Artificial turf fields are typically made of a permeable synthetic grass-like layer sitting atop anywhere from 20,000 to 40,000 shredded tires, depending upon the size of the field. Upon impact, the tire crumb releases small fragments of tire crumb into the air where it lodges in athletes’ shoes, clothing, hair and ears. Playgrounds for young children often consist of painted tire crumb. These surfaces have been found to contain dangerously high levels of lead, arsenic, cadmium, chromium, mercury and a number of dangerous hydrocarbons, with potential toxicity to children and athletes. In addition, there are growing concerns about chemical off-gassing, as well as dangerous temperature levels on fields that can become super-heated to as much as 60-80 F higher than the air temperature. Tires are designed to emit heat like this so that the heat does not build up in a tire on the road, but as a play surface it generates heat-stroke and burn hazards to anyone who comes in contact with them.
Nonetheless, there are an estimated 5,000 synthetic turf fields in the U.S. and many more playgrounds using shredded tires, with more being installed each month.