1. The LD50 of Common Household Toxins on Brine Shrimp
Kailin Edgar
May 17th, 2012

2. Brine Shrimp Tolerate a salt content of between 25 and 35% salt
Can be found in salt flats
Important food source to many wildlife species
Indicators of pollution within water bodies

3. LD50
50% of an organism is killed by a specific concentration of a toxin
Higher threshold=withstand higher concentrations

4. Problem
What is the LD50 of common household toxins on brine shrimp?

5. Hypothesis
If Brine Shrimp are placed in various concentrations of common household toxins such as Lysol, bleach, and laundry detergent then the bleach will be the most harmful product and the laundry detergent will be less harmful (shrimp will have the highest tolerance for the laundry detergent).

6. Materials 1000 ml beaker Stop watch Eye droppers Live brine shrimp
10 ml pipettes
Pipump
Graduated cylinders
Lysol
Small petri dishes
Bleach
Beakers
Washing Detergent

8. Procedure Obtain brine shrimp
Label petri dishes 0%, 10%, 20%, 30%, 40%, and 50%
Place 10mL of water in the 0% petri dish
Place 9mL of water in the petri dish labeled 10% and then add 1mL of bleach
Place 8mL of water in the petri dish labeled 20% and then add 2mL of bleach
Place 7mL of water in the petri dish labeled 30% and then add 3mL of bleach
Place 6mL of water in the petri dish labeled 40% and then add 4mL of bleach
Place 5mL of water in the petri dish labeled 50% and then add 5mL of bleach

10. Procedure Add 30 brine shrimp to each petri dish
Let shrimp sit in water for 5 minutes
Count how many shrimp are still alive in each concentration of the toxin
Record data and behavior
Compare results
Repeat steps 2-14 for each toxin

12. Data

13. Data

14. Data
Number of Shrimp Alive after 5 minutes
Concentration of Toxin (%)

15. Discussion Hypothesis was supported
Bleach was the most harmful toxin killed more than half of the shrimp population in a 10% concentration
Lysol was very toxic but threshold was higher more than 50% were killed in a 20% concentration
Washing detergent was least harmful LD50 was between 40-50%

16. Sources of error
LD50’s are not exact because concentrations were spread apart
Determining whether the shrimp were still alive was difficult and counting the same shrimp twice was very possible

17. Conclusion Household products can be very toxic
Small marine animals exposed to small concentrations of a product may be killed or their swimming severly affected

18. Future Implications
The effect of household toxins on larger marine animals
New, environmentally safe products can be invented to take the place of these toxins without causing the same effects
Ways to expose of these toxins keep them out of the water

19. Questions?