Following the haze, another "invisible killer - ozone" is threatening people's health. According to the website of the Shanghai Environmental Monitoring Center, as of August 6th, Shanghai has experienced 11 consecutive days of ozone pollution, with the Air Quality Index reaching its highest value of 134 at 1 pm that day, with ozone being the main pollutant. So what is ozone pollution? What are its main toxic chemical components?
What is Ozone Pollution?
Ozone is usually present in the high-level atmosphere about 30 kilometers above the ground. It acts as the Earth's protector, effectively blocking ultraviolet rays and protecting human health. However, ozone that appears near the ground, around 10-100 meters, is caused by severe environmental pollution and can have many adverse effects on human health.
Components of Ozone
The main sources of near-ground ozone are a series of nitrogen oxide gases (NOx) and volatile organic compounds (VOC) emitted by internal combustion engines, power plants, vehicle exhaust, and industrial emissions. These are byproducts of burning gasoline and coal. Under sunny and hot weather conditions in late spring, summer, and early autumn, NOx and VOC react chemically with oxygen to form ozone.
Harm of Near-Ground Ozone
Ozone that appears near the ground belongs to ozone pollution and is harmful to health, mainly in the following aspects:
Damage to the Respiratory System
Ozone is highly corrosive. Inhaling ozone can irritate and damage the nasal mucosa and respiratory tract, as well as the bronchioles and alveoli in the lungs. Repeated exposure to ozone can cause chest tightness, coughing, and in severe cases, asthma or respiratory infections, leading to inflammation of lung tissue.
Damage to the Immune System
Ozone can damage the human immune system, induce chromosomal abnormalities in lymphocytes, accelerate aging, and cause birth defects in pregnant women. It can also cause neurotoxicity and lead to memory decline.
Skin Damage
Ozone can damage vitamin E in the human skin, causing wrinkles and black spots.
How to Prevent Near-Ground Ozone Pollution
High concentrations of ozone generally form in the hot afternoons and evenings and dissipate in cooler nights.
Unlike prevention of PM2.5, wearing masks is ineffective for preventing ozone. Environmental protection departments suggest that citizens avoid outdoor activities during the most severe ozone pollution hours in the afternoon, around 2-3 pm. Summer is the peak season for ozone pollution, and it will gradually alleviate starting from September.
