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1
Natural grass vs Synthetic Surfaces for recreation and
Sports: An evidence review
i
Md. Masud-All-Kamal
The University Of Adelaide
Executive Summary:
Appropriate surface provision is fundamental to inspiring individuals to participate in
outdoor sports and recreation activities. Although outdoor sports traditionally have
been played on natural grass fields, the synthetic turf option has gained popularity
over the past few decades around the world and in different states of Australia,
including South Australia. The use of synthetic surfaces in sports and recreation
activities, however, has long been debated, particularly due to their negative
environmental and health impacts, although we have limited understanding about the
impacts per se. This study, therefore, aims to provide a knowledge base for this
debate by exploring the benefits and disadvantages of synthetic turf compared with
natural grass. Findings suggest that natural grass turf has multiple environmental
benefits compared with synthetic turf sports surfaces. Natural grass fields also have
certain health benefits related to heat dissipation and psychological comfort, while
synthetic turf offers health and social benefits in terms of the capacity to sustain
heavy use and accessibility. This review suggests that choosing the right surface
option for outdoor sports needs an adequate consideration of both short- and long-
term environmental, health and wellbeing factors.
1. Introduction
Traditionally outdoor sports and recreation activities have been performed on natural
grass surfaces. Maintenance of grass turf surfaces involves different activities
including mowing, irrigation and control of weeds, pests and disease. Despite
2
significant maintenance, natural turf has a low carrying capacity
1
. Due to the
changes in the profile of sports, particularly at the elite level, expectations for high-
quality sports grounds have increased worldwide. Given this context, replacing the
natural grass with synthetic turf (also referred to as artificial turf) received traction
around the world from the mid-1970s onwards. Several traditional sports such as
hockey, soccer and rugby started to use synthetic turf pitches. Australia has
increasingly embraced artificial turf technology around the same time. In particular, it
started to replace natural grass with artificial surfaces in first-class and international
sports venues, complying with the decision of international sporting governing bodies
to allow artificial turf.
Such popularity impacted the expectation of local sporting clubs and associations
across Australia. In order to provide high-quality sports surfaces, ground
management authorities have increasingly adopted plans to replace natural grass
surfaces with synthetic ones. However, the use of synthetic surfaces in sports and
recreation activities has long been debated, particularly based on their negative
environmental and health impacts, which are not well documented. This study,
therefore, aims to provide a knowledge base by examining the benefits and
disadvantages of synthetic turf compared with natural grass.
2. Scope and objective of the Study
The City of Adelaide is encircled by parklands, which provide residents a myriad of
sporting and recreational opportunities. These activities, together with the events
organised in the park lands, contribute to the physical and mental wellbeing of the
residents, making it one of the world’s most liveable cities. Therefore, the sustainable
management of parklands is crucial to maintain its status as one of the best liveable
cities.
The sustainable management of parklands, however, has always been a challenging
task for authorities concerned. It is challenging in the context of the different
functions that they are required to perform, from accommodating national sporting
1
James, I. (2015) Surface classification, function, construction and maintenance, in Dixon, S.
Fleming, P., James, I. and Carre, M. (eds.) The science and engineering of sport surfaces, Routledge,
Oxon.
3
stadiums to preserving significant remnants of vegetation. This challenge is
magnified by the fact that the metropolitan Adelaide region is poorly serviced by
space. As a result, the parklands service a population that extends well beyond the
residents of the City of Adelaide. Furthermore, inner-city and surrounding urban
density is increasing, and population growth is projected to steadily climb, whilst no
new significant parcels of open space have been identified.
Park-based sports and other physical activities are crucial means for maintaining
health and wellbeing
2
. Considering this, the Adelaide Park Lands Authority adopted
a plan to encourage its residents to engage in sports and recreation activities by
providing improved playing surfaces
3
. As such, the provision of quality surfaces is
considered an important underlying factor because it motivates the community to
engage in sports and exercise activities. City planners, therefore, seeks to deliver ‘fit
for purpose’ facilities for the community so that the participants can perform to the
best of their ability.
A way of providing more opportunities within the existing footprint of formal and
informal sporting areas in the parklands is to increase the carrying capacity of
spaces through the use of alternative surfaces. Synthetic sports surfaces have now
been determined as a viable alternative to natural grass surfaces. However, in order
to make the decision about the appropriate surface provision for sports, it is essential
to shed light on various aspects of synthetic and natural grass turf.
Objective of the study
The objective of this study is to provide strategic direction for the future provision and
management of sports and recreation surfaces in the City of Adelaide. The study
specifically seeks to achieve the following objectives:
Identify international and national trends in relation to sustainable recreation
and sports landscape provision and management;
2
Government of South Australia (2016) Healthy parks and health people South Australia 2016-2021,
South Australia.
3
Adelaide Park Lands Authority (2017) Adelaide Park Land Management Strategy 2015-2025,
Government of South Australia.
4
Assess the short- and long-term environmental impacts of natural and artificial
surfaces for recreation and sports activities; and
Understand the impacts of natural and artificial turf on health and well-being of
the residents in the context of carrying capacity and usability.
3. Methodology
The methodology for this report involved conducting desktop research. This process
involved the identification, collection, review and summary of a wide variety of
sources of literature including peer-reviewed (i.e. scientific journal articles, books)
and grey literature (i.e. technical reports published by governmental agencies,
academic institutions and industry publications). This information was critically
selected and analysed to understand different aspects of natural grass and synthetic
turf, as well as to compare the benefits and disadvantages between natural and
synthetic turf systems. Although some cited reports came directly or indirectly from
industries with a financial interest in promoting natural or artificial turf, data were
cross-checked with other sources to ensure the validity of the conclusions as much
as possible.
4. International and National Trends of sports and recreation surfaces
There is an ongoing debate about the provision of sports and recreation surfaces.
Such debate has been triggered by the increasing popularity of synthetic surfaces
over the natural grass surface. The synthetic surfaces gained popularity as an
alternative to natural turf largely because it permits relatively higher usage and ‘all-
weather’ durability. This means artificial turf offers the benefits of high-intensity use –
often are used for 50 hours per week for team sports.
Synthetic turf was first used in Major League Baseball in the Houston Astrodome
stadium in the USA in 1966. Since then, synthetic turf is increasingly used for
different sports including hockey, soccer and tennis around the word. These sports
are replacing natural grass grounds with synthetic surfaces for a variety of reasons.
The following discussion briefly highlights the historical evolution and recent trends in
surface provision in relation to different sports.
5
Hockey
Hockey was one of the early adapters of synthetic grass pitches. The synthetic grass
pitch was introduced in hockey in the 1970s, because the synthetic turf pitches are
flatter than natural grass surfaces. This resulted in the use of artificial turf for the
international hockey tournament at the 1976 Olympic Games in Montreal. The
introduction of artificial turf led hockey to become much faster and more exciting, and
thereby a more popular sport. At present, synthetic turf pitches are used widely at
many levels of hockey supported by the International Hockey Federation (FIH).
Although Hockey is played on a variety of surfaces, the preferred surface is synthetic
turf. There are three types of synthetic surfaces: sand-filled turf, water-based turf and
hybrid turf. International hockey matches are usually played on a water-based pitch
because it prevents the ball from bouncing up and hitting the players, resulting in
much better quality and speed of play. At present, all FIH tournaments are hosted on
water-based artificial surfaces. Yet, FIH has recently announced that they are going
to allow international tournaments to be played on grass surfaces. In addition, FIH
announced that the 2024 Paris Olympics will not be played on water-based pitches,
in order to save water.
In Australia, hockey was the first sport to start using synthetic grass at the elite level.
Considering a strong and accelerating demand, artificial turf has made rapid
progress in Australian hockey. All international and Elite Premier League games in
Australia are now played on water-based synthetic surfaces, while natural grass
pitches are still used for a significant proportion of games at both junior and senior
levels
4
. In recent years, there has been a move toward using hybrid synthetic turf at
the regional and community level in Australia because hockey can be played wet or
dry on the new generation of hybrid surfaces4. In addition to this, hybrid synthetic
surfaces are being promoted as they can provide a multi-use facility. For instance,
soccer can be played on the same surface.
4
Western Australian Department of Sports and Recreation (2011) Natural grass vs synthetic turf
study, Tredwell Management Services, SA.
6
Hockey is traditionally a winter sport. Yet, with the increase in the provision of
synthetic turf pitches, hockey has become a year-round sport in Australia,
particularly at club level
5
. Synthetic hockey pitches are more durable than natural turf
pitches. While synthetic turf pitches can be programmed to be used intensively, the
natural grass pitches cannot sustain such a high level of use.
Soccer
Synthetic grass was first used by American football and baseball stadiums in the
1970s. Given the all-weather capability, synthetic grass fields became increasingly
common in the United States and Canada. However, due to concerns about the
safety of players, many North American Football grounds had converted back to
natural grass by the early 1990s
6
. Later, a significant advancement occurred in
synthetic sports surface technology that reduced the previous concerns in relation to
artificial turf. As such, the production companies began to make synthetic turf more
and more similar to natural grass fields. This improvement induced the building of
synthetic turf fields for international and national sport events including soccer.
Like American football, the experiment of playing soccer on synthetic turf was
unsuccessful in the 1980s, but later, due to the advent of third-generation turf, soccer
on synthetic turf had gained popularity. Consequently, Fédération Internationale de
Football Association (FIFA) and Union for European Football Associations (UEFA)
recognised the potential of playing football on the artificial turf fields. In 2001, both
FIFA and UEFA developed a guideline to ensure a specific standard to build
synthetic grass fields around the world. The first international game programmed on
artificial turf was in 2003 at the FIFA U-17 World Championship. Following this
successful experiment, FIFA decided to arrange artificial turf for the entire 2007 U-17
World Championship in Peru. At the senior level, 2015 the FIFA Women’s World Cup
was the first international tournament to be entirely played on artificial turf. Yet,
artificial turf became a contentious issue in this tournament as many players raised
concern over injury and different behaviour of balls. In order to avoid such concern,
5
https://www.humanrights.gov.au/sites/default/files/content/racial_discrimination/whats_the_score/pdf/
hockey.pdf
6
Claudio, L. (2008) Synthetic turf: Health debate takes root, Environmental Health Perspective,
116(3).
7
all matches of this year’s Women’s World cup tournament in France are
programmed to be played on artificial grass pitches, and FIFA decided to allow only
natural grass fields for the 2023 Women’s World Cup.
UEFA matches are played on either natural turf or synthetic turf with the exception of
the final, which must be played on natural turf. For UEFA matches, artificial turf fields
are prepared in accordance with FIFA Quality Programme standards and UEFA
Stadium Infrastructure Regulations.
Soccer is the most popular club-based team sport in Australia with more than 1.1
million participants, as per the Australian Sports Commission Survey
7
. In order to
meet the growing demand, the local football associations, clubs and local
government associations are now under pressure to convert natural grass fields to
synthetic ones so that they can train more players and hold more matches. Synthetic
football fields have gained popularity across different states in Australia. In 2017,
there were around 150 synthetic football fields in Australia, with many others under
construction or in the planning stage
8
. The growth of synthetic football turf was
triggered by increased playing capacity from 20-25 hours per week on natural grass
to over 60 hours per week8.
Tennis
Tennis is played globally on a variety of surfaces. There are three major types of
surfaces used for elite-level tennis: natural grass, porous/clay and hard court. For
instance, Wimbledon Championship tournaments are played on natural grass courts,
while Australian Open tournaments are played on hard courts. The International
Tennis Federation has recognised the use of synthetic grass surfaces in international
elite level sport since the 1970s.
Tennis Australia recognises the use of all these types of surfaces; however,
synthetic turf courts are not accredited surfaces by Tennis Australia, and therefore
7
https://www.ffa.com.au/news/football-continues-dominate-australian-club-sport
8
Northern NSW Football (2017) Synthetic fields: A guide to synthetic surfaces for football, New South
Wales. Available at: https://footballfacilities.com.au/wp-
content/uploads/sites/11/2018/10/SyntheticFields-v2-2017.pdf
8
Australian ranking points tournaments both at junior and senior level do not use
synthetic turf. Nevertheless, synthetic turf surfaces are widely used and promoted
for club and community level tennis across Australia. The primary benefit of installing
artificial surfaces for clubs and community centers is that they can increase their
memberships and generate more revenue. Despite an increasing trend in the use of
artificial grass and clay court surfaces across Australia, natural grass courts have
remained a prominent choice for regional and local tennis tournaments
9
.
Given the fact that tennis requires a consistent, even turf coverage and density, local
clubs prefer synthetic courts to lawn courts. The most common surface choices at
the community club level are sand-filled artificial grass and synthetic clay. Synthetic
turf courts provide more playability than lawn courts. Synthetic turf courts are often
compatible with other sports (e.g. hockey), while natural grass and clay courts are
normally not compatible with any other sport.
5. Life Cycle of Natural Grass and Synthetic Sports Surface
5.1 Natural Turf for sports
Natural grass surfaces are considered as appropriate surface provisions for many
sports (e.g. soccer and golf) and other recreation activities. There are several
positive aspects of choosing natural grass turf for sports and recreation activities.
Studies suggest that well-maintained natural grass turf is proven to be
environmentally-friendly, sustainable and carbon-friendly. Yet, natural turf poses
some challenges. The following discussion highlights various aspects of the life cycle
of natural grass surfaces.
5.1.1 Installation
Construction of natural grass turf depends on the level of sports. International and
first-class sports venues are constructed by maintaining stringent standards, while
local ground management authorities aim to install high-quality sports grounds to
9
National Tennis Facility Planning and Development Guide. Available at:
https://www.tennis.com.au/wp-content/uploads/2013/04/TA-National-Tennis-Facility-Planning-and-
Development-Guide.pdf
9
accommodate an increasing number of players. Therefore, construction standards
for elite and premier grounds are higher than those for local sports grounds. In order
to construct a superior quality of sports surface, imported sand profile over the
natural sub-based with sub-surface drainage is installed, which is used for
international and national grade sports. Local sports grounds, on the other hand, are
constructed using natural soils with the provision of surface drainage.
Natural grass turfs are usually prepared by laying sods, while seeding is an
alternative option. Installing grass sods is considered a better choice because it
provides diverse positive benefits. In recent years, grass breeders have developed
new and innovative natural grass solutions for sports fields. As a result, turfgrass has
now become more tolerant of environmental stresses (e.g. heat, excessive rainfall),
diseases and pests. In addition, some varieties of grass are resistant to heavy wear,
meaning that natural grass fields are capable of coping with heavy use.
5.1.2 Maintenance
Once installed, turfgrass establishes roots and develops a relationship with soil and
its microorganism within a short period of time. It, therefore, self-replenishes and can
be sustained for a longer period. However, maintaining playability on turfgrass
involves a range of maintenance activities: irrigation, mowing, fertilisation, weeding,
disinfestation, aeration, vertical cutting and sand dressing. All these activities involve
a sustained effort throughout the year, which has an impact on the environment. The
management of a natural grass turf field and its environmental consequences
depends on diverse factors including the size of the surface, purpose and weather
conditions.
Turfgrass management requires to maintain a certain level of soil nutrient and to
protect grass from pests and diseases. The chemicals used for managing turfgrass
are likely to harm the environment. For instance, runoff from the playing surfaces can
pollute nearby lakes, streams and rivers. Besides, insecticides applied for the control
of pests may also affect beneficial species. Therefore, there is a growing demand for
reducing the use of fertilizer and pesticides. A responsible and judicious application
10
of pesticides, herbicides and fertilizer is necessary in order to reduce the harmful
effects on the environment and public health.
5.1.3 End of Life Disposal
Natural grass turf is self-renewing and therefore does not produce any waste. In
professional sport surfaces, surfaces are replaced every 10-20 years, but this waste
is biodegradable. Therefore, natural grass surfaces have almost no end of life cost.
5.2 Synthetic turf for sports
Synthetic surfaces are now used by many sports as an alternative to turfgrass. This
popularity has increased primarily because it permits all-weather play and can
withstand heavy use. The popularity continues to rise as synthetic turf has been
refined from an abrasive surface to a surface that more closely resembles the
features of natural grass turf
10
.
Construction of synthetic turf fields for sports has evolved over the last 50 years due
to the advancement of turf technology. The first-generation synthetic turf was
introduced in the late 1960s, known as ChemGrass, which was soon referred to as
AstroTurf
11
. This turf was a short-pile nylon carpet without infill, installed over a
compacted soil base. Many stadiums installed AstroTurf around this period, but
some reverted back to natural grass due to players’ complaints about burns and
other injuries. The second-generation turf carpet was composed of much longer fiber
filled with silica sand to keep the fibers upright. A shock-absorbing pad beneath the
carpet was a new feature in second-generation synthetic turf fields. This turf system
was widely adopted within the United States during the late 1980s and 1990s. In the
third-generation turf, a number of new features were added to second-generation
turf. The third-generation system uses a granular material to fill the space between
the carpet pile fibers (see Figure 5.1). Infill materials in third-generation systems
10
Serensits, T., McNitt, A. & Sorochan, J. (2013) Synthetic turf, Madison: American Society for
Agronomy.
11
Jastifer, J. McNitt, A., Mack, C., Kent, R. and McCullough (2019) Synthetic turf: History, design,
maintenance, and athlete safety, Sports Health: A Multidisciplinary Approach, 11(1).
11
consist of crumb rubber, or a combination of crumb rubber and silica sand, as
opposed to the pure sand used in second-generation surfaces. Third generation
surfaces are now commonly used around the world and in Australia.
Figure 1: Components of a third-generation synthetic playing surface
Source: Jastifer et al. (2019)
The third-generation synthetic turf has evolved substantially over the last two
decades as manufacturers are continuously addressing the concerns related to
environment, safety and health
12
. In addition, an increase in variations of synthetic
turf systems has taken place due to meeting the sports-specific requirements. It is
therefore difficult to identify a standard for third-generation synthetic turf system.
5.2.1 Installation
Synthetic turf fields are essentially comprised of two main parts: base design and
surface system design. The surface system design is dependent on the
requirements of specific sports, while the base design is almost universal. A gravel
base is typically installed beneath the carpet and shock-absorbing pad, which
contains a drainage system. The base is typically installed at a depth of 15cm to
12
Toronto Public Health (2015) Health impact assessment of the use of artificial turf in Toronto, City
of Toronto.
12
30cm
13
. Shock-absorbing pads are often installed between the base and the carpet
depending on the thickness of the carpet. They are generally installed at a thickness
between 25 mm and 35 mm. Pads were used to increase shock absorption. The
carpets are made of nylon, polyethylene or polypropylene. The backing and blades
of the carpet are primarily manufactured with recycled plastics and rubbers.
Synthetic turf fields are infilled with crumb rubber, which is often made from recycled
tyres, or a mix of sand and crumb rubber to keep the plastic fibers upright and
provide shock absorption, resembling that of natural grass turf. One estimation
suggests that a large synthetic soccer pitch uses approximately 27,000 tyers
14
.
The installation of synthetic turf is a complex and integrated process. Therefore, the
construction of synthetic turf requires a budget that is significantly higher than that of
natural turfgrass. The following table summarises the cost comparison between
natural and synthetic turf installation in different sports at the community level, based
on a study commissioned by the Department of Sports and Recreation in Western
Australia.
Table 1: Cost comparison between Natural grass and synthetic Turf sports
surfaces for selected sports
Sport
Construction Cost
Natural Grass
Synthetic Turf
Hockey
$186,750
$550,000
Soccer
$212,000
$705,000
Tennis
$27,500
$69,000
Source: DoSR, Western Australia, 2011
5.2.2 Maintenance
A common misconception of synthetic turf sports fields is that they are maintenance-
free, but this is far from reality
15
. Regular maintenance is required to maintain
13
Serensits, T., McNitt, A. and Sorochan, J. (2013) Synthetic turf, Madison: American Society for
Agronomy.
14
Huber, C. (2006). A new turf war - Synthetic turf in New York City Parks. New York, USA: Research
Department at New Yorkers for Parks.
15
Jastifer, J. McNitt, A., Mack, C., Kent, R. and McCullough (2019) Synthetic turf: History, design,
maintenance, and athlete safety, Sports Health, 11(1).
13
playability and safety, and prolong the life span of turf. Standard maintenance
practices include brooming, topdressing, removing surface debris and controlling
weeds, moss and algae. Performing these activities depends on the intensity of use
of a field. In addition to that, deep cleaning is required to remove inorganic (e.g.
chewing gum, tobacco, oil) and organic (e.g. vomit, saliva and animal droppings)
contaminants.
The maintenance activities are performed using equipment and cleaning products.
The operational costs to maintain synthetic turf sports fields are higher than that of
natural grass at a community level. Table 2 provides a comparison of annual
operating costs between natural grass and synthetic turf for selected sports fields.
Table 2: Comparison of annual operating costs to maintain natural grass
versus synthetic turf
Sport
Operating Cost (Annual)
Natural Grass (Community
level)
Synthetic Turf
Hockey
$22,350
$10,000 (Sand filled)
Soccer
$27,250
$25,000
Tennis
$9,500
$4,000
Source: DoSR, Western Australia, 2011
In addition to that, there are replacement costs for replacing synthetic turf at the end
of its life. Unlike natural grass surfaces, synthetic turf has a definite lifespan. The
lifespan of a synthetic surface is dependent on the level of usage, maintenance and
expected performance from the surface. The life of synthetic turf also varies from
sport to sport. For instance, the surface used for club-based hockey could last 8-10
years
16
.
16
Western Australian Department of Sports and Recreation (2011) Natural grass vs synthetic turf
study, Tredwell Management Services, SA.
14
5.2.3 End of Life Disposal
As noted above, synthetic sports surfaces have a specific lifespan. End of life
disposal of synthetic turf involves considerable cost and environmental
consequences. Disposal costs are associated with removal, transportation and
landfill. According to the Synthetic Turf Council, a typical sport field is about 80,000
square feet, which comprises of 400,000 pounds of infill and 40,000 pounds of turf
17
.
The infill within the pile of the carpet becomes waste as it becomes contaminated
over time. At present, turf ends up in landfill, but different initiatives have recently
been taken to recycle synthetic turf. Recycling synthetic turf is challenging as it
contains a variety of polymers, which need specialised technologies. Therefore, very
limited recycling facilities are available, resulting in high transportation costs.
6. Environmental Considerations
Making a decision on preferred sport surfaces needs to consider several
environmental factors. These environmental considerations need to be evaluated
with due care in order to make environmentally sustainable choices. This section
highlights some major environmental aspects in relation to natural grass turf
surfaces.
6.1 Greenhouse Gas Emissions
The turfgrass industry produces greenhouse gasses (GHG). Emissions of GHG
occur through the production of carbon dioxide in fuel combustion, and the
volatilization of nitrous oxide from fertilizers. Growing, installation and management
of turfgrass emit GHG. More specifically, the activities involved in the management
of natural grass turf produce GHG throughout the year. The following table breaks
down the activities that consume energy and cause GHG emissions.
17
Synthtic Turf Council (2015) Removal, Recovery, Reuse and Recycling of Synthetic Turf and Its
System Components, Atlanta, GA.
15
Table 3: Energy use and GHG emissions in the production and maintenance of
natural grass sports surfaces
Direct GHG producers
Indirect GHG producers
Irrigation
Manufacture of Machinery
Mowing
Manufacture of fertiliser/insecticide
Fertilisation/Pest and disease control
Transport of Sand
Topdressing
Production and distribution of fuel and
electricity
Verticutting
-
Aeration
-
Although the maintenance of natural grass turf emits GHG, it can offset emissions by
sequestering carbon dioxide. This means natural turf produces oxygen and reduces
GHG by sinking carbon dioxide carbon in the soil through the process of
photosynthesis. One estimation suggests that turfgrass can sink four times the
amount of carbon produced by maintaining it
18
. The rate of carbon sequestration is
expected to be higher as turf equipment industries are developing products with
greater fuel-use efficiency and lower emissions.
The carbon footprint of synthetic turf is much higher compared to natural grass turf
when the whole life cycle is considered
19
. Yet, research is scant about the total
emission of GHG during the life cycle of a synthetic turf system as opposed to a
natural grass surface. One study has estimated that CO2 emissions from
manufacturing, transporting, installing, maintaining and disposing of a 9000 m2
synthetic turf field in Toronto over a 10-year period is 55.6 tons, while emission from
construction and maintenance of a natural grass field of the same size is 16.9 tons
20
.
The carbon footprint of synthetic turf tends to come primarily from production,
transportation and disposal. The production of artificial turf requires a substantial
amount of fossil fuels as it is a petroleum-based product. Like natural grass,
18
Sahu, R. 2008. Technical Assessment of the Carbon Sequestration Potential of Managed Turfgrass
in the United States, Alexandria, VA, USA. Available at:
http://multivu.prnewswire.com/broadcast/33322/33322cr.pdf
19
Simon, R. (2010) Review of the Impacts of Crumb Rubber in Artificial Turf Applications, University
of California, Berkeley, USA.
20
Meil, J. and Bushi, L. (2007) Estimating the Required Global Warming Offsets to Achieve a Carbon
Neutral Synthetic Field Turf System Installation, Athena Institute, Ontario, Canada.
16
synthetic turf requires regular maintenance that uses fuel-powered machinery. In
addition, unlike natural turf, synthetic turf does not absorb carbon dioxides. As the
installation of synthetic turf requires the removal of a significant amount of soil that
reduces its porosity, it reduces the soil’s capacity to sink carbon. The disposal of
synthetic turf also leaves a significant carbon footprint. Table 4 presents the activities
related to energy use and GHG emission for construction, maintenance and disposal
of synthetic turf.
Table 4: Energy use and greenhouse gas emissions in a life cycle of synthetic
turf
Direct GHG producers
Indirect GHG producers
Brushing
Manufacture of Machinery
Harrowing
Transportation of Materials
Grooming
Manufacture of cleaning chemicals
Watering
Production and distribution of fuel and
electricity
Disposal
-
6.2 Water Use
Maintenance of turfgrasses requires a substantial amount of water for irrigation. The
water requirements of natural grass depend on the species of grass being grown, the
function of the grass, and the climate in which it is grown. Among these factors,
environmental conditions have larger effects on the amount of water usage. In dry
climates, for instance, heavy irrigation is needed in maintaining the quality of natural
grass as rainfall cannot meet the water demand of plants (see Table 5). Studies
suggest that water use is significantly higher than that needed to maintain synthetic
grass turfs
21
.
21
Cheng, H., Hu, Y. and Reinhard, M. (2014) Environmental and Health Impacts of Artificial turf: A
review, Environmental Science and Technology, 48.
17
Table 5: Typical water use per year in maintaining natural grass
Sport
Area (ha)
Water Use (ML/yr)
Hockey
0.70
4.2
Soccer
0.80
4.8
Tennis
0.06
0.4
Source: GoWA
Given the fact that water resources are under pressure due to population growth and
change of climate patterns across different states in Australia, the heavy irrigation
needed for maintaining natural grass turf sports grounds has been questioned. In
particular, an increased drought condition and water shortages over the past decade
added pressure to use water in a sustainable manner
22
. Accordingly, the City of
Adelaide adopted a plan to reduce the usage of mains water and to increase the use
of recycled water and stormwater
23
. Given this context, water needs to be used
efficiently by selecting the right grass species that suits South Australian climate
conditions. Turfgrasses are classified into two groups based on their climatic
adaptation: cool-season and warm-season. Cool-season grasses need a higher
amount of water than that of warm-season grasses. Besides, drought-tolerance of
warm-season turfgrasses (e.g. Kikuyu or Couch) is significantly higher than cool-
season grasses
24
. Therefore, there is a tendency to use warm-season turfgrass
species across different states in Australia, including South Australia.
One positive aspect of natural grass turf is that it absorbs stormwater. Therefore,
there is no need to irrigate throughout the year. Besides, recycled water can be used
for irrigating turfgrass. Another positive aspect of choosing natural grass turf is that it
contributes to increasing the water quality by filtering runoff. Such a process also
reduces erosion of soil quality.
Water requirements in a synthetic sports surface are considerably low compared to a
natural grass field. However, synthetic turf fields require a substantial amount of
water primarily to reduce the surface temperature during sunny summer days.
22
CSIRO and BoM (2014) State of the climate 2014, CSIRO and Bureau of Meteorology, Melbourne
23
See City of Adelaide 2016-2020 Strategic Plan
24
Western Australian Department of Sports and Recreation (2011) Natural grass vs synthetic turf
study, Tredwell Management Services, SA.
18
Irrigation is the most common method used to reduce the temperature of turf, but
that cooling effect is short-lived. A substantial amount of water is also needed to
clean and improve field sanitation. As synthetic turf does not absorb stormwater, it
drains after a heavy rain without the filtration that natural grass usually provides. The
run-off tends to contain a wide range of harmful materials that can contaminate
watersheds. One study found that 25 different chemical species and 4 metals (e.g.
lead, zinc, cadmium) are likely to release into the water from rubber infill of synthetic
turf
25
. Thus, synthetic turf could contribute to water pollution.
6.3 Heat Risks
The effects of various field surfaces on human thermal stress have received
attention due to changes in climate. A study conducted by the Commonwealth
Scientific and Industrial Research Organisation (CSIRO) notes that the surface
temperature is going to increase 3.8°C in Australia by 2090
26
. Such large-scale
warming will enhance heat risks, especially for urban people because of shortages of
vegetation cover and increases of hard surfaces that lead to artificial temperature
rise, commonly known as urban heat island effects. Choosing a surface provision for
sports, therefore, needs to consider changes in climate, particularly the potential
heat risks.
The provision of natural grass fields is advocated because turfgrass is cooler than
synthetic turf. As a living organism, natural grass absorbs water through roots and
transpires water to keep surfaces cooler. The surface temperature of natural grass
turf is usually close to the air temperature because of evaporative cooling. Besides,
turfgrass fields can serve as a source of cooling for the surrounding air, and thereby
reduce the likelihood of heat stress in nearby residents.
The surface temperatures of synthetic turf playing surfaces, on the other hand, are
significantly higher than those of natural grass turf when exposed to sunlight
27
.
25
Claudio, L. (2008) Synthetic turf: Health debate takes root, Focus, 116(3).
26
CSIRO (2009) Climate Change in Australia: Technical report, Aspendale VIC: CSIRO and
Australian Bureau of Meteorology.
27
Thoms, A., Brosman, J., Zidek, J. and Sorochan, J. (2014) Models for predicting surface
temperatures on synthetic turf playing surfaces, Procedia Engineering, 72.
19
Synthetic turf absorbs, retains and emanates heat when exposed to sunlight.
Although the performance and safety of players has been improved due to
continuous improvement of the properties and characteristics of natural turf, these
developments are still to prevent the turf from reaching a higher temperature than
natural grass
28
. For instance, studies on first-generation synthetic turf at
Pennsylvania State University found that synthetic surface temperatures were 25°C–
30°C higher than natural grass
29
. Studies that compared the third generation
synthetic turf and natural grass also recorded a significant difference in surface
temperatures. Petrass et al. (2015) found that the surface temperature of the
synthetic turf was more than 20°C warmer than the adjacent natural grass in Victoria,
Australia
30
. Another study by Brigham Young University researcher in the United
States, which compared the air temperature of natural turf and synthetic grass at the
surface of a football field, found that the surface temperature of synthetic turf was
approximately 30°C hotter than natural grass turf
31
. A recent study conducted in one
eastern suburb of Adelaide found that the artificial turf field was approximately 20°C
warmer than a nearby irrigated turf field
32
. This study also noted that air
temperatures over artificial turf were higher than those of bitumen. These elevated
temperatures heat up surrounding plants, buildings and communities, often killing the
plants. In other words, through absorbing and radiating heat from the sun, synthetic
turf contributes to the urban ‘heat island’ effect.
Another important issue with synthetic turf in relation to heat is that the natural
cooling process is slower than that of natural grass. Therefore, irrigation is the main
method of cooling the synthetic sports surfaces. One study has documented that
surface temperature of turf rebound 20 minutes after irrigation stops is only slightly
28
Villacanas, V., Sanchez-Sanchez, J., Garcıa-Unanue, J., Lopez, J and Gallardo, L. (2016) The
influence of various types of artificial turfs on football fields and their effects on the thermal profile of
surfaces, Journal of Sports Engineering and Technology, 23(1).
29
Buskirk E.R., McLaughlin E.R., and Loomis J.L. (1971) Microclimate over artificial turf. Journal of
Health Physical Education Recreation, 42.
30
Petrass, L., Twomey, D., Harvey, J., Otago, L. and LeRossigno, P. (2015) Comparison of surface
temperatures of different synthetic turf systems and natural grass: Have advances in synthetic turf
technology made a difference, Journal of Sports Engineering and Technology. 229(1).
31
Williams, C,F., and Pulley, G.E. (2002) Synthetic surface heat studies. Available at:
https://aces.nmsu.edu/programs/turf/documents/brigham-young-study.pdf
32
Seed Consulting Services, EnDev Geographic and Monash University (2018). Collaborative Heat
Mapping for Eastern and Northern Adelaide Report. Prepared for the City of Unley on behalf of the
Eastern Region Alliance of Councils and the City of Salisbury.
20
cooler (less than 10 degree) than a non-irrigated surface three hours after
watering
33
. Another study found that irrigation of the synthetic turf had reduced the
surface temperature from 79ºC to 29ºC, but the temperature rebounded to 73ºC after
20 minutes
34
. Therefore, weather conditions are required to be considered duly
before choosing a surface option for outdoor sports.
6.4 Public Health and Safety
Sports surface options have numerous impacts on human health. Environmental and
social determinants of health such as air quality, water quality, physical activity,
social inclusion and disability are often considered as crucial indicators for assessing
health impacts. In line with this framework, this section reviews how different surface
options impact on human health and wellbeing.
Given the numerous health benefits, grass surfaces are considered as a benchmark
standard for safety. As noted earlier, manufacturers are continuously developing the
quality of synthetic turf to reduce the negative impacts on health and environment.
However, some concerns have remained unaddressed. One major health-related
concern is that synthetic turf contains several contaminants and, therefore, the users
are likely to be exposed to toxicological risks. The major concerns stem from the infill
material that is typically derived from recycled crumb rubber that contains a range of
organic contaminants and heavy metals that are suspected to pose a risk to human
health. Available evidence, however, does not support such a claim. For instance, a
Dutch study found that no elevated health risks from playing sports on synthetic turf
pitches with recycled rubber granulate
35
. Likewise, Cheng et al. (2014) report that the
users of synthetic turf fields are not exposed to elevated health risks
36
. Another study
also reports that health risks caused by chemicals released from synthetic turf are
33
Serensits, T. (2011) Is there any way to cool synthetic Turf?, Sports Turf. Available at:
http://sturf.lib.msu.edu/article/2011jun20.pdf
34
Williams, C,F., and Pulley, G.E. (2002) Synthetic surface heat studies. Available at:
https://aces.nmsu.edu/programs/turf/documents/brigham-young-study.pdf
35
Pronk, M.E., Woutersen, M. and Herremans, J. (2018) Synthetic turf pitches with rubber granulate
infill: are there health risks for people playing sports on such pitches?, Journal of Exposure Science &
Environmental Epidemiology.
36
Cheng, H., Hu, Y. and Reinhard, M. (2014) Environmental and Health impacts of artificial turf: A
review, Environmental Science and Technology, 48(4).
21
minimal for users, including vulnerable populations such as children
37
. Yet,
information is limited to reach any certain conclusion about the potential health risks
associated with synthetic turf. In particular, research is lacking on long-term health
effects on users of synthetic turf surfaces.
Synthetic turf fields can also increase the risk of health-related illnesses among
users in summer as they are made of heat-retaining materials. This is particularly
relevant to the case of South Australian, where summer is dry and hot (28.3°C
average). The users of synthetic turf fields are, therefore, susceptible to heat-related
illnesses such as dehydration, heat exhaustion and heatstroke while playing in hot
conditions.
Another debated health issue associated with health is injuries. It is often claimed
that the incidence of injuries on synthetic turf is higher than on natural grass turf. The
current evidence, however, is inconclusive to support such a claim. Research is
scant on sports other than soccer and football, making it difficult to compare sport-
specific injury incidences. In soccer-related studies, findings are inconsistent. A
study compared the risk of acute injuries between third-generation synthetic turf and
natural grass in male professional soccer players and found no significant
differences in injury rate and pattern between turf types
38
. Another study found that
the incidence of injury using a third generation synthetic turf and natural grass was
the same among a group of young female soccer players
39
. By contrast, Steffen et
al. (2007) reported that injury incidence, particularly ankle sprain, among young
female soccer players was higher during matches played on synthetic turf than
natural grass
40
.
When compared with natural grass, synthetic turf serves different health and
wellbeing benefits. Sports and recreational spaces are needed to ensure
37
Norwegian Institute of Public Health (2006) Artificial turf pitches – an assessment of the health risks
for football players. Available at: https://www.isss-
sportsurfacescience.org/downloads/documents/74wa3x7e22_fhiengelsk.pdf
38
Bjørneboe, J., Bahr, R. and Andersen, T.E. (2010) Risk of injury on third-generation artificial turf in
Norwegian professional football, British Journal of Sports Medicine, 44(11).
39
Ekstrand, J., Timpka, T. and Hagglund, M. (2006) Risk of injury in elite football played on artificial
turf versus natural grass: a prospective two-cohort study, British Journal of Sports Medicine, 4o.
40
Steffen, K. Andersen, T.E. and Bahr, R. (2007) Risk of injury on artificial turf and natural grass in
young female football players. British Journal of Sports Medicine, 41.
22
opportunities for all members of a community, particularly for people with disabilities.
Inclusive playgrounds provide social benefits for people with and without disabilities.
One advantage of synthetic turf systems is that they are more accessible compared
to natural grass turf, meaning that synthetic turf surfaces tend to provide more
opportunities for diverse community members such as the elderly, people with
disabilities and people with injuries. Given that synthetic playing surfaces are more
uniform compared with natural grass, it becomes easier to access for people using
mobility aids. Another advantage is that synthetic turf has a significantly higher
capacity to endure use than natural grass. A high-quality natural grass surface can
be used for up to 20 hours per week, while synthetic surfaces can sustain
approximately 60 hours per week
41
. As such, synthetic turf provision is likely to
increase the participation of people in sports, and thereby enhance the physical,
mental and social wellbeing of the participants
42
. A body of literature confirms that
sports participation has positive effects upon the physical, psychological and social
wellbeing of individuals
43
. In this sense, synthetic turf may contribute to improving
community health and wellbeing by engaging more people in sports.
6.5 Ecosystem services and biodiversity
Natural turf is a living organism, and while installed, it develops a relationship with
microorganisms as the roots establish themselves. Turfgrass serves as a habitat for
insects, animals and other organisms. Other benefits to the ecosystem provided by
natural grass surfaces include rainwater entrapment, climate regulation, absorbing
pollutants from air and oxygen generation.
44
As such, natural grass not only provides
ecosystem services but also conserves biodiversity. Synthetic turf, on the other
hand, does not have such ecological benefits and cannot uphold organic biodiversity.
As the base of synthetic turf systems is compacted, the living organisms die, and so
are unable to provide services to clean and absorb water or carbon. Replacement of
41
Sheppard, M. (2019) The smart guide to synthetic sports surfaces; Volume 1: Surfaces and
standards, Smart Connection Consultancy, Melbourne, Australia.
42
Downward, P. and Rasciute, S. (2011) Does sport make you happy? An analysis of the well‐being
derived from sports participation, International Review of Applied Economics, 25(3).
43
Eime, R.M., Young, J.A., Harvey, J. Charity, M.J. and Payne, W.R. (2013) A systematic review of
the psychological and social benefits of participation in sport for adults: informing development of a
conceptual model of health through sport, International Journal of Behavioural Nutrition and Physical
Activity, 10(135).
44
Thompson, G.L. and Kao-Kniffin, J. (2017) Applying biodiversity and ecosystem function theory to
turfgrass management, Crop Science, 57.
23
natural grass with synthetic turf may also inhibit the growth of trees and other
vegetation. Planting trees is discouraged around artificial turf as they may harm the
turf system by penetrating their roots. As the climate is warming, this compounds the
issues of health effects of hot fields due to reduced ability to shade them. Thus, the
synthetic turf may negatively affect the health of the ecosystem.
7. Summary of Findings
This review aimed to understand environmental, health and welfare impacts of
natural grass compared to synthetic turf in the context of sports fields. The
assessment was conducted to expand our understanding of the existing debates in
relation to grass and synthetic turf, which may help the city planners, local councils
and ground managers to make an informed decision regarding sports surface
options. This review, however, does not provide a complete summary of the current
literature, rather it critically examines selected resources to provide insights into the
key environmental and health concerns related to natural and synthetic turf. It is
important to note that given the large variation in design of installations and the
characteristics of natural fields and of artificial turf systems, it is difficult to accurately
compare the environmental and health impacts between natural and artificial
systems. Information is also limited to draw any specific comparison.
Synthetic turf surfaces have become popular in major outdoor sports at the elite,
regional and local levels around the world. Such a trend at elite level sports,
however, has shifted towards natural turf options in recent years in response to
safety and other health-related concerns. This shift is likely to influence the sports
ground authorities’ decisions regarding choosing sports surface options. In Australia,
natural grass fields are increasingly replaced by the synthetic turf, particularly at the
regional and community level. The City of Adelaide is no exception. In this context,
the selection of appropriate turf option for outdoor sports is needed to consider the
following factors:
Carbon footprint of natural turf is much lower than synthetic turf. Natural grass
fields are important carbon sequesterers – removing carbon from the
atmosphere, while synthetic turf fields release carbon into the atmosphere
24
during different stages such as manufacturing, transportation, installation,
maintenance and end-of-life disposal.
Natural grass fields need more water compared to synthetic turf fields for their
maintenance. The requirement of water depends on local climatic conditions.
Hazardous substances from synthetic turf system are likely to contaminate
surface and groundwater, while fertilisers and pesticides used for maintaining
natural grass turf are likely to contaminate water.
Synthetic turf retains heat that contributes to increasing the field surface
temperature and air temperature near fields. It thus may contribute to urban
heat island effect in nearby neighbourhoods. Natural grass turf, by contrast,
reduces urban heat island effects.
Synthetic surfaces release different hazardous substances which may impact
the health of the users. The available evidence, however, shows no elevated
health risks from exposure to synthetic turf. More research is needed to
explore the potential long-term impacts of synthetic turf on human health.
Natural grass fields provide diverse ecological benefits such as upholding
biodiversity and clean air and water, while synthetic turf has negative impacts
on the health of the ecosystem.
The following table presents the key benefits and disadvantages of playing on
natural grass and artificial turf:
Table 6: Comparative features of natural grass and synthetic turf
Natural Turf
Synthetic Turf
Stays cooler on hot days
Can heat up to over 3 times the local air
temperature
Needs more water
Needs less water
Produce oxygen & reduce pollution
Does not produce oxygen & usually
ends up as landfill
Self-replenishing
Eventually requires replacement
Cheaper to install/ high maintenance
cost
Expensive to install/ low maintenance
cost
25
Self-sanitising
Require sanitising
Safer sporting surface
Increased risk of sporting injury
Needs to give rest
Endures extensive use
In conclusion, based on the information and analysis of this study, it can be said that
choosing an option for playing surfaces needs to consider environmental, health and
social factors that this study illustrated. In addition, local environmental contexts and
location of the sports surfaces must be considered duly in order to select the best
surface option for sports. More specifically, the selection of a surface option in
Adelaide Parklands for engaging more people in outdoor sports needs to consider
the long-term vision for parkland management and sustainability.
i
This study was conducted for Adelaide City Council, South Australia, with the
support of IEP scholarship from The University of Adelaide in 2019.