Factors Behind Air Pollution Percentages

Air pollution is a major threat to global health and prosperity, causing more than 6.5 million deaths each year worldwide. It refers to the release of pollutants into the air, which are detrimental to human health and the planet. While air pollution can occur naturally, such as from wildfires, volcanic ash, or windblown dust, it is predominantly caused by human activity, particularly the burning of fossil fuels. These fossil fuels include coal, natural gas, and oil, which are burned for energy production, transportation, and industrial processes. Other human-made sources include cigarette smoke, e-cigarettes, and agricultural burning. Pollutants in the air can be in the form of gases, such as carbon dioxide, carbon monoxide, and nitrogen oxides, or particulate matter, which is made up of tiny particles of chemicals, soil, smoke, dust, or allergens. These pollutants contribute to respiratory and cardiovascular problems, including lung cancer, and can have both short-term and long-term effects on human health.

Fossil fuels and industrial processes

Fossil fuels are a major contributor to air pollution. The burning of fossil fuels releases harmful pollutants into the atmosphere, including nitrogen oxides, sulphur dioxide, and airborne particles such as soot. Fossil fuels include oil, natural gas, and coal, which are used to generate electricity and power transportation and industrial processes. The combustion of these fuels releases nitrogen oxides, which contribute to the formation of smog and acid rain. Additionally, the unearthing, processing, and transportation of fossil fuel deposits can also generate significant air pollution. For example, drilling and mining operations produce large amounts of wastewater, which can be contaminated with heavy metals and other pollutants, and leak into waterways.

The use of fossil fuels in energy production and transportation emits nitrogen pollution and greenhouse gases, such as carbon dioxide (CO2) and nitrous oxide (N2O). These gases remain in the atmosphere for extended periods, intensifying the greenhouse effect and increasing the Earth's average air temperatures. The increased presence of these gases in the atmosphere has far-reaching effects on our climate and ecosystems, including environmental and human health problems.

Furthermore, the burning of fossil fuels releases toxic chemicals such as benzene and formaldehyde, which are linked to serious health issues including cancer and blood disorders. According to a 2017 study, millions of Americans are exposed daily to toxic air pollution from active oil and gas wells, transport, and processing facilities.

To address these issues, businesses and governments are implementing measures to reduce emissions and improve air quality. Leading businesses are taking steps to manage and reduce their greenhouse gas emissions by setting long-term targets and improving energy efficiency. Additionally, governments are introducing regulations and incentives to promote the use of renewable energy sources and reduce emissions from power plants.

The EPA in the United States, for example, has developed national programs aimed at significantly reducing air emissions and improving air quality. As a result of these collective efforts, emissions of common air pollutants and their precursors have substantially decreased since 1980, leading to improved health and quality of life for many Americans.

Vehicle emissions

One of the primary pollutants emitted by vehicles is carbon dioxide (CO2). CO2 is released when gasoline or diesel fuel is burned, and the amount emitted depends on the vehicle's fuel type, fuel economy, and mileage. A typical passenger vehicle emits about 4.6 metric tons of CO2 annually, with higher emissions from diesel fuel compared to gasoline.

In addition to CO2, vehicles also emit other greenhouse gases (GHGs) such as methane (CH4) and nitrous oxide (N2O) from their tailpipes. While the emissions of these gases may be smaller in quantity, they have a higher global warming potential than CO2, making them significant contributors to climate change. Electric vehicles (EVs) have gained attention for their reduced environmental impact, as they do not produce tailpipe emissions and only emit a small amount of GHGs due to air conditioner leakage.

Vehicles also contribute to smog formation, which is a type of ground-level ozone. Smog occurs when emissions from combusting fossil fuels, such as gasoline or diesel, react with sunlight. This can irritate the eyes and throat and cause respiratory issues, particularly in vulnerable populations such as children and the elderly. To address this issue, the Environmental Protection Agency (EPA) provides resources like the Green Vehicle Guide to help consumers choose vehicles with lower smog-forming emissions.

Furthermore, vehicle emissions can include toxic substances such as lead, which has been associated with severe health risks. However, regulations and programs, such as the phase-out of leaded gasoline and the Renewable Fuel Standard program, have successfully reduced lead concentrations in the US by 98% between 1980 and 2005. These efforts demonstrate a commitment to mitigating the health and environmental impacts of vehicle emissions.

Natural sources

Wind-blown Dust

Dust storms from deserts like the Sahara, the Gobi, and the Taklamakan are responsible for PM2.5 pollution due to the size of the grains spread. Wind can also move air pollutants short or very long distances before they cause harmful impacts. For example, parks downwind of power plants that lack modern pollution controls can experience increased smog.

Wildfires

Wildfires generate high levels of PM (particulate matter) pollution, along with CO (carbon monoxide) and NOx (nitrogen oxides). Particulate matter is made up of tiny particles of chemicals, soil, smoke, dust, or allergens that are carried in the air. The smaller the particles are, the worse they can be for human health, as they can enter our lungs and airways and, in some cases, the bloodstream.

Volcanoes

Volcanoes release NH3 (ammonia) and SO2 (sulfur dioxide) during eruptions, which can form secondary PM when combined with other pollutants in the atmosphere.

Indoor pollution

Indoor air pollution is a serious issue that can have detrimental effects on human health. While the specific health consequences depend on the type of pollutant, the duration and level of exposure, and individual factors such as age and pre-existing health conditions, indoor air pollution has been linked to a range of adverse outcomes, including irritation of the eyes, nose, and throat, headaches, dizziness, fatigue, and aggravation of respiratory conditions like asthma. In the long term, exposure to indoor air pollutants can lead to respiratory diseases, heart disease, and even cancer.

There are numerous sources of indoor air pollution. One significant contributor is outdoor air pollution, particularly in cases where there is inadequate ventilation to dilute emissions and remove indoor air pollutants. High temperature and humidity levels can also exacerbate indoor pollution by increasing pollutant concentrations.

Specific sources of indoor pollution include improperly adjusted gas stoves, which can emit high levels of carbon monoxide. Building materials, furnishings, and products like air fresheners can continuously release pollutants, while activities such as smoking, cleaning, redecorating, or engaging in certain hobbies can intermittently release pollutants. Unvented or malfunctioning appliances, such as chimneys, flues, and cracked furnace heat exchangers, can also release dangerous levels of pollutants. Additionally, wood-burning stoves that are not properly maintained and vented can emit harmful substances, including hydrocarbons, contributing to increased respiratory symptoms in children.

Biological sources of indoor pollution include plants, people, and animals. Building materials and conditions that support the growth or dissemination of biological pollutants, such as mould and mildew, can also be significant contributors. Contaminated central air handling systems can further exacerbate the presence of biological pollutants.

Another critical aspect of indoor air pollution is the presence of hazardous substances like asbestos. Improper attempts to remove asbestos-containing materials can release asbestos fibers into the air, endangering the health of occupants. Radon gas, a colorless, odorless, and radioactive gas released from uranium in the soil or rock on which homes are built, is another indoor pollutant that can have severe health implications.

Environmental justice

The United States Environmental Protection Agency (EPA) defines environmental justice as ensuring that everyone has the same level of protection from environmental and health hazards and equal involvement in decisions supporting environmental health. Despite this mandate, disadvantaged communities, particularly communities of color and other marginalized groups, bear a heavier burden of harm from air pollution. This disparity is a result of historical discrimination in areas such as housing, education, employment, and healthcare, as well as underinvestment in these communities.

Research on environmental justice has revealed that certain racial, ethnic, and socioeconomic groups are exposed to higher levels of pollution, have lower overall environmental quality, and experience higher rates of environmentally-driven diseases. For example, studies in the United States have shown that racial and ethnic minorities and low-income communities tend to experience higher ambient pollution levels due to their proximity to highways and polluting facilities. Additionally, rural areas, which are often home to older, non-Hispanic white populations, are less likely to be monitored for air quality, leading to a lack of data and potentially hiding even greater disparities.

On a global scale, countries in the Global South, including those in Latin America, Africa, Asia, and Oceania, suffer the most from air pollution-related premature deaths. Climate change is also expected to disproportionately affect low-income countries, with larger temperature-driven reductions in GDP per capita. Furthermore, within Europe, ethnic minorities such as Roma communities have been found to be more vulnerable to the impacts of climate change, such as flooding.

Addressing environmental justice in the context of air pollution requires recognizing the intersection of social and environmental factors and working towards equitable solutions that protect the health and well-being of all communities, regardless of their racial, ethnic, or socioeconomic characteristics.

Frequently asked questions