2022-04-03-世界卫生组织-WHO_Air_quality_Database_2022_28页_1mb

WHO Ambient Air Quality Database 2022 Update Summary

Introduction

The WHO ambient air quality database (2022 update) is a draft status report that compiles and summarizes ground measurements of air quality pollutants. It aims to provide data for assessing health impacts and monitoring air quality trends, supporting the Sustainable Development Goals. The database includes annual mean concentrations of PM2.5, PM10, and NO2 for human settlements worldwide, based on data from 2010-2019.

Database Overview

• Pollutants and Scope: Includes PM2.5, PM10, and NO2; covers 6,743 human settlements in 117 countries.
• Coverage: Settlements range in size from small towns to large cities, with over 50% classified as urban centers. Data are more abundant in high- and middle-income countries, particularly in China, Europe, India, and North America.
• Data Sources: Primarily from national reports, government websites, and networks like the Global Burden of Disease project, complemented by peer-reviewed studies and regional networks if official data is unavailable.

Key Findings

• Air Quality Levels: High concentrations of PM10 and PM2.5 are widespread in low- and middle-income countries, with some regions exceeding WHO guidelines by six to eight times. NO2 levels show more homogeneity globally.
• Regional Variations: High PM2.5 exposure in Africa, Eastern Mediterranean, and South-East Asia; lower levels in Europe and the Americas. Mega-cities often report high concentrations, with limited comparability due to varying data collection years and methods.
• Temporal Trends: Air quality in major cities has improved or remained stable, with a few exceptions like Delhi.

Compliance with WHO Air Quality Guidelines

• Overall Compliance: Globally, only about 10% of assessed settlements meet the annual mean PM10 or PM2.5 AQGs, increasing to 31-95% across interim targets. For NO2, compliance ranges from 23% to 95%. Higher adherence is seen in high-income countries.
• Income Disparities: Low-income areas show significantly higher exposure to air pollution, with less than 37% of polluted settlements located in low- and middle-income countries.

Data Quality and Methods

• Methods: Annual mean concentrations are derived from ground measurements, aggregated at city level, with emphasis on urban background exposures. Data processing excludes localized hot spots for representative population exposure.
• Limitations: Issues include inconsistent measurement methods, incomplete data, limited temporal coverage, and language barriers hindering full dataset retrieval. Data quality varies by region and income levels.

Limitations and Future Directions

• Current Challenges: Incomplete global coverage, heterogeneity in data quality, and lack of standardized reporting.
• Prospects: Emphasis on integrating low-cost sensors and satellite data to enhance spatial coverage and quality control. WHO is exploring collaborations to continuously update the database with better-quality data through national submissions and expert advice.

Feedback and Updating

Countries and institutions are encouraged to contribute updated or complete data through WHO to improve the database's comprehensiveness and accuracy.

Conclusion

The 2022 update highlights substantial air pollution burdens, particularly in low- and middle-income regions, and underscores the need for improved monitoring and policy action to align with WHO guidelines.