When spring arrives in northern China, it is often accompanied by widespread smog or sandstorms. In recent years, pollution has continued to worsen across the country, and many southern cities have also experienced severe smog. What is smog? Is it a type of weather or visible pollution? What harm does it pose to health, and how can it be prevented? To combat smog, one must first understand it.
The Causes of Smog
Fog and haze were originally natural weather phenomena without human intervention.
However, the significant increase in haze in central and eastern China over the past two or three decades has been primarily caused by anthropogenic emissions of atmospheric aerosols. Today, as smog has become a daily topic, whether it’s haze or fog, human activity likely plays a role, making it no longer entirely a “natural” phenomenon.
The Beijing Municipal Environmental Protection Bureau has publicly stated that extreme adverse weather conditions, high pollutant emissions, and regional PM2.5 transport are the three main reasons for severe air pollution in Beijing. Other cities with serious smog issues can generally be attributed to similar causes. In China, where industrial production continues to grow, “pollutant emissions” are perhaps the most direct contributing factor.
Analyzing from the perspective of pollutants, PM2.5 in various regions contains PM1 (particles smaller than 1 micron in diameter). The components of PM1 include organic carbon aerosols, sulfate aerosols, and nitrate aerosols. Among these, sulfate aerosols mainly come from coal-fired power generation and heating across China (especially in the north), while nitrate aerosols are influenced not only by coal combustion but also by vehicle fuel combustion.
With a large number of pollutant particles floating in the air, and considering the “contribution” of vehicles, smog in large cities is not unexpected.
Additionally, sluggish traffic (studies show that vehicles moving at low speeds emit more exhaust), stable and calm weather, and unfavorable terrain for air circulation are also important factors in smog formation.
Spring Pollution
Some netizens joke, “Spring has willow catkins, summer has burning wheat straw, autumn has sandstorms, and winter has smog.” In such air conditions, protecting one’s health becomes an essential part of maintaining quality of life.
In northern China’s spring, especially on windy days, willow catkins, poplar catkins, and pollen become a nightmare for all people, particularly those with allergies. Poplar and willow catkins not only affect urban environmental hygiene but also pose certain health risks. People with allergic constitutions may experience facial itching or even swelling due to irritation from catkins and pollen. If accidentally inhaled through the nose or mouth, it can lead to coughing or sneezing. Even those without allergies may feel throat discomfort when living or working in environments with a lot of catkins, especially for heavy laborers and outdoor workers.
On windless or low-wind days, haze, fog, floating dust, and sandstorms become new threats. A high concentration of particulate matter in the air can cause respiratory discomfort for many urban residents, and in severe cases, can lead to allergies and respiratory diseases. Therefore, taking protective measures is crucial.
Choosing a Mask
So what measures can we take against smog, dust, and allergies? ——The most important is wearing a mask.
On days with severe smog or when willow catkins are flying, try to avoid outdoor activities. If you must go out, be sure to wear a mask. Regular masks are not very effective in protecting against PM2.5, but they are quite good for blocking willow catkins, sand, and other larger particles. People who work outdoors for extended periods can purchase professional protective masks to avoid chronic health damage from pollutants like PM2.5. Professional masks are slightly more expensive than regular ones, but they are significantly more effective in protecting against various pollutants and pollen.
Currently, there is no universal civilian mask standard in China. N95 and N99 masks are specialized for protecting against dust, bacteria, and other harmful substances. N95 masks filter 95% of particles as small as 0.3 microns, while N99 masks filter 99%. Masks come in various styles, and considering their effectiveness against PM2.5 and even PM1, it’s best to choose N99-standard masks. These masks are less commonly used by the general public, but unlike regular masks, professional N99 masks can guard against the large amount of particulate matter present on smoggy days.
Regular masks, such as medical masks, disposable masks, and silicone masks, can somewhat obstruct airflow and cause breathing difficulties. These types of masks are not suitable for use during exercise or for manual laborers. Children, whose cardiopulmonary functions are not fully developed and have weaker breathing capacity, should avoid wearing masks for extended periods. It’s worth noting that some brands (such as VOGMASK) have designed masks with air valves to ensure smooth breathing, which cyclists and parents might want to try.
In addition, eating fresh vegetables can provide some dietary protection. This is not because vegetables can detoxify the body, but because they contain antioxidants like vitamin C and flavonoids, which help the body resist pollutant damage. The effect may not be significant, but it’s still better than nothing. Another tip is to “drink more water.” Dry respiratory tracts can cause more discomfort, so staying hydrated is a well-known piece of advice.
In summary, the most important way to protect yourself on smoggy days is to wear a mask frequently. When purchasing masks, consumers should pay attention to the type to avoid ineffective choices.
Smog is harmful, and citizens can reduce exposure to minimize harm, as well as adjust through the use of masks and diet. Health is personal, but pollution prevention starts with everyone. While individuals take passive measures to avoid harm, if we can also take proactive environmental steps, there will surely be fewer smoggy days in the future.