Heat risks associated with synthetic athletic fields.

It is well known that humans can suffer adverse health effects when exposed to elevated temperatures. These include heat stress, heat exhaustion, heat stroke, Rhabdomyolysis, heat syncope and acute...

and found them to be much hotter than the local temperature. These conclusions were supported by a more recent study [6] where synthetic turf temperatures of 86.4 C (188 F) were recorded. Again, these values were significantly higher than the local environmental air temperature. Research has also been carried out that shows all artificial turfs, regardless of brand, exceed temperatures of natural turf [7].
What has become evident is that artificial turf can approach natural fields in terms of mechanical performance and safety, but there has been very little progress in reducing the thermal risks [8]. These theoretical risks have resulted in cases of studies that provide cause for concern. For instance, following a burn claim by a collegiate athletic coach, researchers at BYU measured turf temperatures and found them to be 87 F hotter than natural grass [9]. There was an inverse correlation with humidity and a positive relation with air temperature. Measurements at the University of Missouri showed elevated air temperatures (138 F) and elevated turf temperatures (173 F)while adjacent natural turf temperatures were 105 F and local air temperatures were 98 F [10]. But this relationship between air temperature and turf temperature is not always seen. Measurements of the wet-bulb and synthetic turf temperatures taken after a heatrelated death showed very little, if any relation between the two quantities [11]. The conflicting results of these studies are made more challenging by the lack of information provided in references. Consequently, it is not possible to quantify, at this time, how artificial turfs impact local air temperatures. It is likely that the influence varies depending on the specific situation. However, it is certain that elevated risk of heat stress can stem from infrared heating from the ground, regardless of the air temperature. A reasonable response, in the absence of such information, is two-fold. First, emphasis should be placed on the actual temperatures measured at specific fields; forecast temperatures do not necessarily represent field-specific temperatures. Second, a greater level of caution is warranted for athletes playing or practicing on artificial fields, even if the air temperature is not at an otherwise unsafe level.
These risks are acknowledged in some administrations of guidelines, for instance, the NY Department of Health cites the above-referenced study in guidance documentation [12,13]. While there have been some reports of synthetic-turf harm [9][10][11]14,15], to the best knowledge of the author there have been no epidemiological studies on the prevalence of heat stress episodes associated with synthetic turf, compared with natural turf. Such a study could help answer the questions posed here, regarding dangers associated with elevated surface temperatures.
These values should give pause to the use of synthetic turf in warm and sunny situations. Reliance upon regional weather reporting or the wet bulb temperature does not provide a full picture of the threat of heat on synthetic athletic fields. Fortunately, low-cost temperature instruments (e.g., infrared temperature sensors) can be used to measure synthetic turf temperatures and this information can inform rational decisions. More study is needed on this issue and for the development of a science-based guideline for athlete care.

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