Baseball fans must now stick to hot dogs, crackerjacks and beer as Mayor Marty Walsh on Wednesday signed a ban of smokeless tobacco at Fenway Park and all other sports venues in the city. 

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"Our baseball parks are places for creating healthy futures, and this ordinance is about doing the right thing as a community for our young people," Walsh said in a press release. "The consequences of smokeless tobacco are real, and we must do all that we can to set an example.”

Last week, Walsh kicked off the Childhood Cancer Awareness Month to help spread awareness about children battling cancer. In a 2013 study, the CDC found that 14.7 percent of boys in high school and 8.8 percent of high school students reported using smokeless tobacco products on a national level.

They also found that about 535,000 high school kids ages 12 to 17 have tried smokeless tobacco at least once. 

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"With this decisive action, Boston hits a homerun for baseball, cancer prevention and public health," Dr. Howard Koh of the Harvard T.H. Chan School of Public Health said Wednesday . "We thank Mayor Walsh and the Boston City Council for their leadership in setting a historic example for the country."

Walsh teamed up with Curt Schilling, the bloody sock-sporting hero of the 2004 World Series, and other public health officials to ban chewing tobacco and other smokeless products. The City Council voted in support of the ordinance and the mayor signed off on it on Wednesday. 

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"I have seen cancer take the lives of people very important to me like my father, a lifelong smoker, and I have endured the insufferable agony of radiation to the head/neck," Schilling said in a statement. "If this law stops just one child from starting, it's worth the price."

Schilling, a long-time chewing tobacco user, announced in 2014 he had been diagnosed with mouth cancer, which he believes his habit caused.

“I'm proud to sign this ordinance today,” Walsh said. “If we continue to take action steps such as these, Boston will be on its way to becoming a healthier city, full of positive examples for our young people to follow. The consequences of smokeless tobacco are real and can be devastating. We're doing the right thing for our children and I look forward to continuing on the path to making Boston a leader in healthy and active living."

The National Cancer Institute states that chewing tobacco and snuff contain 28 cancer-causing agents and the U.S. National Toxicology Program has established smokeless tobacco as a "known human carcinogen."

The prohibition will go into effect on April 1, 2016.

"Mayor Walsh's signature on this law means Boston is a national leader in reducing the number of young people using smokeless tobacco. Our national pastime should be about promoting a healthy and active lifestyle, not a deadly and addictive product," Matthew L. Myers, President of the Campaign for Tobacco-Free Kids said.

Under the new rules, those who defy the ordinance could face a $250 fine.