Real-world Proof of Handwashing's Effectiveness

Scientists are reporting dramatic new real-world evidence supporting the idea that handwashing can prevent the spread of waterborne disease. It appears in a new study showing a connection between fecal bacteria contamination on hands, fecal contamination of stored drinking water, and health in households in a developing country in Africa. The study is in ACS' Environmental Science & Technology, a semi-monthly journal.

Alexandria Boehm, Jenna Davis, and their students note that almost half of the world's population — over 3 billion people — have no access to municipal drinking water supply systems. They obtain drinking water wells, springs, and other sources, and store it in jugs and other containers in their homes. Past research showed that this stored water can have higher levels of bacterial contamination than its source. But nobody knew why.

The scientists found a strong link between fecal contamination on the hands of household residents and bacterial contamination in stored water in Dar es Salaam, Tanzania. Stored water contained nearly 100 times more fecal bacteria than the source where it was collected. "The results suggest that reducing fecal contamination on hands should be investigated as a strategy for improving stored drinking water quality and health among households using non-networked water supplies," the report notes.