Pink Pan Salt

Description

The Makgadikgadi Pan, a salt pan situated in the middle of the dry savanna of north-eastern Botswana, is one of the largest salt flats in the world. The pan is all that remains of the formerly enormous Lake Makgadikgadi, which once covered an area larger than Switzerland, but dried up thousands of years ago.

Salt is one of the natural resources that has been important to man. Today, between a third and a half of the sodium we consume is added during cooking or at the table (Warlaw & Insel, 1990). Since the effects of excessive salt use are not immediate, there has been a general tendency to take in more salt than the human body needs, and this has been largely influenced by appetite for the taste of the commodity (Swales, 1993). It must be appreciated that table salt is not the only salt. Other sources of salt exist in the natural context and their purity and quality differs. The value of salt has not only been recognized in Western civilization. In Africa for instance, large scale exploitation of salt has been documented (Roberts, 1973; Connah, 1991, 1996; Davison, 1993). Looking back through time, salt has been a trade item of significant value among many societies. Davison (1993) talks of the establishment of caravans between Malawi and the Indian Ocean, trading mainly in salt. Salt has bought food for the people of Kibiro in Uganda (Connah, 1991, 1996). The ways of acquiring salt cannot all be outlined, but it has in many instances created avenues for interaction between individuals, societies and within societies.

Salt is known to chemistry as sodium chloride; table salt contains 40 percent sodium and 60 percent chloride (Warlaw & Inset, 1990). Whilst it is an essential nutrient, if taken in excessive quantities salt can be toxic. In the short term the difference between the two extremes is vast since the body can cope with a wide range of sodium intake (Swales, 1993).

According to Swales it is difficult to establish an optimal salt intake which is consistent with the greatest level of health, since many factors come into play when considering this, such as the environment in which individual lives and the physiological and medical conditions that may influence the body’s requirement for sodium. A low sodium diet coupled with high perspiration losses or diarrhea, can deplete the body of sodium leading to undesirable effects such as muscle cramps, nausea, vomiting, or even shock and coma (Warlaw & Insel, 1990).

When considering the usefulness of salt in the body the sodium component is usually the most emphasized. This emphasis on sodium does not mean that the anion (chloride), is of no physiological importance. As some studies suggest, the changing of the anion component may influence the physiological effect of the sodium ion (Swales, 1993). Swales (1993) mentions that the human body contains on average, about 500 mmol of sodium, some of which (about 200) are bound to bone, and largely metabolically inactive. The remainder are related to water distribution. The body fluid is divided into intracellular, and extracellular fluid spaces with high concentration of sodium in the extracellular fluid spaces (including blood) and low in the intracellular fluid spaces. There is therefore, a substantial concentration gradient of sodium between the intracellular and extracellular compartments whose maintenance is fundamental to life, and can be achieved through a number of transport processes.

Swales further outlines the physiological actions of sodium important in understanding its role in health: sodium gradient is a chemical drive for fundamental cell functions. The tissues in the central nervous system for instance, release of neurotransmitters is associated with the sodium gradient across the cell membrane so that the activity of the brain and peripheral nerves relies upon the sodium gradient. Warlaw & Insel add that impulses are driven down the nerves by the sodium ions. Thus, sodium ions are important for nerve conduction.