1. The Effect of Crumb-Turf Microbial Survivorship
Nate Matthews
Central Catholic
Grade 9

2. Modern Artificial Turf Fields
The purpose is to simulate grass rooted in soil The second layer of pellets, or crumb-turf, tend to be displaced during play Players can come in contact with the turf during play Can be transferred to other locations, like homes
Artificial grass crumb-turf

3. Crumb-Turf Made from granulated virgin rubber or recycled tires
Virgin rubber may contain hazardous chemicals
Rubber from tires has a different chemical makeup, including carbon-black and other potentially dangerous substances
The granular pellets, being very small, are thought to expose the chemicals inside

4. Potential Health Problems Related to Crumb-Turf
Soccer players sick, some cancers
Linked to crumb-turf fields (theory)
EPA now involved, collecting samples and reaching out to players
Other agencies and lawsuits involved

5. Problem Carcinogenicity hard to test Can test for microbial effect
Information may aid athletes and parents
3 different fields were assessed (CCHS, CMU, and Schenley Oval)

6. Hypotheses
Null: the crumb-turf pellets will not effect the microbial survivorship
Alt: the crumb-turf pellets will alter microbial survivorship

7. Microbes
E. Coli (gram negative)
Staph (gram positive)
Escherichia coli (E. coli) present in many environments, normally found in the intestines of mammals
Some are pathogenic, and cause diarrhea or illness outside of the intestinal tract
Can be transmitted through contaminated water or food, or through contact with animals or persons
Staphylococcus epidermidis (staph) is a normal surface symbiont found on humans and other species
Patients with compromised immune systems at risk of developing infection, can be lethal

8. Materials Crumb-turf Escherichia coli (C-600)
Staphylococcus epidermidis
Sterile Dilution Fluid (100mM KH2PO4, 100mM K2HPO4, 10mM MgSO4, 1mM NaCl)
LB Agar plates x 112
LB Media f(0.5% yeast extract, 1% tryptone, 1% sodium chloride)
Pipettes
1.5 mL micro tubes
Ethanol
Spreader bars
Bunsen burner
Weigh boats
Electronic scale (10e-4)
Bags
Gloves
Autoclave

9. Procedure
Turf pellets were collected from fields (kept in bags for sterility)
Turf pellets were sterilized through autoclave
E. coli and Staph were grown overnight in sterile LB media.
Samples of the overnight culture were added to fresh media in a sterile sidearm flask.
The cultures were incubated until a density of 50 Klett spectrophotometer units was reached. This represents a cell density of approximately 10^8-10^9 cells/ml.
The cultures were diluted in sterile dilution fluid to a concentration of approximately 10^5 cells/ml.

10. Procedure (cont)
Pellets were weighed into individual masses of 0.01g, 0.05g, and 0.1g
The following ingredients including the turf pellets were added to 1.5 mL micro tubes
0.1 mL samples were taken from each tube and plated onto LB media plates
Plates incubated at 37°C for 1 day
Colonies were quantified

11. Procedure Conc. Table Turf Mass 0g 0.01g 0.05g 0.1g Microbe 0.1 mL SDF
Total Volume
0.99 mL

12. P-value<10e-6
2e-6
<10e-6
0.045

13. Dunnett's tests E. coli Field and Mass F values (F-crit=2.22)
Variation
CC 0.01g
F-test=-2.90
Sig
CMU 0.01g
F-test=-3.83
Oval 0.01g
F-test=0.33
Not sig
Field and Mass
F values (F-crit=2.22)
Variation
CC 0.05g
F-test=-3.73
Sig
CMU 0.05g
F-test=4.19
Oval 0.05g
F-test=4.34
Field and Mass
F values (F-crit=2.22)
Variation
CC 0.1g
F-test=2.14
Not sig
CMU 0.1g
F-test=-3.83
Sig
Oval 0.1g
F-test=4.62

14. P-value =

15. Dunnett's tests Staph Field and Mass F values (F-crit=3.008) Variation
CC 0.01g
F-test=-3.81
Sig
CC 0.05g
F-test=-3.72
CC 0.1g
F-test=-3.93

16. Conclusion
All p-values (for e. coli and staph) were well below 0.05, so the null was rejected, and the turf had an effect on the microbes
For E. coli, the crumb-turf reduced survival at the lowest mass, but increased it at the higher masses
For staph, all masses of crumb-turf reduced survivorship

17. Limitations
The turf pellets varied in size, so it could have affected surface exposure
Plating was not exactly synchronized
Unknown interaction between bacteria and turf pellets (adherence)?

18. Extensions
Liquefying the turf pellets so that the microbes would not stick
Attaching microbes to the turf and seeing how long they survive
It would be interesting to do this again, as the CMU data showed strange results at highest mass of turf

19. Bibliography
used-playing-fields
surface-your-childs-playground-n258586

20. CC
CMU
Oval 0g 57 49 65 56 61 59 51
0.01g 37 39 42 70 44 38 48 20 43 40 29 55
0.05g 47 80 72 77 93 52 67 89 75 92 32 76
0.1g 81 71 45 85 66 98 78 53 82 88 69 0g
0.01g
0.05g
0.1g
Staph
156
119
132
116
147
110
130
125
108
101
146
111
121
134
129
124
109
159
120 92
107
104
137
114