Heavy smartphone and social media use among kids can lead to poor sleep, anxiety and depression, bullying, attention difficulties and academic challenges. EMS-Forster-Productions/DigitalVision Collection via Getty Images Pennsylvania is moving toward a statewide “bell-to-bell” cellphone ban in public schools. The state Senate and House of Representatives have advanced companion bills that would require students in grades K-12 to keep cellphones turned off or stored away in lockers, backpacks o