White Paper
December 2007
Impact Analysis of Artificial Turf Contrasted with
Natural Grass
Prepared by Laura K. Hitt McCann
Introduction
Many high-profile sports venues have transitioned from natural grass to artificial turf.
The trend commenced with the installation of the brand AstroTurf in Houston’s
Astrodome and continues through today. Technologically, the products available have
“morphed” from being essentially a plastic carpet to “blades” of grass supported with an
infill comprised usually of sand and/or rubber pellets. Despite inherent advantages in
some situations, a conversion from natural grass playing fields to artificial turf should be
done only after careful consideration of the anticipated use and specific setting.
Presentation of Facts and Issues
As sports venues grew large-scale, it became patently clear that the games could be
enhanced if they were brought “in-doors.” In the US, allowing football teams to play in
any weather in any climate was perceived as important to get fans to attend the games.
Whereas the technology to cover a football field was easy, getting the grass to grow in a
covered building and to stand up to the heavy usage of practice and game play proved
extremely difficult. This problem was “solved” when a Research Triangle Park group of
scientists invented AstroTurf. Its first major placement was in the Houston AstroDome in
1965. 1 Though it solved the weather problem, artificial turf was derided by players who
found it hard, unforgiving and more prone to producing injuries during games.
Installations have continued, though acceptance was slow for decades. Recent changes in
production techniques have resulted in an improved product which apparently plays quite
realistically.
Today’s artificial turf is vastly different. The basic technology consists of individual
blades of grass, lubricated with silicon and held erect by a filled base of
sand/silicon/rubberized pellets.
Costs
The relative costs of natural turf versus artificial turf are highly variable depending on
several aspects of the natural turf available. Specifically, natural turf can be soil-based or
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sand-based, with or without specially designed water runoff and irrigation systems.
Considering that Cecil would presumably utilize the current soil-based playing field or a
mid-level in-fill based artificial field, figures presented by the University of Kentucky
turf grass agronomist, Dr. A. J. Powell suggest that the initial installation of an artificial
field would cost around $600,000.2 Annual maintenance would be an additional $3500
per year, if done by Cecil College staff. 3 In contrast, maintaining the existing field would
likely involve on-going costs of $7000 per year.4 The anticipated lifespan of the artificial
fields is 10 years, the soil based field is indefinite.5
Usage and Maintenance Differences
Distinct benefits accrue to the artificial turf: it can be used in any weather and tolerates
about 6 times more playing time per week than a natural turf field.6 In communities
where youth leagues are booked back to back, the extra durability of the artificial turf is
often a deciding factor in its favor. Studies by the international soccer governing body,
FIFA, have shown that injury rates and ball reaction are similar on both surfaces and the
organization now has a certification program for artificial turf field standards.7,8
There has been scientific documentation of the excessive heat generated by the artificial
fields. The rubber fill (composed of approximately 22,000 ground up tires) results in
temperatures up to 86.5 degrees F higher than the natural turf.9 10 The temperature affect
is most extreme at the surface of the artificial turf and dissipates significantly with
vertical distance above the field. The average player is sufficiently tall that there has
been no discernable influence on game-play. Spraying water on the surface did little to
alter the temperature in anything but a temporary fashion.
The artificial turf requires specific caretaking that is not applicable to natural turf. As the
artificial turf is plastic, body fluids, bird waste, dog waste, etc do not biodegrade in a
normal fashion. Chewing gum must be kept off the field. Wastes, mud, etc. must be
cleaned off to avoid the growth of algae or mold and the field must be brushed to
redistribute the pellet fill so that it remains flat and even. This is done every 30-35 hours
of play time.11 As mentioned, the anticipated lifespan is 10 years, at which point the fill
and “grass” will need to be replaced.
Another concern relative to the artificial turf is a bad smell. The rubber fill pellets have
been blamed for an unattractive smell, especially in warm or hot weather.
Environmental Concerns
Both types of field have environmental drawbacks. Depending on the intensity with
which the field is maintained, a natural turf field will require water, fertilizer, possibly an
herbicide for weed control, mowing and spot-seeding. Mowing, in particular, produces
ground level ozone and creates CO2 through the burning of fossil fuels.
Artificial turf fields require little water, but allegations have been made that the rubber
fill contains heavy metals, particularly cadmium, that can leach into the surrounding soil
and groundwater.12 Though suggested, empirical evidence has not been collected to
either prove or disprove this. Certainly, it is justly argued that there is no bio-benefit
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from the artificial turf; it does not contribute to the water shed, and must be viewed as a
largely impermeable surface. There is no filtration as occurs in a grass field, nor is there
the supporting activity of soil bacteria, worms, etc. Though not noticeably fire-prone,
concern has been voiced about the toxic fumes that may be generated if an artificial field
burns.
Recommendation
Until such time as Cecil College needs the additional playable field time that is available
with an artificial turf field, the recommendation is to maintain the current soil-based
playing field. The fairly new technology of the rubber infill has created numerous
environmental questions, particularly relative to the safety of the human and
environmental exposure to the metals and volatile hydrocarbons in the chopped up tires.
Studies have not been performed to quantify these impacts, though in 2004 the Turfgrass
Producers International presented a paper to the EPA requesting study of these issues and
the issue of disposal of the “used” fields.13 As the soil-based field exists, the higher
annual maintenance costs are cumulatively less than the costs that would be incurred in
installing and caring for an artificial field.
Conclusions
Artificial fields are not environmentally “neutral”. The use of tires to create the pellet fill
may jeopardize local water sources and player health due to the heavy metal and organic
compounds in the petroleum based tires. Disposal may be an issue, too, and chemicals
are required for annual care. Though the on-going maintenance may be less costly than
that of a soil based field, it is unlikely to offset the high installation costs under the likely
usage scenario at Cecil College. Since hot weather is not uncommon due to the latitude,
the increase in surface temperature of the artificial turf may be a significant negative to
players.
The current soil based field may require greater water resources and has the likelihood of
requiring herbicide and pesticide treatment. Application of the most bio-friendly
products is appropriate. CO2 production is inevitable, as is ozone, due to the need to
mow the grass. Doing so early or late in the day minimizes the production of ozone, the
CO2 is unaffected by the time of day. A natural field contributes positively to the local
biome in many ways, including the capture of airborne pollution, water filtration,
recharging of groundwater and improved soil health.
Reference:
“AstroTurf Move Brings Brand Home: Was Invented in RTP” Ranii ,David The News & Observer,
Raleigh, N.C. 12/15/2006
1
“Natural vs Synthetic Fields: Comparing the Costs….” Dr. A. J. Powell, University of Kentucky,
presented January 2005 to the Sports Turf Managers Association’s Annual Conference.
2
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“Natural vs Synthetic Fields: Comparing the Costs….” Dr. A. J. Powell, University of Kentucky,
presented January 2005 to the Sports Turf Managers Association’s Annual Conference.
3
“Natural vs Synthetic Fields: Comparing the Costs….” Dr. A. J. Powell, University of Kentucky,
presented January 2005 to the Sports Turf Managers Association’s Annual Conference.
4
“Natural vs Synthetic Fields: Comparing the Costs….” Dr. A. J. Powell, University of Kentucky,
presented January 2005 to the Sports Turf Managers Association’s Annual Conference.
5
“Natural vs Synthetic Fields: Comparing the Costs…” .Dr. A. J. Powell, University of Kentucky,
presented January 2005 to the Sports Turf Managers Association’s Annual Conference.
6
7
FIFA Technical Study 2 with Prozone
A comparative performance analysis of games played on artificial (Football Turf) and grass from the
evaluation of UEFA Champions League and UEFA Cup (accessed October 21, 2007)
http://www.fifa.com/mm/document/afdeveloping/pitchequip/technical%5fstudy2%5f11163.pdf
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Risk of injury in elite football played on artificial turf
versus natural grass: a prospective two-cohort study
J Ekstrand, T Timpka, M Ha¨gglund
Br J Sports Med 2006;40:975–980. doi: 10.1136/bjsm.2006.027623
9
BioCycle World BioCycle December 2005, Vol. 46, No. 12, p. 6
“Synthetic Surface Heat Studies” C. Frank Williams and Gilbert E. Pulley Brigham Young University
undated (accessed October 21, 2007) http://cahe.nmsu.edu/programs/turf/documents/brigham-youngstudy.pdf
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11
FIFA recommendations for field maintenance
(accessed October 21, 2007)
http://www.fifa.com/mm/document/afdeveloping/pitchequip/maintenance_artificial_pitch_en_341.pdf
12
Oct. 14 issue Golf Course Superintendents Association of America, Weekly News. (accessed October 21,
2007) http://www.gcsaa.org/newsweekly/2004/oct/2/industry.asp
13
Oct. 14, 2004 issue Golf Course Superintendents Association of America, Weekly News. (accessed
October 21, 2007) http://www.gcsaa.org/newsweekly/2004/oct/2/industry.asp
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