Air Pollution: What's In Smog?

Smog and air pollution are detrimental to human health and the planet. Smog is a type of intense air pollution that occurs when emissions from combusting fossil fuels react with sunlight. It is composed of nitrogen oxides, sulfur oxide, ozone, smoke, and other particulates. Sources of smog include cars, trucks, factories, power plants, and incinerators. Air pollution, on the other hand, is caused by solid or liquid particles, called aerosols, and certain gases that are suspended in the air. These particles and gases can come from car and truck exhaust, factories, dust, pollen, mold spores, volcanoes, and wildfires. Both smog and air pollution have negative impacts on human health, with smog irritating the eyes and throat and damaging the lungs, and air pollution being associated with diseases of the heart and lungs, cancers, and other health problems.

Ground-level ozone

The formation of ground-level ozone is influenced by various factors, including temperature and sunlight. During the summer months, when there is more heat and sunlight, higher levels of ozone are formed, leading to increased pollution. This is why regions often experience worse air quality during the summer. Additionally, ground-level ozone is less concentrated than stratospheric ozone, but its health effects are a significant concern.

To improve air quality and reduce ground-level ozone, the EPA works with states and tribes to implement plans, such as the state implementation plan (SIP), to meet national air quality standards. These efforts involve regulating emissions from vehicles, power plants, industrial boilers, and other sources of ozone precursors. By reducing the formation of ground-level ozone, we can mitigate its harmful effects on human health and the environment.

Nitrogen oxides

To address the issue of nitrogen oxide pollution, organisations like the US EPA have implemented standards and programs to reduce emissions from vehicles and other sources. The EPA's rules aim to help state and local governments meet the National Ambient Air Quality Standard (NAAQS) for NO2. Additionally, the EPA's Diesel Emissions Act Reduction program provides funding for projects that reduce harmful emissions from diesel engines.

Particulate matter

Additionally, particulate matter can be composed of solid or liquid particles, known as aerosols, which are suspended in the air. These aerosols can come from car and truck exhaust, factories, wildfires, volcanic eruptions, dust, pollen, and mould spores.

The presence of particulate matter in the air can have detrimental effects on human health. Long-term exposure to particulate matter and other air pollutants has been linked to various diseases, including those affecting the heart and lungs, as well as cancers and other health problems. Therefore, it is crucial to monitor and regulate particulate matter to ensure the air we breathe is safe and does not pose risks to our health and well-being.

Fossil fuel emissions

Fossil fuels are a major contributor to air pollution, with fossil fuel emissions releasing large amounts of carbon dioxide, a greenhouse gas, into the air. In 2018, 89% of global carbon dioxide emissions came from fossil fuels and industry, with coal being the largest contributor, responsible for over 0.3 degrees Celsius of the 1-degree increase in global average temperatures. Oil releases a significant amount of carbon when burned, accounting for about a third of global carbon emissions. Natural gas, often promoted as a cleaner alternative, still accounts for a fifth of global carbon emissions.

The combustion of fossil fuels for energy production and transportation is a significant source of air pollution. Cars, trucks, factories, power plants, and engines that burn fossil fuels emit pollutants such as nitrogen oxides, sulfur oxides, ozone, and particulate matter. These emissions contribute to the formation of smog, particularly during warmer and sunnier weather when the upper air inhibits vertical circulation. Smog can irritate the eyes and throat and damage the lungs, especially for vulnerable individuals such as children, the elderly, and those with asthma or allergies.

Transportation is a significant contributor to air pollution, with emissions from vehicles and freight transportation leading to the formation of smog and the release of toxic pollutants. To address this issue, organizations like the US Environmental Protection Agency (EPA) have implemented programs and standards to reduce emissions from vehicles and engines, improve air quality, and protect public health.

The production and use of fossil fuels have severe environmental and health impacts. Fossil fuel extraction, transportation, and refining can lead to oil spills, water pollution, and habitat destruction. Air pollution from fossil fuels can cause acid rain, eutrophication, crop damage, and harm to wildlife and human health. It is important to transition to renewable energy sources and phase out fossil fuel usage to mitigate these harmful effects and reduce global warming.

Industrial emissions

In some cities, industrial emissions are the greatest contributor to atmospheric pollution, surpassing even domestic heating systems. Certain industrial facilities, such as metallurgic, oil refining, and pitch coking plants, have been identified as major sources of carcinogenic hydrocarbons and other harmful emissions. The largest industrial installations account for a significant share of total key atmospheric pollutant emissions, and their waste and energy consumption further contribute to environmental degradation.

To address the issue of industrial emissions, various strategies and regulations have been implemented. For example, the European Union (EU) has introduced EU-wide legislation and the Zero Pollution Action Plan to mitigate the environmental and health impacts of industrial installations. Additionally, organisations like the United States Environmental Protection Agency (EPA) have implemented programs to reduce emissions from transportation sources, resulting in improved air quality and positive health outcomes for citizens.

The classification of industrial emissions can be based on the type of polluting substance, the industrial activity, or the emitting focus. In Spain, for instance, industrial activities are categorised into three groups (A, B, and C) based on their pollution potential. Continuous perimeter monitoring systems are also used to ensure compliance with emission limit values, especially for diffuse emissions that originate from multiple sources within an industrial area.

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