This summer, our CWH intern, Jackson Caudle of Occidental College, researched the costs and benefits of living and artificial turf on athletic fields. Having played football throughout his life, this subject hit close to home. It’s also a timely topic for CWH as we work with the Metropolitan Water District of Southern California (MWD) to connect schools and school districts with water-saving incentives, which includes a turf replacement rebate. In this week’s #SummerScienceFriday, we compare the benefits of natural turf over synthetic turf.
Construction of Athletic Fields
For those not too familiar, synthetic turf is a plastic replacement for grass, created using three layers of material. A top and bottom layer made of plastic mimic the feel of grass and hold in the middle layer, which is typically filled with recycled pieces of tires, other plastics, or sand. In order for the synthetic turf to be laid down, construction takes place over a period of several days, where workers build a concrete border around the area where the turf will be laid and drainage areas are installed underneath. This extra construction can be expensive, but because turf fields do not drain water like natural turf, it is necessary (1).
In comparison, natural turf is easier and cheaper to install. The process starts by rototilling the ground where the turf will be laid. This churns the soil and clears off any organic material that will get in the way of the turf. Long strips of grass are then rolled out, covering prepared soil. Finally, the natural turf is watered to help the seeds grow and take root in the ground (1).
Source: Friends of Rahway River Parkway
It costs approximately $275,000 to install synthetic turf, whereas the cost for installing natural turf onto an athletic field is around $160,000. While it may seem like a lot less money, natural turf costs more in maintenance and additional labor. Synthetic turf is more expensive to lay down and install, but it requires less intensive maintenance, reducing labor costs. Typical maintenance for synthetic turf can involve raking, sweeping, and patching holes in the turf (2). When labor costs are added, both seem to be about equal and the your decision between the two will most likely depend on the health benefits rather than monetary savings.
Human Health Impacts
Due to our Mediterranean climate, Los Angeles is subject to high temperatures year round. Athletes in hot areas are already at risk of heat stroke and dehydration, making it important to choose turf that reduce these harmful health risk. Natural grasses have cooling mechanisms like evapotranspiration, to lower its ambient temperatures. Synthetic turf does not. On average, artificial fields heat up at least 20°C more than grass, which exacerbate the risk of dehydration and heat stroke for athletes on the field (3). Synthetic turf also increases the risk for the release harmful chemicals from infill. Since common infill is recycled car tires, the chemicals from them can be released into the air and breathed by field users.
In addition, the main health concerns associated with artificial turf are skin problems and lung problems. Chemicals in infill can cause dermatitis (skin irritation) and inhalation of tire chemicals which can be worse for people with asthma. Injuries are also more common on synthetic turf. A study showed that there are higher rates of ACL, PCL, and Meniscal tears on synthetic turf in comparison to natural grass fields (4).
While chemical pollutants have been found in infill, studies have not found a direct correlation between those chemicals in air. However, studies have shown that synthetic turf is toxic to nearby plants and aquatic species. The crumbs and synthetic grass contain many toxic chemicals and plastic. When these contaminates are washed away as runoff, they could be harmful to nearby plant and animal communities as well as nearby water sources that runoff washes into (5).