Many Americans fear football concussions, a new poll suggests. Forty percent of Americans would rather have their children play a sport other than football due to concussion concerns, according to a new NBC News/WSJ poll. However, 57 percent said they would be fine with their children playing organized football.

Multiple concussions may lead to lifelong impairment, and the U.S. Centers for Disease Control and Prevention says children are more likely to get a concussion and require a longer recovery time than adults. It's not just concussions that may cause brain damage, either. New research suggests that repeated small hits, even without a concussion diagnosis, may be harmful.

Income played a large factor in Americans' position on the sport. Those with the highest incomes were more likely to be opposed to playing football than those who have the lowest incomes. Awareness of the connection between football concussions and long-term brain injury may vary based on income as well, an HBO Real Sports/Marist poll from October reported. Those with high incomes had heard about the issue more than those who earned less, the poll showed. Also, college graduates were more likely to have heard about the connection.

From 2010 to 2012, America's biggest youth football program saw a 9.5 percent decrease in participation, possibly reflecting the growing concern about concussions.