Environmental Science Class Toxicity Lab Experiment

The environmental science class have been studying toxicity. This activity examined the effects of exposure of an experimental organism to two different toxins. California black worms were observed to determine their normal behavioral patterns. The worms were then exposed to two different toxins (alcohol and caffeine) to see how these chemical altered the worms behavior.

The worms were exposed to high, medium and low concentrations of each toxin. The students noted the changes in their behavior after exposure times of 0 minutes, 3 minutes, 6 minutes and 10 minutes. The worms were then moved into neutral surroundings (distilled water) and their "recovery status" was observed in the same time intervals.

Students are adding the worms to the control solution of distilled water, The worms were left in this solution and observed for 15 minutes to determine their "normal" behavioral patterns.

Students used sterile pipettes to stimulate the anterior and posterior ends of the worms. This was done to ascertain their normal behaviors. Similar stimulation will be used while the worms were exposed to the toxins to see if their reactions are altered.

This was the experimental set up for the experiment. The upper weighing dishes are the "recovery" dishes and contained only distilled water. The lower dishes contained a control (water) and the toxin to be tested. One dish had high concentration, one medium concentration and the last low concentration of the toxin.

Student moving worms from control dish to toxin dishes using a pipette.

Students worked in groups of 4-5 at each lab table. One side of the table carried out the protocol with alcohol as the toxin while the other side of the table used caffeine as the toxin.