> **来源：[研报客](https://pc.yanbaoke.cn)** # 2025 World Air Quality Report Summary ## Core Content The **2025 IQAir World Air Quality Report** provides a comprehensive overview of global air quality for the calendar year 2025. It includes data from **9,446 cities** across **143 countries, regions, and territories**, using a combination of **regulatory monitoring stations** and **low-cost sensors**. This data is collected and validated by various contributors such as government agencies, universities, non-profits, and citizen scientists. PM2.5, a key pollutant, is used as the primary metric in this report, reported in **micrograms per cubic meter (μg/m³)**. It highlights the health risks associated with fine particulate matter, which can penetrate deep into the lungs and bloodstream, leading to serious health issues like respiratory and cardiovascular diseases. ## Main Points - **Global Air Quality Trends**: In 2025, only **14% of global cities** met the **WHO annual PM2.5 guideline** of **5 μg/m³**, a decline from **17% in 2024**. This reflects the ongoing challenge of maintaining clean air, despite international recognition of air pollution as a major global risk. - **Wildfires and Climate Change**: Wildfires, exacerbated by climate change, significantly degraded air quality in 2025, contributing to a global release of approximately **1,380 megatonnes of carbon** from biomass burning. - **Data Expansion**: The report expanded coverage by **33%**, including new countries like **Iran, Syria, and Jordan** from **West Asia**, and others from **Africa**. However, some countries such as **Burundi, Turkmenistan, and Togo** were excluded due to a lack of available data. - **Public Engagement in Bangkok**: Bangkok serves as a model for public engagement in air quality monitoring, with the city partnering with IQAir to install **low-cost sensors** in **nearly 100 schools**, providing real-time data and promoting environmental literacy among students. - **Data Presentation**: The report uses a **color-coding system** based on WHO guidelines and interim targets to visualize PM2.5 levels. This includes **seven distinct colors**, ranging from **blue (safe)** to **maroon (severely polluted)**. ## Key Information ### PM2.5 Breakpoints Based on WHO Guidelines | PM2.5 Concentration (μg/m³) | Color | Description | |-----------------------------|--------|-------------| | 0-5 | Blue | Meets WHO annual guideline | | 5.1-10 | Green | Exceeds guideline by 1-2 times | | 10.1-15 | Yellow | Exceeds guideline by 2-3 times | | 15.1-25 | Orange | Exceeds guideline by 3-5 times | | 25.1-35 | Red | Exceeds guideline by 5-7 times | | 35.1-50 | Purple | Exceeds target levels | | >50 | Maroon | Exceeds target levels | ### Country/Region Ranking (Top 10) | Rank | Country/Region | Annual Average PM2.5 (μg/m³) | |------|----------------|-----------------------------| | 1 | Pakistan | 67.3 | | 2 | Bangladesh | 66.1 | | 3 | Tajikistan | 57.3 | | 4 | Chad | 53.6 | | 5 | D.R. Congo | 50.2 | | 6 | India | 48.9 | | 7 | Kuwait | 45.7 | | 8 | Uganda | 43.0 | | 9 | Egypt | 40.6 | | 10 | Uzbekistan | 38.1 | ### Regional Summary: East Asia - **Cities Covered**: 1,264 cities across **China, Hong Kong SAR, Japan, Macau SAR, Mongolia, South Korea, and Taiwan**. - **Trend Analysis**: **73% of cities** recorded increased PM2.5 concentrations compared to 2024, while **25%** saw decreases and **2%** remained unchanged. - **National Trends**: Two countries saw increases in annual average PM2.5, while five saw decreases. **Japan** had the largest relative increase (**14%**), and **Mongolia** showed the most significant decrease (**31%**). - **Highest and Lowest Polluted Cities**: **Hotan, China** (109.6 μg/m³) was the most polluted city in the region, while **Ngari, China** (5.3 μg/m³) had the lowest concentration, just below the WHO guideline. ### Monitoring Status - **New Cities Added**: **16 new cities** across four countries were added in 2025. **China** contributed the most with **seven additions**, followed by **South Korea** and **Japan** with **four each**. - **Government vs. Low-Cost Sensors**: **98% of the data** in East Asia came from **government-operated monitoring stations**, indicating a strong reliance on official sources. - **Data Availability**: **13 countries** globally met the WHO annual PM2.5 guideline, with most located in **Latin America & Caribbean** and **Oceania**. ## Conclusion The **2025 World Air Quality Report** underscores the critical need for **global collaboration** and **innovative data collection methods** to address air pollution. While some progress has been made, particularly in **Mongolia**, the overall trend indicates that **air quality remains a pressing global issue**. The report emphasizes the importance of **public engagement**, as seen in **Bangkok**, and the role of **community-led monitoring** in filling data gaps. Continued efforts are essential to improve air quality and protect public health, especially for **children**, who are disproportionately affected by long-term exposure to air pollution.