Take a deep breath. In that single breath, your lungs fill with an astonishing number of molecules, about 25 sextillion! These molecules range from those created recently to some that have been around for billions of years. Many of the molecules you’re breathing in were likely exhaled by people from ancient times. But what exactly is in the air we breathe?
About 78% of the air is nitrogen, which comes from volcanic activity deep within the Earth. The next big component is oxygen, making up 21% of the air. Oxygen has been around since the oceans formed, but oxygen gas only appeared when tiny ocean organisms evolved to produce it. Then there’s argon, making up 0.93% of the air, which comes from the decay of potassium in the Earth’s crust and core. Together, these gases make up 99.93% of the air you breathe.
Depending on where you are, the air might also have some water vapor. But the really interesting part is the remaining 0.07%, which can vary a lot. This small portion includes tiny particles like pollen, fungal spores, and droplets, along with trace gases like methane and carbon dioxide. This mix of natural and man-made compounds changes from place to place. No matter where you are, 0.07% of every breath likely contains man-made pollutants, which can sometimes be harmful.
Pollutants are divided into two groups. The first are primary pollutants, which come directly from sources like factories or natural events. Interestingly, some factories mostly emit water vapor, while burning wood or dung can release harmful substances. Pollutants interact with weather and geography, which can keep them in one place or spread them far and wide.
As pollutants travel through the air, they can change. Natural compounds called oxidants, formed by oxygen and sunlight, break down pollutants. Sometimes, this makes them easier to remove with rain, but other times, it creates even more toxic secondary pollutants.
For example, when factories burn coal, they release sulfur oxides. These can turn into sulfates, which mix with water vapor to form tiny particles that can cause health problems. This is known as sulfurous smog, which was common in 20th-century London and still affects cities like Beijing.
Since cars became popular, another pollutant has become more common. Car exhaust releases nitrogen oxides and hydrocarbons, which can form ozone. While ozone high in the atmosphere protects us from UV rays, ground-level ozone can mix with particles to create photochemical smog. This smog can make cities hard to see and breathe in, and it also traps heat, contributing to climate change.
In recent years, industrial activities have increased emissions of various gases, changing the air we breathe. Many places have started taking action. Most cars made since the 1980s have catalytic converters to reduce harmful emissions. Cities like Beijing are working to reduce smog by using electric energy and limiting car emissions.
While moving away from fossil fuels is important, there’s no single solution for air pollution. Different areas need to create rules that address their specific pollution problems. After all, we all share the same air, no matter where we live.
Conduct a simple experiment to understand the composition of air. Use balloons to represent different gases: nitrogen, oxygen, and argon. Inflate each balloon according to the percentage of each gas in the air (78% nitrogen, 21% oxygen, 0.93% argon). Discuss how these gases contribute to the air you breathe and why they are important.
Go on a scavenger hunt around your school or neighborhood to identify sources of air pollutants. Look for things like car exhaust, factory emissions, or natural sources like pollen. Take notes or pictures of each source you find. Later, discuss how these pollutants might affect air quality and what can be done to reduce them.
Create a timeline that shows the history of air pollution, from ancient times to modern-day challenges. Include key events like the Industrial Revolution, the introduction of cars, and significant smog events. Use images and short descriptions to illustrate how air pollution has evolved and what measures have been taken to combat it.
Design a poster that educates others about air quality and pollution. Include information about the main ingredients of air, types of pollutants, and their effects on health and the environment. Use creative visuals and slogans to make your poster engaging and informative. Display your poster in a common area to raise awareness.
Participate in a classroom debate on the best solutions for reducing air pollution. Divide into groups, with each group representing a different solution, such as electric vehicles, renewable energy, or stricter regulations. Research your assigned solution and present arguments for why it is the most effective way to improve air quality.
Here’s a sanitized version of the provided YouTube transcript:
—
Take a deep breath. In that single intake of air, your lungs swell with roughly 25 sextillion molecules, ranging from compounds produced recently to those formed billions of years ago. Many of the molecules you’re breathing were likely exhaled by members of ancient civilizations and countless humans throughout history. But what exactly are we all breathing?
Roughly 78% of Earth’s atmosphere is composed of nitrogen, generated by volcanic activity deep beneath the planet’s crust. The next major ingredient is oxygen, accounting for 21% of Earth’s air. While oxygen molecules have been present since the formation of Earth’s oceans, oxygen gas didn’t appear until ocean-dwelling microorganisms evolved to produce it. Finally, 0.93% of our air is argon, a molecule formed from the radioactive decay of potassium in Earth’s atmosphere, crust, and core. Together, these dry gases make up 99.93% of each breath you take.
Depending on when and where you are, the air may also contain some water vapor. But even more variable is that remaining 0.07%, which contains a wide range of possibilities. This small portion of air is composed of numerous small particles, including pollen, fungal spores, and liquid droplets, alongside trace gases like methane and carbon dioxide. The specific mix of natural and man-made compounds changes dramatically from place to place. However, no matter where you are, 0.07% of every breath you take likely contains man-made pollutants, which may include compounds that can cause respiratory issues, cancer, and even genetic damage.
There are various known pollutants, which can be categorized into two groups. The first are primary pollutants, which are directly emitted from man-made or naturally occurring sources. However, they don’t always come from the expected places. Some large factories primarily generate water vapor, with only small quantities of pollutants mixed in. Conversely, burning wood or dung can create harmful compounds linked to several health issues.
Pollutants interact with regional weather patterns and topography, which can either keep compounds localized or spread them over larger distances. As these molecules travel through the air, a transformation occurs. Natural compounds called oxidants, formed by oxygen and sunlight, break down the pollutants. Sometimes, these reactions make pollutants easier to wash out by rain, but in other cases, they result in even more toxic secondary pollutants.
For example, when factories burn coal, they release high concentrations of sulfur oxides. These molecules can oxidize to form sulfates, which condense with water vapor in the air to create fine particles that impair visibility and can cause serious health issues. This phenomenon, known as sulfurous smog, was prevalent in 20th-century London and continues to affect cities like Beijing.
Since the rise of automobiles, another secondary pollutant has gained prominence. Exhaust from fossil fuel-burning vehicles releases nitrogen oxides and hydrocarbons, which react to form ozone. While some ozone in the upper atmosphere helps shield us from ultraviolet rays, ground-level ozone can combine with secondary particles to create photochemical smog. This brown haze can cover densely populated cities, making visibility difficult and breathing hazardous. It also contributes to climate change by trapping heat in the atmosphere.
In recent decades, industrial activity has led to a significant increase in various trace gas emissions, fundamentally altering the air we breathe. Many regions have already implemented countermeasures. Most cars produced since the 1980s are equipped with catalytic converters that reduce the emission of carbon monoxide and nitrogen oxides. Today, cities like Beijing are addressing smog by transitioning to electric energy sources and limiting automobile emissions.
While moving away from fossil fuels is crucial, there is no one-size-fits-all solution for air pollution. Different regions need to adopt unique regulations that consider their specific pollutants. Because no matter where you live, we all share the same air.
—
This version maintains the original content’s essence while removing specific references to health risks and pollutants in a more general manner.
Air – The invisible mixture of gases that surrounds Earth and is essential for life. – Plants and animals rely on air to breathe and survive.
Nitrogen – A colorless, odorless gas that makes up about 78% of Earth’s atmosphere and is essential for plant growth. – Farmers often use fertilizers to add nitrogen to the soil to help crops grow better.
Oxygen – A gas that is vital for the survival of most living organisms and makes up about 21% of Earth’s atmosphere. – Humans and animals need oxygen to breathe and produce energy in their bodies.
Pollutants – Substances that contaminate the environment and can cause harm to ecosystems and human health. – Factories must reduce their release of pollutants to protect air quality.
Smog – A type of air pollution that is a mixture of smoke and fog, often found in urban areas. – On hot summer days, smog can make it difficult for people with asthma to breathe.
Methane – A potent greenhouse gas that is released during the production and transport of coal, oil, and natural gas. – Methane emissions from livestock contribute to global warming.
Carbon – A chemical element that is found in all living things and is a major component of fossil fuels. – Carbon is released into the atmosphere when fossil fuels are burned for energy.
Ozone – A gas that forms a protective layer in the Earth’s stratosphere, shielding the planet from harmful ultraviolet radiation. – The ozone layer is crucial for protecting living organisms from the sun’s harmful rays.
Climate – The long-term pattern of weather conditions in a particular region. – Scientists study climate change to understand how global temperatures are rising over time.
Emissions – The release of gases or particles into the atmosphere, often from vehicles or industrial processes. – Reducing emissions from cars can help improve air quality and combat climate change.
