# Cosmeceuticals and Thalassotherapy: Recovering the Skin and Well-Being after Cancer Therapies
## 4 Thalassotherapy for Improving Well-Being and Post-Onology Recovery
### Sea Water: Effects on Skin  
The composition of seawater is similar in all oceans and seas, with variations in component concentration. Table 1 shows the average composition of seawater in the world, expressed in mg/L [127]. Seawater is very well known for its curative effects in the treatment of skin diseases such as eczemas, dermatoses, psoriasis, respiratory problems such as nasopharyngeal inflammations, gynecological diseases such as vaginitis, and other infections of the external genital organs. For skin care, it has been used as a moisturizing agent; it also regularizes the sebaceous production, avoiding the consequent formation of scaling of the scalp (dandruff). It is worth to mention the important role of seawater in the absorption of saline and metallic ions, favoring the excretion of toxic residues and a certain oxygenation of tissues [98]. Seawater has been shown to have important effects on skin hydration and regeneration, although there are few scientific studies, since mostly estimonials are available. Most of the studies focus on the hypersaline water of the Dead Sea; a few of them examine the seawater of the Atlantic coasts and others do the deep seawater. From the studies of the last ten years, those carried out by [PERSON] et al. [128; 129] deserve to be cited. In the first study, the effects of sea water and its main components on experimental irritant contact dermatitis induced by sodium lauryl sulphate (SLS) cumulative irritation were investigated, and it was concluded that the effect of sea water may be attributed to skin barrier preservation by NaCl and KCl, and an embilient effect by NaCl [128]. In the second study, the effects of three types of mineral water with NaCl and KCl with different concentrations (500 nM NaCl + 10 nM KCl; 250 nM NaCl + 10 nM KCl, and 250 nM NaCl + 50 nM KCl) were studied in order to assess the most effective water concentration to prevent disruption of skin barrier. The authors suggested that mineral \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Worldwide Average** \\ \hline Chloride, Cl\({}^{-}\) & 18,980 \\ Sodium, Na\({}^{+}\) & 10,556 \\ Sulphate, SO\({}_{4}\)\({}^{-2}\) & 2649 \\ Magnesium, Mg\({}^{+2}\) & 1272 \\ Calcium, Ca\({}^{+2}\) & 400 \\ Potassium, K\({}^{+}\) & 380 \\ Bicarbonate, HCO\({}_{3}\)\({}^{-}\) & 140 \\ Bromide, Br\({}^{-}\) & 65 \\ Borate, H\({}_{2}\)BrO\({}_{3}\)\({}^{-}\) & 26 \\ Strontium, Sr\({}^{+2}\) & 13 \\ Fluoride, F\({}^{-}\) & 1.0 \\ TDS & 34,482 \\ \hline \hline \end{tabular} (TDS: Total Dissolved Solids).  
\end{table} 
Table 1: Seawater composition: major ion concentration (mg/L) in seawater around the world. water with 250 mM of NaCl and 50 mM of KCl may be useful as adjunctive therapy in atopic dermatitis and other chronic dermatitis [129]. Bathing in the Dead Sea waters (with an average concentration of 280 g/K) has been extensively studied: magnesium salts are known to bind water, influence epidermal proliferation and differentiation, and enhance permeability barrier repair [130]. In a study by [PERSON] et al. [131], immersion in magnesium-rich salt solutions from the Dead Sea was investigated (Mavena(r) Dermaline Mg Dead Sea). The experiment consisted of 15 min bathing in a solution containing 5% Dead Sea salt daily for 6 weeks; transepidermal water loss (TEWL), stratum corneum hydration, and skin redness in atopic dry skin (xerosis) were measured, concluding that bathing with Mavena(r) Dermaline Mg Dead Sea salt solution, owing to its high content of magnesium ions, enhanced stratum corneum hydration, improved skin barrier function and reduced skin roughness and inflammation [131]. On the other hand, as has been mentioned, in recent years, the effect of deep-sea water on different skin disorders has been studied. A study in NC/Nga mice model carried out by [PERSON] et al.