On a December day in Lahore, Pakistan's second-biggest city, the smog concealed tall buildings. Men on motorbikes seemed to push through it as they rode. It reeked of diesel and charcoal, compelling the Nadim family to go to the hospital.
"I can't breathe," said Mohammad Nadim, 34. He gestured to his wife, Sonia. "My wife can't breathe." She held their 3-month-old daughter Aisha, who pushed out wet, heavy coughs. "But we are here for our children."