2025年全球空气质量报告_44页_3mb

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

Country/Region Ranking (Top 10)

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.