HOW HAZARDOUS ARE THE “GREEN” Artificial TurfS?
A small but growing number of school districts, municipalities, and universities
in New Jersey and elsewhere are switching from traditional grass athletic fields
to artificial turf. Changed considerably
since 1960s AstroTurf, newer synthetic grass is touted for advantages like
shock-absorption and durability in varied weather conditions. There is no need for mowing, watering, pesticides,
or fertilizer and therefore the turf is advertised as environmentally friendly.
While these advantages have powerful appeal,
synthetic turf comes with an unfortunate host of established and potential
health and environmental risks.
A modern artificial field surface has three layers – drainage, shock
absorbing, and surface. The surface has
polyethylene plastic blades that simulate grass and a several inch layer of
“infill” that keeps the blades upright. The
infill varies by manufacturer and may include ground-up recycled tires,
ground-up soles of athletic shoes, silica sand, and/or new thermoplastic or
rubber material. The silica sand
contains crystalline silica, a proven human carcinogen that causes
silicosis. This “crumb rubber” has been
found to contain additional toxic materials such as:
•
Toxic metals including zinc, lead, arsenic, cadmium, and chromium which have many
harmful effects on humans and the environment.
•
Carcinogens including polycyclic aromatic hydrocarbons (PAHs).
•
Latex and other
rubbers which can cause allergic reactions.
•
Phthalates which have adverse effects on the reproductive organs, lungs, kidneys
and liver.
Crumb rubber can degrade from weather and microbes,
producing new chemicals. Toxic
components can be breathed in, accidentally ingested, contact the skin, and
leach into surface water and groundwater. Besides toxicity, other problems with
artificial turf include:
•
Crumb rubber doesn’t
stay in place. It can move around on the field and sticks to the
skin, shoes, and clothing of staff and students who use the fields. It can end up inside schools, vehicles, and
homes.
•
Excessive heat. Artificial surfaces are dramatically hotter than natural grass fields,
reaching temperatures up to 150 degrees Fahrenheit and possibly contributing to
burns, dehydration, and heat exhaustion. They may be too hot to play on at
times. Watering cools them down but they heat back up quickly.
•
High cost. Artificial fields cost in the range of one-half to two million
dollars.
•
Friction. Some types of artificial turf can cause skin abrasion to a greater
extent than natural grass.
•
Sanitation. Dog, goose, and other droppings do not decompose on artificial turf.
•
Maintenance. The crumb rubber may need to be raked to maintain a uniform depth.
Solvents and adhesives may be needed to repair seams. Leaves, gum, and other
debris need to be regularly removed or they may clog the drainage system.
•
Short Life. Artificial turf has a life expectancy, with proper maintenance, of
five to ten years compared to at least 15 years for grass fields.
•
Disposal. One football field contains approximately 120 tons of crumb rubber or 26,000
recycled tires. Crumb rubber takes more
than 25 years to break down completely.
•
Unpleasant odor. The odor is especially a problem in indoor installations.
•
Loss of habitat. Artificial turf does not support birds, animals, or insects.
•
Combustibility. While shredded tires will burn at a much lower rate than chunk tires,
crumb rubber can certainly be made to burn by arson, producing smoke and toxic
air, soil, and water pollutants.
A 2006
study by the Norwegian Institute of Public Health and the Radium Hospital, Artificial
turf pitches – an assessment of the health risks for football players
examined health risks on turf used in indoor halls, which consist of
artificial turf fiber and rubber granulates.
It looked at exposure via inhalation, skin contact and ingestion,
concluding that that the granulate used in many types of artificial turf
contains chemicals that could harm human health, but in extremely low
concentrations, and these are leached from the granulate in very small
quantities, and air concentrations are very low.
Total
VOC were found at higher concentrations than generally found in homes, but the
study concluded that the values found do not represent an elevated health risk,
adding “… but our knowledge of this area is rather inadequate…”.
Although there is some evidence of a link between phthalate exposure and
development of asthma and/or allergies, at this point – due to a lack of
knowledge – a risk assessment was not possible.
Environment
& Human Health Inc.’s 2007 report Artificial Turf
summarized a study that looked at the leaching potential of metals from tire
crumb samples, as well as chemicals released from the crumbs. In one
experiment, 25 chemicals were identified (with 72-99% certainty) in tire
crumbs, as were metals (mainly zinc, but also selenium, lead and cadmium).
Among the report’s recommendations is to limit exposure to turf fields that
contain rubber tire crumbs until more is known about human exposure issues, and
that those allergic to latex should use caution when using fields or
playgrounds that include these materials.
The Swedish
Chemicals Agency reported that although synthetic turf contains recycled
tire rubber that may cause local environmental risks, the amount of substances
like zinc and phenols that leach from the rubber granulate is small, so any
environmental effects would likely be local, i.e., they won’t reach
watercourses. They recommend that water quality be analysed where the
water is associated with these turf surfaces. They advise that the
recycled tire rubber in the turf need not be replaced immediately, but should
be replaced by alternatives, over the long term and where the material shows
signs of breakdown (e.g., where it forms smaller particles, which are of
greater risk).
The
Connecticut Department of Public Health fact sheet, Lead
in Artificial Turf states that the only way to determine if artificial turf
contains lead is to have the turf tested. Lead
chromate has been used in pigments to colour nylon-based turf. Children playing on the field may be exposed
to lead dust from worn turf fibres that get onto their hands or toys, then is
ingested when the children put these into their mouths.
New
artificial turf products that contain fewer toxic chemicals are being
developed. For example, Ecofill
is advertised as being free from heavy metals, polycyclic aromatic
hydrocarbons, and as emitting much less heat than rubber-based products. GeoTurf apparently
uses materials that are organic or 100% recyclable, and are lead-free and
non-toxic.
What
about UofT’s artificial turf?
UofT has posted
general information about the turf it plans to use, noting that the fields
will not contain any fill (including crumb rubber infill) or lead as a
stabilizer for pigment (it’s not clear if lead will be present for any other
purpose). The turf appears likely to result in increased water runoff– a
drainage system will divert regular runoff into the City’s sewer system and a
large cistern will be located beneath the field to handle excess stormwater.
According
to the UofT
Project Planning Report, the turf material will be composed of knitted or
tufted nylon, polypropylene or polyethylene, with a granular porous asphalt as
sub-base and a shock pad under the turf. To meet world field hockey
requirements, the turf surface will need to be watered during the Games –
allowing for reduced friction and faster ball speed.
What
are the issues [and what did we find]?
Many
types of artificial turf contain rubber materials, which may contain toxic
chemicals, although generally at very low concentrations. Much of the
literature relating to environmental and health impacts of artificial turf
relates to the rubber component. We won’t get into how much the
artificial versus natural turf fields cost – both on a short-term and long-term
basis. There are many analyses published, with a huge lack of consistency.
Environmental concerns raised about artificial turf include:
·
Unlike
with soil, which soaks up rainwater, turf will divert the water into runoff,
which could reach groundwater and drinking water [natural surfaces absorb
and use much of the precipitation; however, projects UofT’s include extensive
planning for dealing with stormwater drainage]
·
Real
grass provides a cooling surface (so important in climate change); artificial
turf heats up in sunlight and can contribute to increase in urban temperatures
[this is a significant concern; in one
study, the surface temperature of an artificial soccer and football
field averaged 117 °F, with a high of 156-157 °F,
while a nearby natural grass field’s surface temperature averaged 78 °F
(high 89 °F). The temperature of concrete was 94 °F
and asphalt 110°F. Irrigation of artificial fields significantly
decreased surface temperatures, but only for a few minutes]
·
It
may be contaminated with harmful chemicals, including metals like lead [this
depends on the turf type –e.g., rubber crumb turf may contain many chemicals;
however the concentrations that leach out are not believed to be significant
risks to the environment ….but there are gaps in the science]
·
Natural
fields filter air/water pollutants; artificial ones don’t. Artificial
fields have a high net carbon loss, while a natural grass field typically has a
net carbon gain.
And
health concerns include:
·
Artificial
turf heats up, contributing to heat stress [watering the turf can reduce the
temperature for a short time, but athletes should be advised to stay hydrated]
·
There
are more injuries on artificial turf [differences in injury rates in
athletes playing on natural surfaces and crumb-rubber turf
have not been consistently shown; artificial turf proponents argue
that turf surfaces are more uniform than natural fields, and offer better
traction and proper hardness levels ]
·
It
may be a breeding ground for bacteria (e.g., methicillin resistant Staphylococcus
aureus), as it cannot get rid of bacteria from sweat, blood, skin cells
deposited during play [A causal relationship between artificial turf and
staph infections has not been shown. Contact with either natural or artificial
turf is an infection risk; the usual precautions for dealing with wounds and
skin abrasions should be followed]
·
People
allergic to latex (i.e., from rubber crumb) are at risk [There have been no
reports of such allergy from contact with artificial turf]
·
Users
are exposed to harmful chemicals [Data are lacking, but the low
concentrations of these toxins is not believed to be a threat to human health]
Caution Advised
Although the desire to improve access to sports fields is clearly
well-intentioned, the risks that accompany synthetic turf need to be carefully
considered. Issues of toxicity, movement,
heat, cost, friction, sanitation, lifespan, maintenance, warranty, disposal costs,
odor, loss of habitat, combustibility, should be thoroughly addressed before
any decision to purchase is made. The
community should carefully consider all the options including natural grass.
There are many manufacturers of artificial turf with different products
and advertising claims. It is reasonable
to expect vendors to identify the chemical ingredients of all turf components
and provide a Material Safety Data Sheet on each component, especially the
crumb rubber. If the crumb rubber is of
unknown composition, that should raise a serious warning.
Tires are known to contain over 60 different substances. Typically,
forty-five percent is vulcanized or cross-linked polymer, forty-five percent is
carbon black, and the rest is dispersing oil, sulfur, synthetic fibers,
pigments, processing chemicals and steel or fiberglass. Tire manufacturers use a variety of
formulation recipes and Ingredients are often kept secret. Therefore the company that produces the crumb
rubber will most likely have to analyze its composition on a regular basis to
provide accurate information on ingredients, since different batches can be
expected to vary in content.
When it comes to synthetic turf, the most sensible approach may be to
follow the precautionary principle of assuming something involving chemicals is
hazardous until scientific evidence proves that it is not. Some public health professionals are calling
for a moratorium on installing any new fields that use ground-up rubber tires
until the hazards are better understood. Some are also recommending that
exposures to already installed fields that contain rubber-tires should be
limited.
Metropolitan Engineering, Consulting &
Forensics (MECF)
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