Indoor Air Pollution using PocketLab Air

I have a PocketLab Air device which I use to demonstration indoor air pollution–specifically particulate matter with candles. In time, I will try to find funding for more devices (they run about $318), but for now, I do a demonstration and students record data.

My device has some melted plastic–too close to a candle during last year’s demo!

PocketLab Air devices connect to an app on your tablet or phone and give real-time levels of PM2.5, ozone, carbon dioxide and AQI. The AQI is based on PM2.5 since the ozone readings are not calibrated on my device. We can see levels increase or decrease which is helpful, but the ppb of ozone is not accurate. The device also shows temperature, barometric pressure and humidity. Click for the student handout.

For distance learning, I made a video of the demonstration that you are welcome to use.

In my demonstration, we take the following readings and data:
-Ambient (background) indoor air levels
-Lighting a Match
-Burning a regular candle (made from paraffin or other petroleum product) in a closed container
-Burning a soy candle in a closed container
-Blowing out the candle

Two candles that I use for the demonstration. I try to find similar sized candles-one that is petroleum such as paraffin and one that is biomass such as soy or beeswax.

Students discuss the other parts of the candle that burn such as the wick and what it’s made out of. We discuss why the regular candle produces more PM2.5 and carbon dioxide than the soy candle (which is made from biomass). While carbon dioxide is not an air pollutant monitored under the Clean Air Act, this is a good demonstration to show levels of carbon dioxide from different sources as a prelude to climate change.

This picture shows a smaller paraffin candle than the picture above. If using a larger candle, you will also need a larger container as it will burn a hole in the plastic lid.

After data and analysis, students read an article “Characterization of Pollutants Emissions from Burning Candles” by
S. Gelosa et. al. which is about candles and indoor air pollution and answer questions.

This demonstration fits best in Unit 7 for AP® Environmental Science, and introduces carbon dioxide as a greenhouse gas (Unit 9).

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