The Affect Sulfates have on Daphnia

Purpose: Hypothesis: To determine if sulfates in shampoo affect biological processes As various concentrations of SLS increase, the effect it has on Daphnia will be observed

Daphnia Also known as the “water flea” Have a life span average of 30 days (1 month) More active in sunlight Are transparent

What They Eat Can eat a variety of things: Yeast Bacteria Soy flour Algae Dissolved organic matter Detritus Over-feeding will pollute the water and kill Daphnia

Preparing the Tank Beware of additional chemicals- they will kill off Daphnia culture Use distilled water only, not tap Make sure light is indirectly on tank Daphnia live best in water with a temperature between 72-75 ˚F It is also best to use a Bio-Foam filter to keep the water circulating and full of oxygen

Daphnia Reproduction Female Daphnia can produce eggs without mating –parthenogenesis In each hatching, there are about 50 eggs These eggs will be held in a blood chamber for a few days until it is time for them to hatch

Sodium Lauryl Sulfate Found in shampoos, shower gels, mouth rinses, toothpaste, car and detergents Type of surfactant-breaks the surface tension of water (makes the suds bubbles) Most shampoos contain about 30% of SLS- a very high concentration

Effects of SLS Associated with causing cataracts-in concentrated amounts Can be drying and harsh for the hair Causes eye irritation, allergic reactions, and hair loss High levels of skin penetration occur at even low concentration

Procedures for Testing- Part 1 Divide Daphnia into Well cups Add a different concentration of SLS into each set of cups-start with the most diluted. We had a control group, as well as groups being tested with different SLS concentrations Leave Daphnia in solution, monitor the time As the time in solution comes to an end, place Daphnia under microscope

Procedures for Testing – Part 2 Place small, thin strands of cotton on top of Daphnia, to keep them from moving Record number of heartbeats, how many times the Daphnia move, if it has eggs, and if its alive or dead Place Daphnia back into tank Repeat with different concentrations

Serial Dilution In the 1000mL volumetric flask, place 1 mL of SLS and fill the rest with water Take 1 mL of that solution and place in another volumetric flask, fill the rest with water. And repeat a second time Place Daphnia in most diluted solution and gradully increase concentration

Materials We Used Algae Tank (16in by 10.5in by 8.5in) Daphnia Sodium Lauryl Sulfate- 29% concentration Well cups A Bio-Foam filter Cotton Balls Volumetric Flasks Digital Microscope Plastic Spoons

Relating to Society By testing different concentrations of SLS on Daphnia, we were able to conclude that small diluted amounts of SLS do not harm or cause complications in pregnancy. However, it was noticed that the majority of the Daphnia in SLS solutions, did not contain eggs.

Technology The technology needed to conduct this experiment has already been invented Though higher resolution microscopes would have made it easier to count the heartbeats and study the bodily functions of the Daphnia

Data Table 1 Control Group Daphnia # of Heartbeats (per min) # of Movements (per min) Have Eggs? Dead or Alive? 1 85 62 Yes Alive 2 127 116 No 3 Dead 4 89 72 5 99 84 Average 100 83.5 40% 20%

Pie Charts for Control Group Mortality Eggs Present

Data Table 2 .00001% SLS- 3.5 hrs Daphnia # of Heartbeats (per min) # of Movements (per min) Have Eggs? Dead or Alive? 1 96 117 No Alive 2 122 27 3 93 66 4 76 69 5 89 82 Average 95.2 72.2 0%

Pie Charts for .00001% SLS Mortality Eggs Present

Data Table 3 .0001% SLS- 24 hrs Daphnia # of Heartbeats (per min) # of Movements (per min) Have Eggs? Dead or Alive? 1 No Dead 2 3 4 5 Average 0% 100%

Pie Charts for .0001% SLS Mortality Eggs Present

Data Table 4 .01% SLS- 10 min Daphnia # of Heartbeats (per min) # of Movements (per min) Have Eggs? Dead or Alive? 1 75 105 Yes Alive 2 79 70 No 3 Dead 4 34 42 5 Average 62.7 72.3 20% 40%

Pie Charts for .01% SLS Mortality Eggs Present

Data Table 5 1% SLS- 15 min Daphnia # of Heartbeats (per min) # of Movements (per min) Have Eggs? Dead or Alive? 1 No Dead 2 89 60 Alive 3 72 77 4 5 67 70 Average 76 69 0% 60%

Pie Charts for 1% SLS Mortality Eggs Present

Affect of SLS concentrations on Daphnia Number of Occurrences Concentration of Solution (%)

Limitations The microscope we used allowed us to see inside the Daphnia but it would have been better if it had a higher resolution If repeating the project, we would clean the tank more often, to prevent the Daphnia from dying due to natural causes and toxic water

Sources (Part 1) www.antfire.com www.caudata.org/daphnia   www.caudata.org/daphnia http://www.gmagazine.com.au/219/ask-g-is-sodium-lauryl-sulphate-really-bad http://www.natural-health-information-centre.com/sodium-lauryl-sulfate.html health-information-centre.com/sodium-lauryl-sulfate.html

Sources (Part 2) http://science.howstuffworks.com/environmental/green-science/sodium-lauryl-sulfate.htm   http://www.newsweek.com/blogs/the-human-condition/2009/10/08/the-science-of-shampoo-what-the-ingredients-mean.html http://www.healthy-communications.com/slsmostdangerousirritant.html http://www.care2.com/greenliving/sodium-lauryl-sulfate-based-shampoos.html http://www.jasoncosmetics.com/sodium_lauryl_sulfate.html