A controversial "violence tax" on guns in the Chicago area was approved Friday by Cook County commissioners, NBCChicago.com reported.

The $25 tax on every gun purchased in the county -- city law prohibits gun sales in Chicago -- is meant to offset health care and other costs of gun violence, Board President Toni Preckwinkle said.

"Gun violence is a real problem for us," she said. "It's a problem for us in our criminal justice system and it's a problem for us in our health care system, and I make no apologies for the proposal."

Preckwinkle said the average shooting victim cost taxpayers $52,000 in acute care because nearly 70 percent of the victims don't have health insurance, NBCChicago.com reported.

The vote follows a violent Chicago summer, when some weekends left multiple people killed and dozens of others injured in shootings, NBCChicago.com reported. The city's murder rate is up 25 percent for the year, and the Cook County Jail is near capacity with 9,000-plus inmates.

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The National Rifle Association ahead of the vote said the "misguided and burdensome" gun tax "continues to penalize law-abiding gun owners for exercising their fundamental right to keep and bear arms."

The gun tax, which takes effect April 1, was passed as part of Cook County's $2.9 billion spending plan for 2013.

As part of the budget, commissioners also approved a $1 tax increase on each pack of cigarettes, making the county's $6.67-a-pack tax the second-most expensive in the country, behind New York at $6.86, NBCChicago.com reported. The new tax will push the price of a pack to more than $10 when it goes into effect March 1.

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A gambling tax increase that commissioners also approved will impose $1,000 annually on slot machines in the county and $200 on video gambling machines. Rivers Casino in Des Plaines would be affected as well as establishments that approved video gaming.

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