Heather ThomasDiane O’ConnellRachelle GleasonRebecca ByerlyPhilip ChurchMentor:Amber BurgettBeth Biro

A Brief History• The side effects of caffeine are not new to the scientific or economic

world.• Caffeine’s economic value stems to the 16th century where Spanish

conquestadors began exporting coffee beans back from South America for trade.

• Also in the 16th century, the first coffee houses began to appear in South America. (They would not arrive in Europe until the 17th century and ultimately in North America until nearly the 19th century.)

• The popularity of the effects of coffee/caffeine is also thought to have been a key contributor as to why Britian sought and obtained control over islands like Jamaica, Barbados and Trinidad.

Where does it come from?

• Caffeine is a natural substance found in some plants but is also toxic to these plants– coffee, coco and Kola nuts – guarana (a popular additive in many energy

drinks) – tea leaves.

Caffeine as a drug?• Caffeine belongs to the group of chemicals called alkaloids and is

the #1 drug used in society today.• It is classified as a stimulant and is used medically as a diuretic or

to increase cardiac function• Some forms of caffeine also function as smooth muscle

relaxers/vasodilators and cardiac stimulants. These forms are usually found in teas.

• The most popular uses today are generally related to the “pick-me-up” that caffeine gives .

Caffeine varies between beverages. Not included are the caffeine amounts in food products such as energy bars, candy bars etc.

Coffee, es

presso

Coffee, St

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Tea, le

af or b

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Green te

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Coca-Cola C

lassic

Mountain Dew

Jolt Cola

Red Bull

XS Energ

y Drin

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Monster E

nergy

Mother En

ergy D

rink

V Energ

y Drin

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Wired X505

NOS

Rat To

xicity

Leve

l0

100

200

300

400

500

600

Caffeine per serving of common beverages (mg per serving)

The Human LD50 level is roughly 150-200 mg per kg of body weight. This means that a 140 lb person would need to consume 9545 - 12727 mg of caffeine or approx. 63 cups of starbucks coffee in one sitting for caffeine to become lethal.

Caffeine content based on data from www.energyfiend.com

Previous studies on caffeine using tadpoles

• No effect on oxygen consumption of bull frog tadpoles Brinley 1931.

• No effect on activity in American Toad tadpoles Smith and Burgett 2005– Contrary to earlier study…

• Caffeine resulted in an increase in activity and a 100% survivorship of Leopard Frog tadpoles Fraker and Smith 2004– If activity increases, will this make

tadpoles more visible to predators or will this make them more evasive?

Caffeine in our water?• Humans cannot fully break down caffeine and as a result excrete

it.

• Recent tests in both Seattle and Boston have revealed small levels of caffeine in the water (140 to 1600 ng) Mickelson 2003– “Just before 9am, for example, caffeine levels in the sewer system are

nearly eight times as high as usual” Mickelson 2003– Could have a high correlation to human morning caffeine consumption

• Aging and cracked sewer lines, excess food/beverages decomposing in landfills, inproper disposal all lead to water infiltrating our water systems.

Results of Mickelson’s Study• Table 6• Target BNA Analytes (including Atrazine)• and Detection Limits (g/L)• BNA Compound MDL RDL• Acenaphthene 0.010 - 0.050• Acenaphthylene 0.010 - 0.050• Anthracene 0.010 - 0.050• Atrazine (Triazine Pesticide) 0.050 0.100• Benzo(a)anthracene 0.025 0.050• Benzo(a)pyrene 0.010 0.025• Benzo(b)fluoranthene 0.010 0.025• Benzo(g,h,i)perylene 0.100 0.250• Benzo(k)fluoranthene 0.010 0.025• Benzyl Butyl Phthalate 0.010 0.025• Bis(2-Ethylhexyl)Phthalate 0.010 0.025

• Caffeine 0.010 - 0.025• Carbazole 0.025 0.050

• 2-Chloronaphthalene 0.010 0.050• Chrysene 0.025 0.050• Dibenzo(a,h)anthracene 0.100 0.250• Dibenzofuran 0.010 0.025• 1,2-Dichlorobenzene 0.050 0.250• 1,3-Dichlorobenzene 0.050 0.250• 1,4-Dichlorobenzene 0.050 0.250• 2,4-Dichlorophenol 0.500 1.000• Diethyl Phthalate 0.010 0.025• Di-N-Butyl Phthalate 0.010 0.025• Fluoranthene 0.010 0.025• Fluorene 0.010 0.025• Hexachlorobenzene 0.025 0.050• Indeno(1,2,3-Cd)Pyrene 0.100 0.250• 2-Methylnaphthalene 0.100 0.500• Naphthalene 0.025 0.050• Pentachlorophenol 0.500 1.000• Phenanthrene 0.010 0.025• Phenol 0.500 1.000• Pyrene 0.010 0.025• 2,4,6-Trichlorophenol 0.500 1.000

Sewer Problems

Run off and Infiltration

Hypothesis

• Caffeine increases the activity of tadpoles (Hyla versicolor ) in the presence of predators (Ambystoma maculatum ).

Experimental System

• Organism - Tadpoles (Hyla versicolor )• Caffeine - AWAKE brand (Walgreens version of

200mg per caplet)• 6 g/L concentration which is the highest

concentration that is not lethal (Smith and Burgett 2004)

• Predator – Salamanders (Ambystoma maculatum)

Predator

Methods

• Amber took Hyla versicolor tadpoles that have been hatched approximately 1 week.

• Tadpoles placed in 18 L control water and 18L at 6g/L concentration of caffeine in water for 19 hours. (Thanks Amber)

•

Methods

• Took 4 plastic shoe box containers and put 2cm x 2 cm grids with sharpies on bottom.

Methods

• 1 No caffeine no predator• 2. No caffeine predator• 3. Caffeine no predator • 4. Caffeine predator

Methods• Made predator traps with bridal tool and duct

taped tool to bottom and sides of box at 1 end for all 4 boxes.

Methods• Filled tubs to about half with water.• Took Ambystoma maculatum Salamanders out

of outdoor ponds and placed 2 in each appropriate box.

Methods• Transfer from holding bins to testing bins with

turkey baster. • Use clickers to keep track of how often each

tadpole crossed a line to indicate activity rates in 10 minutes.

The effects caffeine has on activity levels without predators

avg yes caf avg no cafno predator

0

10

20

30

40

50

60

70

Activity level across a G

rid

•Critical T-Value at df=7 with p=.05 is 2.36•T-Value for caffeine effects w/o predators = 0.765

The effects of predators on activity levels with no caffeine

avg yes pred avg no pred no caffeine

0

10

20

30

40

50

60

70Activity Level Across the

Grid

•Critical T-Value at df=7 with p=.05 is 2.36•T-Value for predator effects w/o caffeine = 2.114

Effects of Caffeine on Activity Levels in the presence of predators

avg yes caf avg no cafyes pred

0

10

20

30

40

50

60

70

80Activity level across Grid

•Critical T-Value at df=7 with p=.05 is 2.36•T-Value for caffeine effects w/predators = 3.954

Effects of Predators on Activity levels in the presence of Caffeine

avg yes pred avg no predyes caffeine

0

10

20

30

40

50

60

70

80

Activity Level across G

rid

•Critical T-Value at df=7 with p=.05 is 2.36•T-Value for predator effects w/caffeine = 1.820

Data Comparison

avg yes pred avg no predyes caffeine

0

10

20

30

40

50

60

70

80

avg yes pred avg no pred no caffeine

0

10

20

30

40

50

60

70

Based on data accumulated, caffeine can be shown to alter the predator effect on tadpole activity

Conclusion• Critical t-value = 2.36• Effects of caffeine alone: reject hypothesis (t-value: 0.765)•Effects of predation alone: reject hypothesis (t-value: 2.114) •Effects of caffeine in the presence of predators: accept our hypothesis (t-value: 3.954)•Effects of predators in the presence of caffeine: reject hypothesis (t-value: 1.820)

Future Questions• Should the FDA require companies to

include an additive that would allow the body to break caffeine down more readily?

• What other variables should the EPA study when looking at the effect of chemicals in water quality test?

Resources

Brinley, F.J., (1931). EFFECT OF CAFFEINE ON THE OXYGEN CONSUMPTION OF FISH AND TADPOLES. Journal of Pharmacology And Experimental Therapeutics. 42(1): 59-63.

Cornelis, M.C., El-Sohemy, A., Kabagambe, E.K. and Campos, H. (2006) Coffee, CYP1A2 genotype, and Risk of Myocardial Infarction. JAMA. 295: 1135-41.

Fraker, S.L., Smith G.R. Direct and interactive effects of ecologically relevant concentrations of organic wastewater contaminants on Rana pipiens tadpoles. Environmental Toxicology. 2004 Jun;19(3):250-6.

Hardy, J. and J. Word. 1986. Contamination of the water surface of Puget Sound. Puget Sound Notes. 10:3-6.

Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M., Zaugg, S.D., Barber, L.B. and Buxton, H.T. (2002). Phar- maceuticals, hormones, and other organic wastewater conaminants in U.S. streams1999–2000: a national reconnaissance. Environ. Sci. Technol. 36, 1202–11. Smith, G.R., Burgett, A.A. Effects of Three Organic Wastewater Contaminants on American Toad, Bufo americanus, Tadpoles Ecotoxicology. 2005 May;14(4): 477-482.