air pollution facts:

Why it exists and how it harms our health.

Anybody who’s opened a paper or watched the news over the last couple of years, has most probably heard about the phenomenon we call air pollution. Hazy views of once vibrant landscapes, cities filled with vehicle emissions and people wearing masks as protection against the air they forcefully breathe – it has all crossed our media platforms. But what exactly is air pollution, and what causes it? And more importantly, how does it affect the well-being of our planet as well as our own health? In this article we will explore the main causes of air pollution, as well as the harmful effects it has on our health and that of our environment.

Causes of air pollution

Air pollution is caused by a variety of factors. Your first thought might immediately go to car engines and their harmful carbon dioxide emissions, and although those do indeed play a part in the pollution of our air, causes are nowhere near limited to that. Natural causes also contribute to air pollution – though in small amounts – and humans have invented a large variety of ways to pollute the air we breathe. The causes listed below are the amongst biggest contributors to air pollution:

Natural causes

do not play a big role in the heavy pollution of the air today, but they do still contribute up to some extent. These sources of pollution depend for a large part on natural cycles, meaning they will be more common under certain circumstances. Natural causes of air pollution include:

Volcanic Activity

Although they are not the main source of climate change (as some people would like you to believe), volcanic eruptions do contribute to air pollution. The sulfuric, chlorine and ash products released into the atmosphere by an eruption can be picked up by the wind and affect large areas, tainting the air and contributing to overall air pollution.


Areas that suffer prolonged dry periods and have a lot of vegetation are especially prone to wildfires. The smoke, carbon monoxide and dust created by these wildfires contribute to the pollution of air. The smoke and carbon monoxide released add to the carbon levels in the atmosphere, which in turn causes the increased greenhouse effect responsible for the warming of the earth.


Dry areas form yet another risk for clean air when they have little to no vegetation, as heavy wind will cause sand-/dust storms that contribute to air pollution. The tiny particles are mixed with the air, forming a natural warming effect and a risk on the health of any living being breathing the air. Plants are affected as well, as the photosynthesis process in hindered by the particulate matter. This means that not only will the air be polluted by the dust, the process responsible for creating new oxygen will be compromised too…

Emissions from Animals and Vegetation

You probably already knew that animals – cattle in particular – release methane into the air as a result of their digestion. A less known fact, is that some plants can actually contribute to air pollution as well. Certain vegetation species (oak trees, willow trees, black gum and poplar for example) emit so-called volatile organic compounds (VOCs) when the weather is warm. Once these VOCs are released into the air, they react with primary anthropogenic pollutants - nitrogen oxides, carbon compounds and sulfur dioxide to be exact - and produce an ozone-rich, low-lying haze.

Man-made causes​

Ever since the industrialization of (most) societies, humans have managed to become the biggest polluters on the planet – by far. Man-made causes of air pollution form the vast majority of air pollution causes, with natural causes making up only a small, almost insignificant percentage. The biggest polluters we’ve created are linked to fossil fuel burning and use of chemicals – things we could easily replace if we really wanted to keep our air from becoming unbreathable… The most polluting man-made causes of air pollution are listed below:

Emissions from Fossil Fuel Burning

Our daily transportation still relies heavily on fossil fuels. Our cars, trains and planes are fed by fossil fuels, and by burning those they emit harmful gasses into the atmosphere. If the combustion is incomplete, vehicles will emit carbon monoxide – a major pollutant, as is nitrogen oxide that is emitted as a result of fossil fuel burning. Emissions as a result of transportation form a major part of air pollution; according to a 2013 study by the UCS, transportation is responsible for more than half the carbon monoxide and nitrogen oxides emitted in the US.

Factories and Industries

Cars, trains and airplanes are not the only heavy users of fossil fuel; Factories and industries such as power plants also run on “dirty” fuels such as coal and petroleum, and their burning emits carbon monoxide, organic compounds and hydrocarbons into the air. According to the Association of Concerned Scientists, industry is responsible for no less than 21% of greenhouse gas emission in the US alone. Electricity generation – also a major form of fossil fuel burning – accounts for another 31% of the greenhouse gas emissions in the US.  Aside from all this, factories and industries also release a huge amount of chemicals with their waste, polluting not only the air but the surrounding land and waterways as well.


Another huge contributor to air pollution can be found in agriculture. Not only does the digestive system of cattle produce quite some methane, in today’s farming practices we also have to take into account the huge amounts of chemical fertilizers and pesticides used on the land – harming not only the air and waterways, but in the long term they will actually have a negative effects on the plants and consequently crop yield as well. Furthermore, large areas of forest are often cleared to make way for the cattle, which of course is not exactly beneficial for clean air. Lastly, ammonia (released mostly from the animals’ manure) is let out into the air, having quite the hazardous effect on its cleanliness and breathability.


Another big player in the release of methane is the ever-growing number of landfills. Not only is this gas contributing to the worsening greenhouse effect, it will also catch flame spontaneously if left unchecked. This is the reason many landfills in India for example, are always smoldering and contribute significantly to the highly polluted air in the country. With our population growing steadily still and our huge appetite for consumption, the need for landfills keeps growing. This will push the methane production in the world even further up.


Minerals are not just extracted from below the surface of the earth without consequences. Mining activities are responsible for huge amount of air pollution and health problems amongst people as a result. This does not only concern workers of the mines, but the inhabitants of surrounding areas as well. During the mining process, heaps of dust and many chemicals are released into the air, causing significant pollution to our air.

Use of Chemical Household Products

The type of air pollution most often overlooked, is the indoor air pollution happening in many people’s houses. With the use of chemical (cleaning) products or painting equipment for example, many toxic chemicals are emitted. If the ventilation in your house is less than optimal, these chemical will keep swarming around the air and have hazardous effects on your health. You can notice this when you’ve just painted a wall for example – if you don’t open a window or two it will become almost impossible to breathe the air in that room.

Effects of Air Pollution

All this pollution getting into our air is obviously not without consequence. Human health suffers, of course, but other consequences on our environment are also worth taking note of, as they will eventually influence us as well… The main consequences of air pollution include, but are not limited to:


When fossil fuels are burned and emit harmful gases, these gases react with the sunlight to form smog. The main sources include emissions from cars, factories, power plants and incinerators – basically, anything that burns coal, gas or natural gas and emits hazardous gasses as a result. Smog is a well-known phenomenon in countries such as China and Japan, where many people are already experiencing the health-consequences such as irritated eyes and skin, damaged lungs and intensified asthma and allergies.  


As a result of incomplete combustion of hydrocarbons, tiny carbon particles are released into the atmosphere. Air mixed with these particles is called soot, but soot is also used to refer to other small particles of chemicals, soil, smoke, dust or allergens in the air, either in gas or solid form. The sources are similar to the sources of smog, but soot is considered even more harmful to the health. The tiny particles can penetrate the lungs and bloodstream, forming a very dangerous threat of lung disease and cancer. And as if that’s not enough, soot has also been proven to be the second-biggest contributor to global warming.

Acid Rain

Acid rain – formed by sulfur oxides and nitrogen oxides emitted into the air by the burning of fossil fuels – doesn’t always have to come in the form of rain. This substance containing harmful amounts of sulfuric and nitric acids can come in the shape of gas or solid particles, as well as snow, rain or fog. These downfalls harm trees and cause water bodies and soil to acidify, significantly endangering the wildlife depending on them.


This phenomenon is responsible for the creation of more and more so-called “dead zones” across the globe. When high concentrations of nitrogen make their way from air to the water, they accelerate the algae grow in the water body. This takes up most of the oxygen available in the water, leaving fish and other living beings without. As a result, nothing but the algae can really survive, and dead zones are created.

Ozone depletion

Ozone occurs on ground-level as well as in the stratosphere. In the stratosphere, it helps protecting us from harmful UV rays and regulating the temperature on earth. On ground-level however, ozone is a pollutant and dangerous for our health. Because of air pollution, we are now heading towards a future with too much ozone on ground-level and too little in the stratosphere (called  ozone depletion).

Damaged crops and forests

Crops, forests and other vegetation are heavily affected by air pollution. Ozone on ground-level for example, reduces crop growth, negatively affects the resistibility of tree seedlings and makes plants more susceptible to diseases, pests and rough weather. Acid rain and ozone depletion also contribute significantly to the damaging of crops and forests.

Climate change

Greenhouse gasses such as methane and carbon dioxide increase the greenhouse effect, meaning too much heat will get trapped in our atmosphere. This in turn leads to climate change; increased occurrence of extreme weather events, rising sea levels, etc. Carbon dioxides mainly come from the burning of fossil fuels, whereas methane comes mostly from agriculture as well as the drilling of gas and oil.

Effects on human health​

The irony is that this largely man-made pollution problem, doesn’t leave us unaffected. In fact, it does quite the opposite.

The most harmful air pollutants for our health are lead, mercury, dioxins and benzene. These pollutants mostly come from coal and gas combustion – especially if the combustion is incomplete.
- Benzene can be found in gasoline and will cause irritated skin, eyes and lungs. If you’re exposed to benzene too much, it could even cause blood disorders.
- Dioxins will affect your liver, harm your immune system, nervous system and endocrine system as well as your reproductive functions.
- Lead is especially dangerous to children, as it will damage their brain and kidneys, lower their IQ and compromise their learning abilities.
- A more well-known pollutant, mercury, can have a negative effect on the central nervous system. Finally, polycyclic aromatic hydrocarbons (PAHs), originating from vehicle emissions, are highly toxic substances that will affect lungs and liver and irritate your eyes and skin. They are also linked to cancer.

To sum it up, air pollution can have negative effects on the health ranging from irritated eyes to death by cancer or lung failure. The health effects include:

  • Irritated eyes, skin, nose and throat

  • Respiratory problems such as:
    - Wheezing
    - Coughing
    - Chest tightness
    - Trouble breathing

  • Worsening of heart- and lung problems

  • Higher risk of heart attack

  • Cancer

  • Damage to the immune system, neurological system, reproductive system and respiratory system

  • In extreme cases: death.

Although everybody breathing polluted air runs the risk of ending up with these health issues, some people run a higher risk than others. People that should take even more precautions are older adults, children, people with heart-/lung diseases and people that are often active outdoors.


As you’ve seen above, air pollution is one of the most serious problems of our time. Climate change and compromised health as a result are just a few of the consequences we as a society will have to deal with. Pollution is already at a critical level, and it will keep worsening if we don’t take steps to prevent it from harming us any further. Switching to clean energy, lessening our consumption and changing our habits are some of the steps we can take to prevent air pollution, and make our way to a future of clean and clear air where we can once again take a breath without worries.