Before you rush out to install a filter to improve water quality, think about this...

I just went for eWASH (emergency water, sanitation and hygiene) training conducted by Singapore Red Cross over the weekend. Designed for responding to emergencies and disaster scenarios, it definitely provides a fresh angle on the old topics of water and sanitation. By the way, to me, water and sanitation are simply 2 sides of the same coin (see earlier post on why people learn about wastewater). You can't work on one (usually water) while ignoring the other (usually wastewater) because wastewater typically has a habit of getting back at you through your water if you neglect it.

But hey, when you progress to WASH (water, sanitation and hygiene), you now have a whole lot more factors to consider in addition to getting safe drinking water. (Admittedly, WASH is commonly associated with developing communities but we in developed countries can certainly learn a few things too.)

1. Do you wash your hands before eating and after visiting the toilet?
2. Do you in fact use or have a toilet?
3. Is the way you store your water free from contamination?
4. Is your garbage and other solid waste properly disposed?
5. Is your food safely prepared, handled and served?
6. Do you know that children excreta is just as hazardous as adults'?

Often times in disasters or developmental work (including our students' overseas community service trips), we are too fixated on providing safe, clean drinking water to our beneficiaries. So much so that we forget about the other aspects of health e.g. sanitation, hygiene. In some situations, tackling those less sexy topics can bring about better results to our beneficiaries.

In any case, before we jump in to install a low-tech rainwater harvesting system or a high-tech reverse osmosis water production unit, perform a needs analysis first, whether in a disaster or development scenario. Work on those needs at the top of the list first and not what we "feel" or "want" to do.

My training session provided an interesting study (can't remember the source to cite though) to help bring things into perspective.

Based on various cases, it ranked the effectiveness of the following 4 methods to decrease morbidity rates of diarrhea. Most effective is ranked first... down to the least effective at the bottom. Guess what is at the top and what is at the bottom???

Figure: Do not underestimate the power of the humble washing of our hands

Answer:

1. Hand washing ~30+%
2. Latrine usage ~30+%
3. Sufficient water quantity ~15+%
4. Water quality ~15+%

So you have it... water quality is important but check that you have covered more critical gaps before jumping straight to improve upon it.

Updated by author 23/3/17:
Dr Yoke of WISE (WASH in Southeast Asia) has kindly recommended the following articles on the above topic.

1. Esrey, S.A. et al. Effects of improved water supply and sanitation on ascariasis, diarrhoea, dracunculiasis, hookworm infection, schistosomiasis and trachoma. Bulletin of the World Health Organization, 69 (5): 609-621 (1991)
2. Fewtrell, L. et al. Water, sanitation and hygience interventions to reduce diarrhoea in less developed countries: a systematic review and metal-analysis. Lancet Infect Dis 2005; 5: 42–52

If you read through them, there exists some uncertainty associated with the data and conclusions. Nevertheless, the idea remains the same - a health programme (even a personal one) should not be overly focused on one particular aspect, say water quality. A holistic approach is ideal but in a non-ideal world in which resources are limited, we should still open our minds to other factors, perform a realistic needs analysis and work on the most critical factor and not on the factor we have a preference to.