(CNN) -- It still makes Fatoma Dia's eyes widen whenever the Hilton hotel cleaning worker sees a bar of barely used soap on a bathroom counter. "This," she says, picking it up with a gloved hand and dropping it in a brown bucket, "is valuable where I come from." The 35-year-old grew up in a mountainous region of southern Sudan where soap can cost more than a day's wages. Because some in the region, could not wash, they got sick. Across the globe, 2.4 billion people do not have access to clean sanitation, according to the World Health Organization. An estimated 1.5 million children die every year because their immune systems are not mature enough to battle diarrheal and respiratory diseases spread in contaminated environments.
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Millions of people in developing countries don't have access to soap or clean water
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Many young children die because their immune systems can't fight diarrheal diseases
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Often, experts say, children and their parents don't even know how to wash their hands
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CDC doctor: "To change a community's habits, reach the children first"
She and other cleaning staff at this @placeholder typically collect several hundred pounds of soap each month.