甚麼是細懸浮微粒（PM2.5）?

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In addition to PM2.5, what other particle size suspended particles?
What are the effects of suspended particles on the human body?
Aerosol measurement method
How to avoid air pollution hazards?
How can we do our part to improve the air quality around us?
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References

PM2.5 refers to fine particulate matter suspended in the air, PM stands for "Particulate Matter", and 2.5 stands for particles with a particle size less than or equal to 2.5 microns (μm), the unit is micrograms per cubic meter ( μg/m3) to express. Because their particle size is very small, they can easily enter the human respiratory system. Compared with larger suspended particles, PM2.5 particles have higher respirability and penetration, and can enter the deep lungs. It is one of the most concerned air pollutants at present with great harm and impact on health.

In addition to PM2.5, what other particle size suspended particles?

In addition to PM2.5, there are other particle sizes that are widely concerned and monitored by various countries. The following is a summary of some common particle sizes, including:

Particle size (μm)	Particle Size Description
PM10	Refers to particle size less than or equal to10 micronsSuspended particles, also known as "coarse suspended particles", easily reach the throat through the nasal hairs and bends of the nasal cavity, mainly from pollen, road dust, construction sites and sandstorms.
PM2.5	Refers to particle size less than or equal to2.5 micronsSuspended particles, also known as "fine suspended particles", are invisible to the naked eye. They can penetrate the air bubbles in the lungs and directly enter the blood vessels and circulate throughout the body with the blood. They mainly come from dust, industrial emissions, and transportation exhaust gases.
PM1	Refers to particle size less than or equal to1 micronSuspended particles, also known as "very fine suspended particles", are invisible to the naked eye and have strong penetrating power. They will not only penetrate the respiratory tract, but may also cause stroke or myocardial infarction. The fatality rate is higher, mainly from industrial emissions and transportation exhaust , Incinerator, etc.
PM0.1	Refers to particle size less than or equal to0.1 micronSuspended particles, also known as "nano-suspended particles", are invisible to the naked eye, usually only affect the surrounding environment, cannot be transmitted remotely, and are more harmful to the human body. Even wearing an N95 mask still cannot prevent them, mainly from industrial Emissions, transportation exhaust, incinerators, etc.

What are the effects of suspended particles on the human body?

Different sources of aerosol pollution have different effects and harms on the human body, and can involve many aspects, including the respiratory system, cardiovascular system and overall health. The following are the main effects of aerosols on the human body:

Respiratory effects: Suspended particles can enter the respiratory system, especially those with smaller particle sizes (such as particles below PM2.5). These tiny particles can penetrate deep into the lungs, causing the onset and exacerbation of asthma, chronic obstructive pulmonary disease (COPD) and other respiratory diseases. In addition, long-term exposure to high concentrations of aerosols may increase lung cancer risk.
cardiovascular system effects: Aerosols can also have adverse effects on the cardiovascular system. When these particles are inhaled, they can easily enter the blood circulation system, triggering inflammation and blood vessel damage, increasing the risk of heart attack, stroke and cardiovascular events. In addition, aerosols can interfere with the function of platelets in the blood, increasing the possibility of thrombus formation.
inflammation and immune response: The presence of aerosols triggers a response from the body's immune system, resulting in an increased inflammatory response.
cancer risk: Certain suspended particles, especially those containing harmful chemicals or heavy metals, may have carcinogenic effects on humans. Long-term exposure to these particles may increase the risk of lung cancer, bladder cancer and other cancers.

Aerosol measurement method

Air Quality Index (AQI)is a numerical indicator used to measure and report the air quality of a specific region. AQI divides air quality into several different categories according to the concentration of different air pollution indicators (such as PM2.5, PM10, ozone, sulfur dioxide, carbon monoxide and nitrogen dioxide, etc.), and grades each category.

The purpose of AQI is to make it easier for the public to understand the current air quality situation and take necessary precautions according to the corresponding guidelines and recommendations. AQI may be different in different countries and regions. The table below refers to the AQI standards of the United States and Taiwan:

Air Quality Index (AQI)	health effects	status color block	activity suggestion
0～50	good	green	Normal outdoor activities.
51～100	medium	yellow	Normal outdoor activities.
101～150	Not suitable for sensitive groups	orange	Consideration should be given to reducing outdoor activities.
151～200	unhealthy	red	Consideration should be given to reducing outdoor activities.
201～300	very unhealthy	purple	Outdoor activities should be reduced and avoided.
301～500	harm	maroon	Outdoor activities should be avoided.

How to avoid air pollution hazards?

Here are some common ways to avoid the hazards of air pollution:

Minimize outdoor activities: When the air quality is poor, especially in the weather of high pollution and smog, try to reduce the time of staying outdoors, especially near pollution sources or areas with dense traffic.
indoor air purification: Using an air purifier indoors can filter out suspended particles and pollutants in the air and provide a relatively clean air environment. But make sure the purifier has the proper filtration performance, especially for capturing PM2.5 and other tiny particles.
Pay attention to indoor air quality: Keep the indoor ventilation well, clean the indoor air filter regularly, avoid smoking and using chemicals and other harmful substances indoors.
wear a mask: When the air quality is poor, wearing an appropriate mask (such as an N95 mask) can reduce the risk of inhaling aerosols and pollutants.
check air quality: Always pay attention to the air quality index (AQI) in your area to understand the air quality status. Information can be obtained through government agencies, weather bureaus or air monitoring websites.

How can we do our part to improve the air quality around us?

Energy conservation: Reduce personal carbon emissions, such as reducing electricity consumption, saving energy, choosing low-carbon transportation methods, etc. Reducing energy consumption helps reduce air pollution and greenhouse gas emissions.
Reduce personal vehicle use: Choose environmentally friendly modes of transportation such as walking, cycling or using public transportation. Reducing personal car use reduces traffic emissions and improves air quality.
Support Renewable Energy: Choose to use renewable energy sources, such as solar or wind power, to supply your home's electricity needs. This helps reduce the need for conventional coal-fired power generation and reduces air pollution.
Support a Green Lifestyle: Includes waste reduction, recycling, resource conservation and sustainable consumption. Choose to buy eco-friendly products, reduce the use of single-use items, and choose sustainable packaging and products.
Promote and promote environmental awareness: Improve people's awareness and awareness of air pollution through publicity and education, so that more people will pay attention to environmental protection issues.
Participate in environmental protection activities: Join environmental protection organizations, volunteer organizations or community groups, and participate in environmental protection activities through collective action.