One major problem with sprawl is that it leads to less and less in-person communication and replaces it with, among other things, mobile phone communication. This is primarily because, if you are stuck in your car for even basic chores, then you're not likely to talk to other humans as frequently as you would if you passed them while walking or biking.
There are many problems with extensive cell phone use from a social standpoint. However, companies that Daily Sprawl trusts are beginning to explain the potential health problems too.
Seventh Generation is one of those companies. This is concerning and certainly warrants additional consideration.