What follows are excerpts from UMass Lowell’s Toxics Use Reduction Institute’s 24-page report published in 2018. To download the full text, click here.
Children's Environmental Health
People of all ages benefit from a safe and healthy environment for work and play. However, special concerns exist for children. Children are uniquely vulnerable to the effects of toxic chemicals because their organ systems are developing rapidly and their detoxification mechanisms are immature. Children also breathe more air per unit of body weight than adults, and are likely to have more hand-to-mouth exposure to environmental contaminants than adults. For these reasons, it is particularly important to make careful choices about children’s exposures.
There is no comprehensive regulatory or testing regimen specifically for artificial turf. The standard cited most frequently by vendors is European Standard EN 71‐3 – "Safety of Toys Part 3: Migration of certain elements" (the European Toy Safety Standard). For communities applying this standard, it is important to understand that it focuses only on metals. It does not cover other compounds that may be found in artificial turf materials, such as volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), phthalates, and others. The standard includes three different safety levels, so it is important to understand which level has been applied. Detailed information on this regulation is available in another TURI publication, Chemicals in Artificial Turf Infill: Overview.
Artificial Turf: Chemicals in Infill
TURI has received many queries from communities and institutions that are working to understand the health and safety profiles of a variety of infill types. Therefore, TURI has reviewed existing literature on these infill types, with a focus on chemicals found in the materials. Additional detail on selected individual infills can be found on TURI’s website.
It is important to note that chemicals in infill are just one piece of the picture. The artificial grass blades pose concerns as well. Toxic chemicals such as lead are found in the artificial grass blades in some cases. It is also important to understand and research the materials used in any pad or underlayment used in the layers below the infill.
Crumb rubber made from recycled tires, also referred to as tire crumb or as styrene butadiene rubber (SBR), is present in a large number of artificial turf fields.
A number of materials are currently marketed as alternatives to recycled tires. Some are based on synthetic materials, while others are mineral- or plant-based, or contain a mixture of natural and synthetic materials. Alternative synthetic infills include ethylene propylene diene terpolymer (EPDM), thermoplastic elastomer (TPE), and waste athletic shoe materials, among others. Mineral-based and plant-derived materials used in infill can include sand, zeolite, cork, coconut hulls, olive cores, and walnut shells, among other materials. Infill can also be made with acrylic-coated sand.
Some vendors may also offer an option of tire crumb coated with polyurethane. Limited information is available on the chemicals in the coating, the ability of the coating to reduce exposure to chemicals in the tire crumb, or the durability of the coating.
Relatively little information is available on the chemicals present in, or emitted from, alternative infills. Some of them may pose less of a concern than tire crumb, but some may introduce serious hazards. Some available information on these materials is provided here, but there is a need for more research on all of these materials. Some of these materials have also been evaluated in a 2017 review by the Norwegian Environmental Agency and in a 2018 review by the National Institute for Public Health and the Environment (RIVM) in the Netherlands.
This overview is not comprehensive. New infills are introduced to the market frequently. It is important to understand that any synthetic material used as infill will pose some concerns related to introduction of rubber or plastic particles into the environment, as well as whatever specific chemicals may be found in the material. Mineral- and plant-based infills can pose hazards as well. In addition to any issues associated with infill, all artificial turf introduces synthetic materials into the environment through the other components, including breakdown over time of the artificial grass carpet.
Environmental concerns include loss of wildlife habitat and contaminated runoff into the environment. A study by the Connecticut Department of Environmental Protection identified concerns related to a number of chemicals in stormwater runoff from artificial turf fields. These include both metals and organic compounds. They noted high zinc concentrations in stormwater as a particular concern for aquatic organisms. They also noted the potential for leaching of high levels of copper, cadmium, barium, manganese and lead in some cases. The top concerns identified in the study were toxicity to aquatic life from zinc and from whole effluent toxicity (WET). WET is a methodology for assessing the aquatic toxicity
effects of an effluent stream as a whole. In another example, a study found that leachate from several artificial turf systems was toxic to aquatic organisms.
Another environmental concern is migration of synthetic particles into the surrounding environment. Both infill particles and broken synthetic grass fibers do not stay limited to the boundaries of the artificial turf field. Photographic evidence collected by community members in Massachusetts show broken pieces of artificial grass fibers widely dispersed in environments surrounding artificial turf fields. Field maintenance
protocols provide for periodic addition of infill to replace infill lost from the field in the course of
play, further demonstrating that not all infill particles remain in place within the field. With growing concern about global microplastic pollution, some communities are working actively to reduce the amount of plastic they introduce into the environment. Little or no research has been conducted on ways in which dust and broken particles from artificial turf fields may contribute to microplastic pollution in the environment.
Acrylic-coated sand particles, according to the manufacturer, pose less risk of migrating into waterways compared with other infills because they do not float; however, they could still generate dust that may move offsite. To the extent that particles migrate off the original field site and enter water resources, there could be concerns about whether sedimentary organisms could incorporate these materials and whether they could enter the food chain in this way.
Disposal of the synthetic materials, including the infill and the shock pad, poses an additional concern. Some synthetic materials may be reusable one or more times, while others may have to be disposed of in a landfill or through incineration when the field is due for replacement. RIVM notes that it may be possible to use waste material from a replaced artificial turf field in some other sporting applications, but also notes that due to the degradation of the material over time, this will not always be possible. also notes that the substructure elements of an artificial turf field may need to be cleaned prior to recycling, if they are contaminated with any chemicals that have leached from infill. For the limited set of infills it analyzes, RIVM assumes an average 10 year service life for artificial turf fields and assumes that the infill materials are not reused on additional fields.
Artificial Turf and Heat Stress
In sunny, warm weather, artificial turf can become much hotter than natural grass, raising concerns related to heat stress for athletes playing on the fields. Research indicates that all artificial turf reaches higher temperatures than natural grass, although some infill materials may become more hot than others. A report by the New York State Department of Environmental Conservation found that surface temperatures on an artificial turf field were 35oF to 42oF higher than those on natural grass. Another study found that the highest temperature measured on artificial turf was 60.3oF greater than that observed on natural grass. In another study, artificial turf fibers reached temperatures of 156oF under direct sunlight, while the crumb rubber infill reached 101oF.
Measurements taken by sports managers at Brigham Young University found that the surface temperature of artificial turf was 37oF higher than asphalt and 86.5oF hotter than natural turf. The hottest surface temperature recorded during the study was 200oF on a 98oF day. Even in October, the surface temperature reached 112.4oF.
Irrigation can lower field temperature for a short time. A study by Penn State’s Center for Sports Surface Research found that frequent, heavy irrigation reduces temperatures on artificial turf, but temperatures rebound quickly under sunny conditions. Another study found that irrigation could lower temperatures by 10 to 20 degrees for a period of at least 20 minutes. Another found that irrigation lowered the surface temperature from 174oF to 85oF; however, the temperature rebounded to 164oF after 20 minutes. Heat-related illness can be a life-threatening emergency. Experts note that athletic coaches and other staff need to be educated about heat-related illness and understand how to prevent it, including cancelling sport activities when appropriate. In one example, a number of students developed heat-related illness after band practice on a new artificial turf field.
Heat can also affect chemical emissions. For example, one study expressed concern about PAH
emissions from tire crumb at elevated temperatures.
Safer Alternative: Natural Grass
Natural grass fields can be the safest option for recreational space, by eliminating many of the concerns noted above. Grass fields may be maintained organically or with conventional or integrated pest management (IPM) practices. Organic turf management eliminates the use of toxic insecticides, herbicides and fungicides.
Natural grass can reduce a field's overall carbon footprint by capturing carbon dioxide. A natural grass field can also provide a number of ecosystem services, such as providing habitat for invertebrates and microorganisms, reducing the heat island effect in urban areas, and helping to control flooding, among others.
Table 3 shows a broad comparison between artificial turf and natural grass, including conventionally and organically managed grass. As shown in the table, artificial turf can pose chemical hazards related to chemicals either present in the surfacing material or applied to the surface. Cleaners, disinfectants and even herbicides may sometimes be applied to the artificial turf surface as well. Natural grass, on the other hand, only contains whatever is already in the ambient environment and generally does not include polymers, rubber and plastic additives, or respiratory hazards such as zeolite. Conventionally managed natural grass may be treated with synthetic pesticides or fertilizers; organically managed natural grass builds soil health, making it unnecessary to apply chemical treatments.
Installation/Maintenance Costs: Comparing Artificial Turf with Natural Grass
In analyzing the costs of artificial vs. natural grass systems, it is important to consider full life cycle costs, including installation, maintenance, and disposal/replacement. Artificial turf systems of all types require a significant financial investment at each stage of the product life cycle. In general, the full life cycle cost of an artificial turf field is higher than the cost of a natural grass field.
Artificial turf poses a number of health and environmental concerns. Those communities that have decided to install artificial turf are encouraged to make careful choices among the materials available to them. This is likely to include requiring some additional testing to get information on organic compounds as well as metals. Communities should bear in mind that existing tests apply only to the sample on which they are conducted, and materials used in artificial turf may vary widely in composition. From an environmental and health standpoint, organically managed natural grass is a safer choice for sports fields. When the full product life cycle is considered, organically managed natural grass also offers lower costs over time.