Solar Cooking

Preventable waterborne diseases are responsible for approximately 80% of all illnesses and deaths in the developing world. Wow.

But thinking like a Wikipedian for a minute, it'd be nice to have a source for this claim. Anyone know where it comes from? (a very interesting article) says "An estimated 1.7 million people in developing countries die annually from diseases linked to unsafe water and sanitation and poor hygiene (Wagstaff, 2002)." so the figure of 2 million for children dying each year might be too high, esp since the 1.7 million includes unsafe sanitation and poor hygiene, not just water borne diseases. Later it says "Among the 10 leading mortality risks in high-mortality developing countries, unsafe water, sanitation and hygiene ranked second, while indoor smoke from solid fuels ranked fourth (WHO, 2002b)." And "Globally, water-related causes account for approximately 80 per cent of all communicable diseases (Ford, 2004)." Unfortunately I can't track down the (Ford, 2004) reference. The cited URL doesn't work. Assuming we believe his number, though, it's 80% of communicable diseases, not 80% of all illnesses and death. The (Wagstaff, 2002) reference is easy to find: but if it contains the 1.7 million figure, I can't find it.

The World Bank says "Approximately 4 billion cases of diarrhea per year cause 2.2 million deaths, most-1.7 million-children under the age of five, about 15% of all under 5 deaths in developing countries." But this is for "inadequate water, sanitation and hygiene", and, they go on to say, "Improved hygiene (hand washing) and sanitation (latrines) have more impact than drinking water quality on health outcomes....Most endemic diarrhea is not water-borne, but transmitted from person to person by poor hygiene practices." So what percentage of the deaths can be attributed to bad water per se? Hard to know, but it sounds like less than half, and maybe far less than that. So it seems to me the figures in the first paragraph are pretty suspect, and (without spending a lot more time) I don't have other figures to use instead. Beth Ogilvie 00:31, 11 March 2007 (UTC)

Isn't clean water essential for hygiene? Alternatives exist, but I'd think they would be less available than pasteurized water and soap. What am I missing? I think sanitation is largely separate from pasteurized water as it refers to the disposal and treatment of human and other waste. However, the use of clean water would greatly reduce the impact of poor sanitation, or so I think. Walter Siegmund 06:16, 11 March 2007 (UTC)

Water source of Mwamongu Village,Tanzania

The problem, apparently, is that many people don't have enough water available - or don't use it for hand washing if they do. The World Bank article says "Most endemic diarrhea is not water-borne, but transmitted from person to person by poor hygiene practices, so an increase in the quantity of water has a greater health impact than improved water quality because it makes it possible (or at least more feasible) for people to adopt safe hygiene behaviors (Esrey et al 1996)." If we got our water from a little pool like this, we might not wash much either.
This is not to say that water pasteurization isn't important in many situations. There are some horrific diseases, guinea worm, for example, that are clearly water borne. Beth Ogilvie 17:21, 12 March 2007 (UTC)
Those are excellent points. Thank you for the explanation. Walter Siegmund 21:20, 16 March 2007 (UTC)
I tried to edit the summary to incorporate your comments, but realized that the 80% number is dubious. For one thing, malaria is a big health problem that is not waterborne. Shistosomiasis is another one that is water-related but is not necessarily addressed by water pasteurization since it can be contracted through the skin. I put the article on the main page per Tom's request, but reverted myself until we can sort these things out. Walter Siegmund 00:23, 17 March 2007 (UTC)
The facts in the introductory paragraph are sourced now; The World Bank; Public Health at a Glance; Water, Sanitation & Hygiene, December 2003 and WHO, UNICEF, JMP, Joint Monitoring Programme for Water Supply and Sanitation; Water supply data at global level, 2004 I couldn't find a source for the table, however. Walter Siegmund 02:38, 17 March 2007 (UTC)

Wax-based pasteurization indicators[]

How well have wax-based pasteurization indicators been tested? When the wax melts at 65 deg. C, are we sure that the water is at the same temperature?

Water is transparent. Sunlight, or much of it, just passes through it. Wax is opaque. Sunlight that strikes it is mostly absorbed, warming the wax. So if a wax-based indicator is surrounded by water and placed in full sunlight, it is possible that the wax may get warmer than the water. So the indicator may show that a safe pasteurization temperature has been reached, when in fact the water is cooler.

DOwenWilliams 15:24, June 14, 2012 (UTC)