[Edited April 18 to clarify concerns about TOMS shoes.]
The article by Darren Richardson that I pointed to in the last blog entry, Shoe company’s ‘One Day Without Shoes’ event leads to soul-searching about soles, mentioned podoconiosis as a reason for wearing shoes. TOMS shoes highlighted it as two of its “Five Facts”:
- In Ethiopia, approximately 1 million people are suffering from podoconiosis, a debilitating and disfiguring disease caused by walking barefoot in volcanic soil.
- Podoconiosis is 100 percent preventable with basic foot hygiene and wearing shoes.
I thought I’d check into this disease a bit further.
Podoconiasis is a form of elephantiasis. Most elephantiasis is caused by parasitic worms, but podoconiasis is something else entirely. It is caused when a certain kind of soil is walked on. Small particles of that soil (almost nanoparticles) pass through the skin and work their way into the lymphatic system, clogging it (or causing a reaction that clogs it). That causes the foot and leg to swell horribly (making it look like an elephant’s leg, almost).
A very good source of information on podoconiosis is in Podoconiosis: non-infectious geochemical elephantiasis, by Gail Davey, Fasil Tekola, and Melanie J. Newport; Transactions of the Royal Society of Tropical Medicine and Hygiene, Volume 101, Issue 12, Pages 1175-1180.
Podoconiosis mainly occurs in equatorial Africa (particularly Ethiopia, but also Uganda, Cameroon, Tanzania, Kenya, etc..), with some occurrences in Central America and elsewhere. However, as mentioned, it requires a particular kind of soil (quoting from the Davey article):
An association between podoconiosis and exposure to the local soil was suspected by Robles at the end of the nineteenth century. However, it was not until Price superimposed maps of disease occurrence onto geological surveys that persuasive evidence of a link with red clays, rich in alkali metals like sodium and potassium and associated with volcanic activity, was provided. The climatic factors necessary for producing irritant clays include high altitude (over 1000 m above sea level) and seasonal rainfall (over 1000mm annually). These conditions contribute to the steady disintegration of lava and the reconstitution of the mineral components into silicate clays, colloid-sized particles of which have been demonstrated in the lower limb lymph node macrophages of those living barefoot on these clays. More recent comparison of soil from an endemic area with that from outside the area revealed high levels of beryllium and zirconium (both known to induce granulomata) but the role of these elements is not yet established.
In many cases, it can take upwards of 30 years for symptoms to occur, and somewhere on the order of 5-10% of the population is affected. There also seems to be a genetic influence. Certain occupations are also at risk (obviously, those who spend a lot of time walking barefoot on these specific soils): farmers, gold miners, and weavers (who sit at a ground-level loom).
It is clear that shoes (or, as discussed in the article, sandals) prevent this condition, though frequent prophylactic washing is also important. Supposedly, this condition even used to occur in Europe (France, Scotland, and Ireland), and disappeared as shoe-wearing became standard. Thus, the efforts of TOMS shoes, when directed to these particularly susceptible populations, has some utility when applied in a very specific manner.
Shoes are tools. Those of us who like to go barefoot realize that there are times that shoes, as tools, are necessary, just as face masks and respirators in mines, as tools, are necessary. Under these conditions, these red-clay, alkali volcanic soils, shoes are necessary tools, and I am not going to say that folks should go barefoot there regardless.
While I recognize TOMS shoes efforts in these areas, it must also be pointed out that their “One Day Without Shoes” really misses that point. They stress that somehow being barefooted is uncomfortable and a real problem everywhere, when that is not the case. They encourage people with feet weakened and softened by shoes to stress them, maybe beyond their current capacity (Darren’s gym analogy is good here), in an attempt to gain their sympathy. Instead, it would be better if TOMS shoes really did stress the real medical condition that requires in a fairly limited portion of the world, for a fairly limited set of people.
To make it clear, I am not endorsing TOMS shoes as a whole. Most of their efforts are misguided, as they seem to think that shoes are required in almost all situations when this is clearly not so. However, when it comes to podoconiosis among these susceptible people, if TOMS shoes provides free protection, it is hard to be heartless and to argue that that is a bad thing and that TOMS should do absolutely nothing. Nonetheless, we can also wonder about follow-up (what happens when those shoes wear out), and we can also wonder if something less drastic than shoes would not be better (since wearing shoes opens one up to other conditions, such as athlete’s foot).