What’s in the air you breathe? - Amy Hrdina and Jesse Kroll

Summary

The video script delves into the composition of the air we breathe, highlighting that it's predominantly made up of nitrogen (78%), oxygen (21%), and argon (.93%), with trace amounts of water vapor and a complex mixture of particles and gases making up the remaining .07%. It explains the historical evolution of oxygen in the atmosphere and the presence of pollutants, both natural and man-made. The narrative further explores primary pollutants, their sources, and how they interact with the environment to form secondary pollutants, such as sulfurous smog and photochemical smog, which pose significant health and environmental risks. The script also touches on the impact of industrialization and transportation on air quality and the measures being taken globally to mitigate these effects, emphasizing the need for region-specific solutions to combat air pollution effectively.

Takeaways

• 🌬️ Every breath contains roughly 25 sextillion molecules, some of which date back billions of years.
• ⚫ Nitrogen makes up about 78% of Earth's atmosphere, originating from volcanic activity.
• 🌿 Oxygen, constituting 21% of air, was produced by microorganisms in the oceans.
• 💨 Argon, at 0.93%, is formed from the radioactive decay of potassium in Earth's crust, atmosphere, and core.
• 🌫 The remaining 0.07% of air is highly variable and contains trace gases and small particles like pollen and fungal spores.
• 🚫 Man-made pollutants are present in the 0.07% of air, potentially causing lung disease, cancer, and DNA damage.
• 🔥 Primary pollutants are directly emitted from sources, including some unexpected ones like burning wood or dung.
• 🌤️ Oxidants formed by oxygen and sunlight can transform pollutants into secondary pollutants, which can be more toxic.
• 🌫️ Sulfur oxides from coal burning can form sulfates, contributing to visibility impairment and lung damage, as seen in historical London smog.
• 🚗 Vehicle exhaust contributes to the formation of ozone and photochemical smog, impacting visibility and respiratory health.
• 🌍 Industrial activity has significantly increased trace gas emissions, altering the air quality worldwide.
• 🛠️ Countermeasures like catalytic converters in cars and electrification of energy infrastructure are being implemented to combat air pollution.
• 🏛️ Unique regulations are needed for different regions to address local pollutants effectively.

Q & A

What is the approximate number of molecules we inhale with a single breath?

With a single breath, we inhale roughly 25 sextillion molecules.

What percentage of Earth's atmosphere is composed of nitrogen, and what is its source?

Approximately 78% of Earth's atmosphere is composed of nitrogen, which is generated by volcanic activity deep beneath the planet's crust.

How much of Earth's air is made up of oxygen, and when did it first appear?

Oxygen accounts for 21% of Earth's air. Oxygen gas did not appear until ocean-dwelling microorganisms evolved to produce it.

What is argon, and what percentage of our air does it constitute?

Argon is a molecule formed from the radioactive decay of potassium in Earth's atmosphere, crust, and core, and it makes up 0.93% of our air.

What is the composition of the remaining 0.07% of the air we breathe, and what does it contain?

The remaining 0.07% of the air contains numerous small particles, including pollen, fungal spores, and liquid droplets, as well as trace gases like methane and carbon dioxide.

What are primary pollutants, and how do they differ from secondary pollutants?

Primary pollutants are toxic compounds that are directly emitted from a man-made or naturally occurring source. Secondary pollutants are formed when primary pollutants interact with natural compounds like oxidants, which can sometimes result in even more toxic compounds.

How do weather patterns and topography affect the spread of pollutants?

Weather patterns and topography can either keep pollutants local or spread them over kilometers away, depending on the conditions.

What is sulfurous smog, and how is it formed?

Sulfurous smog is a type of air pollution formed when sulfur oxides released from burning coal oxidize to form sulfates, which then condense with water vapor to create a blanket of fine particles that can cause severe lung damage.

How does the exhaust from fossil fuel-burning vehicles contribute to air pollution?

Exhaust from fossil fuel-burning vehicles releases nitrogen oxides and hydrocarbons, which react to form ozone. On the ground, this gas can form alongside secondary particles and create photochemical smog, which is harmful to both visibility and breathing.

What measures have been taken to reduce emissions from cars since the 1980s?

Most cars produced since the 1980s are equipped with catalytic converters that reduce the emission of carbon monoxide and nitrogen oxides.

Why is there no universal remedy for air pollution, and what is necessary for different regions?

There is no universal remedy for air pollution because different regions have unique local pollutants. Each region needs to respond with specific regulations tailored to their particular pollutants.

How has industrial activity in recent decades impacted the air we breathe?

Industrial activity in recent decades has led to a significant increase in various trace gas emissions, fundamentally changing the composition of the air we breathe.

Outlines

00:00

🌍 Breathing History: The Composition of Earth's Air

This paragraph delves into the fascinating composition of the air we breathe, highlighting the historical significance of the molecules we inhale. It begins by emphasizing the vast number of molecules—approximately 25 sextillion—that fill our lungs with each breath, some of which date back to ancient times. The primary components of Earth's atmosphere are nitrogen (78%), generated by volcanic activity, and oxygen (21%), which only became prevalent after microorganisms in the oceans began to produce it. Argon, a product of radioactive decay, makes up 0.93% of our air. Together, these gases account for 99.93% of the air we breathe. The remaining 0.07% is a variable mix of particles and trace gases, including man-made pollutants that can have detrimental health effects. The paragraph also touches on the role of regional weather and topography in the distribution of pollutants.

🌿 Primary Pollutants and Their Transformation

This section of the script focuses on primary pollutants, which are toxic compounds directly emitted from both man-made and natural sources. It challenges the common perception by pointing out that large factories may emit mostly water vapor with only small amounts of pollutants, while seemingly harmless activities like burning wood or dung can produce dangerous polycyclic aromatic hydrocarbons. The paragraph explains how pollutants interact with weather patterns and topography, potentially spreading them over large distances. It also discusses the transformation of pollutants in the air, facilitated by natural oxidants formed from oxygen and sunlight, which can either break them down or create even more toxic secondary pollutants. Examples include the formation of sulfates from sulfur oxides, leading to sulfurous smog, and the creation of ozone and secondary particles from vehicle exhaust, resulting in photochemical smog.

🚗 Addressing Air Pollution: Technological and Regulatory Measures

The final paragraph of the script addresses the impact of industrial activity on air quality and the measures taken to combat it. It mentions the significant increase in trace gas emissions due to industrialization and the subsequent health and environmental concerns. The script outlines technological advancements such as catalytic converters in cars since the 1980s, which have helped reduce emissions of carbon monoxide and nitrogen oxides. It also highlights current efforts in cities like Beijing to tackle smog by electrifying energy infrastructure and limiting automobile emissions. The paragraph concludes by emphasizing the need for region-specific regulations to address the unique pollutants present in different areas, recognizing the shared responsibility of protecting the air we all breathe.

Keywords

💡Molecules

Molecules are the smallest units of a chemical element or compound that can exist while retaining the chemical properties of that element or compound. In the context of the video, molecules are the basic building blocks of the air we breathe, which can include a vast array of substances from nitrogen to pollutants. The video emphasizes that the air contains molecules from various sources and time periods, highlighting the complexity and interconnectedness of our atmosphere.

💡Nitrogen

Nitrogen is a chemical element that makes up about 78% of the Earth's atmosphere. It is a colorless, odorless, and tasteless diatomic gas and is generated by volcanic activity. In the video, nitrogen is presented as the most abundant component of the air, which is essential for life on Earth but is not directly used by most organisms for respiration.

💡Oxygen

Oxygen is a chemical element and a gas that constitutes roughly 21% of Earth's atmosphere. It is vital for most life forms for respiration. The video explains that oxygen molecules have been present as long as Earth's oceans, but oxygen gas only became prevalent when certain microorganisms evolved to produce it. Oxygen is a key element in the air we breathe and is necessary for cellular respiration in animals and plants.

💡Argon

Argon is a noble gas that constitutes about 0.93% of the Earth's atmosphere. It is formed from the radioactive decay of potassium and is a colorless, odorless, and tasteless gas. The video mentions argon as one of the trace gases in the air, emphasizing that along with nitrogen and oxygen, it makes up the majority of the atmosphere's composition.

💡Water Vapor

Water vapor is the gaseous form of water and can be found in the Earth's atmosphere, typically making up a small percentage of the air. It is variable and depends on factors such as temperature and humidity. In the video, water vapor is mentioned as a component of the air that can vary depending on when and where you are, and it contributes to the overall composition of the atmosphere.

💡Pollutants

Pollutants are substances that contaminate the air, water, or soil, causing adverse effects on the health of living organisms and the environment. The video discusses both primary and secondary pollutants, highlighting their sources and their impact on human health and the environment. Primary pollutants are directly emitted from sources, while secondary pollutants form from reactions in the atmosphere. The video emphasizes the role of pollutants in air quality and their potential to cause serious health issues.

💡Primary Pollutants

Primary pollutants are toxic compounds that are directly emitted from a source, either man-made or natural. The video explains that these pollutants can come from various sources, including factories and burning of wood or dung, which can produce dangerous compounds like polycyclic aromatic hydrocarbons. These primary pollutants can interact with weather patterns and topography, affecting their dispersion and impact on air quality.

💡Secondary Pollutants

Secondary pollutants are formed when primary pollutants react in the atmosphere, often becoming more harmful than the initial pollutants. The video gives examples such as sulfur oxides, which can oxidize to form sulfates that contribute to the formation of smog. Secondary pollutants can also include ozone formed from nitrogen oxides and hydrocarbons in vehicle exhaust. These pollutants are a significant concern due to their potential to cause severe health and environmental problems.

💡Sulfurous Smog

Sulfurous smog is a type of air pollution characterized by a blanket of fine particles that can impair visibility and cause lung damage. It is formed when sulfur oxides released from burning coal oxidize and condense with water vapor. The video mentions that this type of smog was well-known in 20th-century London and continues to affect cities like Beijing, illustrating the historical and ongoing challenges of air pollution.

💡Photochemical Smog

Photochemical smog is a type of air pollution that occurs when sunlight reacts with pollutants like nitrogen oxides and hydrocarbons, often from vehicle exhaust, to form ozone and secondary particles. The video describes this brown fog as a hazard for both visibility and breathing, particularly in densely packed cities. It also contributes to climate change by trapping heat in the atmosphere, highlighting the multifaceted impact of air pollution.

💡Catalytic Converters

Catalytic converters are devices used in vehicles to reduce the emission of harmful gases, such as carbon monoxide and nitrogen oxides, by converting them into less harmful substances before they are released into the atmosphere. The video notes that most cars produced since the 1980s are equipped with catalytic converters, which have been an important technological response to reducing air pollution from transportation.

💡Electrifying Energy Infrastructure

Electrifying the energy infrastructure refers to the transition from fossil fuel-based energy systems to those powered by electricity, often generated from renewable sources. The video mentions that places like Beijing are battling smog by electrifying their energy infrastructure and limiting automobile emissions. This approach is part of a broader strategy to reduce reliance on fossil fuels and decrease air pollution.

Highlights

Every breath you take contains roughly 25 sextillion molecules.

Many molecules in the air were exhaled by ancient civilizations.

78% of Earth's atmosphere is nitrogen, generated by volcanic activity.

Oxygen accounts for 21% of Earth's air, produced by ocean microorganisms.

.93% of the air is argon, formed from the radioactive decay of potassium.

Dry gases make up 99.93% of the air we breathe.

The remaining .07% of air includes water vapor, natural, and man-made compounds.

.07% of each breath likely contains man-made pollutants, some toxic.

Primary pollutants are directly emitted from man-made or natural sources.

Burning wood or dung creates polycyclic aromatic hydrocarbons linked to cancer.

Pollutants interact with weather and topography, affecting their dispersion.

Oxidants in the air can transform pollutants, sometimes creating more toxic compounds.

Sulfur oxides from coal burning oxidize to form harmful sulfurous smog.

Photochemical smog from vehicle exhaust includes ground-level ozone.

Industrial activity has significantly increased trace gas emissions.

Catalytic converters in cars reduce emissions of carbon monoxide and nitrogen oxides.

Beijing is combating smog by electrifying energy infrastructure and limiting car emissions.

Different regions require unique regulations to address local air pollutants.

We all share the same air, emphasizing the need for global cooperation in reducing pollution.

Transcripts

Take a deep breath.

In that single intake of air,

your lungs swelled with roughly 25 sextillion molecules,

ranging from compounds produced days ago,

to those formed billions of years in the past.

In fact, many of the molecules you’re breathing were likely

exhaled by members of ancient civilizations

and innumerable humans since.

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 around as long as Earth’s oceans,

oxygen gas didn’t appear until ocean dwelling microorganisms

evolved to produce it.

Finally, .93% of our air is argon,

a molecule formed from the radioactive decay of potassium

in Earth’s atmosphere, crust, and core.

Together, all 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 .07%,

which contains a world of possibilities.

This small slice 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 cocktail of natural and man-made compounds

changes dramatically from place to place.

But no matter where you are,

.07% of every breath you take likely contains man-made pollutants—

potentially including toxic compounds that can cause lung disease, cancer,

and even DNA damage.

There’s a wide variety of known pollutants but they all fall into two categories.

The first are primary pollutants.

These toxic compounds are directly emitted

from a man-made or naturally occurring source.

However, they don't always come from the places you'd expect.

Some large factories mostly generate water vapor,

with only small quantities of pollutants mixed in.

Conversely, burning wood or dung can create polycyclic aromatic hydrocarbons;

dangerous compounds that have been linked to several types of cancer,

as well as long-term DNA damage.

In all cases, pollutants interact with regional weather patterns and topography,

which can keep compounds local or spread them kilometers away.

When 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 more easily washed 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 oxidize to form sulfates,

which condense with water vapor in the air to form a blanket of fine particles

that impair visibility and cause severe lung damage.

This so-called sulfurous smog was well-known in 20th century London

and continues to plague cities like Beijing.

Since the advent of cars,

another secondary pollutant has taken center stage.

Exhaust from fossil fuel-burning vehicles releases nitrogen oxides and hydrocarbons

which react to form ozone.

And while some ozone in the upper atmosphere

helps shield us from ultraviolet rays, on the ground,

this gas can form alongside secondary particles and create photochemical smog.

This brown fog can be found covering densely packed cities,

making seeing difficult and breathing hazardous.

It also contributes to climate change by trapping heat in the atmosphere.

In recent decades, industrial activity has contributed to a huge spike

in various trace gas emissions,

fundamentally changing the air we all breathe.

Many places have already responded with countermeasures.

Most cars produced since the 1980′s are equipped with catalytic converters

that reduce the emission of carbon monoxide and nitrogen oxides.

And today, places like Beijing are battling smog

by electrifying their energy infrastructure

and limiting automobile emissions altogether.

But while moving away from fossil fuels is essential,

there's no universal remedy for air pollution.

Different regions need to respond with unique regulations

that account for their local pollutants.

Because no matter where you live, we all share the same air.