Large areas of northern China have experienced severe air pollution, prompting doctors to call on the public to reduce outdoor activities. This has also led to widespread discussions on environmental protection and low-carbon living. The polluted air conditions lasted for several days, and for some, it was their first encounter with the term "smog." Theoretically speaking, smog has two aspects: fog and haze.
Fog refers to an increase in the relative humidity of water vapor. The most suitable humidity level for human living environments is around 50% to 70%, while during foggy days, humidity can reach up to 100%. Haze occurs when humidity is relatively high, around 80%, and mainly involves both visible and invisible components in the air. The harm of smog to the human body is primarily due to increased humidity causing discomfort.
In addition, as everyone knows, PM2.5 measures the solid components, while the invisible components include substances like nitric oxide and sulfur monoxide. Although these substances are not water-soluble, they are strong oxidants, especially causing acute inflammatory damage to the airways and skin mucosa. That’s one aspect. The second aspect is the solid components, particularly PM2.5, which can deposit in the human airways and cause discomfort.
Moreover, these solid components contain highly pathogenic heavy metals and radioactive materials. In addition to damaging the airways, they also harm the lungs. In such conditions, people may feel unwell, experiencing symptoms like coughing and chest tightness. Furthermore, aggravated respiratory symptoms can lead to other diseases, such as discomfort in patients with heart disease or cerebrovascular conditions. These are the main ways such pollutants harm the human body.
Air pollution is highly detrimental to cyclists, and people have taken to cycling to protest air pollution.
Cycling has its benefits and drawbacks. For example, you might not be able to cycle all the way to Jinan, but from a fitness perspective, moderate cycling can indeed strengthen your health. However, it depends on the situation—for instance, in smoggy weather like we’re having now, where the Air Pollution Index (API) exceeds 300, cycling is definitely out of the question.
First, not everyone is suited for cycling.Bicycle. Indeed, those who can maintain balance, are not too old, have clear minds, flexible limbs, good hearing, and vision can benefit from moderate cycling. However, some people are not suitable for cycling—such as those with poor balance, a history of cerebrovascular disease, limb dysfunction, or joint pain. For them, cycling can worsen their condition and even pose risks.
Second, cycling in good weather and a clean environment increases aerobic metabolism, which is indeed beneficial to health. But cycling in areas with heavy exhaust emissions, where the API exceeds 300, can put you at risk of poisoning—so that’s not advisable.