2. Lecture plan
• Introduction. Role of air
• Atmospheric and exhaled air
content
• Hygienic role of air temperature
• Hygienic role of air humidity
• Hygienic role of air moves
• Hygienic role of air pressure
• Respiration at hypoxia
• Hygienic role of air ionization
• Respiration at the high
atmospheric pressure
• Hygienic characteristic of air
pollutions
• Aerosols
• Air pollutions’ health effects.
• Indoor air quality. Indoor air
contaminants’ health effects
• Preventive steps
3. A pasture of life
“While I’m breathing I’m hoping”
Daily, human breaths 9 kg of air
Direct and indirect role of air
4. O2, CO2, and N2
O2 – 16%, 159 mm
Hg at 0 m, 110 mm
Hg at 3000 m above
sea level
O3 absorbs the most
of UV (short waive
light)
CO2 – 0.03%
Sources: processes
of fuel burning out
In metropolies – 1%
Safe CO2 level –
0.07 (K. Flugge) and
0.1% (M.
Pettenkofer)
N2 from organic
compounds to
atmosphere
High biological role
5. Inhaled (atmospheric) and exhaled air
Gas % in inhaled air % in exhaled air
Oxygen 21 13.6-16
Carbon dioxide 0.04 4-5.3
Nitrogen 78.04 78.04
Argon and other gases 0.96 1
Water 5
NB These figures are approximate
6. Compound and partial pressure of oxygen and
carbon dioxide in different mediums
Medium
Oxygen Carbon dioxide
% mm Hg ml/l % ml Hg ml/l
Inhalation air 20.93 159 209.3 0.03 0.2 0.3
Expiration air 16.0 121 160.0 4.5 34 45
Alveolar air 14.0 100 140.0 55 40 55
Arterial blood - 100-96 200.0 - 40 560-540
Venuses blood - 40 140-160 - 46 580
Tissue - 10-15 - - 60 -
Mitochondria’s
area
- 0.1-1 - - 70 -
7. Positive:
breathing, body hardening, etc
Negative, unfavourable:
Unfavourable climate conditions, significant changes in chemical
content, dusts, etc can break normal relationships between our body
and the environment; therefore it can lead to different diseases and
their complications
8. Physical properties of air
Temperature
Humidity
Velocity
Pressure
Ionization
Radioactivity
9. Air temperature, humidity and velocity
• Combined effect
• Chronic cooling or superheating immunological disorders
• 17-19oC,
• Humidity and virulence of bacteria
• Skin diseases
• 30-65%,
• Ventilation, bracing stimulus for a body
• 0.2-0.4 m/s
11. Air pressure
• 760 mm Hg or 100 000 Pa (1000
gPa)
• Daily AP altitude – 4-5 mg Hg,
annual altitude – 20-30 mm Hg
• People sensitive to AP changes:
with rheumatism, hypertension,
ischemic heart disease
• In normal conditions,
hemoglobin’s saturation by
oxygen is 94-97%, at 2 km high it
is 92%, 4 km – 82-85%
12. Hypoxia
The state, which occurs in the
organism with the inadequate
supply of tissues and organs by
oxygen or during the breakdown
of the oxygen utilization in them
in the biological oxidation
process
• Exogenous hypoxia
• Endogenous hypoxia
13. High atmospheric pressure
During diving or caisson work
Pressure is higher than
atmospheric on 1 atm by every
10 m sinking
Caisson sickness:
When the blood “boils”
14. Ionization of air
• Negatively and positively
charged air ions
• Favourable effects of “-” ions
• 3000-4000 ions/cm3 –
therapeutic effect
• 800-1000 ions/cm3 – in rural air
• 100-400 ions/cm3 – in city air
• 30-50 ions/cm3 – in city offices
• Chizhevsky chandelier
23. Indoor air pollution
Contamina
nt
Source Acute health effect
Acetic Acid X-ray development equipment, silicone caulking
compounds
Eye, respiratory and mucous
membrane irritation
Carbon
Dioxide
Unvented gas and kerosene appliances,
improperly vented devices, processes or
operations which produce combustion products,
human respiration
Difficulty concentrating,
drowsiness, increased
respiration rate
Carbon
Monoxide
Tobacco smoke, fossil-fuel engine exhausts,
improperly vented fossil-fuel appliances
Dizziness, headache, nausea,
cyanosis, cardiovascular
effects, and death
Formaldeh
yde
Off-gassing from urea formaldehyde foam
insulation, plywood, particle board, and
paneling; carpeting and fabric; glues and
adhesives; and combustion products including
tobacco smoke
Hypersensitive or allergic
reactions; skin rashes; eye,
respiratory and mucous
membrane irritation; odor
annoyance
24. Indoor air pollution
Contam
inant
Source Acute health effect
Nitrogen
Oxides
Combustion products from gas furnaces and appliances; tobacco
smoke, welding, and gas- and diesel-engine exhausts
Eye, respiratory and
mucous membrane
irritation
Ozone Copy machines, electrostatic air cleaners, electrical arcing, smog Eye, respiratory
tract, mucous
membrane irritation;
aggravation of
chronic respiratory
diseases
Volatile
Organic
Compo
unds
(VOC's)
Paints, cleaning compounds, moth-balls, glues, photocopiers,
"spirit" duplicators, signature machines, silicone caulking materials,
insecticides, herbicides, combustion products, asphalt, gasoline
vapors, tobacco smoke, dried out floor drains, cosmetics and other
personal products
Trichloroethylene, benzene, toluene, methyl ethyl ketone, alcohols,
Nausea; dizziness;
eye, respiratory
tract, and mucous
membrane
irritation;
25. Indoor air pollution
Contaminan
t
Source Acute health effect
Miscellaneo
us Inorganic
Gases
Microfilm equipment, window cleaners,
acid drain cleaners, combustion products,
tobacco smoke, blue-print equipment
Eye, respiratory tract, mucous
membrane irritation; aggravation of
chronic respiratory diseases
Asbestos Insulation and other building materials such
as floor tiles, dry wall compounds,
reinforced plaster
Asbestos is normally not a source of
acute health effects. But cause
mesothelioma
Synthetic
Fibers
Fibrous glass and mineral wool Irritation to the eyes, skin and lungs;
dermatitis
Radon Ground beneath buildings, building
materials, and groundwater
No acute health effects are known
but chronic exposure may lead to
increased risk of lung cancer from
alpha radiation
26. Indoor air pollution
Contaminant Source Acute health effect
Tobacco
Smoke
Cigars, cigarettes, pipe tobacco.
Tobacco smoke is a major contributor to
indoor air quality problems. It contains several
hundred toxic substances including carbon
monoxide, nitrogen dioxide, hydrogen sulfide,
formaldehyde, ammonia, benzene,
benzo(a)pyrene, tars, and nicotine. Most
indoor air particulates are due to tobacco
smoke and are in the respirable range.
Tobacco smoke can irritate the
respiratory system and, in allergic or
asthmatic persons, often results in eye
and nasal irritation, coughing, wheezing,
sneezing, headache, and related sinus
problems. Complaints on burning,
itching, and tearing eyes when exposed
to cigarette smoke.
Microorganis
ms and
Other
Biological
Contaminant
s
(Microbials)
Air handling system condensate, cooling
towers, water damaged materials, high
humidity indoor areas, damp organic material
and porous wet surfaces, humidifiers, hot
water systems, outdoor excavations, plants,
animal excreta, animals and insects, food and
food products
Allergic reactions such as
hypersensitivity diseases
(hypersensitivity pneumonitis,
humidifier fever, allergic rhinitis, etc.)
and infections such as legionellosis are
seen. Symptoms include chills, fever,
muscle ache, chest tightness, headache,
27. Primary sources of indoor air quality
problems (NIOSH, USA)
• Inadequate ventilation 52%
• Contamination from inside
building 16%
• Contamination from outside
building 10%
• Microbial contamination 5%
• Contamination from building
fabric 4%
• Unknown sources 13%
Among physical environmental factors influencing constantly and directly on our body is air, which plays the most important role. Without it is impossible to imagine a long keeping all life functions. You know breathing is a synonym and inalienable sign of life. “While I’m breathing I’m hoping”, so said ancient Romans, and Greeks called the atmosphere as “a pasture of life”. Every day human eats about 1.24 kg of meal, drinks 2 l of water and breath in 9 kg of air (more than 10,000 l).
Air is the most common media factor, which’s a change can easily break the harmonic balance of our body, our health.
Air media gives oxygen, which is necessary for life.
Air takes all gases, which are excreted from our body.
Air influences on thermoregulative processes and many other functions of a body.
Air can transfer dangerous toxic or infectious
Air has indirect impact: through energetic, geologic, hydrologic and climatic processes
It’s known all alive bodies of the planet are depend on oxygen. In human body, the most sensible part is the central nervous system. We take up oxygen and breathe out carbon dioxide. And flora is, vice versa, absorb carbon dioxide and educe oxygen.
For us not relative number (percent) but the absolute means of the oxygen content are very important.
In the normal conditions of sea level, the partial pressure is 159 mm Hg, at 3000 m above sea level – 110 mm Hg.
Ozone is formed during rains and thunderstorms. You can smell it after them. The biological role of ozone is that it absorbs the most harmful part of ultraviolet light (short waive light).
In the atmospheric air the carbon dioxide is 0.03 %. The biggest source of CO2 is processes of fuel burning out. In several regions of Earth the CO2 concentration is about 1%, especially in metropolis areas.
Till recent time hygienists considered the safe content level of CO2 is 0.07 (K. Flugge) and 0.1% (M. Pettenkofer). Even it is thought CO2 with 1-2% do not impact on our functional state. But late studies have shown that breathing in air with 0.5% CO2, has consequence in changes in the respiratory system and cardiovascular system, the brain’s electrical activity. For these changes the CO2 concentration 0.1% is enough.
Chronic influence of the CO2 is studied not enough.
The CO2 is the indirect indicator of pureness of the indoor air. It is the hygienic matter of the CO2.
Nitrogen is circulated in the nature constantly: from organic compounds to atmospheric nitrogen. Biological role of nitrogen and other inert gases is that it dilutes oxygen. We cannot breathe pure oxygen. Up to present it is considered that inert gases are indifferent for a body. But it is revealed that they have narcotic properties.
Atmosphere is a stratum of troposphere adjoining to Earth with high 9-11 km. it’s a mechanic mix of gases. The air content is next: nitrogen – 78.09%, oxygen – 20.95%, carbon dioxide – 0.03%, inert gases, water vapors and other constant admixtures – 1%. Among constant admixtures, we should know ammonia (0.003-0.005 mg/m3), methane (0.0002%), and different nitrogen’s oxides (0.0015 mg /m3).
From the hygienic point of view, dusts (cosmic and terrestrial) have a big importance. Air consists natural and antropogeneous dusts.
In rest conditions our body use 250-300 ml of oxygen and breathe out 200-250 ml carbon dioxide. When well-trained human works hard oxygen utilization increases till 6-7 l/min.
Respiration provides oxygen transportation from atmospheric air to body’s tissues and carbon dioxide elimination from the body.
Atmospheric air distinguishes by its relative constant compound. One liter of dry air consists of 780 ml of nitrogen, 210 ml of oxygen, 0.3 ml of carbon dioxide and 10 ml of inert gases: argon, neon, helium, krypton, xenon and hydrogen
An impact of air can be not only positive but negative, unfavourable. Unfavourable climate conditions, significant changes in chemical content, dusts, etc can break normal relationships between our body and the environment; therefore it can lead to different diseases or complicate their flow.
Among physical properties of air we know temperature, humidity, wind speed, atmospheric pressure, ionization, and radioactivity. These air properties can be considered as environmental factors. These factors cannot influence on a body separately. They have combined influence.
The temperature is influencing on a body by certain humidity, wind speed and atmospheric pressure and so on. There are many combinations of theses meteofactors, when heat emission is high and our body can get a cold. For example, high the combination of high level of humidity and wind speed while low temperature. And vice versa, a combination of high humidity and temperature, and windless results in decreasing heat emission and leads to heat stroke (superheating).
In conditions of very low temperature people can get a frost-bite. Chronic cooling or superheating can lead to lowering of immunological resistance of a body; this results in infection diseases, rheumatism, and tuberculosis.
Not so low temperature impacts positively on a body. It reflects in our central nervous system, which involves protection mechanisms of a body, increases immunological resistance and trains thermoregulative mechanisms. That is way the optimal temperature for adults is 17-19 oC.
Air humidity itself plays a big hygienic role. First of all, a normal level of relative humidity is 30-65%. A very humid air is a good environment for pathogens. They keep their virulence. Also, in humid air our skin is getting nonresistant. It results in skin diseases. in humid air people survive the low temperature with difficulties. In a contrary, in dry air we can survive high and low temperature much easier. Dry air dries our skin. It looses its elastic properties. When the air humidity is less then 10%, we feel that our throat, nose and mouth smart. People suffering from bronchial asthma feel themselves much worse.
In living and working rooms the relative humidity of air should be 30-60%.
In mountains, air is drier than at plains. That is way in mountains people survive winter and hot summer much easier than at sea level.
The atmosphere moves always. Cyclones moving from more heated areas to cooler places bring cloudy and rainy weather. Anticyclones moving from the northern areas to South bring dry and sunny weather.
It is necessary to know directions of air move. It is important, especially in city planning, planning of an industrial factory building. The graphic designation of frequency and winds on quarter is called a wind rose.
A wind speed influences on a body heat exchange and balance in a complex with temperature and humidity. Its influence results in increasing of heat emission by convection and evaporation. In a hot weather the wind makes better our feelings by increasing heat emission, but in winter it worsens our body thermoregulation and promotes sickness.
The moderate and neutral by temperature wind has bracing, stimulative impact.
Hygienic role of the wind consists of that it ventilates, refreshes city roads, promotes airing rooms.
In living rooms the normal speed of air move is 0.2-0.4 m/s.
In working places the hygienic standards of microclimate depends on many factors: a type of profession (intellectual or physical work), work load (energy looses in W or kcal/min)), rate of worker’s activity, seasons of a year.
Atmospheric or barometric pressure is one of the physical properties of air. At see level normal atmospheric pressure is 760 mm Hg or 100 000 Pa (1000 gPa). According Dalton Law this quantity consists of partial pressures of all air gases. Air contains also water steams. In moderate climate partial pressure of water steam is 20 mm Hg at 22 o C. Partial pressure of steam equated in lung with blood at pressure 760 mm Hg and 37 o C is 47 mm Hg. Taking into account that steam pressure in the body is higher than in environment during breathing the body wastes water.
Hygienic role of the air pressure consists of that the strings and direction of the wind, frequency and rain volume depend on its changes. It results in weather change, which has a serious impact on health of people, especially old people.
Usually air pressure altitude is 4-5 mm Hg in a day and 20-30 mm Hg in a year. Some people are very sensitive to even little changes of air pressure. So, people suffering from rheumatism have pains in bones and articulations; people having hypertension feel worsening, stenocardia attacks. People with high nervous excitability can feel fear, insomnia.
In mountain, air pressure becomes lower, and partial pressure of oxygen in air is lower. It results in lowering of partial pressure of oxygen in alveolar air and in blood. It worsens oxidation of venous blood.
In normal conditions, hemoglobin’s saturation by oxygen is 94-97%, at 2 km high it is 92%, 4 km – 82-85%. This lowering oxygen saturation of hemoglobin results in decreasing oxygen supply of body tissues. This cause breaking oxidizing processes in cells.
Hypoxia (the oxygen deficiency) is called the state, which occurs in the organism with the inadequate supply of tissues and organs by oxygen or during the breakdown of the oxygen utilization in them in the biological oxidation process. On the basis of this it is sufficient precision determination of hypoxia, it is expedient to divide all hypoxic states into the exogenous and the endogenous.
Exogenous hypoxia is developed as a result of acting the changed (in the comparison with the usual) factors of environment.
Endogenous hypoxia appears with different physiological and pathologic changes in different functional systems of organism. The reaction of external respiration to hypoxia depends on duration and rate of the increase of hypoxic action, degree of the intake of oxygen (rest and physical load), individual characteristics of organism and totality of the genetically caused properties and hereditary morphofunctional signs (an eco portrait the native inhabitants of high mountain region and population of different ethnic groups).
The initial hypoxic stimulation of respiration observed under the oxygen deficiency conditions leads to the coming out of carbon dioxide from the blood and the appearance of respiratory alkalosis. Hypoxia is combined with hypocapnia. In turn, this contributes to an increase in pH of the brain extracellular liquid. Central chemoreceptors react to a similar shift of pH in the brain cerebrospinal liquid by sharp reduction in their activity. This causes this essential braking of the respiratory center neurons, that it becomes insensitive to the stimuli proceed from the peripheral chemoreceptors. Unique hypoxic "deafness" begins. In spite of preservable hypoxia, gradually hyperpnoea is changed by involuntary hypoventilation, which in a certain degree contributes also to the retention the physiologically necessary quantity of carbonic acid.
High mountain native people‘s and animal’s reaction to hypoxia is not there. In opinion of many researchers this reaction of people, living at sea level, reduced also after their long (at least 3-5 years) adaptation to high mountain conditions.
The basic factors of lasting acclimatization to the high mountain regions conditions are an increase in the content of carbon dioxide and reduction in the oxygen content in the blood at the background of reduction in the sensitivity of peripheral chemoreceptors to hypoxia, an increase in the capillaries density and relatively high level of O2 utilization by tissues from the blood. In mountaineers the diffusivity of lungs and the oxygen capacity of the blood due to an increase in hemoglobin concentration also grow. There is one of the mechanisms, which make it possible for mountaineers under the hypoxia conditions to increase the return of oxygen to tissues and to preserve carbonic dioxide. It is the ability of the increased formation in them of the metabolite of glucose - 2,3 diphosphoglycerates. This metabolite decreases an affinity of hemoglobin for oxygen.
The subject of intensive physiological experiments both in the experiment and in different natural climatic and production conditions is the study of functional interaction of the regulation of respiration and blood circulation systems. Both systems have overall reflexogenic zones in the vessels, which send afferent signals to the specialized neurons of the basic sensitive nucleus of the medulla oblongata - the nucleus of single beam. The dorsal nucleus of respiratory center and vasomotor center are located here in immediate proximity. Separately it should be noted that the lungs are unique organ, where entire minute volume of the blood enters. This ensures not only gas transport function, but also role of the unique filter, which defines the composition of biologically active materials in the blood and their metabolism.
Respiration at the
During the diving and caisson work, men are under pressure higher than atmospheric on 1 atm by every 10 m sinking. Under these conditions increases a quantity of gases, dissolved in the blood, and especially nitrogen. During the rapid lift of diver to the surface the gases physically dissolved in the blood and the tissues do not manage to be isolated from the organism and are formed bubbles - the blood " boils ". The blood and tissues rapidly utilize oxygen and carbon dioxide. The bubbles of nitrogen, which resound by the blood and stop up the small vessels (gas embolism), present special danger. It is accompanied by heavy damages of CNS, the organs of vision, hearing, by severe pains in the muscles and in the joints, by the loss of consciousness. This state, which appears upon the rapid decompression, is called Caisson sickness. Victim must be again placed into the medium with the high pressure, and then gradually produced decompression. The probability of occurrence of Caisson sickness can be considerably lowered during the respiration by special gas mixture, for example helium-oxygen. Helium is almost not dissolved in the blood, it more rapidly diffuses from the tissues.
Ionization of air plays significant hygienic and biological matter. Ionization of air molecules (decomposition of air molecules into electrons and ions) is caused by natural ionizators (radioactive elements, cosmic lights, electrical discharges). Free electrons join to neutral atoms and molecules and convert them into ions with negative charge. There two types of ions: light and heavy ions. Light ions joining with mechanical particles become heavy ions.
It is known that there is an electrical exchange between our body and air. This exchange performed through aero ions.
It is proved that light ions with negative charge have favourable impact on our body. The temperate concentration of them (3000-4000 ions in 1 cm3) affects therapeutically. Such concentrations we can have in resort places nearby forests, sea, in mountains. If in 1ml of pure air concentration of ions is 800-1000, in cities it is only 100-400.
In crowdie rooms with improper ventilation the number of light ions decreases and concentration of heavy ions increases.
That is way in some rooms people use equipment for ionizing air. There is well known chandelier of Chizhevsky.
In physiotherapy, ionized air is used for treatment of bronchial asthma, hypertension, inflammation of respiratory ways, insomnia, neuroses, etc.
All human being begins the 21st century with many ecological problems. Among them constant increase of air pollutions: as the number of the substances as their volumes.
The changes of atmosphere’s content are becoming a very big issue for the mankind, global health. It is a question of the existence of humans and other alive.
The main pollutions sources are industrial plants, traffic and places with open soil. Burning mineral fuel, first of all, charcoal plays significant role in atmospheric air pollution. It is calculated only during burning charcoal for a year about 94 million tons of dust, more than 300 million tons of carbon dioxide, 37 million tons of sulphurous gas and 6 billion tons of carbon acid come into atmosphere.
The power stations have leading position in this polluting.
Today, in the world we throw out more than 100 million tons of sulphurous gas, 50 million tons of soot and more than 15 million tons of carbohydrate.
Besides of power stations, chemical plants, oil refining factories and metal works are main sources of air pollution. They pollute copper dusts, iron, lead, other microsubstances, different toxic organic compounds, which can have carcinogenic properties.
Traffic is becoming one of the biggest air pollution sources. In a car exhaust gas there are carbon oxide, nitrogen oxide, aldehydes, lead components, polycyclic carbohydrates such as 3-4 benzapyren.
Last decades, aircrafts are becoming also one of the main air pollution sources. One airplane throw out exhaust gases hundreds times more than a car.
First of all the layer of air closest to Earth is polluted, otherwise our milieu.
Among universal air pollutions we can allocate carbon oxide, sulphurous dioxide, and other sulphurous and nitrogen compounds, dusts.
Carbon oxide is a gas formed when burning organic substances is incomplete. It has no colour, no smell. In traffic exhaust gas its share is up to 13.5%, in tobacco smoke – up to 1%.
In cities its concentration is 100-200 mg/m3.
In 1950-1970ties in many big metropolises the atmosphere was very polluted by auto and industrial exhausted gases, by dust. Still in many big cities we can see smog.
These pollutants changed very much the chemical properties of air. In air, the dust’s speaks have a cover from water. In these hydro cover, almost all chemical gases can be solved. Among these substances the most dangerous chemicals are sulphurous dioxide and nitric dioxide. They formed in the water acids: sulphuric and nitric acids, which are very reactive for a tissue.
When we breathe air these dusts’ speaks covered by these acids get in our bronchial tissues. Our body is getting poisoned.
The smog becomes more harmful by high level pollution by toxic substance such as sulphuric acid. The reason promoting accumulation of pollution in layers close to earth surface is meteorological situation. If the meteorological conditions impede normal air circulation (steady anticyclone weather along with calm and a temperature inversion), all pollution coming in air accumulates in the first air layer with tendency of concentration to increase.
During this smog period many people, especially sick and old people, get worse feelings, cough, pains during swallowing, asthma, vomiting and epiphora. Such toxic smog situations were in London in 1950ties, in Holland, Germany, Tokyo and many cities. Nowadays, many developed countries improved ecological conditions in cities and rural areas. Nevertheless, still in developing countries we can meet with unfavourable air conditions. The most polluted cities in the world are Cairo, Mexico, San-Paulo, and Delhi.
In Kyrgyzstan situation with air is becoming better, but it is connected with break and stop of our industrial plants. The main source of air pollution in our country is traffic, which use fuel with not so good quality.
Also, there is a photochemical smog, which is caused by exhausted gases and industrial gases. This photochemical smog is formed in polluted air by photochemical reactions caused by shortwave ultraviolet radiation. The main components of the photochemical smog are photo oxidants (ozone, peroxides, nitrites, nitrates), nitric oxides, carbohydrates, etc. this smog can cause irritation of mucous membranes, of throat, asphyxia, exacerbation of diseases.
97% of Europeans are exposed to O3 concentrations above the WHO recommendations.
MAJOR INDOOR AIR CONTAMINANTS.
General. Although asbestos and radon have been listed below, acute health effects are not associated with these contaminants. These have been included due to recent concerns about their health effects. The investigator should be aware that there may be other health effects in addition to those listed.
Acetic Acid. Sources: X-ray development equipment, silicone caulking compounds. Acute health effects: Eye, respiratory and mucous membrane irritation.
Carbon Dioxide. Sources: Unvented gas and kerosene appliances, improperly vented devices, processes or operations which produce combustion products, human respiration. Acute health effects: Difficulty concentrating, drowsiness, increased respiration rate.
Carbon Monoxide. Sources: Tobacco smoke, fossil-fuel engine exhausts, improperly vented fossil-fuel appliances. Acute health effects: Dizziness, headache, nausea, cyanosis, cardiovascular effects, and death.
Formaldehyde. Sources: Off-gassing from urea formaldehyde foam insulation, plywood, particle board, and paneling; carpeting and fabric; glues and adhesives; and combustion products including tobacco smoke. Acute health effects: Hypersensitive or allergic reactions; skin rashes; eye, respiratory and mucous membrane irritation; odor annoyance.
Nitrogen Oxides. Sources: Combustion products from gas furnaces and appliances; tobacco smoke, welding, and gas- and diesel-engine exhausts. Acute health effects: Eye, respiratory and mucous membrane irritation.
Ozone. Sources: Copy machines, electrostatic air cleaners, electrical arcing, smog. Acute health effects: Eye, respiratory tract, mucous membrane irritation; aggravation of chronic respiratory diseases.
Radon. Sources: Ground beneath buildings, building materials, and groundwater. Acute health effects: No acute health effects are known but chronic exposure may lead to increased risk of lung cancer from alpha radiation.
Volatile Organic Compounds (VOC's). Volatile organic compounds include trichloroethylene, benzene, toluene, methyl ethyl ketone, alcohols, methacrylates, acrolein, polycyclic aromatic hydrocarbons, and pesticides. Sources: Paints, cleaning compounds, moth-balls, glues, photocopiers, "spirit" duplicators, signature machines, silicone caulking materials, insecticides, herbicides, combustion products, asphalt, gasoline vapors, tobacco smoke, dried out floor drains, cosmetics and other personal products. Acute health effects: Nausea; dizziness; eye, respiratory tract, and mucous membrane irritation; headache; fatigue.
Miscellaneous Inorganic Gases. Includes ammonia, hydrogen sulfide, sulfur dioxide. Sources: Microfilm equipment, window cleaners, acid drain cleaners, combustion products, tobacco smoke, blue-print equipment. Acute health effects: Eye, respiratory tract, mucous membrane irritation; aggravation of chronic respiratory diseases.
Asbestos. Sources: Insulation and other building materials such as floor tiles, dry wall compounds, reinforced plaster. Acute health effects: Asbestos is normally not a source of acute health effects. However, during renovation or maintenance operations, asbestos may be dislodged and become airborne. Evaluation of employee exposure to asbestos will normally be covered under the OSHA Asbestos standard.
Synthetic Fibers. Sources: Fibrous glass and mineral wool. Acute health effects: Irritation to the eyes, skin and lungs; dermatitis.
Tobacco Smoke. Sources: Cigars, cigarettes, pipe tobacco. Acute health effects: Tobacco smoke can irritate the respiratory system and, in allergic or asthmatic persons, often results in eye and nasal irritation, coughing, wheezing, sneezing, headache, and related sinus problems. People who wear contact lenses often complain of burning, itching, and tearing eyes when exposed to cigarette smoke. 6 Tobacco smoke is a major contributor to indoor air quality problems. Tobacco smoke contains several hundred toxic substances including carbon monoxide, nitrogen dioxide, hydrogen sulfide, formaldehyde, ammonia, benzene, benzo(a)pyrene, tars, and nicotine. Most indoor air particulates are due to tobacco smoke and are in the respirable range.
Microorganisms and Other Biological Contaminants (Microbials). Includes viruses, fungi, mold, bacteria, nematodes, amoeba, pollen, dander, and mites. Sources: Air handling system condensate, cooling towers, water damaged materials, high humidity indoor areas, damp organic material and porous wet surfaces, humidifiers, hot water systems, outdoor excavations, plants, animal excreta, animals and insects, food and food products. Acute health effects: Allergic reactions such as hypersensitivity diseases (hypersensitivity pneumonitis, humidifier fever, allergic rhinitis, etc.) and infections such as legionellosis are seen. Symptoms include chills, fever, muscle ache, chest tightness, headache, cough, sore throat, diarrhea, and nausea.
Casual Factors. Modern office buildings are generally considered safe and healthful working environments. However, energy conservation measures instituted during the early 1970's have minimized the infiltration of outside air and contributed to the buildup of indoor air contaminants. Investigations of indoor air quality (IAQ) often fail to identify any harmful levels of specific toxic substances. Often employee complaints result from items such as cigarette smoke, odors, low-level contaminants, poor air circulation, thermal gradients, humidity, job pressures, lighting, work-station design, or noise.
Incidence. The range of investigations of indoor air quality problems encompasses complaints from one or two employees to episodes where entire facilities are shut down and evacuated until the events are investigated and problems corrected. Complaints are often of a subjective, nonspecific nature and are associated with periods of occupancy. These symptoms often disappear when the employee leaves the workplace. They include headache, dizziness, nausea, tiredness, lack of concentration, and eye, nose, and throat irritation. In approximately 500 indoor air quality investigations in the last decade, the National Institute for Occupational Safety and Health (NIOSH) found that the primary sources of indoor air quality problems are:
• Inadequate ventilation 52%
• Contamination from inside building 16%
• Contamination from outside building 10%
• Microbial contamination 5%
• Contamination from building fabric 4%
• Unknown sources 13%
Tobacco Smoke. Sources: Cigars, cigarettes, pipe tobacco. Acute health effects: Tobacco smoke can irritate the respiratory system and, in allergic or asthmatic persons, often results in eye and nasal irritation, coughing, wheezing, sneezing, headache, and related sinus problems. People who wear contact lenses often complain of burning, itching, and tearing eyes when exposed to cigarette smoke. 6 Tobacco smoke is a major contributor to indoor air quality problems. Tobacco smoke contains several hundred toxic substances including carbon monoxide, nitrogen dioxide, hydrogen sulfide, formaldehyde, ammonia, benzene, benzo(a)pyrene, tars, and nicotine. Most indoor air particulates are due to tobacco smoke and are in the respirable range.
Microorganisms and Other Biological Contaminants (Microbials). Includes viruses, fungi, mold, bacteria, nematodes, amoeba, pollen, dander, and mites. Sources: Air handling system condensate, cooling towers, water damaged materials, high humidity indoor areas, damp organic material and porous wet surfaces, humidifiers, hot water systems, outdoor excavations, plants, animal excreta, animals and insects, food and food products. Acute health effects: Allergic reactions such as hypersensitivity diseases (hypersensitivity pneumonitis, humidifier fever, allergic rhinitis, etc.) and infections such as legionellosis are seen. Symptoms include chills, fever, muscle ache, chest tightness, headache, cough, sore throat, diarrhea, and nausea.
Casual Factors. Modern office buildings are generally considered safe and healthful working environments. However, energy conservation measures instituted during the early 1970's have minimized the infiltration of outside air and contributed to the buildup of indoor air contaminants. Investigations of indoor air quality (IAQ) often fail to identify any harmful levels of specific toxic substances. Often employee complaints result from items such as cigarette smoke, odors, low-level contaminants, poor air circulation, thermal gradients, humidity, job pressures, lighting, work-station design, or noise.
Incidence. The range of investigations of indoor air quality problems encompasses complaints from one or two employees to episodes where entire facilities are shut down and evacuated until the events are investigated and problems corrected. Complaints are often of a subjective, nonspecific nature and are associated with periods of occupancy. These symptoms often disappear when the employee leaves the workplace. They include headache, dizziness, nausea, tiredness, lack of concentration, and eye, nose, and throat irritation. In approximately 500 indoor air quality investigations in the last decade, the National Institute for Occupational Safety and Health (NIOSH) found that the primary sources of indoor air quality problems are:
• Inadequate ventilation 52%
• Contamination from inside building 16%
• Contamination from outside building 10%
• Microbial contamination 5%
• Contamination from building fabric 4%
• Unknown sources 13%
Indoor air conditions in different rooms also have hygienic importance. In hospital wards, school auditoriums, other communal rooms, significant changes in chemical and physical air conditions can be found as a result of an improper ventilation and big gathering people. These unfavourable changes in air can lead to negative reactions in our body.
