Synthetic turf research
Dr.Mcnitt PResentation
Dr. Mcnitt presentation
To help the community understand the science behind synthetic turf, the board has collected a number of informational resources. There are several files at the bottom of this page that explore the different types of in-fill used with synthetic turf, along with commonly asked questions regarding synthetic turf research.
The board also invited one of the nation's top turf experts, Penn State's Dr. Andrew McNitt, to present at a recent board meeting. Dr. McNitt gave an in-depth presentation and answered a range of questions from the board of ed. He then answered over a dozen questions from the community in the days after. Both his presentation and subsequent answers were highly informative.
Q: Does the water supply of the surrounding neighborhoods become contaminated when rain water runs off the artificial turf?
A: There are tens of thousands of these fields located throughout the world. I am unaware of any reports of issues where a water supply has been ‘contaminated.’
Q: What is the lifespan of a synthetic turf field? More specifically, how often do school districts with a similar budget need to replace their synthetic fields?
A: This is a difficult question to answer with definitive certainty. The warranties are typically 8 years long and I believe a school district should plan to replace the surface every 8 years. The base will likely last very much longer through several resurfacing events. You may get more than 8 years out of a surface but surfaces break down due to traffic and due to UV light so trying to guess longevity based on either alone is often inaccurate.
Q: How have injuries to the youth and high school athlete increased or decreased by synthetic turf fields?
A: This has not been well documented. It is difficult to accurately track injuries from high schools and also difficult to consistently track field conditions. I’m somewhat confident that a well maintained synthetic turf field is safer than a very poorly maintained natural grass field and vice versa. You might want to review the studies posted on this page regarding high school athletes. https://plantscience.psu.edu/research/centers/ssrc/research/synthetic-turf-injuries.
Q: Is there a difference amongst synthetic field types? If yes, how does that affect the injury rate?
A: Assuming the question refers to different infilled synthetic turf types, the answer is yes it has been studied some but a consensus or even really a consistent trend in the data is not yet evident.
Q: Does the amount of rubber within the field have an effect on an athlete?
A: Yes the amount of rubber relative the fiber length likely has some bearing on what the athlete experiences. The deeper the rubber, the softer the field. The lower the infill the more fiber ‘reveal’ and thus the cleats interact with a greater amount of fiber and likely have higher traction. Too much crumb rubber and very little reveal can result in very poor footing with players slipping etc.
Q: Do you have any financial incentive or impact for the proposed field system to be installed at Cornwall Schools?
A: I have no financial incentive or impact for this or any other synthetic turf field installation. In fact, I do not know which brands or models of synthetic turf are being considered for this project. In the end, I am a proponent of natural turf fields but understand that synthetic turf has its place.
Q: Knowing the proposed field type (synthetic turf) that will be installed, would you confidently have your children and grandchildren play on the surface?
A: I have no hesitation allowing my children or grandchildren to interact with synthetic turf.
Q: In your opinion, is there a benefit to using recycled rubber in-fill from another stadium that has had the chance to 'off-gas'? This would be virgin rubber that was used on a previous field and later reclaimed."
A: I suggest that the school consider using a percentage of recycled crumb rubber primarily due to the reduced cost. My understanding is that most synthetic turf companies do not use 100% reused crumb rubber but do use a very high percentage mixed with a much smaller amount of ‘new’ crumb rubber.
Q: Dr. McNitt cited 2 studies regarding the safety of Synthetic Turf from 2008 (CT)and 2010 (NY) in his presentation. Do any more recent scientific studies/ research (completed or ongoing) exist that investigate the potential hazards of synthetic turf fields, especially by age (adults vs. children)?
A: You can find several studies on our PSU website that explore the safety of synthetic turf: https://plantscience.psu.edu/research/centers/ssrc/research/synthetic-turf-health
https://plantscience.psu.edu/research/centers/ssrc/research/synthetic-turf-research-penn-state
Q: Dr. McNitt stated in his presentation that turf dust is real but too small and not a big concern, as the dust cloud is normally knee height. What was the average height of the knees as well as the average height of the individuals involved in his observation/ study?
A: I don’t recall mentioning the height of a dust cloud. My only mention of knee height was when describing the heat that comes off synthetic turf - that while synthetic turf does reach higher temperatures than grass, the heat dissipates at knee level.
Q: Dr. McNitt’s presentation listed over a few slides chemical compounds present in Synthetic Turf and crumb infill. Is this listing complete of all chemicals and which, if any, are proven known carcinogens?
A: Those slides were explaining the chemicals present in organically-grown strawberries, not synthetic turf. That was to prove a point - that almost all products contain chemicals. But as the NYS DOH points out in its fact sheet about synthetic turf, not all chemicals are readily absorbed by all routes.
https://health.ny.gov/environmental/outdoors/synthetic_turf/crumb-rubber_infilled/fact_sheet.htm
Q: Dr. McNitt’s knowledge and expertise is impressive. Is it his opinion that Synthetic Turf fields are 100% safe for school age children, young adults and the environment? If so, which synthetic turf and infill manufacturers are the industry leaders (Top 3)?
A: Nothing is 100% safe, not synthetic turf, not natural turf, not the cleaning products we use in our house everyday nor the clothing we wear. Everything has an associated risk. We must always weigh the risk/benefit and make informed decisions. Here is an article aimed at helping to assess the risk/benefit ratio.
https://pubs.ciphi.ca/doi/full/10.5864/d2019-026
I hesitate to list the ‘top 3’ synthetic turf manufacturers. Here is a list of the manufacturers currently in use on game day fields in the NFL
A turf
Fieldturf
Hellas
Shaw
Act Global
Turf Nation
Q: Dr. McNitt cited the elevated thermal rise of Synthetic Turf is primarily felt through shoes. Are the hazards of heat poisoning the same for children as adults?
A: I’m not sure ‘heat poisoning’ is the correct term. Again, heat transferred through the shoes to the athlete must be dissipated by the athlete. I suspect that smaller humans heat up and cool down faster than larger humans due to their greater skin to mass ratio.
Q: A report out of Washington in 2017 found that, anecdotally, soccer goalies were more prevalent at being diagnosed with a certain type of cancer. While that report was not a peer-reviewed scientific study, have similar reports been submitted from areas around the US that have installed synthetic fields?
A: The article cited take what I consider to be a very well balanced approach. The authors list a number of references that should be of intertest to the questioner. They also list these key points.
Key Points
- In 2014, crumb rubber in synthetic turf fields was hypothesized to cause cancer in adolescents and young adults who used the fields, particularly lymphoma and primarily in soccer goalkeepers.
- The concern has induced some school systems and park departments to abandon plans to install synthetic turf fields and governments to initiate major toxicology studies, the results of which are expected to take years to obtain.
- Meanwhile, the state of the science of adolescent and young adult cancer causation does not support the hypothesis. On the contrary, the potential for decreasing exercise by reducing access to playgrounds and sports fields may increase the rate of cancer occurrence in later life.
I am not aware of studies specific to your question. I do not follow this literature closely but as a professional in this field am typically made aware of relevant studies with new conclusions.
Q: Dr. McNitt compared synthetic turf fields to tire dust on roadways in making his case for the safety of synthetic turf. Since multiple studies (NIH, CDC, American Lung Association, etc.) have noted the increased risk of cancer, heart disease, and respiratory issues for those who live in proximity to roads, due to traffic pollution including tire dust…and since ESPN reported that the nationwide initiative to repurpose tires as turf began in the 1990s because tires were deemed “unsafe for landfills because of their chemical make-up, toxic flammability and attractiveness to mosquitos”…doesn’t his comparison of synthetic turf to tires in fact raise additional questions about the safety of synthetic turf for our children?
A: You are correct, I did make that observation perhaps erroneously. It’s important to realize that tire dust that abrades from tires being driven on a road contain many other compounds picked up from chemicals abraded from the road surface or deposited on the surface by other fluids and materials from vehicles. The recycled tires are different as they do not contain the quantities of these compounds.
This article describes the differences:https://reader.elsevier.com/reader/sd/pii/S0048969720313358?token=608C8E281219D6269BF829E3CFF977465A5F9245F4EFCF140AA993051EAAA0EBD822E52242773AF35E4D62F04AAD95EF&originRegion=us-east-1&originCreation=20220309001645
As stated above, there is risk in everything we do each day. We can each find articles that intimate that the risk is either very concerning or somewhat low. I’ve attached one review from Canada for reference.
There are always study limitations and gaps in knowledge. If there were not, then there would be no need for additional scientific studies. As stated, there is always some risk. Obviously driving down the road is a risk, being exposed to new carpet compounds in your house is a risk, eating canned food is a risk, it’s a matter of assessing that risk.
Q: Dr. McNitt stated the preponderance of evidence shows the risk is “really small” and cited the New York State metadata report as supporting evidence. But the NYS DOH site currently states: “some uncertainty remains due to study limitations…limited information about effects of direct ingestion and direct contact with crumb rubber, and limited sources and ages of crumb rubber tested.” In 2015, the head of the EPA likewise noted data gaps on the health effects of “exposure for ingestion.” Also, Dr. McNitt’s list appears to omit a 2014 study cited in the Journal of National Cancer Institute that concluded “the quantity of toxic substances” released by synthetic turf “does not make it safe for public health.” Furthermore, the conclusions of the Consumer Products Safety Commission in 2008 that Dr. McNitt mentioned were later called into question when the chairman of this same commission later told ESPN: “that 2008 statement did not even reflect the technical staff's views at the time. There was a political effort to state something that may not actually reflect the state of play.” Don’t these reports and statements indicate Dr. McNitt cannot definitively state that synthetic turf fields will not expose our student athletes to elevated and unnecessary risks of cancer, asthma attacks, or other serious health issues?
Answer pending. Check back.