Pure Home Water, Ghana manufactures and distributes AfriClay Filters in an effort to bring clean water to 1 million people. So far they have delivered filters to provide 100,000 people clean water.
The process is simple. Water is placed in a clay filter and gravity pulls the water through the pores left in the clay during firing.
Sediment and bacteria are filtered out in several ways:
Physical straining: the particles are too large to fit through the pores in the clay
Sedimentation or adsorption: particles come to rest on or stick to the clay
Inertia: friction in the pores keeps the particles from passing through
Bacteria are also killed by a coating of colloidal silver (a disinfectant), which we apply to all filters that pass our quality control tests. While sediment and bacteria are filtered out, the molecules of water are small enough to pass through the pores in the clay.
The filters are sold to those who will use them. The effort has shown a willingness to pay by villagers in remote Northern Ghana (those earning < US$1/day). I imagine (I am just guessing) the prices are subsidized; in the last decade more (most?) appropriate technology solutions will have those benefiting pay something for the benefits they receive.
My nephews are working on a similar effort in India, using bio sand filters, I plan to post more on that later. There is current a campaign to help fund the delivery of water filters to Indian villages.
That dirt I ate as a kid is maybe why I have been relatively healthy. Ok, probably that hasn’t been the most important factor. But it may be that some dirt and germs (kids licking their dirty hands and the ice cream melts on it, etc.) is actually more important for their long term health than finishing off the broccoli (of course, a healthy diet requires eating a bunch of vegetables, more than most kids eat).
The hygiene hypothesis has become a popular explanation for the boom in asthma, allergies and other health problems. Boiled down to one sentence the hypothesis is that exposure to germs early in life creates a healthy immune system and too little exposure results in a hypersensitive immune system (that is not as effective and leads to things like allergies).
A recent closed science paper, Microbial Exposure During Early Life Has Persistent Effects on Natural Killer T Cell Function, found mice exposed to more germs early on where healthier:
Exposure to microbes during early childhood is associated with protection from immune-mediated diseases such as inflammatory bowel disease (IBD) and asthma. Here, we show that, in germ-free (GF) mice, invariant natural killer T (iNKT) cells accumulate in the colonic lamina propria and lung, resulting in increased morbidity in models of IBD and allergic asthma compared to specific pathogen-free (SPF) mice. This was associated with increased intestinal and pulmonary expression of the chemokine ligand CXCL16, which was associated with increased mucosal iNKT cells. Colonization of neonatal—but not adult—GF mice with a conventional microbiota protected the animals from mucosal iNKT accumulation and related pathology. These results indicate that age-sensitive contact with commensal microbes is critical for establishing mucosal iNKT cell tolerance to later environmental exposures.
The microscopic battles waged in our bodies every day and over our lifetimes are amazing.
According to the Centers for Disease Control, between 1980 and 2006 the percentage of obese teenagers in the United States grew from 5 to 18, while the percentage of pre-teens suffering from obesity increased from 7 to 17.
Obesity is widespread due to our national-scale system of food production and distribution, which surrounds children – especially lower-income children – with high-calorie products…
90 percent of American food is processed – according to the United States Department of Agriculture – meaning it has been mixed with ingredients, often acting as preservatives, that can make food fattening.
Now, in another report finished this October after meetings with food-industry leaders, the MIT and Columbia researchers propose a solution: America should increase its regional food consumption.
Only 1 to 2 percent of all food consumed in the United States today is locally produced. But the MIT and Columbia team, which includes urban planners and architects, believes widespread adoption of some modest projects could change that, by increasing regional food production and distribution.
To help production, the group advocates widespread adoption of small-scale innovations such as “lawn to farm” conversions in urban and suburban areas, and the “10 x 10 project,” an effort to develop vegetable plots in schools and community centers. Lawns require more equipment, labor and fuel than industrial farming nationwide, yet produce no goods. But many vegetables, including lettuce, cucumbers and peppers, can be grown efficiently in small plots.
As Albright sees it, the effort to produce healthier foods “fits right in with the health-care reform effort right now because chronic diseases are so costly for the nation.” America currently spends $14 billion annually treating childhood obesity, and $147 billion treating all forms of obesity.
Good stuff. We need to improve health in the USA. The current system is unhealthy and needs to be improved. The public good from improving the health of society is huge (both in terms of individual happiness and economic benefits).
A talking head with some valuable info. I remember my father (a statistics professor) getting me to understand this as a small child (about 6 years old). The concept of growth and mathematical compounding is an important idea to understand as you think and learn about the world. It also is helpful so you understand that statistics don’t lie but ignorant people can draw false conclusions from limited data.
It is unclear if Einstein really said this but he is often quoted as saying “compounding is the most powerful force in the universe.” Whether he did or not, understanding this simple concept is a critical component of numeracy (literacy with numbers). Also quoted at times as: “Compound interest is the eighth wonder of the world.” My guess is that people just find the concept of compounding amazing and then attribute quotes about it to Einstein.
In 1951 the husband-wife team of Joshua and Esther Lederberg, microbiologists at the University of Wisconsin, demonstrated that their elegantly simple proof that preexisting mutations, not gradual tolerance, accounted for the many instances of new drug resistance… This meant that every new antibiotic became a powerful new force for bacterial evolution, winnowing away every bacterium but the otherwise unremarkable one that could survive its effects. With its competition gone, that lucky mutant could populate, giving rise to a newly resistant colony overnight.
Since bacteria can grow remarkably quickly, eliminating all but a small number just means that the new population boom will come from those few, resistant, ancestors. But that is not the only reason bacteria are so challenging to fight. They have been around billions or years and have survived because they can adapt well. Bacteria, in fact, can get their genes from distantly related bacteria. So if one bacteria gains immunity another bacteria can get that immunity by getting genes from that other bacteria (seems like science fiction but it is actually science fact).