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Potemkin
01-29-2005, 02:33 PM
"How to do it" PDF files are located here.
http://www.sodis.ch/files/SODIS_Manual_med.pdf High res 14.5mb file

http://www.sodis.ch/files/SODIS_Manual_screen.pdf Low Res 3mb file


Plastic bottle cleans up water-borne diseases

swissinfo January 7, 2005 10:09 AM

http://www.swissinfo.org/xobix_media/images/sri/2005/sriimg20050106_5450948_0.jpg
Plastic bottles may offer the best and cheapest solution to clean up water polluted by the Asian tsunami.

Swiss researchers say the Sodis system suffers from only one drawback – people’s refusal to admit that something so economical could be so effective.

In the wake of the December 26 tsunami, the Geneva-based World Health Organization (WHO) has pinpointed water-borne diseases as one of the biggest threats to survivors’ well-being.

It estimates that to 150,000 people could face outbreaks of cholera, typhoid and dysentery, along with diarrhoea. Every year, there are already 1.6 million diarrhoeal deaths related to unsafe water, most of them children under the age of five.

Scientists at Switzerland’s Federal Institute for Environmental Science and Technology have been promoting a cheap solution to the WHO fears for over a decade.

Cheap alternative

Solar water disinfection, or Sodis, is already in use in 20 countries, and is a cheap alternative to expensive water purification systems.

People can clean water in clear plastic bottles, simply by filling them up, shaking them and then leaving them in the sun for at least six hours, if possible on a sheet of corrugated iron or a roof.

The radiation from sunlight and the increased temperature of the water are enough to kill many forms of bacteria and viruses.

Martin Wegelin, who leads the rural water treatment programme at the Institute, says he has been in contact with the WHO, the Swiss Agency for Development and Cooperation (SDC) and Unicef since the killer waves struck nearly two weeks ago.

While these organisations’ mandates mean they won’t implement Sodis themselves, they are giving it a second look.

Peter Kaufmann, head of the SDC’s drinking water group, has recommended the use of the system in the areas affected by the tsunami.

“We think that Sodis will be particularly useful in villages where there were no proper water treatment systems before,” he told swissinfo.


Sodis is a low-tech and efficient solution for water treatment (Sodis)


Scaling up

Wegelin is also confident that the solar disinfection system can be used in major disaster zones.

“One project we have in Lombok, at the other end of Indonesia, has reached 100,000 people in just one year,” he said. “So I think you could scale up this type of project.”

The Swiss researcher says that one hurdle is a lack of local partners. “We rely on their expertise because they have developed valuable information in local languages, and they know how to promote this technology,” he told swissinfo.

Wegelin reckons that in the aftermath of the tsunami, easily replicable water treatment techniques with low operational and maintenance costs are a must.

“Water treatment systems that have been shipped to the disaster areas so far are expensive and can only help a few hundred people,” he said.

Fear of disease

Sodis projects are underway in other Asian countries, including India, Sri Lanka and Thailand. While none of the areas involved was struck by the tsunami, some of them are close to the disaster zones.

Solar disinfection is generally well accepted where it has been introduced in the past. According to Wegelin, the hardest part is convincing populations that such a cheap water treatment method can be efficient.

But he says that the threat of water-borne diseases might help the message filter through.

“What we have seen is that when people are truly afraid, they take notice,” he told swissinfo. “In Asia, diarrhoea is quite common, but when locals hear the word ’cholera’, they start to fear for their lives.”

swissinfo, Scott Capper


URL of this story
http://www.swissinfo.org/sen/Swissinfo.html?siteSect=105&sid=5451211

Ought Six
01-29-2005, 08:01 PM
This may be a good emergency field expedient, but I would not make it a standard practice. It will certainly not kill cryptosporidium or giardia cysts. Also, there was a recent study trying to find out why wealthy Marin County, California had the highest breast cancer rates on the planet by far. They determined that one of the primary factors was the fact that all these women left plastic sports bottles and bottled water in their cars in the sun. The heated water leached highly carcinogenic chemicals out of the plastic in the bottles.

Potemkin
01-29-2005, 08:44 PM
This may be a good emergency field expedient, but I would not make it a standard practice. It will certainly not kill cryptosporidium or giardia cysts. .


From the notes, if the directions are followed correctly it should kill giardia. See the chart below from http://www.sodis.ch/files/notes.pdf.
It is an expedient measure for developing countries and the directions must be followed.

Personally, I would use my Big Berkie but this is better than nothing.

.
Also, there was a recent study trying to find out why wealthy Marin County, California had the highest breast cancer rates on the planet by far. They determined that one of the primary factors was the fact that all these women left plastic sports bottles and bottled water in their cars in the sun. The heated water leached highly carcinogenic chemicals out of the plastic in the bottles

Sorry, this information was based on bad data.

http://www.skepticism.net/discussion/fullthread$msgnum=623

Back in March, this site noted the controversy over breast cancer rates in Marin County, California. Marin County is one of the wealthiest counties in the United States and also has one of the highest breast cancer rates -- 198 cases per 100,000 population compared to a national average of 139 per 100,000 for the rest of the country.

Activists who believe that pollution is a major contributor to breast cancer seized on this cancer cluster as evidence for their views, although a number of alternative explanations were possible. But now it turns out that there is an even better explanation -- the data that claimed Marin County had a breast cancer incidence of 198 cases per 100,000 population appears to have been faulty.

The faulty data came to light after research in 2002 said that the rate of cancer for white women in Marin County had increased from 191 cases per 100,000 in 1998 to 230 cases per 100,000 in 1999. That sort of massive jump was extremely suspicious.

It turns out that such estimates had been using faulty data from the U.S. Census Bureau that dramatically undercounted the population of women in Marin County. Census data from 2000 showed that the 1990 estimates that such studies had been using underreported the number of white women 45-64 in Marin County by close to 20 percent. Revised breast cancer rates have not been released.

Ironically, another recent study of breast cancer among women in Marin County will also not please the activist who want pollution to be the cause and accuse researchers of "blaming the victim" anytime another cause is put forward.

A study by researchers at the University of California, San Francisco and published in the online journal Breast Cancer Research found a strong correlation between alcohol consumption and breast cancer among women in Marin County. Women who consumed two drinks a day had twice the breast cancer risk, and the risk increased with self-reported alcohol consumption.

That study was small, comparing 285 Marin County women with breast cancer to 286 healthy women living in the county. But it did find no correlation between breast cancer and length of time living in Marin County, suggesting the high breast cancer rate in Marin County has something to do with a confounding factor that women there share rather than something to do with Marin County itself.

Source:

Marin County breast cancer rates not as high as once thought. Justin Pritchard, Associated Press, April 4, 2003.

Study: Marin breast cancer related to alcohol consumption. Associated Press, May 7, 2003.

Deb Mc
01-29-2005, 09:14 PM
Potemkin,

Thank you for posting this - neat stuff! Just forwarded it to my cousin down in South Florida who was hit by Charley last summer. Hope she doesn't need it this year...

Potemkin
01-29-2005, 09:29 PM
Potemkin,

Thank you for posting this - neat stuff! Just forwarded it to my cousin down in South Florida who was hit by Charley last summer. Hope she doesn't need it this year...

No problem.

Here is some additional research aout UV and PET water bottles.

http://www.sodis.ch/files/aqua00.pdf

A.T.Hagan
01-29-2005, 09:35 PM
Even when used as per the directions it's not a perfect water sanitization method, but if you have no better way to get the job done then it's definitely a way to go.

Pat mentions this method in his Water Treatment FAQ

http://athagan.members.atlantic.net/PFSFAQ/Water_TreatmentFAQ-v2.2.html
<i><b>Sol-Air Water Treatment</b>

If sufficient dissolved oxygen is available, sunlight will cause the temporary formation of reactive forms of oxygen such as hydrogen peroxide and oxygen free radicals. This form of water treatment is called solar photooxidative disinfection or sol-air water treatment. Sol-Air water treatment has been shown to dramatically reduce the level of fecal coliform bacteria. There is some evidence that other bacteria and viruses may be affected also. While not as reliable as other methods, it does offer a low-tech solution in emergencies. Sol-Air treatment requires bright sunlight, and has been shown to be effective when ever the sun causes a distinct shadow to be cast. Exposure to 4.5 hours of bright sunlight has been shown to cause a thousand fold reduction in fecal coliforms in lab tests.

In order for Sol-Air to be effective, oxygen must be present. Experiments have shown that shaking a bottle filled 3/4 with air will restore oxygen levels to near saturation. As the treatment continues, some of the oxygen will come out of solution, while other oxygen will be consumed by the killed pathogens, so the shaking should be repeated every few hours. Data shows that maximum activity occurs when the water temperature is above 50° C (122° F), so this method may be unsuitable in colder climates unless special solar collectors are used.

Either glass or plastic bottles may be used. Plastic bottles will allow short wave ultraviolet radiation to pass, increasing the rate of microbial inactivation, but may yellow with age, reducing light transmission, and may leach plasticizers into the water at the elevated temperatures that will occur. The leaching of plasticizers can be reduced by using bottles of PET (polyethlyene terephtalate) rather than PVC. Glass bottles on the other hand are more durable. Research has used bottles with 2 liters of capacity, but if the water is free of turbidity, larger containers can be used. Plastic bags, or some sort of flat glass container represent the ideal container as this maximizes the solar energy received per ounce of water.

Bottles should be filed 3/4 full in the early morning with water as free of turbidity as possible. After capping the bottles should be shaken vigorously for a few minutes then placed upright in the sun, where they will be not be shaded later in the day. The shaking should be repeated at least three times during the day. At the end of the day the water should be reasonably freed of bacteria, though it is most practical to let the water cool for consumption the following day. Each day a new batch should be treated due to the lack of a residual disinfected.

After consumption of the water the bottle should be air dried to prevent algae growth with continual use.</i>

.....Alan.

Ought Six
01-30-2005, 05:36 AM
P:

Thank you for the corrections. Good info.

================================================================

ATH:"Even when used as per the directions it's not a perfect water sanitization method, but if you have no better way to get the job done then it's definitely a way to go."Agreed, and that is pretty much just what I said in my first sentence of my previous post.

Potemkin
09-09-2005, 04:55 PM
Btt