The Effect of Plants on Air Quality By Ethan Potthoff, Julia Houston, and Jeff Hyer Research Question: What effect do house plants have on air quality in an enclosed room? Background Information: ●What is the reason for your interest in this area? The reason for our interest in this area stemmed from our curiosity in whether plants affected PM levels. We wanted to see if a room with plants would have a lower PM level than a room without plants--under a controlled setting. ●What is meant by PM 2.5? PM 2.5 is an air pollutant that is a concern for people’s health when the level is high. Consists of tiny particles, 2.5 um in diameter and smaller. Reduces visibility and makes the air appear cloudy and overcast. ●What is the air that causes PM 2.5? What are the sources of PM 2.5? Components of PM 2.5 include: sulfates and nitrates, organic compounds, trace elements ( including metals), elemental carbon, and water. Sources of PM 2.5 include: road dust, slash burning, wildland fires, vehicle exhaust, power plants, volcanic eruptions. ●Describe the size of a PM 2.5 particle. Compare it to something in our world.The size of a PM 2.5 particle is small, 2.5 um in diameter or less. As a comparison, human hair is 60 um in diameter. ●What is the EPA limit for PM 2.5? The EPA annual limit/standard for PM 2.5 is 12 micrograms per cubic meter and the twenty-four hour fine particle standard is 35 micrograms per cubic meter. ●What percent of time do we spend indoors? Americans spend ninety percent of our time indoors, and the air quality inside is worse than it is outside. Sources contributing to particulate matter indoors include: cleaning, cooking, smoking, tobacco smoke, burning candles, and wood stoves. Hypothesis: We predicted that plants would not have a significant effect on air quality in the room because plants, although they convert carbon dioxide to oxygen, do not have the capability to filter other particles out of the air. Particles such as dust in rooms will not decrease because they will not be filtered through plants, but carbon dioxide levels may decrease. Methods: We used the DustTrak to collect air quality data. We sampled the air in a basement bedroom from 9 P.M. on January 12, 2016, to 9:30 A.M on January 15, We then placed five plants in the bedroom, and collected an additional set of data. The second set of data, with plants, was collected from 9:45 A.M. on January 15, 2016, to 10 P.M. on January 17, The bedroom, also known as the sample site, is shown in the images below. As you can see, it is a normal bedroom consisting of a window, closest, nightstand, lamp, and bed. The floor is made of carpet. In both data samples, the bedroom door was closed to prevent further variables.The independent variable is the presence or absence of plants, and the dependent variable is the measured amount of particulate matter. Controlled variables include: sample site, location of DustTrak, duration of test, and number of plants. During both tests, the DustTrak was plugged into the outlet, far right, and placed on the floor--see image 1. Results: Test Durations: 2.5 Days Improvements: We could improve our project by testing the samples for a longer period of time. This would allow us to determine whether the presence of plants effects particulate matter over an extending period of time. In addition, we could collect two more data sets--Trial 2 and Trial 3. Increasing the number of measurements eliminates error, and gives us the ability to calculate an accurate average. Also, repeating the experiment would determine whether or not our data represents a normal situation and is not just a fluke. Three data collections is the standard scientific practice. However, the accuracy of an experiment does increase as the number of experimental repeats increases. Finally, we could test different species of plants, and determine whether or not specific types of plants have a greater effect on particulate matter. Conclusion: Through our results, we found that the presence of plants has little to no effect on the levels of air particulate in the air, which supports our hypothesis. Our data shows similar averages for each test as well as similar maximum and minimum values which supports our conclusion. This result is due to the fact that plants convert CO 2 to O 2, and do not act as filters to the air meaning the air particulate should not change with the presence of plants. This result is significant to oppose the idea that plants created a better air quality unless the plant has some way of filtering the air particles. References: projects/top_research-project_signal-to-noise- ratio.shtml ●Slutz, Sandra, and Kenneth L. Hess. "Increasing the Ability of an Experiment to Measure an Effect." Science Buddies. Science Buddies, n.d. Web. 20 May ●"Fine Particles Question and Answers." Fine Particles (PM 2.5) Questions and Answers. New York State Department of Health, Feb ○2011. Web. 18 May ●Westervelt, Amy. "How Our Buildings Are Making Us Sick." Forbes. Forbes Magazine, 8 Aug Web. 18 May TEST 1: Average: Minimum: 0 Maximum: START: 1/12/ :10:58 END: 1/15/2016 9:30:58 TEST 2: Average: Minimum: 0 Maximum: START: 1/15/2016 9:45:10 END: 1/17/ :05:10 Image 1Image 2Image 3