Air Pollution: Understanding The Meaning And Its Impact

Air pollution is the contamination of the indoor or outdoor environment by any chemical, physical, or biological agent that modifies the natural characteristics of the atmosphere. It is caused by solid and liquid particles and certain gases that are suspended in the air. These particles and gases can come from car and truck exhaust, factories, dust, pollen, mould spores, volcanoes, and wildfires. Air pollution poses a major threat to health and climate, causing around 7 or 8 million deaths each year. It is a significant risk factor for a range of diseases, including stroke, heart disease, asthma, lung cancer, and other respiratory illnesses.

Natural sources of air pollution

While most harmful air pollution is caused by human activity, natural sources of air pollution are varied and include wildfires, sandstorms, sea spray, volcanoes, vegetation, decomposition, lightning, radon gas, wind-blown dust, and more. These natural sources release pollutants that affect air quality and can pose health risks and contribute to climate change.

Wildfires

Wildfires are one of the largest sources of black carbon, which is very harmful to human health and the environment. Black carbon, also known as soot, can lead to lung and heart diseases and premature death. It reduces sunlight, impacts plant ecosystems, and absorbs solar heat, contributing to global warming at a rate up to 1,500 times greater than that of CO2. Wildfire air pollutants can cause a range of adverse health effects, including difficulty breathing, an increased risk of asthma, heart failure, and premature death. While wildfires can be a natural phenomenon, largely human-driven global warming has exacerbated their frequency and intensity.

Volcanoes

Volcanoes emit massive amounts of sulphur dioxide, hydrogen sulfide, radon, sulfuric acid, hydrogen, carbon monoxide, hydrogen chloride, hydrogen fluoride, helium, and other gases into the atmosphere during eruptions. These emissions can increase background pollution levels for years, even in areas far away from the original source.

Vegetation and Organic Compounds

Organic compounds from plants, sea salt, suspended soils, and dust (such as from the Sahara) can contribute to air pollution. Methane, a colourless gas produced in the stomachs of ruminant animals like cows and sheep when bacteria break down their food, is another natural source of air pollution. Livestock is the biggest source of methane, which is a significant greenhouse gas that contributes to climate change.

Wind-Blown Dust and Sandstorms

In dry regions lacking vegetation, such as deserts, high winds can lift sand and dust particles into the air, causing sandstorms and dust storms. These storms can transport pollutants over short or long distances, affecting air quality in downwind areas.

While natural sources of air pollution can be significant, they typically do not create ongoing pollution problems like human-generated sources. However, understanding and addressing the impacts of both natural and human-made pollution are essential for improving air quality and mitigating health and environmental risks.

Health effects of air pollution

Air pollution is the contamination of the indoor or outdoor environment by any chemical, physical, or biological agent that modifies the natural characteristics of the atmosphere. It refers to the release of pollutants into the air—pollutants that are detrimental to human health and the planet as a whole.

Air pollution is now the biggest environmental risk factor for early death, responsible for more than 6 million premature deaths each year. It is a significant risk factor for a number of diseases, including stroke, heart disease, lung cancer, COPD, and respiratory infections. The most deadly components of air pollution are ozone, nitrogen dioxide, and sulfur dioxide.

Ozone, a powerful lung irritant, is formed in the atmosphere through reactions of volatile organic compounds and nitrogen oxides, which are formed as a result of the combustion of fossil fuels. Short-term exposure to ozone can cause chest pain, coughing, and throat irritation, while long-term exposure can lead to decreased lung function and cause chronic obstructive pulmonary disease. In addition, ozone exposure can aggravate existing lung diseases.

Nitrogen dioxide is a reddish-brown toxic gas with a strong odour, produced primarily by the transportation sector. It can form acid rain and haze, and cause nutrient pollution in water. Nitrogen oxides can also lead to the development and exacerbation of asthma and bronchitis, and an increased risk of heart disease.

Sulfur dioxide, emitted into the air by the burning of fossil fuels that contain sulfur, causes eye irritation, worsens asthma, increases susceptibility to respiratory infections, and impacts the cardiovascular system.

Particulate matter, or particle pollution, refers to a mixture of tiny bits of solids and liquids in the air. Coarse particles can cause nasal and upper respiratory tract problems, while fine particles penetrate deeper into the lungs and can cause heart attacks, strokes, asthma, and bronchitis, as well as premature death from heart ailments, lung disease, and cancer.

Black carbon, a component of particulate matter, is released from burning fuel, especially diesel, wood, and coal. Exposure to black carbon is associated with an increased risk of heart attacks, stroke, hypertension, asthma, chronic obstructive pulmonary disease, bronchitis, and various types of cancer.

Additionally, air pollution can impact mental health. Studies have found that people living in areas with poor air quality had a higher rate of bipolar disorder and major depression. Furthermore, exposure to air pollution during pregnancy can lead to preterm births and low birth weight. It can also cause slow brain and behaviour development in children.

Protecting Yourself from Air Pollution

To protect yourself from the harmful effects of air pollution, it is important to be aware of the air quality in your area. Tools like the EPA's Air Pollution Monitor can help you stay informed. When the air quality is poor, it is recommended to limit your time outdoors, especially for children and those who are physically more susceptible to the impacts of air pollution, such as the elderly, pregnant women, and people with existing diseases. If you must go outside, try to stay away from heavily trafficked roads, and consider wearing a mask labelled "NIOSH" with either "N95" or "P100".

It is also important to ensure your indoor air quality is good, as indoor air pollution can also have detrimental health effects. Keep your home well-ventilated to reduce the concentration of pollutants, especially when cooking, using cleaning products, or after painting or bringing in new furniture.

Air pollution from fossil fuels

Air pollution refers to the contamination of the indoor or outdoor environment by any chemical, physical, or biological agent that modifies the natural characteristics of the atmosphere. It is caused by the release of pollutants that are detrimental to human health and the planet. Fossil fuels are a major contributor to air pollution, with the combustion of fossil fuels releasing harmful pollutants into the atmosphere.

The burning of fossil fuels, such as coal, gasoline, and natural gas, releases a range of pollutants, including particulate matter, carbon monoxide, ozone, nitrogen dioxide, and sulfur dioxide. These pollutants have detrimental effects on human health, with exposure causing respiratory and other diseases. Fine particulate matter, or PM 2.5, which is released from the burning of fossil fuels, has been linked to various health issues, including strokes, heart diseases, lung cancer, and acute and chronic respiratory diseases.

The health impacts of air pollution from fossil fuels are significant, with recent studies indicating that it is responsible for a substantial number of premature deaths worldwide. One study found that air pollution from fossil fuels contributed to approximately 8.7 million deaths globally in 2018, with similar estimates in subsequent years. The combustion of fossil fuels has also been associated with long-term exposure to ozone air pollution, or smog, which can irritate the eyes and throat and damage the lungs.

Fossil fuel use in industry, power generation, and transportation are major sources of air pollution. The transition to renewable energy sources or nuclear power has been identified as an effective means of reducing air pollution and improving public health. Policies and interventions that support sustainable land use, cleaner energy and transport, energy-efficient housing, and better waste management can also help reduce air pollution from fossil fuels.

Additionally, air pollution from fossil fuels has global implications, contributing to the climate crisis. The consequences of burning fossil fuels, such as melting glaciers, rising sea levels, and increasing global temperatures, further emphasize the importance of addressing this issue. The phase-out of fossil fuels and the adoption of clean, renewable energy sources are crucial steps in mitigating air pollution and its associated health and environmental impacts.

How to reduce air pollution

Air pollution is the contamination of the indoor or outdoor environment by any chemical, physical, or biological agent that modifies the natural characteristics of the atmosphere. It refers to the release of pollutants into the air—pollutants that are detrimental to human health and the planet.

Reduce energy consumption

• Turn off electrical items when not in use.
• Choose efficient appliances and heating systems.
• Opt for a fan instead of air conditioning.
• Install low-flow showerheads.
• Wash laundry in cold water and line dry.
• Add insulation to your home.
• Use energy-efficient light bulbs.
• Turn off the lights and open the blinds to let in natural light.

Reduce vehicle emissions

• Walk or ride a bike when possible.
• Limit idling your vehicle to no more than 30 seconds.
• When buying a new car, choose the most efficient, lowest-polluting vehicle, or an electric car.
• Keep your car tyres properly inflated and ensure your car is serviced regularly.
• Use public transport where possible.

Reduce waste and emissions

• Start a recycling program at home or work.
• Print and photocopy on both sides of paper.
• Use less paper by sending emails instead of posting letters.
• Reuse items where possible instead of throwing them away.
• Compost food waste instead of sending it to landfill.
• Use a small bin and take it out regularly so you don't need to use bin liners.

Reduce exposure to chemicals

• Eliminate the use of toxic chemicals at home and opt for natural substitutes.
• Choose sustainable, non-toxic products.
• Avoid using chemical pesticides and fertilisers in your garden.
• Use an air purifier to reduce indoor air pollution.
• If you have a fireplace, use an EPA-approved wood-burning stove.

Support initiatives for change

• Support policies and investments that promote sustainable land use, cleaner energy, and transport.
• Advocate for stricter environmental regulations and renewable energy sources.
• Encourage local businesses, city offices, and schools to adopt more sustainable practices.
• Contact your local representatives to express your support for cleaner air initiatives.
• Participate in community initiatives to reduce toxic sources through local actions.

Air pollution and climate change

Air pollution refers to the contamination of the indoor or outdoor environment by any chemical, physical, or biological agent that modifies the natural characteristics of the atmosphere. It is the presence of substances in the air that are harmful to humans, other living beings, or the environment. Pollutants can be gases like ozone or nitrogen oxides, small particles like soot or other chemicals like lead.

Climate change can affect air quality, and certain air pollutants can, in turn, affect climate change. For example, hot sunny days associated with a warming climate can increase ground-level ozone in some areas. Ground-level ozone is also a greenhouse gas that contributes to climate change by trapping heat in the atmosphere.

Many of the sources of outdoor air pollution are also sources of high CO2 emissions. For example, the burning of fossil fuels for power generation, industry, and polluting transport are major sources of both particulate matter and CO2. Black carbon, a component of fine particulate matter, is one of the largest contributors to global warming after CO2. It warms the Earth's atmosphere by absorbing sunlight, accelerating the melting of snow and ice.

There are various pollution control technologies and strategies available to reduce air pollution. For instance, industrial plants can install scrubbers, such as flue gas desulfurization or catalysts, to remove nitrogen oxides. Regulatory initiatives, partnership programs, and individual actions can all help reduce air pollutants and greenhouse gas emissions.

Frequently asked questions