth and nose.

If there is a soft metal strip on the mask, the metal strip surface is usually outward, and use both hands to press the soft metal strip on the cheek along the bridge of the nose, so that there is no gap between the mask and the face as far as possible.

In addition, the mask is made of special material. When it is discarded, it can be treated with general garbage without putting it into paper for recycling.