Filtering has become, undeniably, a prevailing cultural practice; a norm of the subculture of U.S. backpackers.

Yet there is sufficient evidence to suggest that the practice is not a useful means of avoiding disease.

A comparable fact is that more than half the U.S. population consume dietary supplements, in spite of adequate research showing clearly, that healthy adults get no benefit from these products.

Back-country water filtering in U.S is a cultural and behavioral fact that is now best viewed, academically at least, through the science of anthropology, independently from medicine or public health.

(I freely offer this as an idea for your next brilliant, useless graduate research thesis at Moo U!)