# Potential Possibilities of Using Peat, Humic Substances, and Sulfurous Waters in Cosmetology
## 3 Peat
### Formation and Division of Peats  
A peat bog is a type of wetlands that is poorly oxygenated with hardly permeable soil, specific vegetation (swamp and swamp-meadow plants' habitats), and organic sediment accumulation processes. It may be formed by the landfilling of aquatic environments (terrestrialization) or marshy terrestrial environments (paludification) [30,31]. Most habitats where peat is formed consist of two layers, the upper (acrotelm), oxygenated layer, in which intensive decomposition of organic matter occurs during periods of lower groundwater levels. In deeper, less oxygenated layers (catotelm), the decomposition of organic matter is slow. The boundary between these layers is determined by the level of the minimum water table in summer and is approximately 10-50 cm. According to some criteria, the minimum thickness of peat should be 20-70 cm so that a given habitat can be called a peat bog [9]. Peatlands cover approximately 4 million km\({}^{2}\), of which 3.460 million km\({}^{2}\) (around 80%) are peat bogs in the boreal and subarctic zones, and they store one-third of global soil carbon [15,16]. Almost one-third of European peat deposits are found in Finland, one-fourth are found in Sweden, and the remaining amount is found in Poland, Great Britain, Norway, Germany, Ireland, Estonia, the Netherlands, France, and Latvia [30,31]. Currently, there is no uniform peat classification system and there are different divisions depending on the scientific discipline or country. The division of peat is based on differences in topography, geomorphology, type of vegetation, and physical and chemical features [32]. The basic differences are presented in Table 1.  
Depending on the usage purposes, peat can be also characterized in numerous ways. The most important chemical and physical properties important for the environment, as well as for many areas of the economy and industry, are presented in Table 2. Water retention is a very important parameter assessing the suitability of peat and depends mainly on the content of humic acids. This parameter increases with the increase in the concentration of humic acids (in high-moor sphagnum, peat is higher) and with an increasing degree of decomposition (usually higher in low-moor sphagnum peat due to the higher content of aerobic and anaerobic bacteria and fungi) [33]. To determine the degree of decomposition (the ratio of cellulose and hemicellulose to the concentration of humic acids), a 10-point von [PERSON] scale is used, marked with symbols from H1 to H10. The higher the degree of decomposition is, the higher the value is on the scale and, thus, the better the healing properties are of the peloid. In Poland, peat with a degree of decomposition from H6 to H10 is used in medicine. This method was developed for homogeneous beats, in their natural state, fully hydrated, and originating from raised bogs. It is not used in the case of low peat, which is often silty, due to low accuracy [33; 34]. \begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{3}{c}{**Subtype of Peat Bogs**} \\ \cline{2-3}
**Features of the Peat Bog** & **Low-Moor Sphagnum Peat** & **High-Moor Sphagnum Peat** \\ \hline Water supply & groundwater, lake water & rainwater only \\ \hline Nutrients & high content & low content \\ \hline Water capacity & moderate & very large \\ \hline Plant species\({}^{\prime}\) composition & rich & poor \\ \hline Dominant ingredient & vascular plants & sphagnum mosses \\ \hline pH & neutral to acidic & strongly acidic \\ \hline Content of organic parts in dry matter & 95\% & 75\% \\ \hline Area of occurrence in Poland & 6.5\% & 89\% \\ \hline \hline \end{tabular}
\begin{tabular}{c c} \hline \hline \multicolumn{3}{c}{high water absorption and sedimentation} \\ Other & volume, high sorption properties, low \\ \multicolumn{3}{c}{thermal conductivity} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The most important features of low and high peat bogs [32].