Qualité de l’air à Linyi

How bad is the air pollution in Linyi city?

Linyi is a prefecture-level city in the south of Shandong province, China, as such it administers 12 county-level divisions, including three districts and nine counties. In 2019 the population was estimated at being over 10.6 million people, with 2.3 million living in the metropolitan areas of Lanshan District, Luozhuang District and Hedong District. Its name suggests that it lies close to the Yi River. Its economy is based on the fact that its wholesale market is ranked third in all of China with an approximate annual turnover of US$5 billion.

In the first half of 2021 Linyi was experiencing a period of “Moderate” quality air with a US AQI reading of 65. This is an internationally recognised system that allows comparisons to be made between different cities, even if they are in different countries they still use the same metrics. It follows the guidelines laid down by the World Health Organisation (WHO). It is calculated by measuring six main pollutants most commonly found in polluted air. In Linyi, the concentration levels of the six main pollutants were as follows: PM2.5 - 19 µg/m³, PM10 - 56 µg/m³, ozone (O₃) - 116 µg/m³, nitrogen dioxide (NO₂) - 15 µg/m³, sulphur dioxide (SO₂) - 7 µg/m³ and carbon monoxide (CO) - 400 µg/m³. Even though this level is not as high as some, all levels of air pollution can be dangerous. The advice given under these circumstances would be to stay indoors and close the doors and windows to prevent more dirty air from entering the rooms. Those people who are more susceptible to polluted air should avoid venturing outside until the quality of air improves. You can check the latest figures in the table at the top of this page.

Is the air pollution in Linyi the same all year round?

Air pollution can be very volatile as it can be affected by many variables such as the temperature and level of sunlight throughout the various seasons. The figures for 2020 have just been published by the Swiss air monitoring company, IQAir .com.

By looking at these figures it can easily be seen that the level of air pollution varies considerably throughout the year. The summer months from the start of May until the end of September were the months that offered the cleanest air with readings classifying it as being “Moderate” with figures between 12.1 and 35.4 µg/m³. The springtime months of February, March and April saw a slight decline in air quality when the figures recorded classified it as being “Unhealthy for sensitive groups” with readings between 35.5 and 55.4 µg/m³. Similar numbers for autumn with October and November returning 48.2 and 54.1 µg/m³, respectively. The remaining 2 winter months of January and December saw another decline when figures slipped into the “Unhealthy” bracket with readings between 55.5 and 150.4 µg/m³.

Air quality was first recorded in 2017 when the average annual figure was 56.4 µg/m³. An improvement was seen the following year when 50.2 µg/m³ was recorded. However, it slipped back the following year to 57.7 µg/m³ before showing a marked improvement in 2020 when the figure was just 48.4 µg/m³ but this could be artificially lower because of the restrictions put into place because of the COVID-19 pandemic. Many vehicles were prevented from being used because factories and offices had been instructed to cease operation for the time being. The closure of the factories also meant they were no longer polluting the air, albeit on a temporary basis.

Where does the air pollution in Linyi come from?

Autumn and winter, haze frequently occurs, but summer air pollution also cannot be ignored. As the temperature continues to rise, in many cities, ozone has replaced PM2.5 (fine particulate matter) as the primary air pollutant. This "invisible killer" ozone is more harmful. For this reason, the Linyi City Ecological Environment Bureau recently issued an initiative and invited the people of the city to be experts in ozone emission reduction. In recent years, with the joint efforts of all walks of life in the city, the air quality in the city has continued to improve, and there are more and more sights of blue sky, white clouds and twinkling stars.

However, in the summer and autumn seasons, ozone (O₃) has gradually become an important constraint affecting the improvement of air quality. According to statistics, in 2018, 2019 and 2020, the number of days exceeding the standard due to ozone pollution in our city was 63, 72 and 63 days respectively, which seriously affected the increase in the proportion of good days.

O₃ pollution at ground level is mainly caused by the photochemical reaction of NOx and volatile organic compounds (VOCs) under high temperature, sufficient sunshine, and dry air.

NOx is basically man-made emissions, mainly from fossil fuel combustion, motor vehicle exhaust, industrial production process emissions, etc.; VOCs come from a wider range of sources, including petrochemical, pharmaceutical, chemical, household, auto repair, industrial coating, packaging and printing, sheet metal, etc.

What can be done to try and improve the air quality in Linyi?

To reduce the generation of O₃, the "raw material supply" (NOx and VOCs) of its pollution reaction must be reduced. Therefore, strengthening the comprehensive management of VOCs, especially reducing the production and emission of VOCs during high temperature periods, is of great significance to the control of ozone pollution.

It is suggested that any use of volatile organic compounds that have no alternatives should only be used when the temperatures are lower.

As far as possible, use environmentally friendly materials for interior decoration, such as water-soluble, low-volatile materials or materials with Chinese environmental labels, and avoid construction during periods when the temperature is higher. Do not barbecue in the open air, do not burn straw, garbage, fallen leaves and other substances, and reduce the emission of oil fume, exhaust gas and other pollutants.

What are the risks to health from air pollution in Linyi?

Some of the direct health effects of exposure to air pollution include irritation of the eyes, nose, and throat; shortness of breath; coughing; exacerbating pre-existing diseases such as asthma attacks and chest pain. Age, pre-existing diseases, other risk factors for diseases, and sensitivity to pollutants can all affect a person's response to pollutants.