UNICEF and the World Health Organization reported mixed progress in the global effort for improved water and sanitation on Monday.

A joint report by UNICEF and the WHO showed that in 2008, 87 percent of the world population had improved sources of drinking water while less than two thirds used improved sanitation facilities.

Clarissa Brocklehurst, UNICEF's water, sanitation and hygiene chief, attributed the disparity to fundamental differences between water and sanitation. "Whereas water can be addressed on a communal basis, sanitation is a personal and household issue," said Brocklehurst via telephone from New York.

Access to drinking water is on track to reach the millennium development goal targets (MDGs), but sanitation is not. The MDGs stipulate that by 2015 those without access to improved drinking water should decrease to 12 percent, while those without improved sanitation should decline to 23 percent of the global population. By 2008 the first figure dropped to 13 percent while the second -- those without improved sanitation -- was 39 percent, almost double the goal.

Despite that, Brocklehurst is optimistic. "Using behavior change as the basis for our approach, it's possible to see a sanitation revolution in the next few years," Brocklehurst said. " If you build a toilet without addressing the underlying behavior, it's not effective."

Every year 1.5 million children die from diarrhea diseases. Eighty-five percent of the deaths are due to poor water and sanitation.