Air Quality

Introduction:

Overall air quality is a vital environmental issue that affects all ecosystems and human health. Air pollution, as defined by the U.S. Environmental Protection Agency (EPA), refers to the presence of harmful or excessive quantities of substances in the atmosphere. These substances can be subdivided into gases, particulate matter, and biological matter. Not only can these substances be detrimental to human health (i.e., worsening asthma, shortening life expectancy, the ability to exercise, increasing the risk of cancer, etc.) but they can damage natural ecosystems (i.e., acid rain, stunting plant growth), and contribute to climate change. Understanding the different types of air pollutants, their sources & their scales is crucial for developing effective mitigation strategies.

When most people think about air pollution or quality, most minds gravitate what the air is like outside. However, indoor air quality is greatly affected by building materials (i.e., wood, brick, insulation, etc.), appliances, and the quality of cleaning products used (i.e., think “eco-friendly” cleaning solutions).

In this lab, you will investigate sources of air pollutants in your environment on both a large (your community) and smaller scale (your home), how they are measured and where you can find air quality data. From there, potential personal mitigation solutions can be potentially composed to improve the quality of your own health and life.

Materials:

• Packaging tape
• 7 index cards
• Ziploc bags
• Magnifying glass or Microscope

Procedure (Part 1) – Measuring Air Quality in Your Home

1. Decide upon 4 locations in your home that you would like to test for particulate pollution. Record this in the first data table below.

2. Write a hypothesis regarding which location in your home would have the highest air quality and why. What about the lowest quality and why? Record the two hypotheses below.

3. Create 5 separate particulate collectors.
   • Using a quarter make a circle in the center of each index card.
   • Place a piece of tape over the whole so that the sticky side of the tape is exposed. Write your name and location number on each card (one will be a control).
   • Place each particulate collector in a Ziploc bag and close immediately.
   • When you arrive home, remove the particulate collectors from their bags, and leave them exposed to the air at 4 locations where particulate levels may differ for at least 24 hours. Designate card #1 as a control and leave it sealed in the bag. (NOTE: if you want to hang the particulate collectors you can punch a small hole in one end and attach a piece of string.)
   • After 24 hours retrieve the cards and place them back in their Ziploc bags. Bring them back to the next class (lab) meeting. Examine the index cards, including your control, with a magnifying glass (or microscope, if desired). Count the number of particulates that fell on each one within the circle and record these numbers in the data table.
   • Examine and describe the particulates (identifying them if possible) and record this in Data Table 1.

Data Table 1:

Graph: Create a bar graph comparing the number of particulates found in each location.

Questions:

1. Did your results support or refute your hypothesis? Why or why not?
2. Is there any relationship between the particulates and the location they were found?
3. What was the purpose of the control?
4. What were some sources of error in your experiment?

Part 2 – Measuring Outdoor Air Pollutants by Looking Up Data:

The Air Quality Index (AQI) measures levels of particulates, ozone, nitrogen oxide, carbon monoxide and sulfur dioxide.  Fill out Data Table 2 below using the current data:

Data Table 2:

https://www.airnow.gov/ (or any weather site)

1. Explain any differences/similarities you see in the AQI data for all the areas you researched.
2. Next, go to the worldwide air quality map found here:  www.aqicn.org to answer these questions:
3. Which city has the highest reading for AQI?
4. What do each of the colors for the AQI mean?
   

   Green
   Yellow
   Orange
   Red
   Purple

    

5. Which city do you think has the highest potential for atmospheric ozone?

   What is the current data for Denver, CO?

   AQI –

   Primary pollutant-car emissions –

   Ozone level –

   NO_x level –

Part 3 – Measuring Outdoor Air Pollutants by Analyzing Car Exhaust

Materials:

• Clean white socks
• 3 to 5 cars (different years)
• Microscope or magnifying lens

Procedure:

1. Decide upon 3 to 5 cars, of different years, that the class will test.
2. Write a hypothesis regarding which year of car would produce the highest emissions and why. What about the lowest emissions and why? Record the two hypotheses below (in the space above the data table).
3. Each group will collect 3 white socks and proceed outside. One sock will be used by the instructor as a control.
4. Proceed to one vehicle in your group and place a sock on the car’s exhaust pipe.
5. Start the car engine for 5 seconds while pressing on the gas.
6. Turn off the car and slowly pull off the sock.
7. Repeat for the other cars in your group.
8. Return to the lab and fill out Data Table 3 below.

Data Table 3:

Questions:

1. Did your results support or refute your hypothesis? Why or why not?
2. Take a picture showing the socks in your group, side-by-side and with appropriate labels, attach and submit with the question sheets.
3. Did you notice any other patterns regarding particulate size or type with engine type or any other quality regarding the cars (besides the year)? Explain with details.