The Goal of this blog is to stimulate discussion about a subject near and dear to my heart. As a father of two, who play sports, I am always interested in making sure they are playing in the best environment for the sport, but also avoiding unnecessary risk. Don’t get me wrong, I am not an over protective person. But my tax dollars go toward building these play areas, and I feel that if risk can be prevented without adversely affecting the sports experience, then we as the public have a requirement to do so.
Synthetic turf has gotten a lot of attention over the past several years. Most of that attention has been related to the safety and health issues (if any) related to the components used in the manufacturing of the actual turf. Things such as lead in the colorants used to make the fibers green, yellow, red or even blue (which is not used in most modern fibers), and potential hazards related to the granular rubber used as the “infill” in the turf (which has been dispelled from various public and private research reports. Visit www.syntheticturfcouncil.org and check their newsroom for the reports) .
Again, both of the above concerns have now been squelched by various research reports that have been conducted at both the private and public level.
But there IS a safety issue that has not seen any press, but one that is in fact arguably the most important aspect of any synthetic turf surface. It relates to how a synthetic surface feels and plays when compared to a “living grass” surface. (We use the turf LIVING GRASS, because by the time all the fertilizers and pesticides are used to keep a playing field looking good, there is hardly anything “natural” about it.) Most importantly, the “G-Max” a field will provide when a player – often times kids – fall and hit their heads. To give you perspective, a well conditioned living grass field will provide a G-max (which is the amount of energy your skull and brain feel during impact) of between 80-120 G’s. Eighty G-s is considered a pretty moist grass and soil condition, and 120 is at the upper limit, where the soil is dryer and the earth packed a little tighter. Picking the best of both, A G-max of 100 could be considered optimal, because it gives even a living grass field room to stiffen and still live within the desired range. But anything higher than 120 g’s would fall outside what you would want on a living grass field.
Which gets to the crux of the matter. Synthetic turf fields harden over time. This is caused but the infill compacting due to players running around on the field. It has been shown that maintenance can slow the process, but it cannot prevent it. So although a synthetic turf field may deliver a G-max within the living grass field range when it is new, a vast majority of these fields in their later years (keeping in mind that the warranty is 8 years) produce a G-max significantly higher. So much higher, in fact , that the likelihood of a head inury could be DOUBLE that on a natural grass field.
To give you an example, according to the Abbreviated Injury Scale (AIS), a field with a G-max of 165 (which is common in fields older than 4-5 years), will have TWICE the relative risk of producing a moderate head injury than a field with a g-max of 100 G’s. http://www.trauma.org/archive/scores/ais.html . Yet the leading turf company in the industry actually PROMOTES a higher g-max, indicating that in order to get an optimal playing surface, you need a g-max between 120- 180 g-s. That same company says a G-max of 100 is too “soft.” But if that were true, then why does everyone still prefer to play on a living grass field instead of synthetic? (By the way, did you know that at a G-Max of 200, your skull will fracture and there is a chance of death? So do you want your field to be 90% of the way toward THAT event? But we will get into the ASTM and the archaic standard it uses later in this blog).
The reason we all can’t play on living grass is because schools and parks departments need more playing time, and that many hours on the field simply kills living grass. But we can achieve a living grass quality field with synthetic turf. FIFA, the world governing body for Soccer, the most popular sport in the world, has already established the ways to measure a fields’ performance, and the values it needs to demonstrate. Called the FIFA Quality Concept. http://www.fifa.com/mm/document
This type of testing goes way beyond a simple G-max test, and measures the stiffness of a field, so it’s fun and fast to play on. It also measures the way the ball rolls and bounces, the athletes footing, and a myriad of other factors. They established these values by using sensors on athletes as they played on living grass. They then set those values as the benchmark to the synthetic turf industry. So it IS possible to achieve these “living grass” qualities with a synthetic turf field and the Sportslabs study proves it. But keep in mind, these values are not easy to hit, AND MAINTAIN, unless you rethink the construction of the field and how various new components and technologies can get you there. These higher quality, longer lasting surfaces do typically cost a little more than laying “carpet over stone”, which is the current predominant method. And we are now seeing companies come to market with more sophisticated systems that provide a safer playing environment, and actually enhance the sport, by making surfaces that play more “natural.”