Riccardo Liguori Find out how these invisible enemies are threatening our health and the planet, and what we can do to address them
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Have you ever experienced that annoying burning sensation in your eyes and throat when the air is unbreathable? It’s not just “smog“. It’s a cocktail of toxic substances that are severely impacting our health and the environment. Let’s meet the five main culprits of this story.
Sulfur oxides (SOx): the kings of acid rain
These gases, particularly sulfur dioxide (SO2), irritate the eyes and upper respiratory tract, as well as nasal mucous membranes and lungs. They are the culprits behind the infamous acid rain, which corrodes monuments and buildings, lowers the pH of lakes, rivers, and seas, and depletes the soil.
Where do they come from? Primarily from the combustion of fossil fuels like coal and oil, as well as some industrial processes and thermal power plants.
Nitrogen oxides (NOx): the silent killers
Nitrogen dioxide (NO2) is the most well-known member of this family. Nitrogen oxides (NOx) not only irritate the lungs and worsen asthma but also contribute to the notorious photochemical smog, the toxic haze that envelops cities on hot, sunny days. NOx can react with other air pollutants (like hydrocarbons and sulfur oxides) to form tropospheric ozone and fine particles. Nitrogen oxides also contribute to the formation of nitric acid (HNO3), which can cause acidification of soil and water.
And guess what? NOx mainly comes from vehicle exhaust and power plants.
Carbon monoxide (CO): the oxygen thief
This colorless and odorless gas is a real oxygen thief. Toxic and non-irritating, it can reach high concentrations without adequate ventilation. When inhaled, it binds to hemoglobin in the blood, preventing it from carrying oxygen to our organs.
How is it produced? Mainly, once again, by motor vehicles and domestic heating systems.
Ground-level ozone (O3): the bad ozone paradox
Ozone is a strange gas: in the stratosphere, it protects us from UV rays, but at ground level, it becomes an enemy.
Tropospheric ozone is a secondary pollutant, the result of a chemical reaction between NOx and volatile organic compounds in the presence of high temperatures and strong sunlight. Its effects include lung damage, asthma, and bronchitis.
Particulate matter (PM): the fine dust
These tiny particles, especially the infamous PM2.5 (and the larger PM10), are so small they can penetrate deep into our lungs and bloodstream. The damage they cause includes respiratory problems, cardiovascular diseases, and even cancers.
The sources? Vehicle traffic, industrial emissions, and biomass combustion.
What we can do to breathe cleaner air
The point is always this: breathing clean air is a right, and being informed about the risks of air pollution and acting to reduce it is a duty for all of us.
Where should we start? A good beginning could be:
- Supporting the transition to renewable energy sources. Reducing dependence on fossil fuels is essential to decrease pollutant emissions.
- Choosing sustainable mobility. Walking, cycling, using public transport, or driving electric cars is a great start.
- Consuming less energy. Reducing energy consumption helps cut greenhouse gas emissions (and saves us money).
- Supporting ambitious environmental policies that invest in reforestation projects, urban redesign, and biodiversity conservation.
