Air Pollution: What's In The Air We Breathe?

Ambient air pollution is a leading environmental risk factor that affects the health of urban and rural populations worldwide. It is a broader term for air pollution in outdoor environments, which occurs when pollutants reach high enough concentrations to affect human health and/or the environment. The World Health Organization (WHO) estimates that ambient air pollution caused 4.2 million premature deaths globally in 2016, with 88-89% of these occurring in low- and middle-income countries. Long-term exposure to air pollution reduces life expectancy, mainly due to cardiovascular and respiratory diseases and lung cancer. Short-term exposure can also cause a range of adverse health effects, including impacts on lung function, exacerbation of asthma, and increases in hospital admissions. The sources of ambient air pollution include the burning of fossil fuels, traffic-related emissions, industrial activities, agricultural activities, and wildfires.

Ambient air pollution is a broader term for outdoor air pollution

The World Health Organization (WHO) defines ambient air pollution as potentially harmful pollutants emitted by industries, households, cars, and trucks. These pollutants include particulate matter (PM), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2). The greatest burden of ambient air pollution is found in the WHO South-East Asia and Western Pacific Regions, with 89% of premature deaths occurring in low- and middle-income countries.

Sources of ambient air pollution include the burning of fossil fuels, traffic-related emissions, industrial activities, agricultural activities, and wildfires. The health risks associated with exposure to ambient air pollution are well-documented, with long-term exposure reducing life expectancy due to cardiovascular and respiratory diseases and lung cancer. Short-term exposure can also cause adverse health impacts, such as effects on lung function, exacerbation of asthma, and increased respiratory and cardiovascular hospital admissions.

There are successful policies and interventions that can reduce ambient air pollution. For example, promoting clean technologies, improving waste management, ensuring access to clean household energy solutions, shifting to clean modes of power generation, and improving the energy efficiency of buildings can all contribute to reducing air pollution levels and protecting public health.

In summary, ambient air pollution is a serious environmental and public health issue that requires coordinated action by local, national, and regional policymakers to implement effective policies and interventions. Reducing ambient air pollution will not only improve air quality but also cut emissions of short-lived climate pollutants and greenhouse gases.

The World Health Organization (WHO) estimates that 4.2 million premature deaths were caused by ambient air pollution in 2016 and 2019

Ambient air pollution is a term used to describe air pollution in outdoor environments. It occurs when pollutants reach high enough concentrations to affect human health and/or the environment. Urban outdoor air pollution is a specific type of ambient air pollution that affects populations in urban areas, typically in or around cities. Ambient air pollution contains a range of pollutants, including particulate matter (PM), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2). These pollutants can have significant health impacts, including respiratory and cardiovascular issues, lung cancer, and possible links to dementia and cognitive decline.

The high number of premature deaths attributed to ambient air pollution highlights the urgent need to address this issue. WHO has identified several successful policies and interventions that can reduce air pollution levels. These include implementing clean technologies to reduce industrial emissions, improving waste management practices, transitioning to cleaner modes of power generation and transport, and promoting energy efficiency in homes and buildings.

By taking concerted action in these areas, local, national, and regional policymakers can significantly reduce ambient air pollution, protect public health, and reduce the number of premature deaths attributed to poor air quality. It is important to note that the WHO's estimates may be conservative, as they do not include deaths caused by all air pollutants. The actual number of deaths attributable to ambient air pollution may be even higher.

In addition to the human health impacts, ambient air pollution also affects the environment. For example, black carbon, a component of soot emissions from diesel vehicles and other sources, contributes to regional environmental disruption and accelerates glacier melting. Therefore, addressing ambient air pollution is crucial not only for human health but also for mitigating environmental damage.

The leading causes of death are ischaemic heart disease, strokes, chronic obstructive pulmonary disease, and lung cancer

Ambient air pollution refers to the contamination of the outdoor air we breathe. It is a major environmental health problem affecting everyone, regardless of their location or economic status. In 2019, it was estimated that ambient air pollution caused 4.2 million premature deaths worldwide, with 89% of these occurring in low- and middle-income countries.

The leading causes of death globally are ischaemic heart disease, strokes, chronic obstructive pulmonary disease (COPD), and lung cancer. These conditions have strong links to air pollution, which is a key risk factor for non-communicable diseases.

Ischaemic heart disease is linked to long-term exposure to particulate air pollution, which contributes to oxidative stress, inflammation, and the progression of atherosclerosis. Short-term exposure to fine particulate matter may also trigger acute events, such as myocardial infarction.

Strokes are also associated with air pollution. Smaller nanoparticles can enter the alveolar spaces of the lungs and may infiltrate the bloodstream, affecting systemic organs. While the relative risk of stroke may be small for an individual, the widespread exposure to air pollution means the absolute risk at a population level is significant.

Long-term exposure to air with high concentrations of pollutants increases the incidence of COPD. Air pollution exacerbates existing symptoms, impairs lung function, and increases hospitalisation and mortality rates.

Lung cancer is also caused by particle pollution, which increases the risk of early death. Fine particles enter deep into the lungs and are linked to cancer. Sources of these particles include vehicle exhaust, coal-fired power plants, and other industrial sources.

Addressing air pollution is crucial to protecting public health and reducing mortality rates from these leading causes of death. Implementing cleaner technologies, improving waste management, transitioning to clean energy sources, and promoting sustainable transport options are essential steps to improving air quality and public health outcomes.

Pollutants with the strongest evidence for public health concerns include particulate matter (PM), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2)

Ambient air pollution is a major environmental health problem affecting people globally. It is associated with 6.7 million premature deaths annually, with 4.2 million of these occurring in low- and middle-income countries.

Particulate matter (PM) is a complex mixture of extremely small particles and liquid droplets containing acids, organic chemicals, metals, and soil or dust particles. PM is categorised by size and is the fraction of air pollution most reliably associated with human disease. It contributes to cardiovascular and cerebrovascular disease through mechanisms such as systemic inflammation and direct translocation into systemic circulation. The World Health Organization estimates that PM air pollution causes approximately 800,000 premature deaths each year.

Ozone (O3) is a harmful ground-level air pollutant formed in the troposphere by the interaction between sunlight and precursor gases, mainly nitrogen oxides (NOx) and volatile organic compounds (VOCs). High O3 levels are observed during warm seasons and are associated with adverse respiratory health outcomes, including aggravating asthma and chronic obstructive pulmonary disease. Exposure to O3 is a significant cause of premature mortality, especially during the summer.

Nitrogen dioxide (NO2) is a toxic gas found in polluted regions, particularly near the ground. It is produced from burning fossil fuels for transportation, power generation, industrial activity, and wildfires. NO2 plays a crucial role in the formation of ground-level O3 and PM pollution. TEMPO measurements have detected high levels of NO2 over multiple urban areas in North America, including cities and major highways.

Sulphur dioxide (SO2) emissions have historically caused significant environmental damage, as seen in the loss of lichen species across England. However, background level concentrations of SO2 in the UK have decreased to the point where they no longer pose a threat to plant health, leading to the recovery of lichen populations. International shipping is a large and increasing source of sulphur emissions, suggesting it will become a significant contributor to UK SO2 emissions in the future.

Policies and investments supporting cleaner transport, energy-efficient homes, and better waste management can reduce outdoor air pollution

Ambient air pollution is a term used to describe air pollution in outdoor environments. Poor ambient air quality occurs when pollutants reach high enough concentrations to affect human health and/or the environment. Urban outdoor air pollution is a specific type of ambient air pollution experienced by populations in urban areas, usually in or around cities.

Ambient air pollution is a leading environmental risk factor affecting populations around the world, resulting in an estimated 4.2 million premature deaths in 2016, and 4.2 million in 2019. The greatest number of these premature deaths occurred in low- and middle-income countries, with 89% of premature deaths in 2019 occurring in these areas. The World Health Organization (WHO) estimates that 12.5% of deaths could be prevented by improving air quality worldwide.

As most sources of outdoor air pollution are beyond the control of individuals, local, national, and regional policymakers must take concerted action. Successful policies and investments in cleaner transport, energy-efficient homes, and better waste management can significantly reduce outdoor air pollution.

Cleaner Transport

Transportation sources in 2010 were responsible for more than a quarter of U.S. greenhouse gas emissions. Policies have since been implemented to encourage the use of cleaner fuels and engines, and the development of more fuel-efficient vehicles. For example, the EPA and the U.S. Department of Transportation have jointly set standards for medium- and heavy-duty vehicles that will improve fuel efficiency and cut carbon pollution. The shift towards cleaner, more efficient modes of power generation and transportation, such as walking, cycling, and rail networks, can help reduce emissions and improve air quality.

Energy-Efficient Homes

Access to clean household energy solutions for cooking, heating, and lighting can significantly reduce ambient air pollution. Improving the energy efficiency of buildings and making cities more compact and green can also help reduce air pollution and improve public health.

Better Waste Management

Improved management of urban and agricultural waste, including capturing methane gas emitted from waste sites and using it as biogas, can help reduce air pollution. Additionally, reducing industrial smokestack emissions through clean technologies can mitigate the environmental impact of waste management practices.

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