For beginners, here is a link to that material and I advise you to look through it and read the comments from him in order to understand the dependence on which we will build on.
The first thing I would like to say is that it is not necessary to consider the material from the point of view of one binary logic, where there are only two values (true, false), here, in conditions of uncertainty and in the absence of some data, reasoning from the point of view of fuzzy logic is more suitable .
Go!
Seasonality and Vitamin D
Let's go back to the Northern and Southern Hemispheres of the Earth (Fig. 1). This strict division into hemispheres is conditional and the transition from one to the other (in terms of climate, flora and fauna) is smooth, as in Fig. 2 with thermal belts.
Fig 1. Territory of the Northern Hemisphere (highlighted in yellow) and the Southern Hemisphere
Fig 2. Thermal zones of the Earth The
world is complexly arranged almost two hundred independent states, some are located on islands and do not have land borders with neighbors, some, on the contrary, not only border on many, but they are also transit, through which many transport routes pass. Almost every state faced the coronavirus pandemic, somewhere they took strict quarantine measures, closed their borders, isolated themselves, somewhere they took it easier, and in some places they did not accept anything at all, Therefore, in such a situation, when it is difficult to describe this whole system with intertwining continents , states and various measures taken by them helps to simplify this model.
The simplification is to consider this model of the World as divided into two hemispheres, and with such a division, we will see how the spread of the coronavirus immediately aggravated exactly with the beginning of the autumn-winter season in each hemisphere, and slept already in the spring and summer. And if you look in particular, it is clearly seen in the extreme countries that are farther from the equator (therefore, last time we chose Australia, South Africa, Argentina, Great Britain, Canada and Russia).
Seasonality is obvious, people still do not fully understand that they have awakened a new "flu" , more infectious and deadly. Perhaps in one of the following materials I will tell you how influenza and coronavirus are similar.
The seasonal wave has a seasonal beginning (autumn-winter), a distinct period, an increase in infections, a plateau and a decline. Separate local in time and space waves are just flashes. Therefore, the spread of the coronavirus pandemic should be considered in the context of the full period (seasonal cycle), and this is the first wave in the Southern Hemisphere (March-August) and the second in the Northern Hemisphere (September-?). The first wave of the Northern Hemisphere (after the outbreak in China) was not a complete period and came at the end of the winter season, so in some places it did not even have time to reach the plateau and was suppressed by various measures within the states.
Now you often hear that coronavirus infection is more easily tolerated by people with sufficient levels of vitamin D in the body and there seem to be different studies of scientists on this topic, but so far I have not seen a single work in which they somehow connected geographical, cultural, physical and other features and predicted the seasonality of this virus. All these studies are almost the same, and they were done after the fact, that is, people got sick, did tests, someone suffered easier, someone harder, and someone did not transfer it at all, they collected this data, counted and posted - that's all the work!
There are no general tests for vitamin D, perhaps these researchers are therefore unable to find a connection ...
Spain, Italy ... And Uzbekistan.
In the comments to that material, these countries were touched upon, so I will disclose here in more detail.
The more you study this topic, the more discoveries for yourself. Surprisingly, it turned out that a large percentage of the population of the Mediterranean Sea and southern countries in general lacks vitamin D in the body, while having more than 300 sunny days a year outside the window. Each country has its own characteristics of this phenomenon, somewhere it is a siesta (extended lunch break), somewhere it is the widespread use of sunscreen (more than 90% protection from ultraviolet radiation), somewhere traditional clothing (in the countries of the East, where they wear closed clothes), and in some places even gastronomic features (it turned out that tomatoes protect from ultraviolet radiation).
But there is also a common thing is skin phototypes.
Fitzpatrick Scale or Fitzpatrick Skin Phototype Scale, also Fitzpatrick test, is a numerical scale based on the classification of human skin color.
Fig 3 Skin phototypes according to Fitzpatrick
Fig 3.1 Skin phototypes according to Fitzpatrick
Classification of skin phototypes according to Fitzpatrick:
- Celtic. People of this phototype have the lightest skin tone. They almost never tan (their skin does not accept tanning), the risk of sunburn (burning) is very high.
- Light European. This type of skin is also characterized by a light complexion and high sensitivity to UV radiation. The risk of burnout is great, as in the previous case. However, the light European skin phototype is slightly tanned.
- . , . .
- . - . – . .
- -. . . .
- . . . .
The phototype determines the amount of time a person can spend in the open sun without the risk of sunburn.
That is, the darker the skin of a person, the more time and more power of solar radiation it needs for the body to start the mechanism for producing vitamin D.
Now let's move on to the next dependence. Various foreign sources report that in the West, increased morbidity and mortality from coronavirus is observed among blacks (and in general among southern migrants).
And the main conclusion is that all this is due to class inequality. But the matter is possible in something else ...
Fig 4. Map of the World by the level of solar insolation
Here we recall the Fitzpatrick scale, look at Fig 4.the world map by the level of solar insolation for the region in which the Negroid race was formed (Africa) and the region in which some of its representatives live now (USA, Canada, Europe) and we understand that people of this phototype the skin in these latitudes is chronically lacking in sun, and with it, as a result, vitamin D in the body.
The medal has two sides, if one side of the US medal is with African Americans and a chronic lack of sun for their skin type, then the second is Australia and New Zealand, where the majority are white Europeans with an excess of sun for their skin type and, as a result, Australia and New Zealand are one of the leaders in the number of melanoma diseases.
To be continued…