Solar water disinfection (SODIS) is a way of disinfecting water using only by sunlight and plastic bottles. SODIS is the freest and the most effective method for decentralized water treatment. It usually practices at the household level and this method is recommended by the World Health Organization. It is a very viable method for household water treatment and safe storage. SODIS is already using in numerous developing countries. Educational articles and studies of the method are available in many languages, each very close to the English language version.
Exposure to sunlight has been shown to kill diarrhea-causing microorganisms in polluted drinking water. But don not forget about time of this method. If you left the water bottles in the sun for the proper length of time, the water may not be safe to drink and could cause illness. If the sunlight is less strong, due to overcast weather or a less sunny climate, a longer exposure time in the sun is necessary.
If to speak about African people, there are just forty-six percent of have got safe drinking water.
This fact has shown that the SODIS method (and other methods of household water treatment) can have very effective results of removing pathogenic pollution from the water. However, there always is a way to catch infectious diseases by another way. For example, due to a general lack of sanitation and hygiene.