When you think of gas masks, you might picture bulky, military-style gear from movies or museums. But did you know that you might already own a mask that uses similar technology? With the rise of new diseases and the increasing number of wildfires—more than tripling from 1996 to 2021—these masks might become a regular part of our lives. As wildfires burn longer and cover more land, their smoke affects more people each year. Climate change is also causing more hot, sunny days, which speeds up the creation of harmful ground-level ozone.
So, how do these masks work, and can they really protect us from harmful air? The first thing to know is that a mask needs to fit tightly to be effective. If it doesn’t, even the best mask won’t work well. Assuming your mask fits properly, it can catch pollutants in two main ways: by size or by attracting certain chemical compounds.
Let’s look at wildfire smoke as an example. When forests burn, they release a mix of chemicals. Close to the fire, the concentration of pollutants is so high that no filter can help, which is why firefighters use their own air supply. But further away, the situation is different. The smoke contains tiny solid or liquid particles, mostly smaller than 2.5 microns in diameter. These particles are especially dangerous for children, the elderly, and people with respiratory or heart conditions. Luckily, most of these particles are big enough to be trapped by basic filters made of materials like polypropylene or glass strands, which are about 1/10 the width of a human hair.
Under a microscope, these filters look like a dense forest. At this scale, they have a special ability. Normally, when using a sieve, you filter out objects larger than the holes. But these polypropylene strands can catch particles much smaller than the gaps between them. When a particle hits a thread, it sticks due to van der Waals forces, similar to how Velcro works. Additionally, size-based filters can use electrically charged fibers to attract particles not already on a collision course. This is how a simple N95 mask can capture at least 95% of particulate matter, while an N100 mask or a high-efficiency particulate air (HEPA) filter can capture at least 99.97% of particulates. With a tight seal, this level of protection can filter out most airborne pollution.
Unfortunately, some pollutants are too small for size-based filters, like ozone molecules, which are only slightly larger than the oxygen we breathe. Exposure to ozone is linked to respiratory problems and other health risks. Our best chance to filter out ozone is through activated carbon masks. At the microscopic level, activated carbon has a highly porous structure that can trap tiny ozone molecules. However, this material needs help to capture other pollutants like hydrogen sulfide, chlorine, and ammonia. For these threats, we can combine activated carbon with simple chemistry. If the pollutant is acidic, we can infuse the filter with a basic chemical, causing a reaction that traps the gas. Similarly, acids can be used to capture basic pollutants.
Even with the right mask, it’s smart to check air quality indicators and stay indoors when the threat level is high. Just like a mask, it’s important to ensure your home is well sealed. You can do this by closing windows, turning off fans that vent outside, and using HEPA filter-equipped air purifiers or DIY alternatives like the Corsi-Rosenthal box. Following these guidelines can help us breathe easier as we work on preventing these pollutants in the first place.
Using household materials, design and build a simple model of a gas mask. Consider how you can incorporate both size-based and chemical attraction filtering methods. Present your model to the class and explain how it works to filter out pollutants.
Conduct an experiment to understand how filters work by using sieves of different sizes to separate various materials like sand, rice, and flour. Relate your findings to how gas masks filter particles of different sizes, such as those found in wildfire smoke.
Research the air quality in your area over the past year. Identify the main pollutants and their sources. Create a presentation to share your findings with the class, and suggest ways to protect yourself from these pollutants using masks and other methods.
Perform a demonstration to show how activated carbon can absorb pollutants. Use a small amount of activated carbon to filter colored water or a strong-smelling substance. Discuss how this relates to the chemical attraction filtering method used in gas masks.
Create a simple air quality monitor using materials like a fan, a filter, and a particle counter app on a smartphone. Use it to measure the air quality in different areas of your school or home, and discuss the results with your classmates.
Here’s a sanitized version of the transcript:
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You might think of gas masks as clunky, military-looking devices often seen in movies or museums. However, you may already own a mask that uses similar technology. In the near future, we may need to rely on these filters as part of our everyday lives. Emerging diseases and the increasing frequency of wildfires—more than tripled from 1996 to 2021—are contributing factors. As fires burn longer and cover more land, their smoke affects more people each year. Climate change is also leading to more hot, sunny days, which accelerates the production of harmful ground-level ozone.
So, how do these masks work, and can they protect us from airborne threats? The first rule of filters is ensuring a tight seal. Without that, even the best mask is ineffective. Assuming your mask fits well, this technology can capture pollutants in two main ways: by size or by attracting specific chemical compounds.
For example, let’s consider wildfire smoke. When forests burn, they produce a variety of chemicals. At close range, the concentration of pollutants is so high that no filter can help—this is why firefighters use their own air supply. However, further away, the situation changes. While there are still various chemicals, they mostly aggregate into tiny solid or liquid particles smaller than 2.5 microns in diameter. This particulate matter is particularly dangerous for children, the elderly, and those with respiratory or cardiovascular conditions. Fortunately, most of these particulates are large enough to be captured by basic filters made of polypropylene or glass strands, which are about 1/10 the width of a human hair.
Under a microscope, these filters resemble a dense forest, and at this scale, they have a unique property. Typically, when using a sieve, you filter out objects larger than the holes. However, these polypropylene strands can catch particles much smaller than the gaps between them. When a particle collides with a thread, it sticks due to van der Waals forces, similar to Velcro. Additionally, size-based filters can use electrically charged fibers to attract particles not already on a collision course. This is how even a simple N95 mask can capture at least 95% of particulate matter, while an N100 mask or a high-efficiency particulate air (HEPA) filter can capture at least 99.97% of particulates. With a tight seal, this level of protection can filter out most airborne pollution.
Unfortunately, some pollutants are still too small for this method, including ozone molecules, which are only slightly larger than the oxygen we breathe. Exposure to ozone is linked to respiratory issues and other health risks. Our best chance to filter out ozone is through activated carbon masks. At the microscopic level, activated carbon has a highly porous structure that can trap tiny ozone molecules. However, this material needs assistance to capture other pollutants like hydrogen sulfide, chlorine, and ammonia. For these threats, we can combine activated carbon with simple chemistry. If the pollutant is acidic, we can infuse the filter with a basic chemical, causing a reaction that traps the gas. Similarly, acids can be used to capture basic pollutants.
Even with the right mask, it’s wise to check air quality indicators and stay indoors when the threat level is high. Just like a mask, it’s important to ensure your home is well sealed. You can do this by closing windows, turning off fans that vent outside, and using HEPA filter-equipped air purifiers or DIY alternatives like the Corsi-Rosenthal box. Following these guidelines can help us breathe easier as we work on preventing these pollutants in the first place.
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This version maintains the informative content while removing any potentially sensitive or alarming language.
Gas Masks – Devices worn over the face to protect the wearer from inhaling harmful gases and pollutants in the air. – During the science experiment, students learned how gas masks can protect firefighters from smoke inhalation during a wildfire.
Pollutants – Substances that contaminate the environment, especially the air, water, or soil, and can cause harm to living organisms. – The factory was fined for releasing pollutants into the river, which affected the local fish population.
Wildfire – An uncontrolled fire that spreads rapidly through vegetation, often in forested or grassland areas. – The recent wildfire in the national park destroyed thousands of acres of forest and displaced many animal species.
Ozone – A molecule composed of three oxygen atoms, found in the Earth’s stratosphere, that absorbs most of the sun’s harmful ultraviolet radiation. – Scientists are concerned about the depletion of the ozone layer, which could lead to increased UV radiation reaching the Earth’s surface.
Respiratory – Relating to or affecting the organs and processes involved in breathing. – Air pollution can cause respiratory problems, making it difficult for people to breathe properly.
Filters – Devices or materials that remove impurities or particles from air, water, or other substances. – The laboratory used special filters to ensure that no contaminants entered the clean room during experiments.
Chemicals – Substances with a distinct molecular composition that are produced by or used in a chemical process. – The chemistry teacher explained how different chemicals react with each other to form new compounds.
Air Quality – The measure of the condition of air based on the amount of pollution it contains. – The city has implemented new policies to improve air quality and reduce smog levels.
Climate Change – The long-term alteration of temperature and typical weather patterns in a place, often linked to human activities. – Scientists are studying the effects of climate change on polar ice caps and global sea levels.
Protection – The action of safeguarding something from harm or damage. – Environmentalists advocate for the protection of endangered species and their habitats.
