New experiments

Now, we are going to grow lentils plants to study the effect of home pollutants on growth and development of lentils. This morning we have put 10 lentil seeds into containers with potting soil. We have recycled used yogurt cups for this experiment. We have watered them. When seeds germinate, we will treat them with the pollutants and we will study the growth of plants. We will have untreated plants, watered only with water, as control experiments. 

New results

We have repeated some experiments. Seed didn't germinate in water with detergent at concentrations of 5% and 10% (weight/volumen concentration). So, we have studied lentils germination at lower concentrations (1% and 0,5%). We have tested another washing up product and we have repeated the experiment with hydrogen peroxide. In the previous experiment, seeds germinate with high concentrations of acetone; this wasn't the expected results as this product is toxic. So we have tested the effect of nail polish remover on germination as this product contains acetone. No seeds have germinate with concentrations of 10% and 5% (w/v); we are going to test lower concentrations this week. Finally, fabric softener doesn't seem to affect lentils germination as concentrations as high as 20% doesn't inhibit germination.

Please, study this data and make your own conclusions. Write them as comments.

Our first results

After a week, we have our first results. In our control experiments, all the seeds irrigated with water have germinated. But we have observed differences between treatments. Here you have a table with our results. What are your conclusions? Is there any experiment with unexpected results? Will we have to repeat any experiments?

Control plate

Washing up liquid, 5%.

Grease remover 5% and 10%.

A new research project for our younger students: Home pollutants

Surely, your family has lot of chemical products for domestic use at home. Some of them are detergent or fabric softener; we use them for washing our clothes. Bleach, grease remover or antilime cleaner are used for cleaning our houses. All of them contain toxic chemicals we leave to the environment. And it is the same with other products we use with our own body like the alcohol or the hydrogen peroxide we use to disinfect wounds or the nail polish remover we use for cleaning our painted fingernails. Do they affect living beings?

This is the main goal of the project we are beginning. We are going to study if this products are toxic for the environment, especially for plants. We want to know if they affect aspects of plants biology as germination, growth and development of plants.

We begin our experiments studying the effect of these products on the germination of seeds. We are going to use lentil seeds (Lens culinaris). We have prepared seed germination chambers with Petri dishes; we have placed paper towel inside the plates and we have added 20 ml of the different solutions of chemical products. We have put 16 seeds per germination chamber.

We are going to carry out control experiments. In some plates we will add only water. We want to know the viability of seeds irrigated only with water. Later on, we will compare the number of germinated seeds in plates with water and chemical products. We consider that seeds have germinated when they show a little root at least one millimeter long. We will study seeds germination for a week.

(Spanish version)