Air Pollution: Is It Improving Or Worsening?

Air pollution is a mix of hazardous substances from human-made and natural sources, including vehicle emissions, fuel oils, natural gas, manufacturing by-products, and wildfires. It is a major threat to global health, causing approximately 6.5-8.1 million deaths annually. Air pollution is associated with various diseases, including asthma, strokes, heart attacks, cancer, and respiratory illnesses. It also impacts the planet, damaging vegetation, ecosystems, water and soil quality, and contributing to climate change. Despite the harmful effects of air pollution, clean air projects often lack sufficient funding, and many countries lack adequate pollution standards. However, regulations such as the Clean Air Act in the United States and the Ambient Air Quality Directives in the EU have been implemented to improve air quality and reduce health risks.

Air pollution's impact on health

Air pollution is a well-known environmental health hazard, and it is the single largest environmental health risk in Europe. It is caused by the presence of contaminants in the atmosphere, such as dust, fumes, gas, mist, odour, smoke or vapour. These pollutants can be harmful to human health, especially when inhaled into the lungs. The main pathway of exposure from air pollution is through the respiratory tract, which can lead to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, and brain, among other organs.

Particulate matter (PM), carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2) are among the pollutants with the strongest evidence of adverse health effects. Fine particulate matter, such as PM2.5, poses the greatest health risks as these particles can be inhaled and accumulate in the respiratory system. They can penetrate deep into the lungs, enter the bloodstream, and travel to other organs, causing systemic damage to tissues and cells. This can lead to reduced lung function, respiratory infections, aggravated asthma, and an increased risk of chronic diseases, including lung cancer.

Short-term exposure to high levels of air pollution has been associated with increased emergency department visits and hospital admissions due to respiratory problems, cardiac issues, and asthma exacerbations. Long-term exposure, on the other hand, increases the risk of developing non-communicable diseases such as stroke, heart disease, chronic obstructive pulmonary disease, and cancer. Maternal exposure to air pollution during pregnancy is also associated with adverse birth outcomes, including low birth weight and pre-term birth, and an increased risk of hypertensive disorders.

Additionally, air pollution disproportionately affects certain populations, including children, the elderly, pregnant women, and individuals with pre-existing heart and lung diseases. Socioeconomic factors also play a role, as people in low-income neighbourhoods and communities of colour are often more vulnerable to air pollution due to their proximity to industrial sources of pollution and underlying health disparities. Overall, air pollution has severe health consequences, and addressing this issue is crucial to protect public health and reduce the risk of diseases and premature deaths.

The economic costs of air pollution

Air pollution is responsible for a wide range of economic costs, from healthcare costs associated with pollution-related illnesses and deaths to environmental damage and lost ecosystem services. Poor air quality has been linked to decreased workplace productivity and tourism, affecting economies worldwide.

In 2018, the global economic cost of air pollution was estimated at $2.9 trillion, equivalent to 3.3% of the world's GDP. This figure accounts for the impact of air pollution on the economy, including higher rates of asthma, diabetes, and chronic respiratory diseases, resulting in reduced ability to work and lower participation rates in the labor force. For example, in 2019, India's economy lost an estimated $95 billion, or 3% of its GDP, due to reduced productivity, work absences, and premature deaths caused by air pollution. Similarly, in 2018, the cost of dirty air in China amounted to 6.6% of its GDP, while in the US, it accounted for 3% of its GDP.

The economic burden of air pollution is not limited to direct healthcare costs but also includes other factors such as sick leave and preterm births. In 2018, disability due to chronic diseases cost the global economy $200 billion, while sick leave and preterm births cost $100 billion and $90 billion, respectively. Additionally, air pollution from wildfire smoke in the US is estimated to cost $16 billion annually, associated with 6,200 respiratory hospital visits and 1,700 PM2.5-related deaths.

While the overall economic costs of air pollution are significant, implementing air pollution control strategies can result in substantial economic benefits. Research on the Clean Air Act in the US found that the economic benefits of air pollution mitigation were 30 times higher than the costs. Similarly, an 85% economic benefit has been attributed to reductions in premature mortality associated with particulate matter pollution exposure. These findings highlight the potential for significant economic gains by investing in cleaner technology and green industry development.

Air pollution and climate change

Air pollution is the leading environmental cause of illness and premature death worldwide. Fine air pollution particles, or aerosols, are responsible for 6.4 million deaths every year from diseases such as heart disease, stroke, and lung cancer. About 95% of these deaths occur in developing countries, where people are exposed to far higher concentrations of air pollution.

Climate change is causing more frequent and intense heatwaves, which lead to more wildfires and higher emissions of harmful greenhouse gases and particulate matter. Hotter and drier conditions also increase the rates of photochemical production, leading to higher levels of air pollution. Climate change is also causing longer summers, increased droughts, and increased pollen, which contribute to worsening air quality.

However, addressing air pollution and climate change together can bring significant health and climate benefits. Reducing outdoor air pollution can lower emissions of carbon dioxide (CO2) and short-lived climate pollutants (SLCPs) such as black carbon and methane, which contribute to global warming and ill health. SLCPs have a much greater warming potential than CO2, so interventions to reduce SLCP emissions can deliver climate benefits in a relatively short time.

To tackle these interconnected issues, it is essential to transition from fossil fuel-based power to renewable energy sources, promote public and private transport that does not rely on fossil fuels, cut industrial emissions, and reduce emissions from agriculture. These solutions can improve air quality, slow global climate warming, and protect ecosystems.

Sources of air pollution

Air pollution is a serious issue that has been affecting human health and the environment for centuries, since humans started burning materials for fuel. While natural sources like wildfires, wind-blown dust, and volcanoes can contribute to air pollution, human-generated sources are often the primary culprits. These sources are typically categorised into four groups: mobile, stationary, area, and natural sources.

Mobile sources, such as cars, trucks, buses, trains, and planes, are a significant contributor to air pollution. In the United States, mobile sources account for more than half of all air pollution, with automobiles being the primary culprit. Older diesel engines, in particular, produce alarmingly high levels of fine particulate pollution. To address this, federal regulations have been implemented to make vehicles and equipment more efficient and less polluting, such as removing lead from gasoline and reducing sulfur in diesel fuel.

Stationary sources refer to large industrial sites that emit pollutants from a single location. This includes power plants, factories, refineries, and industrial boilers. These sources emit a variety of pollutants, including ozone, sulfur dioxide, nitrogen dioxide, nitrogen oxides, and particulate matter. Power plants are a major concern, as parks downwind of them can experience increased smog and haze-forming pollutants.

Area sources encompass smaller, more dispersed sources of pollution that can collectively have a significant impact. This includes agricultural areas, cities, residential wood burning, local businesses, heating and cooling equipment, and gas-powered yard equipment. Residential wood burning, in particular, has been increasing over time and has become a major source of fine particle emissions.

Natural sources, while not always causing ongoing pollution problems, can sometimes be significant. This includes wind-blown dust, wildfires, and volcanic eruptions. However, human-generated pollution is more persistent and widespread.

It is important to note that the sources of air pollution vary depending on the location and time of year. Additionally, the health impacts of air pollution are severe, with millions of premature deaths attributed to it annually. To address this global issue, interventions and initiatives are being promoted to support sustainable land use, cleaner energy, improved waste management, and more efficient transportation.

Air pollution control and regulations

Air pollution is a pressing issue that poses significant risks to human health and the environment. To combat this, various regulations and initiatives have been implemented to control and reduce air pollution, particularly in urban areas.

In the United States, the Clean Air Act (CAA) serves as the comprehensive federal law that regulates air emissions from both stationary and mobile sources. The CAA authorizes the Environmental Protection Agency (EPA) to establish National Ambient Air Quality Standards (NAAQS) to safeguard public health and welfare. Under the CAA, major stationary sources, such as power plants, are required to install pollution control equipment and meet specific emissions limitations. The CAA also mandates controls on air pollution from mobile sources, including motor vehicles and non-road engines, by regulating fuel composition and emission-control components.

State and local governments play a crucial role in implementing strategies to control transportation sector emissions. For instance, the New York City Department of Environmental Protection (DEP) is responsible for updating and enforcing the Air Pollution Control Code (Air Code), aiming to protect and improve the city's air resources. Similarly, Colorado has enacted laws such as HB21-1189 and HB22-1244 to regulate air toxics, requiring fenceline monitoring, community monitoring programs, and public data accessibility.

At the European level, the European Commission has established clean air policies with the aim of improving ambient air quality and tackling air pollution. The EU has set ambient air quality standards for all member states and has established national reduction commitments for five main air pollutants. Additionally, the EU cooperates with strategic partners to address transboundary air pollution and provides financial support to countries implementing clean air-related policies.

To summarize, air pollution control and regulations are essential to mitigate the adverse effects of air pollution on human health and the environment. Through comprehensive laws, standards, and initiatives, governments and organizations strive to reduce emissions, improve air quality, and ultimately, protect the well-being of their citizens.

Frequently asked questions