Vietnam ranked 36 out of 117 nations with highest PM2.5 values in the world

Vietnam ranked 36 out of 117 nations with highest PM2.5 values in the world

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Introduction

The 2021 Global Air Quality Report by IQAir/AirVisual shows that globally, only 3% of cities and no countries had an average annual PM₂.₅ concentration below the 2021 WHO air quality guideline. This report analyzed PM₂.₅ concentration data from 6,475 cities and 117 countries and territories.

Vietnam

The average annual population weighted PM₂.₅ concentration in Vietnam in 2021, was 24.7 μg/m³, showing a decrease compared to 28.1 μg/m³ in 2020 and 34.1 μg/m³ in 2019. Vietnam ranked 5th in the Southeast Asia and 36th out of 117 countries with the highest PM₂.₅ concentrations around the world.Hình 2 However, all 15 cities analyzed in this report in Vietnam did not meet the WHO recommendation (5 μg/m³). In Hanoi, the average PM₂.₅ concentration in 2021 decreased by 4.5% compared to 2020, from 37.9 μg/m³ to 36.2 μg/m³, and achieved Level 3 target of the WHO recommendation. According to the ranking of capital cities with the highest fine particulate matter pollution, Hanoi ranked 15th out of 107, and ranked 10th out of the 15 most polluted cities in Southeast Asia. In addition, PM₂.₅ values from monitoring stations in Thai Nguyen, Ho Chi Minh City, and Hai Phong were among the top 10 highest in the region according to the ranking by IQAir/AirVisual. Meanwhile, air quality in Ho Chi Minh City, Da Nang, and Hue was showing signs of improvement in 2021, falling below the level of 25 μg/m³ (QCVN 05:2013 threshold) in 2021. Hình 3

Official results of the report by IQAir/AirVisual

  • No country had an annual average PM₂.₅ concentration below the WHO air quality guidelines in 2021.
  • Only 222 out of 6,475 cities in the report met the new WHO 2022 air quality guideline for fine particulate matter.
  • 93 cities reported annual average PM₂.₅ concentrations exceeding the WHO guideline by more than 10 times.
  • The top 5 most polluted countries in 2021 were Bangladesh, Chad, Pakistan, Tajikistan, and India. New Delhi, the capital of India, was also the most polluted capital for the fourth consecutive year.
  • Air quality in China continued to improve in 2021. More than half of the reported cities in China had lower pollution levels in 2021 than in previous years. Pollution in the capital city of Beijing has been continuously improving for 9 years due to emission controls and the closure of high-emitting power plants and industries.
  • Air quality monitoring remains limited in Africa, South America, and the Middle East, although many low-cost sensors have been installed and widely used by non-governmental organizations and citizen scientists.