Uncover the Mystery of PM2.5
Hello, I'm PM2.5, a tiny particle that flows around in the air you breathe. I may be small—less than 2.5 micrometers in diameter—but don't underestimate my impact on your health and the environment! I am so slim that could easily be breathed into your body, traveling in your blood vessel, and cause respiratory and cardiovascular disease! To raise your attention, I wrote this blog to tell you more about myself.
 |
| The size of PM2.5 Source: https://www.epa.gov/pm-pollution/particulate-matter-pm-basics |
My Origins: Where Do I Come From?
Well, actually I've been floating in the atmosphere for billions of years. However, rapid industrialization is giving birth to most of my peers. My birthplaces include factory chimneys, vehicle exhaust pipes, incinerations, and residential heating. This is what you call "primary sources." Industrial production, transportation, and agricultural burning are important primary sources.
But that's not all! I can also form in the atmosphere via complex chemistry reactions involving NOx and SO2. You call these "secondary sources," which are even more hazardous due to extra pollutants.
 |
| Source: https://theconversation.com/air-pollution-can-increase-the-risk-of-covid-infection-and-severe-disease-a-roundup-of-what-we-know-201813 |
Besides, my body is composed by soil dust, ions (SO42−, NO3−, NH4+, etc.), carbonaceous aerosols, trace elements, and so on[1].
 |
| The ions' role in PM2.5 formation Source: https://www.researchgate.net/figure/Role-of-ammonia-in-PM25-formation-a-SO2-and-NOx-oxidation-enhanced-by-NH3-b-SO4-and_fig4_343872447 |
 |
| PM2.5 particles under an electron microscope Source: https://kknews.cc/zh-my/science/ane246x.html |
How to Tame Me: Strategies to Cope PM2.5 Pollution
Technological Innovations
The core of technological innovations is to reduce the primary sources of my emissions:
In the industrial aspect, the progress of chemical agglomeration technology[2] highly improves the efficiency of electrostatic precipitators, a lot of my peers are trapped in the stack and have no way to pursue freedom in the atmosphere.
In transport aspects, electric vehicles and hybrid cars are on the rise, reducing the number of fossil fuel-powered engines on the roads.
In agricultural aspects, better techniques for disposing of waste biomass than burning are gaining popularity, like anaerobic digestion. It not only stops my presence but also turns waste into resources!
Policies
Governments are also making policies to reduce my presence. Regulations targeting emissions from energy production, transportation, and agriculture have shown positive effects. For example, China's Air Pollution Prevention and Control Action Plan has effectively reduced PM2.5-related health issues[3].
https://www.youtube.com/watch?v=YQH-6AMLRiU
How to Protect Yourself From Us: Understanding AQI
| Source: https://www.vecteezy.com/vector-art/1114727-air-quality-index-with-color-scales |
Unfortunately, we are still causing trouble in some regions. To protect yourself, a useful tool is the Air Quality Index (AQI). The number of AQI is mostly contributed by me and tropospheric ozone. The picture below will tell you how to read the AQI number:
 |
| Source: https://www.iqair.com/newsroom/what-is-the-difference-between-china-us-aqi |
The most effective way to block me is to wear a mask, but ordinary cotton yarn and fashion masks do not have much effect on me. Common medical masks such as N95 and KN90 have a good protective effect!. When the air quality is poor, it is not appropriate to open the window, and you need an air purifier. In addition, some potted plants such as spider plants and bamboo plants in the room also have a certain effect on the adsorption of me.
Conclusion
Controlling PM2.5 pollution like me requires a combined effort of technology, policy, and public awareness. Next time you see a hazy sky, remember my journey and all the efforts that human done to keep the air clean. With continued innovation and regulation, we can reduce my impact and breathe easier.
References
[1]Liu, Z., Gao, W., Yu, Y., Hu, B., Xin, J., Sun, Y., Wang, L., Wang, G., Bi, X., Zhang, G., Xu, H., Cong, Z., He, J., Xu, J., & Wang, Y. (2018). Characteristics of PM2.5 mass concentrations and chemical species in urban and background areas of China: Emerging results from the CARE-China network. Atmospheric Chemistry and Physics, 18(12), 8849–8871. https://doi.org/10.5194/acp-18-8849-2018
[2]Tucker, W. (2000). An overview of PM2.5 sources and control strategies. Fuel Processing Technology, 65–66, 379–392. https://doi.org/10.1016/s0378-3820(99)00105-8
[3]Yue, H., He, C., Huang, Q., Yin, D., & Bryan, B. A. (2020). Stronger policy required to substantially reduce deaths from PM2.5 pollution in China. Nature Communications, 11(1). https://doi.org/10.1038/s41467-020-15319-4
Buy me a cup of coffee :-)
Comments
Post a Comment