Science Buddies: "Ask an Expert"

Im doing an experiment using 50 radon kits to test various homes with and without granite countertops to see if granite effects the radon level in a home by releasing radon. (The radon kit must be left exposed in a home for 2 days and then sent back to a lab to get a reading back.) I am thinking of testing homes in three different neighborhoods in my area and testing an even number of homes with and without granite. In each home, I will use two radon kits, one on the granite and one in a room that is far from the granite. Also, in each neighborhood, one radon kit will be used to measure the amount of radon on an empty plot of land to see how much radon is being released from the earth. The amount of granite in the home will be estimated by its surface area. Furthermore, I will be asking the owner of the home I test not to open the windows in the home for a few days before and while the radon kit is in his house.

I am unsure if I am have left out anything important from my experiment. Could an expert please let me know if I could do anything differently to make my project better?

Thank you.

Hello and welcome to the forum!

This sounds like an interesting experiment. I've done some web searching, and have some questions for you. First, as you know, you need a pretty large number of samples to be sure of your data - and you are planning on 50 test kits. However, it looks like that would amount to testing 20 - 25 homes total. One article I found said that only

a small number of commercially available samples have

turned up positive for radon. Also,

experts agree that most granite countertops emit radiation and radon at extremely low levels

and

a physicist from Rice University who has been studying the issue tested 20 home samples and found most to be completely harmless. However, Bill Lope reported on NBC's TODAY that in a few samples that he had measured, levels were too high to be considered safe

I'm wondering if there might be too high a chance that your data proves nothing? In other words, if you get one or two counter tops that measure "hot", that may not be statistically significant. Also, depending on where you live, you may find houses that are "hot" all by themselves, independent of the counter top installed.

Since the granite contains uranium, and possibly would be radioactive independent of radon emission, have you considered using a Geiger counter instead of radon test kits? 50 radon test kits might cost between $500 and $1000, while a Geiger counter might cost between $200 and $500. With a Geiger counter you can get instantaneous results, and it measures more than just radon emission. If you're ambitious, there are even plans to build your own here http://www.imagesco.com/articles/geiger/01.html

Let us know how your experiment turns out!
Keith