We have been working on an ecology project with our scientists, Carol Thornber and Risa Goldstein.

These are our scientists, Carol and Risa, in our classroom.

Our Experiment

The students and Risa, Carol and Ms. Benson decided to do an experiment looking at how different pollutants affect the growth of plants. We hypothesized that plants given water would grow better than those given solutions with various "pollutants", but of course we didn't know how plants would react to different pollutants. We picked common substances for our pollutants. We chose to use lima bean seeds, since they are large and grow quickly. We planted seeds in potting soil. We gave the seeds either: water (control), sunscreen solution (sunscreen + water), soap solution (liquid soap + water), or shampoo solution (shampoo + water).

Here we are setting up our experiment

Seeds were "watered" as necessary to keep the soil moist. There were 18 seeds/treatment. We measured plant size and the number of leaves per plant over several weeks.

Seeds given either soap or shampoo did not grow at all (we had maybe 1 germinate from each of these categories and then quickly die). Seeds given either water or sunscreen did germinate and grow. However, those given water grew significantly higher and had significantly more leaves than those given sunscreen.

Thus, we concluded that soap and shampoo are very bad for bean growth, and that sunscreen is slightly harmful for beans. (of course, this may vary by the concentration of sunscreen, etc...but we didn't get into that!!)