Sunday, January 16, 2011

Drinking From Troubled Waters

Author: Farah Cherry, MD

Imagine if I told you that I had the cure to the number one cause of illness in the world. You would want every one on planet Earth to have access to this cure as cures are a hard find. Now imagine if I told you that this cure was clean water. The reason I was compelled to write this article was to raise awareness about the most serious threat to human health in the world as well as the solutions to this problem.

Clean water is essential to sustain human life, and yet nearly 1 billion people, or nearly one sixth of the entire world population, lack access to it. Each year water related illnesses kill approximately 4 million people, half of whom are children under the age of 5 years. Thousands of children in the developing world will drop out of school because of water insecurity, as these children must spend the valuable part of the day fetching water for their families to cook and eat. If more than 2/3 of planet Earth is covered by water why is there such a shortage? Actually the problem is not a question of scarcity but rather of access.

While 2/3 of the Earth’s surface is comprised of water, a small fraction of it is available for humans to drink. Of all the Earth’s water, only 3% exists as freshwater (drinkable) and the remaining 97% is comprised of salt water from oceans. Surprisingly, of this 3%, only 0.3% is made up of water we call surface water (i.e. lakes, rivers, streams, reservoirs) which also happens to be the primary source of drinking water for people in the world. Despite this astoundingly miniscule percentage (0.3% of 3%), this water is adequate to meet all our daily needs though not without dangers. Freshwater carries a heavy load of microorganisms commensurate with disease.

Thanks to advances in technology and public health, the question of water is no longer a proverbial one. We now understand the impact of clean water on health, productivity and the economy. With this understanding scientists are finding ways to ensure that people have this basic human right. I talk specifically about technologies in the point-of-use (POU) water treatment industry because I believe that this level of water treatment has the greatest potential to provide access to clean water world wide. It is currently the least costly and most easily distributed form of water treatments.

POU water treatment includes any treatment of water that occurs at the location where the water is to be used (eg in the home or at an industrial site), as opposed to in a community plant from which the water will be distributed to many locations or persons. The current POU water treatment technologies available to individuals include reverse osmosis, ultraviolet disinfection, membrane filtration, sand filtration and a fifth category I call “NOCE” (Not Otherwise Classified Elsewhere) which includes boiling, pasteurization, chlorination and natural/chemical coagulation of water. I want to further focus on membrane filtration technology which uses synthetic materials to separate adulterated particulate matter (including pathogenic microorganisms) from water sources. There are a variety of membrane filtration processes which differ based on the degree of separation of this adulterated particulate matter. For example, membranes are capable of performing particle filtration, microfiltration, ultrafiltration or nanofiltration. Of all the technologies mentioned, membrane filtration is the easiest to manufacture and distribute in addition to being the least costly.

Hollow fiber membranes filters belong to the family of membrane filters capable of carrying out ultrafiltration (filtering of matter as small as the smallest known virus, cyst, protozoan and bacterium). Developed in the late 1970’s, it’s primary function was the filtering component in hemodialyzers. It is still the primary filtering component in most hemodialyzers worldwide. It’s use was extended from filtering the blood of end-stage kidney patients to filtering drinking water- the proverbial blood of life! It’s now available for anyone to buy and it’s small enough to fit in your pocket. Filters that contain these hollow fiber membranes do not use energy last a lifetime and never breakdown. Though they don’t filter out chemicals or any elements on the Periodic Table, the truth is this: in many water supplies, the most serious health threats are posed not by chemicals or minerals but by infectious organisms in the water. So if more people in the world have access to a cell phone than to clean water, why not donate a filter using the hollow fiber membrane technology to every family in need of one?

*The statistics presented here were obtained from the WHO and the United Nation Human Development Report

About the author:
Farah Chery M.D. is a freelance writer whose current focus is medical mission work in Haiti.

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