Today, at least 5 million people in about 30 countries disinfect their drinking water daily with SODIS, and 750,000 more join the ranks each year. SODIS works by exposing contaminated water to the sun's UV rays, destroying the genetic material and cellular structure of viruses, bacteria, and protozoa. PET plastic bottles work best, as they're both durable and allow much of the UV radiation to pass through them. Bottled water is left outside for at least six hours (or 48 hours if it's cloudy), and then stored for future use. Since both polluted water and plastic bottles are abundant in many developing countries, SODIS is catching on and cutting the incidence of diarrhea by more than 85% in some places.
The problem of finding safe water to drink affects a lot more than 5,000,000 people: the article puts the number at 1,200,000,000. Annually, 1.8 million children die of diarrhea related to contaminated water.
So why isn't a cheap, practical and effective solution not an instant success? Heierli rephrased the question in a more telling way in his report: "Why is it so hard to get safe water to the poor--and so profitable to sell it to the rich?"
Basically, it's a marketing problem. Even in places where SODIS training is readily available, only about half of the households trained in the technique actually adopt it. SODIS training cannot be stopped after the first year of promotion. "People need reminders to form solid habits," says Meierhofer. They also need to be convinced of its value: Families capable of spending the modest time and money for SODIS often prioritize other things (such as buying soft drinks).
Let that sink in for a minute. Families capable of making a tiny investment in time and money to save their children from a horrific slow death "often prioritize other things".
Are children so disposable in those societies that a few thousand more or fewer dying is of no consequence? Do parents in those societies place such little value on their children?
Is this the reason that the Third World remains poor and sick -- that it is unwilling to make a sufficient effort to build an infrastructure for its future if that takes away from current consumption?