The exact composition of the Dead Sea water varies mainly with season, depth and temperature. In the early 1980s, the concentration of ionic species (in g/kg) of Dead Sea surface water was Cl− (181.4), Br− (4.2), SO42− (0.4), HCO3− (0.2), Ca2+ (14.1), Na+ (32.5), K+ (6.2) and Mg2+ (35.2). The total salinity was 276 g/kg.[20]
These results show that the composition of the salt, as anhydrous chlor
ides on a weight percentage basis, was calcium chloride (CaCl2) 14.4%, potassium chloride (KCl) 4.4%, magnesium chloride (MgCl2) 50.8% and sodium chloride (common salt, NaCl) 30.4%. In comparison, the salt in the water of most oceans and seas is approximately 97% sodium chloride. The concentration of sulfate ions (SO42−) is very low, and the concentration of bromide ions (Br−) is the highest of all waters on Earth. The salt concentration of the Dead Sea fluctuates around 31.5%. This is unusually high and results in a nominal density of 1.24 kg/l. Anyone can easily float in the Dead Sea because of natural buoyancy. In this respect the Dead Sea is similar to the Great Salt Lake in Utah in the United States. The Dead Sea area has become a major center for health research and treatment for several reasons. The mineral content of the water, the very low content of pollens and other allergens in the atmosphere, the reduced ultraviolet component of solar radiation, and the higher atmospheric pressure at this great depth each have specific health effects. For example, persons experiencing reduced respiratory function from diseases such as cystic fibrosis seem to benefit from the increased atmospheric pressure. The region's climate and low elevation have made it a popular center for several types of therapies:
Climatotherapy: Treatment which exploits local climatic features such as temperature, humidity, sunshine, barometric pressure and special atmospheric constituents
Heliotherapy: Treatment that exploits the biological effects of the sun's radiation
Thalassotherapy: Treatment that exploits bathing in Dead Sea water
Treatment for psoriasis
Climatotherapy at the Dead Sea is an effective therapy for patients with psoriasis, who benefit from sunbathing for long periods in the area due to its position below sea level and subsequent result that many of the sun's harmful UV rays are reduced. Treatment for rhinosinusitis
Rhinosinusitis patients receiving Dead Sea saline nasal irrigation exhibited significantly better symptom relief compared to standard hypertonic saline spray. Treatment for osteoarthritis
Dead Sea mud pack therapy has been suggested to temporarily relieve pain in patients with osteoarthritis of the knees. According to researchers of the Ben Gurion University of the Negev, treatment with mineral-rich mud compresses can be used to augment conventional medical therapy.