Test and Change the Air Quality of Your Environment

Abstract

Do you ever wonder if the air inside is cleaner or dirtier than the air you breathe outside? In this science experiment, you will test it using an air quality monitor. Have you ever wondered how lighting a candle in your room impacts your air quality? Did you cook and not turn on the fan? How did it affect your breathing, and how did it impact the air quality? In this project, you can see how these environmental factors can improve or worsen the air you breathe every day. 

Summary

Areas of Science

Environmental Science
Human Biology & Health

Difficulty

Method

Scientific Method

Time Required

Short (2-5 days)

Prerequisites

None.

Material Availability

Readily available.

Cost

Average ($50 - $100)

Safety

Limit exposure to areas with poor air quality. 

Credits

Laura Ohl, PhD, Science Buddies Alumni

Science Buddies is committed to creating content authored by scientists and educators. Learn more about our process and how we use AI.

https://www.youtube.com/watch?v=nGo3A980PtE

Objective

In this science project, you will use an air quality sensor to measure the air quality of multiple indoor and outdoor locations. Then, you will test how different interventions can influence the air quality.

Introduction

Clean air is fundamental to our ability to breathe, which is essential to living a healthy life. Furthermore, air pollution is a leading environmental risk factor for poor health around the globe. During the COVID-19 pandemic, air quality came to the forefront of concern during the airborne spread of this upper respiratory virus. This led schools to test for proper ventilation and indoor air quality to ensure that bringing students back into the school environment wouldn't be a significant risk factor for getting this highly infectious disease. However, indoor air quality, even in schools, has been a growing concern before the global pandemic.

According to the US Environmental Protection Agency (EPA), people in the US now spend about 90% of their time indoors. However, many of us don’t test indoor air quality, where we spend most of our time. Indoors, many contaminants like dust, mold, and pet dander can impact our air quality. There are even ways we can reduce or prevent our exposure to these allergens and fungi in our homes. However, one crucial question to test is whether our indoor air quality is better or worse than our outdoor air quality. 

But how do we know what good air quality is and isn't? One way is to measure the particulate matter in the air using a sensor. We can easily measure the fine inhalable particles 2.5 micrometers or smaller, known as PM2.5, with at-home monitors. These particles are very small and can be harmful to your respiratory health. It's important to remember that these at-home devices do not measure many the potential pollutants that impact our air quality. The scale below is more inclusive, known as the Air Quality Index (AQI), as seen in Figure 1. This scale is commonly used in weather forecasting and atmospheric chemistry research, and was developed by the Environmental Protection Agency (EPA) to report on the overall safety of our air. This scale factors in many chemicals and pollutants, including fine particulate matter and potentially dangerous chemicals in our air, like carbon monoxide. To understand this scale, the higher the value is, the more polluted the air is and the less safe it is to breathe in. We inhale air all day, and every day of our lives. So, air quality is of the utmost importance for our everyday health. 

Image Credit: Laura Ohl, PhD / Science Buddies

Image showing the a non-linear increase in particulate matter and other air pollutants the worse the air quality index.

Figure 1. The air quality index scale measures the overall air quality, including all air contaminants. The arrow indicates an air quality in the moderate range (yellow) with an air quality measurement between 51 and 100 ppm.

How can we improve indoor air quality? The air in our homes is often filtered through air conditioning units or air conditioning systems. However, these filters only go so far as to remove some particulate matter from the air and rely on our ability to replace them frequently to keep the air quality good. Other factors contribute to the air quality and airflow in the home. Different types of filtration are commonly used in homes, such as ventilation systems. Some examples include kitchen air vents and bathroom fans. In the kitchen, fans can be used to displace air and prevent inhalation of cooking oils. In bathrooms, fans reduce excess moisture from building up by removing the moist air from the small space of the bathroom and reducing the amount of mold growth over time. In this science project, you will compare indoor and outdoor air quality and test how you can influence air quality with interventions or changes. For example, by testing how using a fan, cleaning a space, or opening a window changes the air quality of a room. 

Terms and Concepts

• Air pollution
• Pandemic
• Air Quality
• Ventilation
• Environment
• Infectious disease
• Contaminants
• Particulate matter
• Atmospheric chemistry
• Air Quality Index (AQI)
• Filtration
• Ventilation systems
• Interventions

Questions

• What is air pollution and why is it a concern for global health?
• How did the COVID-19 pandemic illuminate issues with air quality?
• Why is reduced ventilation risky for the spread of infectious diseases?
• How much time do people spend indoors according to the EPA?
• What is the scale created by the EPA that measures how safe our air is?
• Are there environmental pollutants we should be aware of that can improve or worsen our air quality?
• How can we improve or worsen our indoor air quality?

Materials and Equipment

• Air quality monitor
  • We recommend the AirBeam Mini Sensor (has PM_2.5)
    • Note: If you use a different device, double-check what it measures (particulate matter or specific chemicals) in the air to ensure you're making appropriate scientific conclusions. 
• Smartphone with Bluetooth and/or wifi connection (if needed for monitor)

This project follows the Scientific Method. Review the steps before you begin.

Comparing Indoor and Outdoor Air Quality

To compare and contrast indoor air quality to outdoor air quality, you will measure the air quality of three indoor environments and three outdoor environments at multiple different sublocations within the environment at different times. Then, you will test different interventions to see if you can influence indoor air quality.

1. Choose three indoor and three outdoor locations to measure the air quality.
2. Measure the air quality using your device according to the manufacturer's instructions.
3. Record the air quality in the first indoor location from three different sublocations within that location. For example, measure the air quality in three corners of a single location or room.
4. Repeat for at least two additional separate indoor locations. 
5. Record all of your results for your indoor measurements in Table 1.  
6. Record the air quality of the first outdoor location from three different sublocations within that location. For example, the air quality can be measured at three spots around a house. 
7. Repeat for at least two additional separate outdoor locations.
8. Record all of your results for your outdoor measurements in Table 1.  
9. Calculate the average air quality for each location using Equation 1.
10. Calculate the average indoor and outdoor air quality using each of your 3 locations using Equation 2. 

Swipe left to see more

Environment location	Indoor/Outdoor	Air quality (at PM2.5)	Average air quality	Average indoor or outdoor air quality
1.	Indoor	Sublocation 1 -  Sublocation 2 -  Sublocation 3 -
2	Indoor	...
3.	Indoor
4.	Outdoor
5.	Outdoor
6.	Outdoor

Table 1. Example data table to compare indoor and outdoor air quality.

$$AQ\: Location\: = \frac{AQ\: Sublocation\: 1\: +\: AQ\: Sublocation\: 2\: +\: AQ\: Sublocation\: 3}{Number\: of\: Sublocations\:}$$

Equation 1. Calculating the average air quality (AQ) of one location from 3 sublocation measurements. 

$$Average\: AQ\: of\: Locations\: = \frac{AQ\: Location\: 1\: +\: AQ\: Location\: 2\: +\: AQ\: Location\: 3}{Number\: of\: Locations\:}$$

Equation 2. Calculating the average overall indoor or outdoor air quality (AQ) from 3 locations average air quality.

Interventions to Alter Air Quality

To test different interventions to see if you can influence your air quality.

1. Choose three different indoor locations where you can change the quality of the air. You can use the EPA’s indoor air quality house tour for ideas (in the bibliography) or choose from some of the suggested examples below:
   1. Examples: turn on/off the ventilation system or a fan in a room, create a cross-breeze by opening a window, vacuum or clean/dust, light a candle indoors, cook with/without ventilation, turn on/off space heaters, and turn on the stove to cook with/without a fan, proximity to known air pollutants (highway or factory exhaust)
2. Choose an intervention to test how it impacts the room's air quality. Predict how your interventions will affect the air quality, forming a hypothesis for each intervention. 
3. Measure the pre-intervention or baseline air quality in three sublocations throughout the room. Record your results in Table 2. 
4. Calculate the average air quality pre-intervention using Equation 3. 
5. Implement the intervention for at least 10 minutes.
6. Measure the post-intervention air quality at the same sublocations as the pre-location measurements. Record your results in Table 2. 
7. Calculate the average air quality post-intervention using Equation 4.

Swipe left to see more

Location	Intervention	Pre-intervention air quality	Average pre-intervention air quality	Post-intervention air quality	Average post-intervention air quality
1.		Sublocation 1 -  Sublocation 2 -  Sublocation 3 -		Sublocation 1 -  Sublocation 2 -  Sublocation 3 -
2.		...		...
3.

Table 2. Example data table to collect results of indoor interventions on air quality. 

$$Average\: AQ\: Pre-Intervention\: = \frac{AQ\: Sublocation\: 1\: +\: AQ\: Sublocation\: 2\: +\: AQ\: Sublocation\: 3}{Number\: of\: Sublocations\:}$$

Equation 3.The average air quality (AQ) pre-intervention.

$$Average\: AQ\: Post-Intervention\: = \frac{AQ\: Sublocation\: 1\: +\: AQ\: Sublocation\: 2\: +\: AQ\: Sublocation\: 3}{Number\: of\: Sublocations\:}$$

Equation 4. The average air quality (AQ) post-intervention. 

Conclusion

• What locations had the best and worst air quality? Why do you think that is?
• Based on your results, would you say indoor air quality is better or worse than the overall outdoor air quality? Use your results to inform your answer.
• Air quality generally worsens with increased particulate matter. What interventions improved or worsened the air quality from the baseline measurements? 
• What factors most influence air quality outdoors or indoors? Use examples from your experiment to inform your answer.

Ask an Expert

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Global Goals

The United Nations Sustainable Development Goals (UNSDGs) are a blueprint to achieve a better and more sustainable future for all.

This project explores topics key to Good Health and Well-Being: Ensure healthy lives and promote well-being for all at all ages.

Variations

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