Background: Solar radiation reduces the bacterial content of water, and may therefore offer a method for disinfection of drinking water that requires few resources and no expertise.
Methods: We distributed plastic water bottles to 206 Maasai children aged 5-16 years whose drinking water was contaminated with faecal coliform bacteria. Children were instructed to fill the bottle with water and leave it in full sunlight on the roof of the hut (solar group), or to keep their filled bottles indoors in the shade (control group). A Maasai-speaking fieldworker who lived in the community interviewed the mother of each child once every 2 weeks for 12 weeks. Occurrence and severity of diarrhoea was recorded at each follow-up visit.
Findings: Among the 108 children in households allocated solar treatment, diarrhoea was reported in 439 of the 2-week reporting periods during the 12-week trial (average 4.1 [SD 1.2] per child). By comparison, the 98 children in the control households reported diarrhoea during 444 2-week reporting periods (average 4.5 [1.2] per child). Diarrhoea severe enough to prevent performance of duties occurred during 186 reporting periods in the solar group and during 222 periods in the control group (average 1.7 [1.2] vs 2.3 [1.4]). After adjustment for age, solar treatment of drinking water was associated with a reduction in all diarrhoea episodes (odds ratio 0.66 [0.50-0.87]) and in episodes of severe diarrhoea (0.65 [0.50-0.86]).
Interpretation: Our findings suggest that solar disinfection of water may significantly reduce morbidity in communities with no other means of disinfection of drinking water, because of lack of resources or in the event of a disaster.
PIP: During December 1995-March 1996 in Kajiado Province, Kenya, 206 Maasai children, 5-16 years old, whose drinking water was contaminated with fecal coliform bacteria, were assigned 1.5 liter plastic bottles in which to store their drinking water. These bottles were re-used commercial table water bottles. The families of the children had only community sources for drinking water: 2 open water-holes and 1 tank fed from a piped supply. These water sources were not suited to chlorination. Scarce fuel and indoor air pollution precluded boiling water inside the hut. In the presence of their mothers, 108 children (the solar group) were told to fill the bottles with water at dawn, leave them in full sunlight on the roofs of their homes, and wait until midday before drinking from the bottles. The remaining 98 children (the control group) were told to leave the bottles in their homes. The purpose of the study was to evaluate the effect of solar disinfection on diarrheal disease in these Maasai children. Over a 12-week period, children in the solar group suffered fewer diarrhea episodes than those in the control group (4.1 vs. 4.5; adjusted odds ratio [AOR] = 0.66). They also were less likely to have diarrhea episodes severe enough to prevent them from doing their chores (1.7 vs. 2.3; AOR = 0.65). These findings suggest that solar disinfection of water may reduce diarrhea in communities with no access to other means of disinfection.