11.

Sick building syndrome

The term "sick building syndrome" has come into vogue during the past
several years and refers to a range of occupant complaints and illnesses.
Poor quality indoor air is believed to be responsible for a substantial part of
the sick building syndrome that has been reported, but the indoor
environment is extremely complex and other factors also undoubtedly
contribute to the problem. Thermal conditions, such as temperature and
humidity, and microbial agents such as dust mites, can produce sick building
syndrome symptoms in the occupants of buildings. Inadequate fresh air
supply and uncomfortable conditions can be found in naturally ventilated
buildings which often receive less fresh air, and certainly less filtered air,
than mechanically ventilated structures.
Sick building research has identified a number of physical and chemical
factors that may combine to create an uncomfortable indoor environment.
The removal of a single pollutant or pollutant source will do little to reduce
the incidence of sick building syndrome if, as is so often the case, the causes
of sick building syndrome are multifactorial ar\d probably synergistic.
As sick building syndrome is unspecific, it can be argued that the
assessment of sick building syndrome symptoms reflects mainly the general
tendency to complain. It is evident that it is necessary to increase the
outdoor air supply in the indoor of buildings, to minimize the exposure to
indoor pollutants that might induce symptoms compatible with sick
building syndrome furthermore building materials, building constructions
and indoor activities should be selected on the principle that the level of
■indoor air quality should be the best or the concentration of lnegative
agents should be as low as reasonably achievable.

12. Industrial Smog

Industrial smog consists mostly of a mixture of sulphur dioxide and
suspended participate matter including a variety of solid particles and
droplets of sulphuric acid formed from some of the sulphur dioxide These
substances form a graysh haze explaining why cities where this type of
smog predominates are sometimes called gray air cities This type of air
pollution tends to predominate during the winter (especially in the early
morning) in older heavily industrialized cities like London Chicago which
typically have cold wet winters and depend heavily on coal and oil heating
manufacturing and producing electric power.
 13. Photochemical smog consists of a mixture of primary pollutants
such as carbon monoxide nitric oxide and secondary pollutants such as
nitrogen dioxide nitric acid ozone hydrogen peroxide PANS and formaldehyde
produced when some of primary pollutants interact under the influence of
sunlight Cities in which photochemical smog predominates usually have
sunny, warm, dry climates. They are generally newer cities with few
polluting industries and where large numbers of motor vehicles are the
major source of air pollution.
Examples include Los Angeles , Sydney, Buenos Aires.
This type of smog tends to occur in summer monts between noon and 4 pm.
The first step in the formation of photochemical smog occurs during the
early morning traffic rush hours when NO from automobiles builds up and
reacts with O2 to produce NO2, a yellowish brown gas with a pungent
shocking odour.

17. Increased Global Warming from the Greenhouse Effect

The average temperature of the earth's atmosphere is maintained by a
system in which the amount of energy the earth absorbs from the sun
primarily as visible and ultraviolet radiation is balanced by the amount
radiated back into space as degraded infrared radiation or heat (Fig. 4.4.a)
Carbon dioxide, water vapor and other gases such as ozone in the
troposphere, methane, nitrous oxide and CFCS play a key role in this
temperature regulation process (Fig.4.5.b). These gases, known as
greenhouse gases, acting somewhat like a pane of glass in a greenhouse, let
in visible light from the sun but prevent some of the resulting infrared
radiation or heat escaping and reradiate it back toward the earth's surface.
The resulting heat build up raises the temperature of the air in the lower
atmosphere, a warming action commonly called the greenhouse effect If
there were no greenhouse gases in the atmosphere, the earth would be a
cold and lifeless planet with an average atmospheric temperature of -18°C.

18. Stability conditions

The degree of stability of the atmosphere must be known if we wish to
estimate the ability of the atmosphere to disperse pollutants received from
man-made sources.
Consider a parcel of air at some given altitude, ft has the same temperature
and pressure as the air surrounding it. Our test for atmospheric stability will
be based on the following thought: experiment. If we imagine raising the
parcel of air slightly, it will experience less atmospheric pressure, so it will
expand.
The internal energy in the parcel will be reduced so its temperature will
drop. Assuming the parcel is raised fast enough to be able to ignore any
heat transfer between the surrounding air and the parcel, the cooling will
follow the adiabatic lapse rate.
19. Temperature inversions
Temperature inversions represent the extreme case of atmospheric stability,
creating a virtual lid on the upward movement of pollution. There are several
causes of inversions, but only two of major importance from an air quality
standpoint.
Subsidence inversions are associated with high-pressure weather systems,
known as anticyclones. Air in the middle of a high pressure zone is
descending, while on the edges, it is rising. Air near the ground moves
outward from the centre, while air aloft moves toward the centre from the
edges. The result is a massive vertical circulation system. As air in the
centre of the system falls, it experiences greater pressure and is compressed
and heated. As is often the case, this compressive heating warms the
descending air to a higher temperature than the air below, whose
temperature is dictated primarily by conditions on the ground. The result is
an inversion, located anywhere from several hundred meters above the
surface to several thousand meters, that lasts as long as the high-pressure
weather system persists.
Since subsiding air is getting warmer, it is more and more able to hold water
vapour as it descends. Without sources of new moisture, its relative
humidity drops; thus there is little chance for clouds to form. The result is
that high-pressure zones create clear, dry weather with lots of sunshine
during the day and clear skies at night. Clear skies allow solar warming of
the earth's surface. This helps create superadiabatic conditions under the
inversion during the daytime and, hence, good mixing. At night, the surface
can cool quickly by radiation, which may result in a radiation inversion
located under the subsidence inversion.

22. What are radioactive substances?

Radioactivity is produced by the spontaneous decay of the isotopes of some
elements whose nuclei are unstable. The radiation can take a number of
different forms .In some cases it is as particles and in others it is
electromagnetic. Five types of radiation may occur: alpha and beta particles,
neutrons, gamma rays and X-rays. An alpha particle is large, consisting of
two neutrons and two protons, whereas a beta particle is an electron.
Gamma and X-rays have no mass. Radio waves, infrared light and ordinary
light are nonionizing electromagnetic radiation, which does not have enough
energy to cause ionization of atoms in living tissue. Although X-rays are a
form of high-energy ionizing radiation that can pass through the body and
cause damage, they are not given off by radioisotopes. The most common
form of ionizing electromagnetic radiation released from radio-isotopes is
high-energy gamma rays, which are more penetrating than X-rays.
The rate at which a particular radioisotope spontaneously emits one or more
forms of radiations is usually expressed in terms of its half-life:the length of
time it takes for half the nuclei in a sample to decay by emitting one or more
types of ionizing radiation and change into another non radioactive isotope.

23. Nuclear fusion is a nuclear change in which nuclei of certain heavy

isotopes with large mass numbers such as uranium-235 split apart into two
lighter nuclei, known as fission fragments. This process also releases more
neutrons and energy.
the 2 or three neutrons produced by each fission can be used to fssion
many additional uranium- These multiple fissions taking place represent a
chain reaction that releases an enormous •amount of energy.
Nuclear fusion is a nuclear change in which two nuclei of isotopes of light
elements such as hydrogen are forced together at temperatures of 100
million to 1 billion degrees Celsius until they fuse to form a heavier nucleus
with the release of energy. because such high temperatures are needed to
force the positively charged nuclei to join together, fusion is much more
difficult to initiate than fission. But once initiated, fusion releases far more
energy per gram of fuel than fission. Fusion of hydrogen atoms to form
helium atoms is what takes place in the sun and other stars.

26. What can we do with radioactive wastes? (storages of radioactive

wastes )
The long-term safe storage or disposal of high-level radioactive wastes is
believed to be technically possible. However it is essentially impossible to
establish that any method will work over the thousands of years required
before the wastes decay to safe levels. Some of the proposed methods are:
1. Bury it deep underground .The favorite methods is to concentrate the
waste, convert it to a dry solid, fuse it with glass or a ceramic material, seal
it in a metal canister and bury it permanently in deep underground salt,
granite or other stabile geological formation that are earth-quake-resistant
and waterproof. Some geologists question this approach, arguing
that extensive drilling and tunneling can affect such rock structures and
present geological knowledge is not sufficient to predict the paths of ground
water flows that could contaminate ground water drinking supplies with
radioactive wastes.
2. Shoot it into space or into the sun. Even if technically feasible, costs
would be very high and a launch accident of a space vehicle could
disperse high-level radioactive wastes over a wide area of the earth's
surface.
3. Bury it under the Antarctic ice sheets. The long-term stability of the ice
sheets is unknown and it could be destabilized by heat from the wastes;
retrieval would be difficult or impossible if the method failed.
4. Dump it into downward deep ocean bottom sediments. The long-term
stability and motion of those sediments are unknown and wastes could
eventually be spewed out somewhere else by volcanic activity; waste
containers might leak and contaminate the ocean before being carried down;
retrieval would probably be impossible if the method failed.
5. Change it into harmless or less harmful isotopes. Presently there is no
known way to do this, even if it should become technically feasible, costs
would probably be extremely high and new toxic materials and lower-level
radioactive wastes created would also require safe disposal.

27. The peculiar case of radon gas

Radon-222 is an invisible, odorless, naturally occurring radioactive gas
produced by the radioactive decay of radium-226, a by-product of the decay
of uranium-238. Small amounts of radon-producing uranium-238 are found
in most soil and rock. But it is much more highly concentrated in
underground deposits of uranium, phosphate and granite rock. When radon
gas from such deposits percolates upward to the soil and is released
outdoors, it disperses quickly in the atmosphere and decays to harmless
levels. When the gas is released inside mines or seeps into buildings or
water in underground wells over such deposits, it can build up to high levels.
Radon-222 gas itself is not a threat because when inhaled it is promptly
exhaled or carried away from the lungs by the blood.

28. Sources, types and effects of water pollution

Water pollution Is any physical or chemical change in surface water or
groundwater that can adversely affect living organisms. The level of purity
required for water depends on its use. Water too polluted to drink may be
satisfactory for washing steel, producing electricity at a hydroelectric power
plant, or cooling the stem and hot water produced by a nuclear or coal-fired
power plant. Water too polluted for swimming may not be too polluted for
boating or fishing.
For purposes of control and regulation it is convenient to distinguish between
point sources and nonpoint sources of pollution from human activities. Point
sources are those that discharge pollutants, usually through pipes, ditches
and sewers into bodies of water at specific locations. Examples include
factories, sewage treatment plants (which remove some but not all
pollutants), electric power plants, underground coal mines, oil tankers.
30. Physical proprieties of sound [noise pollution]
Most urban dwellers are regularly exposed in their neighbor-hoods and jobs
to levels of noise that interfere with communication or sleep.
Workers who run a high risk of temporary or permanent hearing loss include
weavers, riveters, bulldozer and jackhammer, mechanics, bar and night-club
employees.
Noise is often defined as an unwanted sound. To gain a satisfactory
understanding of the effects of noise, it would be useful to look briefly at the
physical properties of sound.
The sound is a succession of small and rapid variations of pressure around
the atmospheric pressure and it has a constant speed. The sound is
characterized by two dimensions: level and frequency. The level of sound
pressure is the important factor, which describes the relative force of the
sound. It is measured in decibels (dB), which is a ratio of the sound pressure
and a sound pressure of reference. The frequency characterizes the height of
the sound. It is measured in Hertz (Hz) = the number of cycles of pressure
in a second. But when we talk about a noise, which is an unpleasant sound
we don’t consider it like a physical phenomenon, but we take it into account
of its results on man. The results like fatigue or lesions of hearing depend
on a third factor : the period of noise.

31. The presence or absence of buildings, the geometry of Spaces,

the human scale of architecture and relationships between spaces and
buildings and feelings of security and community, all take their cue from the
shape, form and quality of the built environment. The quality of the built
environment is determined by the quality of the spaces between buildings
and the opportunities for interaction with others in the spaces that separate
buildings and give cities their distinctive qualities.
The built environment is a result of a number of social and economic
processes that are central to, and determine the rate at which we proceed in
the direction of sustainable development^
The attention for sustainable building started to grow about 20 years ago,
mainly due to the increasing need to save energy. The oil crisis in the
beginning of the seventies was an important turning point. From that
moment onwards, governments started to be actively involved in energy
saving. In a later stage, the increasing environmental awareness led
to durable building projects and legislation.

32. Definition of sustainable development is that of the Brundtiand

Report (WCED 1987): "development the meets the needsof the present
without-compromising the ability of future generations to meet their own
needs." The Brundtiand Report went further in trying to establish meaning:"
in essence, sustainable development is a process of change in which
exploitation of resources, the direction of investments, the
orientation of technological development and institutional change are all in
harmony and enhance current and future potential to meet human needs
and asp/ration. sustainable development does require a sustained
economy/Taut this, has to be achieved while sustaining the environment.
Pollution managers are key individuals at this interface between economic
activity and a sustainable environment.

34. The impact of the construction activities

Construction activities can have a serious effect on the environment. The
first of these is the impact on land-use, every construction project on a
green field site takes land away from other activities. Construction involves a
modification of the land on which the item is located. Second, construction
uses a large amount of natural resources, many of which are non-renewable
generally, construction materials are being used at unsustainable rates.
Another issue relating to the use of construction materials the amount of
avoidable waste generated. Third, construction leads to a high level of
energy consumption. Much of this is accounted for by the extraction and
processing of materials. Some metals used in construction, such as
aluminum, steel and zinc, as well as plastics are highly energy intensive.
Smaller amounts of energy are used in transporting the materials to the
construction sites and in their installation during site processes. Moreover,
with the completion of every new constructed item, additional demands are
put on increasingly scarce energy and water supplies. The final major
environmental consequence of construction activity worth highlighting here
is its contribution to air pollution. Particles of various sizes, some of which
are harmful to humans, are released in the production and transportation of
materials such as cement products.

36. Possible solutions to incorporate sustainability in building:

1. Reduction of non-renewable materials consumption:
> reduction of wood consumption;
> materials life-cycle analysis.
2. Reduction of non-renewable energy consumption:
> use of materials with low embodied energy;
> use of simple assemblage systems;
> use of passive solar design technologies;
> collection and filtering of rainwater for domestic use;
> collection and treatment of sanitary wastes for the production of
methane gas and fertilizers.
3. Reduction of construction costs:
> use of locally available materials (reduction of transp. costs);
> use of "humble" building techniques (reduction of costs).
4. Minimization of impacts on air: > use of non-polluting mat.
5. Improvement of the human well-being in buildings:
> use of low voltage current generation systems .
6. Reduction of construction waste production:
> ordering of products with minimal packaging;
> ordering of products in fixed dimensions;
> reuse of excavated soil.
7. Reduction of demolition waste production:
> pre-selection and registration of waste materials;
> "in-situ" separation of waste materials;
8. Minimization of impacts on soil: > previous specification of areas for
the storage of materials;
> minimization of deforestation;
> minimization of soil disturbance caused by excavation;
> minimization of access roads construction.
9. Protection of impacts on water courses:> deviation of waste water
and collection into absorption trenches.
10. Minimization of impacts on air:
> use of non-polluting materials.

37 . Alternative Energy Resources

So much progress in the technologies for producing energy
, from renewable sources has been made over the past years that . some of
them can now complete with traditional energy technologies and others are
coming close to doing so. The
potential, over the next years, for the use of renewable resources is
considerable.
If the full range of energy efficiency measures were introduced then
renewable could supply all the energy needed. Wind, water, photovoltaic and
biogas could be fuel electricity production, and solar energy, biogas and
solar hydrogen could meet all other energy requirements.

39. Intelligent Buildings

The intelligence of a building is manifesting itself during the construction,
realization and exploitation.
Three main characteristics of intelligent building are the following:
> ecological building- is a healthy building for all its occupants;
> solar or low-energy building- the exploitation of the1 building is highly
economically effective;
> building with automatic service control- optimization is based upon both
ecological and energetic criteria for creation of artificial environment.
Architecture of the building is characterized by many factors
as: its function, aesthetics, economy and engineering.
Characteristic features of intelligent building are presented in the
Buildings are strongly influenced by the structures and materials applied.
Intelligent buildings have to employ ecologically clean materials and
composites. On the other hand intelligent building is characterized by indoor
climate with its components thermal comfort, acoustical comfort, optical
comfort aerodynamic comfort, cleanliness of the air.
Energy consumption is determined by numerous factors:
> building orientation;
> accumulation within thermal mass of walls and roof;
> total area of transparent constructions;
> physical properties of envelope structures;
> air change;
> heating temperature;
> furniture and carpets, window curtains and shutters;
> heat transmission loss;
> air change loss;
> solar radiation gain;
> free heat gains.
Required characteristics of intelligent building are expressed by
interaction of following tools:
> interaction of annual energy consumption, ecologically optimal indoor
climate and thermo-optical properties of transparent constructions of
intelligent building;
> interaction of annual energy consumption, ecologically optimal indoor
climate and intelligent building orientation toward cardinal points;
> interaction of annual energy consumption, ecologically optimal indoor
climate and both regulated and non-regulated air change in intelligent
building;
> interaction of solar system (active, passive and combined) and energetic
regime of intelligent building.
Intelligent building has to be healthy. In order to design buildings for healthy
living, designers must have criteria. Some factors for which criteria are
required