Oxygen and skin
We actually need more oxygen today than many years ago. Why ? We just saw how oxygen was such an important element for the human metabolism and more precisely for the skin. There are no blood vessels in the outer layers of the skin. Capillaries are responsible for supplying the skin cells with nutrients. Circulation in the capillaries are at best, not very good. Prior to few facts that will be discussed in the next chapter, the capillaries become less permeable and let little or no oxygen and nutrients pass to the extracellular fluid, which surrounds the cells.

The lymph drainage system is responsible for removing the waste of the cells. To have healthy skin, the skin must be properly balanced with oxygen, water, nutrients, good capillary circulation and good lymph
drainage. The ability of skin to repair itself after injury lies in the ability to grow new vessels from the capillaries.

Leibsohn’s studies showed that the skin requires at least 7% of the normal resting, total body oxygen consumption : 4% for the epidermis and 3% for the dermis.

Many references are made in scientific literature regarding the importance of skin respiration.

Babok writes about experiments with animals. The skin of rats were painted and the animals died. Rohrig did the same with frogs. It has been shown that fatal effects were due in a large part to the lack of cutaneous respiration and not due to absorption of toxic materials.
 
Horikoshi, Bain and Carter clearly demonstrated that the growth of human epidermal keratinocytes was at its best with an Oxygen tension at 133 mm Hg when the normal human rate does not exceed 100 mm Hg.

Amersbach , Nutini and Cook have found the measurement of skin respiration a valuable dermatological tool. They discovered that in case of vitamins deficiency, the rate of skin respiration decreases.To sum up, we have to bear in mind that skin breathes ; it is the place of permanent exchange of oxygen and carbonic gas with same functions as our lungs.

Skin is very vulnerable to hypoxia (lack of oxygen) because of internal facts (biological clock, genetics..) and external facts (pollution, smoking....).
 

Pollution in the major city

Today, we cannot get enough oxygen to the cells by inhalation. Roughly speaking, even if oxygen rate is known to be efficient by 15% to 21%, a person under polluted area suffer from hyposphyxia (lack of oxygen) when the breathes air with a rate of carbon dioxide gas superior to 0.06%. Because this gas 0.09% and 0.14%. If oxygen decreases, sulfur dioxides become dangerous (causing metabolic cell disorders), nitrogen dioxide (high toxic rate for cells), hydrocarbons (cancerogenices), and particles from diesel engines (decrease of hydration).