Next summer, Canada will host the women’s World Cup. For the first time ever, the athletes will be playing on artificial turf at all six venues. Many big-name international stars are suing FIFA, the international governing body of soccer, and the Canadian Soccer Association over the use of artificial turf at the World Cup. These players include U.S. stars Abby Wambach and Sydney Leroux, Germany’s Nadine Angerer and Mexico’s Teresa Noyola.

One big issue the women have with playing on the turf is the higher risk of injury. According to ESPN Sports Science, skin abrasions are up to three times more likely on turf than natural grass because of increased friction. Also, in the same study it is shown that the stress on the ACL joint can be increased by up to 45 percent.

Another difference between artificial turf and natural grass is the increase in temperature. In the six host cities, the average temperature for June is 75 degrees. But according to Sports Science, the temperatures can be 33 to 55 degrees warmer on turf because it retains more heat than grass. This leads to increased dehydration and slower reaction time.

The players are claiming that the refusal to change the playing surface by FIFA is gender discrimination.

“The reality is, the men would never play [the World Cup] on field turf,” Wambach said. “So for me, it’s a women’s rights issue, it’s an equality issue.”

In the official documents of the lawsuit, the players claim FIFA is violating the Human Rights Code by making the women play on the turf instead of the men.

“The surfaces on which FIFA has either demanded or permitted the women to play are more dangerous than the surfaces on which the men are asked to play,” according to the official documents of the lawsuit.

FIFA and the CSA have said they will not put grass down over the turf, and that turf is “the future of soccer;” 24 countries are to attend the World Cup in Canada, which begins on June 6.