Somewhere in your town, there is a wide expanse of nubby plastic grass that no one has to water or mow.
Maybe it’s where your children play. Maybe it’s the soccer field of a middle school, the football green of a university, the rolling carpet of a golf course, or the soft landing place of a playground. In some parts of the country, particularly areas frequently stricken with drought, artificial grass might even be blanketing yours or a neighbor’s front lawn.
A few miles from my hometown, the first artificial grass was invented in the early 1960s by David Chaney and a team of researchers in Research Triangle Park, North Carolina (soon afterward, it was patented by two Monsanto employees and originally sold under the name “Chemgrass”). Dubbed “Astroturf” after its use in the Houston Astrodome during Major League Baseball season in 1966, use of synthetic grass eventually became widespread in sports stadiums, landscaping, and more. In arid regions, artificial grass has often been marketed as an environmentally friendly way to conserve water and to minimize the use of fertilizers, pesticides, and weed-killers.
Today’s synthetic turf “infill” is often made from recycled tire crumb rubber, which helps to provide cushioning, traction, and drainage to the grass-like surface. Although artificial turf may look relatively innocuous, the use of tire crumb rubber has raised public health concerns. Research from the National Toxicology Program (NTP) found that crumb rubber contains substances with known human health harms, like phthalates and bisphenol-A (BPA). Crumb rubber also contains polycyclic aromatic hydrocarbons (PAHs), which are a class of chemicals that can bind to or form small particles in the air, making them easily inhaled. Research has linked PAH exposure to breast cancer, childhood cancers, lung cancer, exacerbated asthma, and increased rates of lung and cardiovascular diseases. When children and young people play on synthetic turf, it’s often in a rough-and-tumble way that can increase their likelihood of being exposed to the chemicals in infill, either through skin contact or inhalation.
The Synthetic Turf Council, an organization that represents manufacturers of artificial turf, insists that the materials used in synthetic grass products are safe, and the Consumer Product Safety Commission (CPSC) says that there is no elevated health risk from playing on artificial turf. But new research casts further doubt on these claims.
European scientists analyzed 91 samples of football field infill from 17 countries on 4 continents, seeking to assess the levels of 42 chemicals linked with human health harms. Seventy-eight of the samples analyzed were made of crumb rubber, and 13 samples were alternative infill materials, made from substances such as cork granules, coconut fiber, or plastic.
The researchers’ findings confirmed the widespread presence of hazardous chemicals in the infill samples. Most of the crumb rubber samples contained PAHs considered to be carcinogenic by the European Chemicals Agency (ECHA), endocrine-disrupting phthalates, and other chemicals categorized as “substances of very high concern.” Three of the crumb rubber samples contained levels of PAHs exceeding the ECHA’s safety limit. In addition, both the crumb rubber and plastic infill are microplastics, which do not biodegrade in the environment and are an emerging concern for human health.
In acknowledgment of public health concerns, the US Environmental Protection Agency (EPA), Centers for Disease Control (CDC), and CPSC are currently engaged in a multi-agency research effort to more thoroughly assess the potential human health harms of exposure to tire crumb rubber on playgrounds and playing fields. But parents may not want to wait for further research to take precautions to protect their children’s health.
The CPSC recommends the following steps to limit exposure to potentially hazardous chemicals on rubber-surfaced playgrounds and artificial turf fields:
- Avoid mouth contact with playground surfacing materials, including mouthing, chewing, or swallowing playground rubber.
- Avoid eating food or drinking beverages while directly on playground surfaces, and wash hands after contact with rubber-surfaced playgrounds or artificial turf.
- Limit time at rubber-surfaced playgrounds or artificial turf fields on extremely hot days.
- Clean hands and other areas of exposed skin after visiting rubber-surfaced playgrounds or artificial turf fields, and consider changing clothes if evidence of tire materials (e.g., black marks or dust) is visible on fabrics.
- Clean any toys that were used on a rubber-surfaced playground after the visit.
Though it may never lose its color, grass that doesn’t have to be watered isn’t always greener—especially when it comes to our children’s health.