Ben Murphey said a hypodermic needle complete with syringe pricked the thumb of his son Chase while he played in the sand under lifeguard tower 1 at Ocean Beach."I had no idea what could happen to him. All I thought was that he's going to get hepatitis or HIV. It was very, very scary. I was petrified," Murphey said.Chase was rushed to Rady Children's Hospital, and Murphey said, "They said the chances of him actually getting something serious are very, very slim, but it's not zero."Murphey said there was not enough residue on the needle to test it, so he and his family must wait.As for dangerous debris on San Diego beaches, cleaning and maintaining the beach isn't the job of lifeguards. That job falls on the San Diego Department of Park and Recreation, which uses a device attached to a tractor to rake city beaches weekly.Park and Recreation Director Stacey LoMedico said she remembers two hypodermic needles were found in the last five years."The reality is we have millions of people who come to the beach. It's an open beach and park, so we can't catch everything," said LoMedico.The needle found under the lifeguard tower could have been medical, but Murphey, a lifelong Ocean Beach resident, said he fears it was left by a drug addict who hid under the tower. He is asking beachgoers for help."If anybody sees somebody doing something bad, call the police and let them know what's going on," Murphey said.Will the father of two do anything differently at the beach now?"Yeah, he can't play underneath the lifeguard tower anymore," Murphey said. "But we're not going to stop coming to the beach; [it's a] beautiful beach, we love the ocean. We're not going to let that change our lives."Murphey said doctors told him Chase must take blood tests every few months for the next year before they can clear him.Park and Recreation officials are advising parents to teach children about dangerous objects and to report any they find.