Air Quality Insights: Ambient Pollution Database Explained

Ambient air pollution is a critical risk factor for noncommunicable diseases (NCDs), causing an estimated one-quarter of all adult deaths from heart disease, 25% from stroke, 43% from chronic obstructive pulmonary disease, and 29% from lung cancer. The World Health Organization (WHO) maintains a global ambient air quality database, which is the world's most comprehensive database on ambient air pollution. The database collects annual mean concentrations of fine particulate matter (PM10 and PM2.5) from over 4300 cities in 108 countries. PM2.5 includes pollutants such as sulfate, nitrates, and black carbon, which pose the greatest risks to human health. The database reveals that 99% of the world's population lives in places where air pollution levels exceed WHO guideline limits, with the highest levels in the Eastern Mediterranean Region and in South-East Asia.

The database collects annual mean concentrations of fine particulate matter (PM10 and PM2.5)

Particulate matter (PM) refers to a mixture of solid particles and liquid droplets in the air. PM10 and PM2.5 refer to particulate matter with diameters of 10 micrometers or less and 2.5 micrometers or less, respectively. These particles are so small that they can be inhaled and cause adverse health effects, with PM2.5 posing a greater risk to health. PM10 can induce adverse health effects, with several studies suggesting a link between long-term exposure and respiratory mortality. The effects of PM10 are less clear, but it is still harmful.

PM2.5, on the other hand, has been linked to premature death, particularly in individuals with chronic heart or lung diseases. Long-term exposure can also hinder lung function growth in children. In California, PM2.5 exposure has been associated with thousands of premature deaths, hospitalizations for cardiovascular and respiratory diseases, and emergency room visits for asthma each year.

The World Health Organization (WHO) monitors exposure levels and health impacts, including deaths and illnesses, of ambient (outdoor) and household air pollution at the national, regional, and global levels. WHO guideline limits for air pollution are exceeded in the areas where 99% of the world's population lives.

The WHO Ambient Air Pollution Database collects annual mean concentrations of fine particulate matter, including PM10 and PM2.5. This data is crucial for understanding the health impacts of air pollution and developing strategies to mitigate its effects. The database provides valuable information on the levels of particulate matter in the air, helping to identify areas with high pollution levels and potential risks to human health.

Ambient air pollution caused 4.2 million deaths in 2016

Ambient air pollution is a leading environmental risk factor affecting populations worldwide. In 2016, it caused an estimated 4.2 million premature deaths worldwide, according to the World Health Organization (WHO). This figure represents the latest WHO estimates of air pollution's death toll as of November 2021. The deaths were attributed to exposure to fine particulate matter of 2.5 microns or less in diameter (PM2.5). It is important to note that the WHO does not include deaths caused by other air pollutants like ozone in its estimate, so the actual figure may be higher.

The burden of disease from ambient air pollution is significant. According to the WHO, 58% of the 4.2 million deaths in 2016 were due to ischaemic heart disease and strokes, 18% to chronic obstructive pulmonary disease and acute lower respiratory infections, and 6% to lung cancer. These health impacts are a result of long-term exposure to air pollution, which reduces life expectancy. Even short-term exposure to polluted air can have adverse health effects.

The sources of outdoor air pollution are diverse and often beyond the control of individuals. They include natural sources such as dust from deserts and anthropogenic sources, with the latter requiring concerted action from policymakers. According to the Lancet Planetary Health, pollution was responsible for approximately 9 million premature deaths in 2015, making it the leading environmental risk factor for premature death. While there have been reductions in deaths from household air pollution associated with extreme poverty, these gains have been offset by increased deaths from ambient air pollution and toxic chemical pollution.

The problem of air pollution is not limited to developing nations. Even in the European Union, where many cities comply with PM concentration guidelines, the average life expectancy is estimated to be 8.6 months lower due to PM exposures from human sources. This highlights the serious risks to health from exposure to PM, O3, NO2, and SO2. Ozone (O3), for example, is a significant factor in asthma morbidity and mortality, while NO2 and SO2 contribute to asthma, bronchial symptoms, lung inflammation, and reduced lung function.

To address the health impacts of air pollution, the WHO air quality guidelines recommend reducing annual average fine particulate matter (PM2.5) concentrations from levels of 35 μg/m3 to the guideline level of 10 μg/m3. This reduction could decrease air pollution-related deaths by around 15%. Additionally, as almost the entire global population (99%) is exposed to air pollution levels that increase their risk of heart disease, stroke, chronic obstructive pulmonary disease, cancer, and pneumonia, further investments in pollution control are needed.

The Eastern Mediterranean Region and South-East Asia have the highest levels of ambient air pollution

Ambient air pollution is a major threat to health across the globe. Almost 99% of the global population is exposed to air pollution levels that increase their risk of diseases, including heart disease, stroke, chronic obstructive pulmonary disease, cancer, and pneumonia. The World Health Organization (WHO) monitors the exposure levels and health impacts of air pollution at the national, regional, and global levels.

The Eastern Mediterranean Region and South-East Asia are two regions with high levels of ambient air pollution. According to WHO data, the Eastern Mediterranean Region has the highest levels of PM10 concentration among the six WHO regions. PM10 refers to particulate matter less than 10 micrometres in diameter. While there is a near absence of land-based PM2.5 data in the region, computer models and satellite-derived maps indicate that almost all countries in the Eastern Mediterranean Region exceed the WHO guideline for PM2.5. Natural sources, such as sand and dust storms, contribute significantly to the pollution levels. However, the lack of adequate regulations and monitoring systems in some countries of the region exacerbates the problem. Afghanistan, Egypt, Iran, Iraq, Lebanon, Libya, Pakistan, Saudi Arabia, Syria, and Tunisia are among the countries suffering from outdoor air pollution in this region.

South-East Asia, on the other hand, faces high levels of pollution from seasonal sources, such as peatland fires, and traditional farming practices. Southeast Asia is home to 56% of the world's peatlands, and the slash-and-burn farming method has led to increased emissions of particulate matter and other pollutants. While countries like Vietnam and Indonesia have made progress in reducing their reliance on solid fuels since 2010, the region still struggles with high levels of ambient air pollution.

Both the Eastern Mediterranean Region and South-East Asia face significant health impacts due to air pollution. In the Eastern Mediterranean Region, air pollution is responsible for a large number of premature deaths, with over 400,000 people dying prematurely in 2012 as a result. Similarly, in South-East Asia, air pollution is the leading environmental risk factor for poor health. Residents in this region are routinely exposed to levels of air pollution above the guidelines set by the WHO, increasing the risk of various diseases and premature mortality.

Addressing air pollution in these regions is crucial to protect public health and reduce the burden of diseases associated with poor air quality. Efforts to improve air quality monitoring, air quality management, and local infrastructure development are underway in both regions. Additionally, initiatives such as the Regional Environmental Health Strategy and Action Plan 2014-2019 in the Eastern Mediterranean Region aim to outline a roadmap for tackling the health impacts of air pollution. By implementing policies, regulations, and interventions, these regions can strive towards reducing ambient air pollution levels and mitigating their adverse effects on human health.

More than 4300 cities in 108 countries are included in the database

The World Health Organization's (WHO) global ambient air quality database is a comprehensive collection of PM10 (particulate matter with an aerodynamic diameter of 10 microns or less) and PM2.5 (fine particulate matter with a diameter of 2.5 microns or less) monitoring data from over 4,300 cities in 108 countries. This database, last updated in 2018, provides valuable insights into the levels of air pollution worldwide and helps identify areas with dangerously high pollution levels.

The inclusion of more than 4,300 cities in 108 countries in the WHO database emphasizes its global reach and significance. This extensive coverage allows for a more comprehensive understanding of air quality on a global scale. By collecting data from various geographical locations, including high-, middle-, and low-income countries, the database captures a diverse range of air pollution scenarios.

The database plays a crucial role in monitoring and addressing air pollution, a critical risk factor for non-communicable diseases (NCDs). According to WHO estimates, air pollution causes approximately 24% of adult deaths from heart disease, 25% from stroke, 43% from chronic obstructive pulmonary disease, and 29% from lung cancer. With such alarming statistics, the database becomes an essential tool for policymakers, researchers, and health organizations to identify hotspots of high pollution levels and implement effective mitigation strategies.

One notable aspect of the database is its expansion over the years. Since 2016, more than 1,000 additional cities have been incorporated, indicating a growing global commitment to measuring and addressing air pollution. This expansion also reflects an increasing recognition of the importance of data collection and transparency in tackling this global health challenge.

The WHO database collects annual mean concentrations of fine particulate matter, including PM10 and PM2.5. These pollutants, composed of sulphates, nitrates, and black carbon, pose significant risks to human health. By monitoring these pollutants, the database provides valuable information for assessing air quality and its potential impact on public health. This data is crucial for official reporting, such as world health statistics and the Sustainable Development Goals, driving global efforts to improve air quality and protect human health.

The database collects PM measurements and estimates from established public air quality monitoring systems

The World Health Organization (WHO) maintains a global ambient air quality database that collects PM measurements and estimates from established public air quality monitoring systems. The database was updated in 2018 and contains data for 3,570 cities in 97 countries for PM10 and 2,628 cities in 81 countries for PM2.5. PM10 and PM2.5 refer to particulate matter (PM) with an aerodynamic diameter of 10 micrometres or less and 2.5 micrometres or less, respectively. These particles are small enough to penetrate deep into the lungs and the cardiovascular system, posing significant risks to human health.

The WHO database reveals that air pollution levels are generally lower in high-income countries, particularly in Europe, the Americas, the Western Pacific, and Oceania. In contrast, high PM levels are found in low- and middle-income countries in Africa, Southeast Asia, and Latin America. These disparities are often due to a lack of funding and inadequate staffing in the affected regions, hindering their ability to effectively reduce air pollution.

The database plays a crucial role in raising awareness about urban air pollution, which has been dubbed a "silent killer." According to WHO, air pollution increases the risk of death and disease from various ailments, including chronic obstructive pulmonary disease (COPD), lung cancer, ischaemic heart disease, stroke, and acute lower respiratory diseases. It disproportionately affects vulnerable groups, such as children and the elderly.

By collecting and analyzing data from established public air quality monitoring systems, the WHO database provides valuable insights into the global air pollution landscape. This information is essential for countries to take targeted actions to reduce air pollution levels, protect public health, and work towards sustainable development goals. The database serves as a vital tool in the ongoing efforts to mitigate the harmful impacts of air pollution on human well-being and the environment.

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