How to protect against PM 2.5? Are air purifiers with HEPA filters effective?

How to protect against PM 2.5? UseHEPA filterIs the air purifier effective?

PM 2.5 refers to particulate matter in ambient air with an aerodynamic equivalent diameter of less than or equal to 2.5 micrometers, while the preceding PM stands for Particulate Matter, meaning particulate matter, also known as atmospheric aerosol particles.

The source of atmospheric aerosol particles can be either naturally occurring or produced by human activity, but in terms of health hazards, the latter will have a greater impact.

Hazards of PM 2.5, PM 10, PM 0.1

The composition of airborne particulate matter is relatively complex, but to put it in perspective, the main ones that have a serious impact on human health are particulate matter with a diameter of less than 2.5 micrometers (PM 2.5), particulate matter with a diameter of between 2.5 and 10 micrometers (PM 10), and particulate matter with a diameter of less than 100 nanometers (PM 0.1).

Outdoors, these particles are mainly generated from the combustion of various fuels, such as burning coal for heating, automobile exhaust, petrochemical metallurgy textile and other industrial emissions. While indoors, pollutants that come in from outside, grease from frying, and second-hand smoke are their main sources.

Particles larger than 10 microns in diameter are easily intercepted by our nasal hairs, and these larger particles are unable to enter the lungs and other organs. Particles less than 10 microns in diameter are called PM, and these substances are distributed through the nose and mouth, with PM 2.5 even penetrating into the alveoli, increasing the risk of respiratory and lung diseases.

What's more, PM 0.1 can pass through the lungs and affect other organs, including the brain. According to medical studies, prolonged inhalation of high levels of PM 0.1 can lead to asthma, lung cancer, respiratory diseases, cardiovascular diseases, preterm births, as well as birth defects in infants, low birth weight and premature death.

At the same time, their harm varies depending on the harmful nature of the substances attached. For example, adsorption of heavy metals and benzene carcinogens have different effects on the human body.

How do I take precautions when I'm outside?

At present, the domestic air quality is generally poor, which is unable to change the fact in a short period of time, for the haze or some specific respirable particles, wearing a mask may be the only feasible method.

1. Ordinary medical masks, cotton masks (invalid)

Ordinary medical masks can only block particles with a large diameter, and the cheeks of such masks on both sides are not able to fit tightly to the face, the air will enter from both sides, which greatly reduces the blocking effect, and is not enough for haze prevention and blocking respirable particles.

Secondly, cotton masks are also ineffective at blocking PM because the gaps between the gauze used to make them are so large that they are equivalent to an unobstructed flow of fine particles like PM 2.5, and are therefore ineffective as well.

Ordinary medical masks, cotton masks: ineffective.

2. N95, KN95 level masks (effective)

N95 is an air filtration rating recommended by the CDC, and N95 means that a mask made from certified materials is able to block more than 95% of particles with a diameter of 0.3 microns or larger. These masks will fit snugly around the face, so they are much more effective than regular masks, but they also have to be worn correctly to be most effective.

KN95 is our air filtration rating standard, and its definition can be said to be the same as N95. It is worth noting that these two rating systems, there are N99, KN90, KN100 and other levels, but the filtration rate is too high will make the user in the movement of breathing problems, the heart also causes a certain burden, but the harm outweighs the good, so the general recommended use of N95 and KN95 grade masks can be.

A special reminder to readers who love sports, if the outdoor air quality is poor, it is not recommended to wear a mask to the outdoor sports, because the N95 level of masks will in fact cause some obstruction to people's breathing, wearing a mask exercise is easy to cause a lack of oxygen phenomenon, aggravate the burden on the lungs and the heart, so when the air quality is bad try to choose the indoor exercise it.

N95, KN95 rated masks: effective.

How can people be careful when they are indoors?

1. Air purifier, fresh air system (HEPA filter) (effective)

The main way to remove PM 2.5 and other particles indoors is to use air purifiers and fresh air systems equipped with HEPA filters, but air purifiers and fresh air systems belong to different air circulation methods. Air purification is an internal cycle, filtering indoor air to discharge clean air; fresh air system is an external cycle, exchanging indoor air with outdoor air to achieve the role of air circulation.

HEPA filter

Some people will ask with the new air system is not the same as the introduction of outdoor haze inside the home? So now the home air system will also be equipped with HEPA filters, filtering the outdoor air transported to the indoor, and then the indoor air out, a continuous cycle.

Currently air purifiers and fresh air systems using HEPA filters are the best way to remove PM 2.5 and other particles indoors, with removal ranges covering PM 0.1, PM 2.5, and PM 10.

Air purifier, fresh air system (HEPA filter) to remove PM 2.5: Effective.

2. Green plants in addition to PM 2.5 (ineffective)

In the last article about formaldehyde removal, we have introduced the plant deformaldehyde is not reliable. For PM 2.5 and other particles, sulfur dioxide, carbon dioxide and other gases, plants also have a certain adsorption capacity, but the efficiency is very low, the role of the scope is also very limited, if you are not to set up the home into a botanical garden model, it is difficult to rely on plants to purify the air.

So, when you buy plants in fact, only consider whether it looks good on the line, relying on it to adsorb PM 2.5, purify indoor air, absorb formaldehyde, bacteria, radiation, through are useless.

Greenery to remove PM 2.5: Ineffective.

3. Eat "lung-cleansing food" (ineffective)

In addition to physical haze, the Internet is also rumored to consume animal blood (duck blood, pig blood), Sydney, silver fungus, Luo Han Guo and other so-called "lung-cleansing food", can help the body to discharge inhaled dust and fine particles.

As mentioned above, PM 2.5 enters the lungs and even penetrates deep into the alveoli and stays in our lungs. PM 0.1, which is much smaller in diameter, will enter through the lungs into the bloodstream and travel through the bloodstream to other organs. Therefore, from the flow of these particles and food, it can be seen that they do not actually have the opportunity to come into contact, and the role of helping to expel these particles can not be said.

As a matter of fact, the meaning of "lungs" in traditional medicine is different from that in modern medicine. The traditional medicine of the lungs mainly refers to slow down the symptoms related to the respiratory tract, such as coughing, phlegm and so on, as for the removal of PM 2.5, or honestly to buy an air purifier, go out and wear a good mask.

Eating "lung-cleansing foods": ineffective.

Summarize: rely on masks outside, rely on air purification at home

As a matter of fact, the most effective solution to the air pollution problem is, of course, to control it at source, such as the use of clean energy, the strengthening of green construction, the implementation of new energy transportation, and so on. And masks and air purification, can only be considered in the current air governance is not effective, the public can take the compromise measures.

All in all, don't go out if you can avoid going out when the air quality is low. It is recommended to wear N95 grade masks, and when using them, you need to read the instructions carefully and replace them regularly. In addition, indoor air purification can be purchased air purifiers, or the addition of fresh air systems, these devices HEPA filters also need to be replaced regularly, depending on the environment, the service life of 6 months to 1 year.