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					       It is obligatory to learn
       Ecology (Gr. oikos = home, logos=science) – the branch of biology concerned the
relationship between an organism or a group of organisms and other living things and with
their environment (organisms = biotic components and abiotic factors or conditions =
inorganic or organic matter, climate). The concept and name “ecology” were introduced by
Ernst Haeckel (1866). Defining the ecology now we should emphasize the influence of the
organisms on their environment. It is especially important from the view point of a modern
man, who is not only an element of the biosphere, but also is changes the biosphere. The
environment in the definition means a part of surrounding conditions having influence over
natality and surviving of the organisms.
       Human ecology is an interdisciplinary science. It is interested in dynamic biological
and social processes between men (individuals, populations and societies) and their
environment – natural (biosphere), social (sociosphere), technical (technosphere) and also
cultural (noosphere).
  Medical ecology is a part of human ecology. It concerns pathogenic influence of
  environmental factors or conditions in broad mind (biosphere, technosphere, sociosphere,
  noosphere) on human populations and also with the health effects of the environment

  Basic terms of ecology:

  Biosphere – the zone of the earth in which living things are found, also the global

  the sum of all ecosystems.

  Population – a collection of individuals of the same species, living in a geographic area, in

  the same region.

  Biocenosis (= community) – a collection of populations living together in specific region,

  an abiotic environment (called biotope).Components of the community (biotic
  components) include producers (autotrophs), consumers (heterotrophs – herbivores,
  carnivores, omnivores) and decomposers (heterotrophs – saprophages, saprophytes,
  detritiovores, decomposers, scavengers) forming food chains.
Ecosystem – a functional ecological unit composed of biocenosis and the environment
(biotope); a dynamic and complex whole not fully isolated from surrounding units but
interacting; functional unit in equilibrium (homeostasis), characterized by energy flow and
matter circulation.

Ontocenosis – a collection of organisms living together in organs of human organism.

                        Consumers III

                                                                   organic matter

                        Consumers I

                        Producers                           s


Fig. Diagram of energy flow in ecosystem.
Energy flow through ecosystems:

- photosynthesis – capture of sunlight energy, using water and carbon dioxide and
producing oxygen and carbohydrates; only 2% of sunlight energy is available for

- respiration – splitting carbon and hydrogen from carbohydrate and recombining them to
release energy and produce carbon dioxide and water;

- every transfer of energy results in less useful energy available;

- energy is neither lost nor gained;

- kinds of energy: chemical, mechanical, thermal.

Succession (ecosystem development and change over time):

    - a directional and predictable process of community development that involves
changes in species composition and community processes with time; the sequence of
communities that replace one another during succession, each is called a seral stage of
succession; early seral stages are pioneer stages, while the final seral stage is called the
climax community;

    - results from modification of the physical environment by the community itself; the
populations tend to modify the physical environment, making conditions favorable for
other species;

    -culminates in a stable ecosystem in which biomass and symbiotic relationships are
maximized per unit of energy flow; as succession proceeds from early seral stages towards
the climax, energy flow tends to shift from productivity (in early stages) to maintenance (in
later stages).

    Primary succession occurs on an area that has not previously been occupied by a
biotic community (such as newly exposed rock surface or volcanic island). It tends to
proceed more slowly.

    Secondary succession occurs in an area from which a biotic community was removed
(such as when a forest is clear cut). It tends to proceed more rapidly.
    The natural ecosystems, affected by humans, are changed and destroyed, devastated.
The development of human culture (“industrial revolutions”) has brought us to our current
stage of environment exploitation.
         Ecological interactions could be divided on infraspecies and interspecies
(0) indicates no significant effect on one species population;
(+ ) indicates positive effect on one species population;
( - ) ) indicates negative effect on one species population.
Neutralism ( 0 , 0 )
    -    neither population affects the other.
The antagonistic interactions
Competition ( - , - )
    -    between members of the same species for food, nesting materials, mates etc,
    -    between members of two or more species for resources (sunlight, food, habitat, etc)
Antibiosis ( 0 , - )
     -   one population affects the other by own metabolites, causing death or stopping growth of
         the other population (e.g. fungi producing antibiotics and bacteria, plants producing
         volatile oils and microorganisms)
Penicillin was the first discovered antibiotic. In 1929 Fleming noted that bacteria colonies
(Staphyllococcus aureus) around the fungus colonies (Penicillium notatum) were lysed. Fungal
metabolite, that may be used to control bacteria, was named penicillin. Later other antibiotics
produced by microorganisms were found, e.g. streptomycin, produced by Streptomyces griseus.
Now the list of antibiotics used in medicine is long. They are useful in bacterial and fungal
infections. The problem is the development of antibiotic resistance in bacterial cells.
Parasitism ( + , - )
     -   one population (usually the smaller organism) adversely affects the other, but requires the
         other population for its survival;
Parasite is an organism which exploit another organism (host) as a source of food and often
always as a surrounding of life, doing detriment to the hosts organism. The parasite does not
kill its host. Parasites can attack their hosts only in order to gain food (for instance biting
insects), or they live in the body of their host (or hosts) all his life (e.g. Plasmodium). The
organ in which parasite lives is called ontohabitat.
Predation ( + , - )
     -   one population (the predators, usually the larger organisms) is feeding on others (the
         preys) but requires the other population for its survival;
The relationship between the predator and prey are slowly evolving mechanisms that maintain
stable population levels. An increase in prey population allows increase in predator population,
which acts as negative feedback, decreasing prey population. The curves of the relationship
between the number of predator and victim show that the increase in the number of victim
always precedes the increase in the number of predators.
The protectionist interactions
Commensalism ( 0 , + )
    -   one population benefits from association but the other population is unaffected;
Most of these interactions are facultative. From the medical point of view, the important one
is the occurrence of opportunistic fungi, which normally live in various organs of our
organism, and sometimes become pathogenic.
Phoresis ( 0 , + )
    -   a fairy loose association in which one organism, usually smaller that the other, uses the
        larger organism as a transport host (e.g. flies and bacteria).
Mutualism ( + , + )
    -   both populations benefit from the mutual association;
These interactions are frequently very intimate and obligatory. Both partners derive benefits.
For instance lichen, which is composed of fungus and alga. In our intestine the bacteria
Escherichia coli, are very beneficial to us, because of vitamins B12, C and K production.
The Biosphere

       The term "Biosphere" was coined by Russian scientist Vladimir Vernadsky in 1929.
The biosphere is the life zone of the Earth and includes all living organisms, including man,
and all organic matter that has not been decomposed yet. Life evolved on earth during its
early history between 4.5 and 3.8 billion years ago and the biosphere readily distinguishes our
planet from all others in the solar system. The chemical reactions of life (e.g., photosynthesis-
respiration, carbonate precipitation, etc.) have also imparted a strong signal on the chemical
composition of the atmosphere, transforming the atmosphere from reducing conditions to and
oxidizing environment with free oxygen. The biosphere can be divided into distinct
ecosystems that represent the interactions between a group of organisms forming a trophic
pyramid and the environment or habitat in which they live. The biosphere includes:
aerosphere, hydrosphere, lithosphere and antroposphere.


       The atmosphere is the gaseous envelope that surrounds the Earth and constitutes the
transition between its surface and the vacuum of space. The atmosphere consists of a mixture
of gases composed primarily of nitrogen, oxygen, carbon dioxide, and water vapor. It extends
some 500 km above the surface of the Earth and the lower level (troposphere) constitutes the
climate system that maintains the conditions suitable for life on the planet's surface. The next
atmospheric level, the stratosphere (12 to 48 km), contains the ozone layer that protects life on
the planet by filtering harmful ultraviolet radiation from the Sun.
The aerosphere contains the lower level of atmosphere (troposphere) and a part of
stratosphere (to 22 km). Since the Industrial Revolution, man has been altering the
composition of the atmosphere by burning fossil fuels. There is growing concern about rise in
concentrations of carbon dioxide, methane, nitrous oxide, and chloroflurocarbons in the
atmosphere because these "greenhouse" gases trap heat energy emitted from the earth surface
and increase global temperatures (global warming). In addition, chloroflurocarbons cause
depletion of the Earth's ozone shield that protects the Earth surface from the harmful effects
of ultraviolet radiation.

       The hydrosphere includes all water on Earth. In one respect, the planet Earth is a
misnomer in that 71% of the earth is covered by water and only 29% is terra firma. Indeed,
the abundance of water on earth is a unique feature that clearly distinguishes our "Blue
Planet" from others in the solar system. Not a drop of liquid water can be found anywhere else
in the solar system. It is because the Earth has just the right mass, the right chemical
composition, the right atmosphere, and is in the right distance from the Sun (the "Goldilocks"
principle) that permits water to exist mainly as a liquid. However, the range of surface
temperatures and pressures of our planet permit water to exist in all three states: solid (ice),
liquid (water), and gas (water vapor). Most of the water is contained in the oceans and the
high heat capacity of this large volume of water (1.35 million cubic kilometers) buffers the
Earth surface from large temperature changes such as those observed on the moon. Water is
an universal solvent and the basis of all life on our Planet.
Links to other components: Water cycles between the various components of the Earth system
via the hydrologic cycle. Aerosphere: Water is transferred between the hydrosphere and
biosphere by evaporation and precipitation. Energy is also exchanged in this process.
Biosphere: Terrestrial plants withdraw water from the ground using their root systems and
transport water and nutrients through the vascular system to stems and leaves. Evaporation of
water from the leaf surface (called transpiration) is effective at transferring water to the
atmosphere. Lithosphere: Water is the primary agent for the chemical and mechanical
breakdown of rock, called weathering, to form loose rock fragments (regolith) and soil. By the
process of erosion, water sculpts the surface of the Earth as precipitation that falls on the land
making it way by to the sea.


       The lithosphere is the solid Earth that includes continental and oceanic crust as well as
the various layers of the Earth's interior. The lithosphear as a part of biosphear contain some
hundred meters of the Earth's interior and exterior part of the Earth. Ninety-four percent of the
earth is composed of the elements oxygen, iron, silica, and magnesium, and the interior of the
earth is layered both chemically and mechanically. The lithosphere is not static, but its surface
(crust) is in a constant state of motion that gives rise to movement of the continents.

The impact of human activities with negative influence on environment.
       Throughout history, the world’s population has expanded. Massive and still increasing
population, combined with the environmentally detrimental repercussions of industrialization
has begun to take a serious toll on our planet’s ecosystem. Overpopulation, in conjunction
with industrialization on a global scale, has led to continuingly deteriorating environmental
conditions. Such expansion has begun to affect the environment in many ways.
Human Impacts –The Aerosphere.
       The Enhanced Greenhouse Effect or Global Warming. This process occurs mainly
due to human industrialization. The excess Carbon Dioxide and other greenhouse gases
(methane and freons) being released into the atmosphere trap retain the sun’s heat, reflecting
it back to Earth. As a result, the Earth’s average temperature is gradually rising. Studies have
shown that the Earth has warmed an approximate 0.5 Celsius degrees over the past 100 years.
This number is estimated to rise to 3 degrees before the end of this century. Although this
number may seem relatively small, this temperature increase can cause significant changes in
the climate across the globe, affecting various forms of life.
       Some scientists speculate that Global Warming may lead to droughts, excessive heat
waves, forest fires, violent storms and famines. Melting of the icecaps is another concern.
Major costal cities across the globe can be flooded, or completely submerged. Many animals
that live in Arctic habitats will also be lost forever. With warmer temperatures, comes more
disease or heat related problems, appear such as heat stroke. These and many other examples
demonstrate the severity of Global Warming. Although this topic is a deep concern for
environmentalists many believe that there is no need to panic. The Greenhouse Effect is a
gradual process, allowing time for research on how to approach this problem.
       Ozone Depletion refers to the loss of stratospheric ozone due to the presence of
CFC’s (chlorofluorocarbons – mainly freons) and some carbohydrates (metan). Ozone is
broken down naturally in the stratosphere by sunlight and chemical reactions with compounds
containing nitrogen, hydrogen, and chlorine. In a normal atmosphere the ratio of ozone being
created to ozone breaking down remains fairly constant. The greatest amount of ozone is
found at an altitude of twenty-five kilometers and is known as the ozone layer. Ozone's
unique properties allow it to act as a protective layer around the Earth. It acts like a sunscreen,
filtering damaging UV rays. This layer is thickest at the poles and thinnest at the equator.
       The depletion of ozone due to human activities occurs in the stratosphere. When
chlorofluorocarbons reach the stratosphere, they break up ozone molecules. Small quantities
of CFC cause significant reduction in stratospheric ozone. Stratospheric ozone, called “good”
ozone, as mentioned above prevents harmful UV radiation from reaching the Earth’s surface.
Excessive exposure to UVB radiation may cause skin and eye irritation, may lead to skin
cancer, also is harmful for many plants important in agriculture.
       CFC were used for numerous applications (in air conditioners as coolants, for cleaning
electronic circuit boards, as solvents, in the past used as a propellant in aerosol cans).
Every year since the early 1980’s, a huge hole in the ozone layer opens up over Antarctica. A
similar thinning occurs over the North Pole. These “holes” may be responsible for increasing
rates of deadly skin cancer in recent years.
       Air pollution refers to any substance that degrades the quality of air. There are many
natural sources of air pollution (dust, volcanoes, forest fires, etc.). However, there are natural
mechanisms to reduce these pollutants (i.e. rain, wind).
       Anthropogenic (human caused) air pollution is a problem because substances are
emitted into the air faster than the natural mechanisms can eliminate them. As a result these
substances accumulate. Anthropogenic pollution contains many synthetic substances very
toxic because they interfere with living organisms. There are often no natural mechanisms to
remove them from the atmosphere.
       Primary Pollutants are substances emitted into the atmosphere that have a direct effect
on air quality, such as Hydrocarbons (benzene, toluene, etc), carbon dioxide, etc.
       Secondary Pollutants are substances that are the product of primary pollutants reacting
together in the atmosphere. (Nitric Oxides and Sulfur Oxides react with water to form nitric
acid and sulfuric acid - form acid rain and acid fogs. In this case nitric acid and sulfuric acid
are secondary pollutants).
Carbon Dioxide, Carbon Monoxide, Nitric Oxides, Sulfur Oxides, Hydrocarbons and
Particulates are the six important pollutants.
       Major source of carbon dioxide, carbon monoxide, sulfur oxides, nitric oxides, and
particulates is combustion of fossil fuels. Hydrocarbons are also produced form combustion of
fossil fuels, but their main source is the petrochemical industry (oil refineries, metal smelters,
rolling mills, plastic factories, chemical manufacturers). Sulfur oxides and nitric oxides react
in the atmosphere to produce sulfuric acid and nitric acid. The main source of both oxides is
automobiles, refineries, coal power plants. Acid precipitation causes extensive damage to both
terrestrial and aquatic ecosystems. Acidified streams and lakes undergo marked changes in
vegetation, invertebrate populations, and fish populations.
       Hydrocarbons (Volatile Organic Compounds)
In chemistry, any carbon-containing compound is referred to as organic. However, these
substances can be extremely toxic (e.g. PCB’s, dioxins, benzene, acetone, formaldehyde, etc.)
can be carcinogens – cause cancer. They may act as mutagens – cause mutation, or as
teratogens – cause birth defects. There are literally thousands of toxic organic compounds
produced by various industries.
        People living in areas near chemical plants often have much higher risk of cancer and
birth defects (so-called "cancer clusters").
        Particulates are small particles emitted into the air. Anthropogenic particulates often
contain heavy metals (e.g. lead, mercury, cadmium, arsenic, selenium). These substances
accumulate in tissues. In addition, many particulates are respiratory irritants and can cause or
increase the effects of bronchitis and asthma. Particulates are especially prevalent in urban
areas and in industrial areas.
        Ozone is a secondary pollutant when it appears near the ground (tropospheric ozone)
- it is a severe respiratory irritant – therefore tropospheric ozone is often referred to as the
“bad” ozone. Tropospheric ozone is a product of mixing of nitric oxides, hydrocarbons, and
oxygen in the presence of heat and sunlight. Conditions that favor ozone production are hot,
sunny days, when there is little or no wind. Ozone is also a component of urban smog and can
cause eye, nose, and respiratory problems in both humans and animals.

Human Impacts – The Hydrosphere.
        Any substance that degrades the quality of water causes water pollution. Many of
these pollutants are similar to the ones found in air pollution. However, water pollution is
much more complicated because we have so many different uses for water and, therefore,
there are many ways that water pollution can affect us.
        Organic Chemicals come mainly from agricultural sources and industries. Most
dangerous are carbon containing molecules – pesticides, PCB, dioxins, solvents, etc. These
substances are directly toxic to humans and wildlife, thus causing ecosystem disruption. Also,
many of these substances act as carcinogens, teratogens, or lower fertility.
        Dead Organic Matter comes from sewage, urban garbage, agriculture. It consists of
carcasses, plant and animal wastes, raw sewage and leads to high biological oxygen demand
(BOD). This disrupts aquatic ecosystems, eliminates oxygen dependant species (like fish).
Pathogens come from raw sewage and human wastes (also medical wastes) Pathogens are the
microorganisms or their byproducts which cause human diseases (cholera, typhoid, dysentery,
giardiosis, etc).
       Nutrients come mostly from agricultural sources (nitrogen and phosphorous – used to
fertilize crops). Nutrients cause “algal blooms” in aquatic systems. The end result is the loss
of all oxygen dependant species.
       Heavy Metals come from agriculture, industries, and urban run-off. Heavy metals like
mercury, selenium, cadmium, lead, and chromium have direct toxic effects and therefore lead
to ecosystem damage and human health problems.
       Acids mostly from industrial and domestic sources are directly toxic to many
organisms Some industries dump strong acids directly into aquatic systems – this leads to
ecosystem failure.
       Sediments come from construction sites, agriculture, forestry, and urban run-off.
Sediments alter energy flow through the water and alter bottom environments. Many aquatic
organisms can only live in clear waters with rocky or gravelly bottoms - sediments eliminate
these species.
       Heat comes from industries and power plants. Excessive heat from industrial cooling
water causes water to lose oxygen and eliminates any cold-water species that are present in
the system.
       Radioactivity - main sources are industries, hospitals, and medical research facilities.
Radioactive substances are extremely toxic in even very small quantities and can cause cancer
and death to both humans and other organisms.

Human Impacts – The Litosphere.
       Human negative influence on litosphere occurs mainly in its superficial layer. Soils,
their living organisms, and the plant ecosystems rooted in them, have developed in close
synchrony ever since plants evolved. Man's intervention, by cutting forests, seeding grassland
and planting crops amounts to a major shock to earth. Man's ignorance and unfriendliness
towards the soil may lead to his own destruction. It is estimated that due to man’s intervention
approximately half of World’s soil deposits are degradeted. The main reasons of soil
destruction are forest cutting, alkalization or acidification of soil, land desertification.
        Contamination of soils by lead is a major concern in many countries at the moment. It
is believed that the primary cause of the increased levels found oils is car exhaust emissions.
Although unleaded petrol has been available for some time now the lead particles still remain
from the time when lead was added to fuel as a thinner. Agriculture is an industry, which
works directly with the soil and as a result it is bound to have some effects on the make up of
the soil. The use of pesticides and fertilizers causes many implications, not only for the
environment and wildlife involved but it may also affect human activity such as drinking
water, or leisure activities like swimming and fishing. Bioaccumulation and biomagnification
of these poisons as they move along the food chain is also a major problem, which has an
influence on the whole ecosystem.
Human Impacts – Loss of Biodiversity
       Every year it is estimated that 1000 to 2000 species go extinct (3-5 species per day).
At the current rate of extinction, close to ¼ of all terrestrial plants will be extinct in 50 years.
There is debate over these numbers, though all scientists agree that the loss of biodiversity is
an extremely serious problem.
Human Impacts - Ecological Catastrophies
       Difficult to predict ecological catastrophies present another serious challenge for
biotop. Forest fires, hurricanes, volcano eruptions, draughts or floods and earthquakes are
examples of natural catastrophies.
       However a significant number of catastrophies is caused by human activities
(industrial catastrophes, nuclear explosions, terrist assaults, toxic contamination from leaking
pipes or containers, etc.). The frequency of natural catastrophies has been increasing
expotentially. For example in the nineties of the 20 th Century natural catastrophies occured 5
times more frequently than in the seventies, possibly due to global warming effect. It is
noteworthy, that developing countries are most affected by natural catastrophies. A number of
disciplines co-operating with ecology such as catastrophe medicine, rescue medicine
contribute to solve this problem.

       House is e very specific habitat for people. We can even indicate indoor and outdoor
environmental factors. According to the studies conducted in the United States adults spend at
their houses approximately 60% of a day (twenty-four hours); whereas at work and outside
buildings 25% and 2%, respectively.
       Our house can partially protect us from an unfavorable influence of abiotic factors of
biotope (temperature, moisture, solar radiation, noise, dusts and chemical pollution of air) as
well as of biotic ones (predacious, poisonous and parasitic animals and also microbe-vectors,
poisonous plants, pathogenic bacteria and fungi). Yet, it should be stressed that often there is
an important correlation between the intensity of external abiotic factors (temperature,
moisture, air-pollution with sulphur-dioxide and dusts) and indoor ones.
       Its flora and fauna, sometimes pathogenic, also characterize each house. In some
household goods (flower-vases and other utensils, heat exchangers) as well as in hospital ones
(tubes, catheters, containers) we can find living pathogenic bacteria (i.e. blue pus bacterium –
Pseudomonas aeruginosa, Vibrio cholerae, staphylococcal bacteria, Klebsiella sp.) existing in
the shape of so called biofilms. Particular resistance of organisms from biofilms towards some
chemical factors depends not only on the protective extracellular substance produced by them
and enzymes (i.e. penicillinase) but also on mutual protectionist interactions – transmission of
stimuli to reproduction and microcolonies formation, feeding with useless metabolites of
another species, etc.
       It is also important to remember that a house itself can be the source of many threats
for its inmates. We should take into consideration oxidization products (carbon oxide and
dioxide, nitric oxide, aromatic hydrocarbons) arising in heating-units, cookers and also during
smoking tobacco. Refrigerating-units can produce volatile and semivilatile organic
compounds (formaldehyde, benzene, tetrachloroethylene, chloroform, methylene chloride,
trichloroethane, carbon tetrachloride, aromatic and aliphatic hydrocarbons) as well as terpens
in other forms (limonene, pinen); insecticides, polichlorobiphenyles from different houdehold
units, furniture, paints, clothing materials and also from food. Some poisonous substances
were used in the past in paints (lead components) and in building materials (asbestos fibres).
We should also remember about noxious radiation of radon, radium and uranium, which can
be found in plasters, and walls of houses. Injuries of extremities, burns of surfaces of a body,
intoxications are the result of mechanical and chemical damages and also electrocution.
       The health and comfort problems observed among building occupants are generally
divided into two categories:
   1. Building-associated symptoms (often called sick building syndrome)
   2. Building-related illness (BRI)
       Building-associated symptoms are common and are generally nonspecific: discomfort
problems affecting the eyes, nose and throat. There are no definitive clinical tests available to
establish the diagnosis of sick building syndrome, rather building-associated symptoms are
recognized by identification of indoor air quality (IAQ) environmental problems or higher
combined symptom rates among a group of building occupants.
       In contrast, building-related illnesses are uncommon and by definition are more
serious in prognosis than mere discomfort. Physician diagnosis by clinical investigation of
symptoms is the usual means of recognizing building-related illnesses. Building-related
illnesses can have a long latent (or asymptomatic) period after exposure begins before
symptoms are experienced, such as occurs with lung cancer after indoor radon exposure.
       The three categories of building-related illnesses generally recognized are:
   1. Toxic illness
   Example: carbon monoxide poisoning
   2. Infectious diseases
   Example: Legionnaires’ disease
   3. Allergic diseases
   Example: asthma, hay fever, hypersensitivity pneumonitis
Building-related illnesses generally require a prolonged recovery time or may become a
chronic problem for the particular patient, even after removal or remediation of the building
exposure that caused the illness in the building.
       House is not only a part of biosphere and technosphere but also is a very important
compound of sociosphere and noosphere. United Nations Organization (UNO) in the
Declaration of Human Rights (1948) accepted the conception of “roof over one’s head” as
the fundamental right of each human being.
       It should be emphasized that modern house should be “ecological”, it means that it can
not be imminent over human environment – it has to secure protection from noxious indoor
and outdoor factors; it also has to be energy-sparing, it should secure the proper management
with household refuse and close relationship with human environment.

       Ecosystem of a modern man consists not only of technosphere’s factors but also of
social conditions (sociosphere). Sociosphere contains family, neighbour, social, tribal,
nationalistic and even national ties as well as the activity of public organizations, urbanization
and professional factors, security issues, economic activity. We can not also ignore the
significance of cultural factors (noosphere) i.e. educational and scientific activity, economical
and legal opinions, achievements of computer science, role of health care, artistic
creativeness, recreation, meaning of political, ethical, religious opinions, etc. All those factors
make the macroecosystem of a human being of the 21st century multidimensional.
       Town is the specific kind of anthropogenic “ecosystem” of a civilized man. According
to the UNO’s criterion we can talk of a town if it has over 20 thousand inhabitants. This
particular environment is characterized by the predominance of factors associated with
technosphere. It is also characterized by the specific flow of matter and energy. Within the
area of a town we can notice lower intensity of solar radiation, higher mean temperature,
lower moisture, weaker winds, greater cloudiness and precipitation. The environment of a
town has also other specific features such as: greater intensity of noise, magnetic fields,
vehicular traffic and nights’ lighting.
       All the above-mentioned factors can have an influence on animals’ population
(changes of feeding period and reproductive cycle, degradation of unions, reduction of
variety) as well as on some disturbances in plants (changes in vegetation cycle, expansion of
xerophytes, occurrence of parasites, reduction of variety). Among the area of a town we can
find even greater density of invertebrates and vertebrates than in natural conditions.
       The influence of anthropopressure is particularly intensive in the environment of a
town with all unfavourable effects of this activity towards human population, animals and
plants (urbicenosis). In town, the death rate of human population is usually higher than in
surroundings. Tuberculosis, cardiovascular diseases due to atheromatosis, hepatic cirrhosis,
lung cancer, allergic diseases and others occurs more often in town. It should be emphasized
that so-called civilization-related diseases (cardiovascular and nervous system disturbances,
cancers, some intoxications – occupational and drug poisoning, results of communication
accidents) concern approximately 70% of urban population in Poland.
       Prospects of further developments in medical ecology and anthropogenic
activities, favourable to biosphere, ecosystems, and human populations, seem to be
prosperous. Efforts of numerous institutions and ecological organisations (in Poland the
number of organisations declaring ecological objectives amounts to some 700, including the
Polish League for Nature Conservation with 700 thousand members) have made so far the
public aware of human and human environment ecology issues as well as have stimulated
activity of competent international and national authorities. Now, on the verge between 20 th
and 21st centuries, bearing in mind Goetel’s* maxim, “what technology spoiled, technology
should repair” – I would also add “and science” – we can expect unbelievable achievements
of technology and science.

       The above relates well to emerging era of nanotechnology. This technology can
construct devices of 10-9 m in size, e.g. molecular “forceps” made of DNA molecule that are
driven by the energy of the fissure of the molecule bonds, nanoinjector of a few nanometres in
diameter enabling insertion of genes into a cell, an “engine” as small as a virus, driven by the
energy of ATP and reaching the speed of 8 rpm, molecular transistors – those recently
developed are 20 nm in length and have gates consisting of three-atom layers – and even a
processor that will be constructed of almost 1 billion nanotransistors of switch rate of
1.51018 per second, supplied by electric tension below 1 V. Some of the devices will be able
to self-replicate. There are designed nanorobots for rapid diagnostic tests, performing some
special surgical operations, delivering drugs inside the patient organism into unreachable so
far areas, according to a prescribed programme, nanodevices removing impurities at
molecular level and destroying viruses and bacteria or neoplastic cells.

       Generally, atom represents the limit of nanostructures as a creation of smaller
structures would require elemental transformation. So-called quantum dots (crystals of some
hundreds atoms) attached to particles of medical significance enable tracing their performance
in organism from emission of radiation at a given wavelength. A transistor based on a single
electron move has been constructed. In other words, control over a single electron has been

       The studies in this field are so advanced that one can say of a new discipline –
nanomedicine. Countries of high scientific creativity (e.g. Japan, USA, Germany, United
Kingdom, France) set aside almost 1 billion dollars a year for such studies.

       * Goetel Walery (1899 – 1972) – Polish geologist, traveller, activist for nature conservation.
  A significant advance in targeted synthesis of new drugs, molecules with specific atoms, of
  a given geometry and a system of orbitals has been done. This was achieved by computer
  simulation, which requires machines of extremely high computational power. Such
  machines are being predicted by nanotechnology. Recently crystallographic model of
  abnormal protein from neoplastic cells in chronic myeloid leukemia was obtained with use
  of computer. As a consequence – for the first time, following many attempts – was
  matched an active, with possibly most correlated structure, chemical compound (STI-571)
  that proved to be an effective drug at early stage of the disease (at later stages some
  patients produce drug-resistant mutations of neoplastic cells).

  Complex electronic neural networks are another significant achievement of science and
  technology. They process and even produce new programmes. Numerous converters and
  integrated circuits connected at random create complex systems displaying surprising
  properties of “artificial intelligence”. They show ability to learn and self-regulate while
  existing without a programme and network database. They represent models to simulate
  and analyze biological systems – from organism to ecosystem and biosphere. An example
  is cyber-ecosystem Tierry in which computer programmes bearing properties of organism
  undergo mutations and evolve into a variety of programmes including those using
  instructions of adjacent ones (“parasites”) or those simplified that replicate by groups with
  own instructions.

  It appeared possible to convert the signals from cat visual thalamus cells in the way the
  image seen by cat (human face) was displayed on the screen, what gives a prospect for
  producing “replaceable parts” for human brain and even constructing electronic
  connections to operate a machine with thoughts. Successfully alterations were converted in
  potential of brain cortex in a paralyzed patient, whose images, move with his hand or leg,
  into a code understandable for computer to shift a cursor indicating proper letters on the
  screen. Spacecraft technologies helped to build artificial heart (fuel pumps rule) and
  devices for fast tests (body temperature for 2 s, blood analysis for 30 s).

       An advance in renewable (power of wind and water, processed wastes, energy of the
Earth interior and oceans, improved use of solar radiation) and even new energy sources
arrangement can be expected. Silicon nitride was obtained, which - combined with oxygen or
nitrogen - can represent a safe, easy to store and transport source of energy that can easily be
used in power stations not producing carbon dioxide but sand as a result of use.
       Thanks to biotechnology and genetic engineering many new varieties of plants with
expected properties and higher crops volume have been obtained. In the European Union they
account for 60% of foods (such products should be marked as GMO). Cultivable plants able
to assimilate nitrogen from air (about 30 genes) as well as transgenic trees of fast and
extensive growth in wood mass are planned to be created. Some races of breeding animals
have been saved from extinction. A transformation of malarial anthropophilic anopheles’
strain to zoophilic one safe to humans is underway. A gene coding a toxin active against
trypanosoma causing Chagas disease was built-in into the genome of bacteria inhabiting the
alimentary tract of hemipteran, which carries these protozoa. Also, genome of gnats was
modified to prevent them from transmission of yellow fever to humans. Methods to avoid
development of microbe resistance to drugs are planned as well as ways to use bacteriophages
against bacteria harmful to humans. Experiments on production of human organs in transgenic
animals for xenotransplantation are carried out. Cultures of maternal cells which can
transform to some human cells or tissues were obtained. Insulin and a vaccine against virus
hepatitis B, both obtained by genetic engineering, are applied in medicine, also in Poland.
Successful attempts to “teach“ dendritic cells to recognise neoplastic proteins are reported.
Encouraging are prospects of use monoclonal antibodies in medicine. Introduction of
appropriate gene into patients suffering from the absence of protein coded by this gene is
planned (partial success was achieved in haemophilia).

       Biotechnology and genetic engineering not always have positive results. Introduction
of toxin Bt (Bacillus thuringiensis israelensis) gene into maize for controlling its pests
appeared to be fatal for other insects present in the environment. Safety of GMO product has
not been proved nor denied. Greenpeace representative (2001) protested against introducing
transgenic organisms to the environment since genetic engineering deemed them “pieces
containing DNA” and results of such action are irreversible, fixed and bear unknown risk. The
lack of harmful evidence does not mean the safety for consumers and environment. More
attention is paid to troubles in growing such plants – the necessity to purchase approved seeds
every year, intensity of culture resulting sometimes in environment degradation, decrease in
biodiversity, pollution of ecosystem with new genes (hybrids of transgenic mustard, oat or
maize with related weeds have been detected). An allergic action of new proteins from food
should also be borne in mind. The same is true for possibility of transmission of antibiotic
resistance genes to bacteria inhabiting the alimentary tract. The Polish law (2001) - more strict
than in the European Union - established the obligation of obtaining a permission for any
researches conducted in genetically modified structures.

  There are also objections against creating animal-human chimeras - no matter the purpose,
  including organs (heart, liver, kidneys) transplantation. In the USA opponents of
  “anthropoanimals” applied for patent protection of chimeras in order to prevent their
  creating. Some states (USA) put in force the law forbidding reproductive or therapeutic
  cloning (obtaining maternal cells from several-day human embryos) whereas in the UK
  therapeutic cloning is permitted. An infection with prions and viruses as a result of
  xenotransplantation of transgenic organs in human is emphasized. In Poland one should
  take into account the necessity of harmonization of the applied and medical ecology law to
  the law of the European Union.

  The Universal Declaration on the Human Genome and Human Rights unanimously
  adopted by the member states of UNESCO (1997) emphasizes the fact that human genome
  represents the foundation of humankind unity, dignity and diversity. None of genome
  investigations or their use in contradiction to human dignity can be considered as more
  important than human rights and fundamental freedoms. The International Bioethics
  Committee of UNESCO contributes to the promotion of the rules of this declaration and
  the studies of emerging issues.

  Summing-up results and opportunities of present-day medical ecology, it is worth bearing
  in mind not only the fact that every day some dozens of species become extinct irreversibly
  but also that every 8 seconds a child dies from drinking contaminated water and one out of
  three suffers from malnutrition. According to the recent estimations our health depends in
  5-10% on genetic factors, in 10-20% on medical care, with the rest remaining for the most
  important: conditions of our biosphere, sociosphere, noosphere, and technosphere. Thus, I
  am of the opinion that the guideline for medical ecology functions in view of human and
  his environment should be: “not to damage to not repair”.