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What is air pollution?

Air pollution is a local, regional and global problem caused by the emission of pollutants, such as gases, chemicals and small particles. Air pollution has negative impacts on human health and the environment, and for the most part, is invisible to the naked eye.

Examples of air pollutants include: nitrogen dioxide (NO2), ozone (O3), sulphur dioxide (SO2), methane (CH4), carbon monoxide (CO), volatile organic compounds (VOCs) and particulate matter (PM).

Why is air pollution important?

Clean air is important for a healthy environment. When polluted, the air around us can pose a major health risk for humans and ecosystems. 

Air pollution can cause severe health implications such as asthma, cancer and cardiovascular diseases. These health effects are most important to vulnerable groups such as children and the elderly. 

The health of our ecosystems relies on clean air too, and damage to these can affect agriculture and biodiversity.

Orange maple leaves tarred with black soot

Effects of air pollution

Air pollution poses a significant health risk and causes damage to our environment. It is the largest environmental health risk we face today, according to the World Health Organisation.

In the short term, air pollution causes symptoms including coughing, eye irritation and headaches.

But over a long-term, it becomes far more dangerous. Long-term exposure to air pollution contributes to cardiovascular diseases and some types of cancer. People with pre-existing conditions such as asthma are likely to feel the effects even worse, as air pollutants such as nitrogen dioxide inflame our airways

Air pollution can affect lung development in children, starting from pregnancy onwards, and has been linked to low birth weight too.

Particulate matter smaller than 10 micrometers, known as PM10, poses higher health risks as they are small enough to be inhaled deep inside our lungs. From here, particles can even sometimes enter our bloodstream.

Ozone is known for protecting our atmosphere from harmful ultraviolet radiation, but at ground level it can cause severe health problems. Ozone causes breathing problems, triggers asthma, and contributes to lung diseases.

Scientists believe that air pollution may contribute to mental health issues, and increase the risk of dementia.

Air pollution also affects our environment. Harmful gases, such as nitrogen dioxide and ozone, damage forests and crops. Plus, they deplete nutrients in soil and waterways. 

High levels of pollution create a semi-transparent haze in the sky, which makes visibility worse for transport drivers. 

Air pollutants contribute to increased climate change, causing extreme weather and food supply disruptions.