Nothing sends more kids to the hospital than asthma. So when doctors at Children's Hospital in Boston noticed they kept seeing an unusually high number of asthmatic kids from certain low-income neighborhoods, they wondered if they could do something about the environment these kids were living in.

Source: http://www.npr.org/blogs/health/2013/03/18/174393981/to-control-asthma-start-with-the-home-instead-of-the-child