Making Filthy Water Drinkable Through Nano-Filtration

This video about a nano-filtration system presents a potential partial solution to the potable water situation plaguing the worlds poor and the proposed solution would indeed help reduce disease from water-bourn illnesses in numerous situations; however, there are also many situations existing in rural regions where there is virtually no surface water available. In these cases, provisions must be made for obtaining the water. Once the water is available, systems such as the one put forward can provide a viable low-cost means for purification.

In many cases, well drilling can provide the water from aquifers; however, aquifers can be contaminated with dissolved salts from lead, arsenic, etc. in the ground and other water treatments (not available from the nano-filtration systems) are necessary. In other cases, it is possible to catch/gather rainwater and store it in cisterns for later purification and drinking; this water is often free of contaminating salts, but it can be quite costly to provide water for large groups of people. In another situation, provision of desalinated water for the poor or distressed peoples near to the oceans is possible by means of technologies available to the military (or owners of RO desalination systems for yachts). Again this is typically costly.

My point is that there is no "one size fits all" solution to the problems of providing safe potable water to the poor. The need for individuals to invest their time and efforts to caring for and providing water to the poor will likely be with us for many decades.

Asbestosis is caused by sub-micron particles of asbestos which are able to travel to the lungs due to their small size and then cause scar tissue because they can not be dissolved by the body. It seems to me that any nano particles of chemically-resistant material are likely to do the same thing. Are we rushing to embrace nano technology without adequate consideration of the health effects of exposure to them?