Washington, DC (AHN) - Almost a third of U.S. households rely solely on cell phone, according to a new government survey. Some 28.9 percent of households receive all or nearly all of their calls on mobile handsets, the Centers of Disease Control and Prevention announced Wednesday.

The figure, part of the agency's National Health Interview Survey, is an increase over the 16 percent of cell phone-only homes found in the last half of 2007. In 2005, just five percent of homes depended totally on cell phones.

The change holds significance for political organizations and emergency services. Polling organization traditionally randomly call landline phones, avoiding mobile phones because of laws prohibiting such calls to cell phones.

For emergency workers, cell phones may not provide the same location information as landline connections.

The survey also found cell phone-only users are more often younger, low-income, minorities and rent rather than own their homes.