Baseball Commissioner Bud Selig says he will propose a ban on chewing tobacco on the field in the new players’ contract. His pledge is part of a push by Major League Baseball (MLB) to rid the sport of a habit that has long been part of the game’s culture.

This winter, Selig received a letter from public health officials in 15 cities with Major League teams, urging MLB to ban tobacco use by all ballpark personnel. They noted links between smokeless tobacco and oral cancer, gum disease and other health issues. They also pointed to statistics from the Centers for Disease Control and Prevention showing that use of smokeless tobacco among high school boys has risen 36 percent since 2003.

In response to the letter, Selig said MLB will propose smokeless tobacco restrictions at the Major League level that are similar to those currently in place in the Minor Leagues, where smokeless tobacco, including dip and chew, are banned in ballparks.

The Associated Press reports several members of Congress are also calling for a chewing tobacco ban in baseball.

Matthew Myers, President of the Campaign for Tobacco-Free Kids, told the AP that baseball players have a responsibility as role models for young teens who don’t understand the health risks of chewing tobacco.

“Baseball players are free to do what they want when they’re not at the ballpark, when they’re not on television,” Myers said. “Our concern is that their behavior is affecting another generation of children.”