How solar cooking with a solar box cooker led to the opportunity to bring world-class water testing to communities, leading to an understanding of the relationship between fecal contamination of drinking water sources and waterborne disease.
Date(s): 1987-2005. Album by Bob Metcalf. Photos by Bob Metcalf. 1 - 129 of 129 Total. 2206 Visits.
1 The presence of the bacterium Escherichia coli indicates recent fecal contamination of water.
2
3 First step: gas from lactose broth at 35°C.
4 2nd step: 2nd lactose broth incubated at 44.5°C +/- 0.2°C. Gas produced by 'thermotolerant coliforms'
5 Most strains of E. coli produce gas at 44.5°C
6 But so do environmental coliform bacteria like this Klebsiella sp. The thermotolerant coliform test is not specific for E. coli.
7 The burden of collecting and using firewood to cook food for ~2.5 billion people in developing countries
8 Tree cutting leads to deforestation and land degradation
9 Barbara Kerr and Sherry Cole developed a practical solar box cooker in 1976.
10 Regular solar cooking in Sacramento since 1978.
11 Solar cooking in Sacramento, California, June, 1991
12 Bolivia, 1987, teaching how to build and use a solar box cooker. No simple water test available.
13 Solar baked potatoes after 2 hours of sunshine in Bolivia
14 Guatemala, January, 1988.
15 Built solar box cookers but no simple water test available.
16 In 1988, a new approach to test for E. coli is announced. Colilert, a defined substrate test
17 Colilert contains ONPG that all coliforms metabolize to produce a yellow color. It also contains MUG, which only E. coli with its beta-glucuronidase enzyme cleaves to cause fluorescence with UV light.
18 Colilert was available as a dry powder in glass tubes to test 10 ml of water. Made by Access Medical Systems, CT.
19 First used Colilert in Djibouti on UN Food and Agriculture Organization project, October 1988
20 Djibouti demonstration on World Food Day, October, 1988
21 January, 1989, Sierra Leone. With Colilert, water testing could be included with building solar box cookers.
22 First solar box cooker made in Sierra Leone
23 Solar Box Cookers made at workshop
24 Cake baked in solar box cooker for 2 hours
25 Fish soup & rice solar cooked
26 First Water Pasteurization Indicator made by Fred Barret, USDA
27 Distribution of Colilert tubes to 41 workshop participants to sample home water source.
28 Tubes can be incubated next to one's body to obtain next day results.
29 Body incubation of Colilert tubes
30 Next day results.
31 Clear = no coliform bacteria. Yellow (ONPG+) = coliform bacteria present, possibly E. coli
32 Shine a long-wavelenth UV light on tubes. Blue fluorescence = MUG (+), E. coli is present (right tube). MUG (-), E. coli not present.
33 39 of 41 tubes were ONPG + (yellow), coliform bacteria present, perhaps E. coli.
34 26 of 41 samples were MUG (+), indicating the presence of E. coli. Not a low disease risk, as >10 E.coli/100 ml = >1 E. coli/10 ml Colilert tube
36 Noukchott, Mauritania, 1991. 24 urban water samples were inoculated into Colilert tubes
37 Solar box cooker made at workshop.
38 Of 24 urban samples, 20 were ONPG (+), 12 were MUG (+), indicating not a low disease risk.
39 Nepal, 1993. Colilert results from this source were ONPG (+), MUG (-), low disease risk
40 IDEXX took over production of Colilert from ACCESS in 1993.
41 Solar box cookers in Nepal, 1993. With Trickle Up Program.
42 Solar Box Cooker made during Trickle Up workshop
43 Colilert results, urban and rural water sources tested
44 22 total sources tested. 21 ONPG (+), 9 MUG (+)demonstration that these 9 sources were not low disease risk.
45 PML materials for 200 tests sent to Nepal NGO in 2010
46 In 1995, Solar Cookers International developed the simple Cookit solar cooker. The Cookit could be scaled
47 SCI introduces Cookit to refugees at Kakama Refugee Camp, Northwest Kenya, February, 1995
48 Dadaab Refugee Camp near Kenya-Somali border. Cookits introduced here September, 1995
49 Dadaab - refugees receive small amounts of food - but how to cook it?
50 Tree trimmed for fuel in Dadaab
51 Camp Cholera in Dadaab
52 Somali women returning from 8 hour journey to collect wood, Dadaab refugee camp, Kenya, 1995
53 Refugee children returning with sticks after a long journey.
54 Bob and Gladys introducing Cookit solar cooker to Somali refugees
55 Introduction of the Cookit solar cooker. Foods cooked inside clear plastic bags.
56 Solar cooking works!
57 Cookit among refugee dwellings.
58 Refugee family with Cookit.
59 Dadaab Refugee Camp, Kenya, 1995.Testing borehole water with Colilert. ONPG (+), MUG (-)Low disease risk
60 In 1994, 3M introduced E. coli Count Petrifilm to test 1 ml, as is done in the food industry.
61 To use Petrifilm, label sample source and time
62 Add 1 ml of water sample to nutrient circle
63 Use flat side of plastic spreader to gently distribute 1 ml over entire circle
64 Petriflms covered with firm cardboard enables incubation on one's body. Invisible bacteria to develop into visible colonies in 12-16 hours.
65 Results usually in 12-18 hr. E. coli = blue colonies with gas. Coliforms from environment = red with gas.
66 First use of E. coli Count Petrifilm on raw camel milk in Dadaab refugee camp, 1995
67 Inoculated Petrifilms with 1 ml. Incubated on body between cardboard pieces to obtain overnight results.
68 Next day results. > 200 E. coli/ml before pasteurization, very high disease risk.
69 Colilert and Petrifilm tests correlate with WHO disease risk categories. E. coli level listed as lowest common denominator instead of per 100 ml.
70 Colilert and Petrifilm results also correlate with MSF treatment guidelines in emergencies.
71 Students at California State University, Sacramento, who contributed to water pasteurization work
72 Heating water to 65°C will pasteurize water and make it safe to drink.
73
74 Water Pasteurization Indicator (WAPI). When water reaches 65°C (149°F), wax melts and falls to the bottom. Water is pasteurized.
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76 Article on Cookit and WAPI to pasteurize water, 1999
77 WAPI used by Dadaab refugees, 1995. They received Cookit to cook food and to pasteurize water and camel milk.
78 Fuelwood problems in Meatu District, Tanzania, 2000
79 Water source, Meatu District, Tanzania
80 Sampling water source, Meatu District
81 Removing water sample for Colilert and Petrifilm tests, Meatu District
82 Water source, Meatu District
83 Water seller collecting water in Meatu District
84 Components of the Portable Microbiology Laboratory to test water in Meatu District
85 Materials for 25 water tests in gallon-sized plastic bag to make a Portable Microbiology Laboratory.
86 UN-Habitat Booklet on Water Testing, 2010
87 Any table becomes a laboratory to test village water sources
88 Testing numerous water sources in Meatu District, 2000
89 Results from one village. 1 ml Colilert MUG+, correlates with E. coli colonies on Petrifilms.
90 Results of Meatu water tests.
91 Village chiefs and village health workers in 3 day workshop, 2001.
92 Demystifying microbiology, teaching community about bacteria and water testing
93 Topics covered include bacteria size, growth, E. coli as indicator, Colilert & Petrifilm tests, WHO disease risk guidelines
94 Next day results. All local water sources from dry riverbed were high/very high risk.
95 Village chief knows that MUG+ Colilert means that E. coli was in the town's river water source, unsafe water
96 Health worker finds >10 E. coli on Petrifilm, a very high risk of disease
97 Water testing workshop for Saka Saka village, 2002. Boniphace translates into Kiswahili.
98 Two water sources in Saka Saka. From a pump (green bucket) and an open stream (yellow bucket).
99 Adults will sample either pump or stream water
100 Mixing inoculated Colilert tubes, to incubate overnight
101 Inoculating Petrifilms
102 Inoculating Petrifilms
103 Next morning demonstration of solar cooking, solar water pasteurization
104 Read results: Pump water yellow, MUG -, no E. coli. Stream yellow and MUG+, E. coli present.
105 Examining Petrifilms
106 Petrifilm results are clear.
107 Stream water (front) with ~100 E. coli colonies on each Petrifilm, very high disease risk. Pump water (back) with environmental coliforms,no E. coli, low disease risk.
108 All villagers see results of grossly contaminated stream water, no E. coli contamination of pump water.
109 Solar cooked rice in 2 hr
110 Boniphace shows wax melted in Water Pasteurization Indicator (WAPI), water safe to drink
111 Providing a year's supply of water testing materials to Saka Saka health workers to monitor pump water
112 After only an afternoon and a morning session, Saka Saka village understands the microbiology of water testing.
113 Competence in water microbiology is established in the village.
114 Guest House (hotel) in Meatu District
115 River water provided for guests
116 After testing river water, collect for solar pasteurization
117 Heating river water in Cookit to pasteurize
118 Temperature >60°C in 2 hours
119 WAPI wax melted, water is pasteurized
120 Evidence-based microbiology that contaminated water has been pasteurized.
121
122 Poster at 2001 American Society for Microbiology Annual Meeting
123 Poster at 2003 American Society for Microbiology Annual Meeting
124 Poster at 2005 American Society for Microbiology Annual Meeting
125
126 Nepal, 2016 workshop led by Katherine Parker
127 With a PML, anyone can be a water microbiologist. FOTO staff, Lower Nyakach, 2020
