Environmental factors and human health man, like any other kind, is part of nature and has its own particular ecological niche. This niche has three aspects - a niche space, and multi-dimensional trophic niche.
Today humanity is completely realized niche space: it populated the all suitable habitats on the planet - all continents and all terrestrial biomes. Now we want to expand this niche: the projects are settling the oceans, the North Pole drifting station work for years, expand settlements in Antarctica. Man tries to settle even outer space.
At a global scale for the species homo Sapienza already there are no natural boundaries: rivers, mountains, oceans, which are tens of thousands of years served as barriers to dispersal of other species, man overcomes a matter of hours and minutes.
In the trophic aspect of humanity is also progressing. Although, like tens of thousands of years ago, people on other parts of the food chain is either herbivorous or carnivorous by consumers, its menu has changed. For much of its history, humanity produces almost 98% of the food due to dilution of less than 40 species of plants and 8 species of animals.
However, only in the last 50 years, launched the industrial breeding of several dozen species of fish introduced into the agriculture of about 250 species of higher plants have developed technologies of industrial cultivation of about 50 species of macroscopic marine algae, more than 10 species of edible mushrooms. The share of these non-traditional objects in the human diet is over 10% and continues to grow.
Therefore, even without careful analysis shows: modern man is constantly expanding its niche sites and trophic niche. But, according to the fourth law of B. Commoner, should pay for everything. And we are already paying - reducing our multidimensional niche.
Ways to implement multidimensional niches are not obvious - they are associated with human genetic potential and its interaction with the environment. Modern molecular biology and genetics intensively trying to take control of the human genotype. In particular, it has created, tested and perfected methods of artificial animal, vegetative propagation of man - the so-called cloning, by 2005, it is planned to decipher the nucleotide sequences of all human genes (International Program Human Genome), to develop techniques for integration of any natural or artificial gene in any eukaryotic cell, including human (genetic engineering today successfully implemented in prokaryotic cells is also relatively positive results plants and animals). Moreover, in the early 90's opened a gene that at a certain age includes in the body processes the rapid aging and death - the so-called gene-killer, a suicide gene.
And already in 1997, was developed and successfully tested on animals technique of blocking. The man was a means to achieve biological immortality.
Today, in spite of all the advances, man has not yet learned to change their aims genotype, and therefore the stability boundary of his body against various environmental factors remained almost the same. For example, as tens of thousands of years ago, people are considered optimal for: air temperature 18-35 ° C and atmospheric pressure 80-150 kPa, pH 5,5-8,0 drinking water, its content of nitrates 2-15 mg / l . However, fewer and fewer habitats where these factors are within range of the optimum Rights: water low in nitrates and optimum pH is very much in the tundra or in the highlands, but the temperature and pressure in the mountains and go beyond the boundaries of the optimum. Conversely, in the plain, where the pressure and the temperature optimum, water is increasingly polluted by nitrates. Despite this, people live on the plains and in the mountains.
Here comes into play the principle of limiting factors, if any one of them is outside the tolerance range, it becomes restrictive. When the value of this factor has not yet reached the lethal limits, but it came from the area of optimum body experiences physiological stress. In our example: in the mountains - a mountain sickness, and in the plains of the high content of nitrates - general weakness and depression.
This situation reflects the discrepancy multidimensional niches and in the mountains and in the plains areas of optimum man, at least with respect to certain environmental factors.
Per person, as well as on the whole being, a particular factor affects not alone, and in concert with others, and depending on the nature of the interaction of a range of tolerance may vary. For example, when the relative humidity LP% temperature 28 ° C is the optimum area. But with 70% humidity, this is the temperature goes beyond the optimum and into the zone pessimum: accelerated breathing, there is a feeling of breathlessness and fever, depression, a person may lose consciousness.
So, health - one of the general indicators of the degree of optimality of the multidimensional niche. Most (more precisely - almost always) we do not know which of the factors of the environment at the moment is limiting, but if the population's health, nation or humanity as a whole is deteriorating, so that our multi-dimensional niche has become smaller. The scale of health changes and allow us to estimate the scale of constraints: does it only on a separate population that works in a particular area, is in-planetary.
Man is part of nature and environmental factors affect it just like any other kind. Even in the absence of human impact human health depends on a number of abiotic and biotic faktorov.Vyhod values of these or other factors beyond the range of the optimum condition worsens, reduces its stability and resistance to various diseases. Abiotic factors influencing the person in the past, and continue to influence today.
Cosmic, solar and geophysical factors.
Sun's impact on human health was seen in ancient times. However, detailed studies of this began only in the XVIII - XIX centuries. Today we know that the Sun's influence is primarily connected with the 11-year cycle of solar activity, which results in increase of the perturbation of the magnetosphere and ionosphere. Such perturbations, in turn, cause an increase in the electromagnetic field of the Earth, and this is a direct effect on the body. In the years of high solar activity, or when there are magnetic storms are becoming more frequent violations of the cardiovascular and nervous systems, mental and behavioral disorders.
Bursts of solar activity leads on the one hand, to weaken the immune system, on the other - to enhance aggression of pathogens and infections natural carriers. Consequently, the likelihood of infectious diseases, including those of the epidemic, particularly influenza, cholera, dysentery.
Another factor - the level of ultraviolet radiation. That's it for almost the entire history of the biosphere determined the frequency of mutations. In small doses of ultraviolet light is necessary for the evolution of the biosphere: mutations create genetic diversity of populations and thereby supply the material for natural selection.
For a man in small doses ultraviolet useful: it produces antiseptic and bacteriostatic effect, prevents incendiary processes in the hair bags, inhibits the growth of pathogenic fungi which cause diseases of the skin - ringworm. In large doses, UV radiation is dangerous: it is mostly deleterious mutations (so that a useful mutation accounts for approximately a few thousand deaths). Excessive exposure increases the likelihood of malignancy - cancer, sarcomas, leukemia.
Human Teratology: Environmental Causes of Birth Defects
UCSD Department of Pediatrics & the Skaggs School of Pharmacy and Pharmaceutical Sciences bring together world-renowned experts in the field of Human Teratology in a new series providing clinicians an update on the environmental causes of birth defects. In this program, Anthony Scialli, M.D., Reproductive Toxicology Center, discusses Bringing Information to the Clinician and the Public - the Pregnancy Label and Other Resources. Series: "Human Teratology: Environmental Causes of Birth Defects" [3/2007] [Health and Medicine] [Professional Medical Education] [Show ID: 12174]
