Chengdu's Pollution Problem: Is It That Bad?

Chengdu, the fourth-largest city in China, has over 15 million residents and 4 million vehicles, with 27% of PM2.5 emissions coming from transport, increasing risks to public health, the economy, and the environment. The economic loss from transport-related air pollution in Chengdu was $3 billion in 2013, and that number is on the rise, with private cars and trucks being the biggest emitters. Chengdu's air pollution is further exacerbated by its geographical location in the Sichuan basin, which results in less wind and higher humidity, allowing vehicle emissions and industrial fumes to accumulate. The city experiences its worst air quality during the winter months, with December, January, and February being the most polluted.

Chengdu's air pollution is worse than Beijing's

Chengdu, like many other cities in China, struggles with air pollution. In 2016, protests broke out in Chengdu in response to heavy smog. The city's air quality index (AQI) is often well above the limit, indicating poor air quality.

Chengdu's air pollution is, surprisingly, worse than Beijing's. While Beijing is infamous for its pollution, Chengdu's air quality has been declining in recent years. A comparison of PM2.5 data for the first half of 2018 showed that Chengdu barely edged out Beijing by 1 microgram. This is significant because PM2.5 refers to fine particulate matter, which is believed to be the most damaging to human health. These small particles can penetrate deep into the lungs and enter the bloodstream, causing serious health issues.

Chengdu's air pollution levels are consistently high, with the city averaging over twice the 24-hour limit of 25 micrograms recommended by the World Health Organization (WHO). On particularly bad days, the levels can reach up to ten times the safe limit. When considering the annual limit of 10 micrograms, Chengdu averages almost six times the safe level. This puts Chengdu well into the dangerous zone in terms of air quality and the potential health risks for its residents.

The pollution in Chengdu can be especially harmful to sensitive groups, including children, the elderly, and pregnant women. It is important for individuals in Chengdu to take precautions to protect themselves from the harmful effects of air pollution. This includes monitoring the AQI, timing outdoor activities to avoid high-pollution periods, and using indoor spaces with purified air when possible. Additionally, the increasing awareness of the dangers of PM2.5 has led to the development of affordable products and services that can help individuals protect themselves from harmful pollutants.

While Beijing has taken steps to improve its air quality, such as addressing vehicle emissions and industrial pollution, Chengdu may need to implement similar measures to combat its air pollution problem. Both cities continue to face the challenge of balancing economic growth with the need to improve air quality and protect the health and welfare of their citizens.

Sources of Chengdu's air pollution

Chengdu, the fourth-largest city in China, has over 15 million residents and 4 million vehicles, with 27% of PM2.5 emissions coming from transport, increasing risks to public health, the environment, and the economy. The topography of Chengdu, situated on the western edge of the Sichuan Basin, results in still air that traps polluted air in the basin. The primary sources of Chengdu's air pollution are vehicle emissions and industrial activities.

Vehicle emissions are a significant contributor to Chengdu's air pollution. The increasing number of cars, trucks, and other vehicles on the road leads to high levels of pollutants such as nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter (PM2.5). In 2013, the economic loss attributed to transport-related air pollution in Chengdu was $3 billion, with private cars and trucks contributing $2.2 billion, or 73% of the total.

To address this issue, Chengdu's government has implemented various measures, including strict parking management, restricting vehicle use through an "odd-even" license plate system, and encouraging the use of electric and hybrid vehicles. These regulatory measures aim to reduce the number of vehicles on the road and promote more sustainable transportation options.

Industrial activities also play a significant role in Chengdu's air pollution. The city has seen an increase in the number of factories being built each year, emitting pollutants such as sulfur dioxide (SO2) and fine particulate matter (PM2.5). These industrial emissions contribute to the haze and smog that often blanket the city, impacting air quality and public health.

Additionally, the burning of fossil fuels, such as coal, for energy production, contributes to Chengdu's air pollution. This releases pollutants such as nitrogen oxides (NOx), sulfur dioxide (SO2), and particulate matter into the atmosphere, further degrading air quality.

To tackle air pollution, Chengdu has implemented various initiatives, such as the Sustainable and Livable Cities Initiative, which provides recommendations on reducing transport-related emissions and improving air quality. The city also encourages the use of air purifiers and masks to protect residents from the harmful effects of polluted air.

Air pollution's impact on health

Chengdu, a city in China, has been facing issues with air pollution, with levels of PM2.5 (fine particulate matter) that are comparable to, and sometimes even exceed, those of Beijing, a city infamous for its pollution. This is concerning as studies have shown that even levels below the 24-hour limit of 25 micrograms are harmful to human health, and Chengdu often averages over twice that amount.

Air pollution consists of various contaminants in the atmosphere, such as dust, fumes, gases, and smoke, which can have detrimental effects on human health. The main pathway of exposure is through the respiratory tract, where pollutants lead to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting vital organs like the lungs, heart, and brain. Almost every organ in the body can be affected by air pollution, as some pollutants are small enough to penetrate the bloodstream via the lungs and circulate throughout the body, causing systemic issues.

Particulate matter (PM), especially the fine particulate matter (PM2.5), is one of the most critical pollutants affecting human health. Short-term exposure to high levels of PM can lead to reduced lung function, respiratory infections, and aggravated asthma. Long-term or chronic exposure increases the risk of non-communicable diseases like stroke, heart disease, chronic obstructive pulmonary disease, and cancer. Other significant pollutants include carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2).

The health effects of air pollution can vary depending on factors such as the type of pollutant, length and level of exposure, individual health risks, and the cumulative impacts of multiple pollutants. Smog, for example, can irritate the eyes and throat and damage the lungs, especially in children, the elderly, and those who work or exercise outdoors. Additionally, air pollution can have economic impacts, with higher medical costs and missed workdays for residents in polluted areas.

It is important for individuals in polluted areas like Chengdu to take precautions to protect themselves. Monitoring air quality, timing outdoor activities, and using indoor spaces or side roads to avoid direct traffic fumes can help reduce exposure. While gyms and indoor spaces in Chengdu may not have air purifiers, indoor air generally has around 50% fewer pollutants than outdoor air. There are also affordable products and services available to help monitor and reduce personal exposure to pollutants.

Air pollution in Chengdu during winter

Chengdu, China, is known to experience high levels of air pollution during the winter months. The air quality in Chengdu is influenced by a combination of factors, including increased power usage, vehicle emissions, proximity to industrial areas, and unfavourable topography. The city's location among mountains can hinder the dispersal of pollutants, leading to a buildup of harmful substances in the air.

During winter, Chengdu typically records elevated levels of fine particulate matter, specifically PM2.5. These tiny particles, measuring less than 2.5 micrometres in diameter, are considered particularly detrimental to human health. They can penetrate deep into the respiratory system, causing respiratory and cardiovascular issues. The concentration of PM2.5 in Chengdu's air has been found to exceed the World Health Organization's 24-hour limit of 25 micrograms, sometimes reaching up to ten times that amount on severely polluted days.

The Air Quality Index (AQI) is a commonly used metric to assess air pollution levels. Chengdu often observes high AQI readings during winter, with values ranging from 75 to 190 or more. At such levels, the pollution becomes tangible, leaving a layer of dust on surfaces and adversely affecting people's health and moods. The elderly, children, and pregnant women are among the most vulnerable segments of the population, requiring extra precautions during periods of intense pollution.

To cope with the winter pollution, residents of Chengdu are advised to monitor the AQI and limit their exposure to heavily polluted outdoor air. This can include timing outdoor activities to coincide with lower pollution levels, opting for side roads or paths away from direct traffic fumes, and using indoor spaces for workouts when possible. Various apps and tools, such as "Air Matters: Global Air Quality & Pollen Data" and the Laser Egg by Kaiterra, can help individuals stay informed about real-time pollution levels in different districts of Chengdu. While the city has made progress in addressing pollution through initiatives like relocating factories away from residential areas, the winter season continues to present challenges in maintaining healthy air quality.

Apps and websites to monitor Chengdu's air quality

Chengdu, China, is known for its high levels of air pollution. The air quality often exceeds the World Health Organization's 24-hour limit of 25 micrograms, sometimes by up to ten times that amount.

Apps

• Air Matters: Global Air Quality & Pollen Data – provides local air quality readings from different districts in Chengdu and allows you to compare air quality globally.
• Laser Egg by Kaiterra – a user-friendly and cost-efficient app that displays the PM2.5 reading on an LED screen. It can also be synced to your phone and unplugged to measure air quality on the move.
• IQAir Earth – provides a real-time, 3D animated air pollution map and allows you to get updates on the air quality of your favourite places.

Websites

• Chengdu Air Pollution: Real-time Air Quality Index – provides real-time PM2.5 Air Quality Index (AQI) data for Chengdu.
• China National Urban Air Quality Real-time Publishing Platform – provides real-time air quality data for various cities in China, including Chengdu.
• Chengdu Environmental Protection Agency – provides real-time air quality monitoring data for Chengdu.
• U.S. Consulate Chengdu Air Quality Monitor – provides air quality data for Chengdu.

Frequently asked questions