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AIR POLLUTION SOURCES

AIR POLLUTION SOURCES
Air is one of the essential factors making life on the Earth possible. Protection of air from pollution is a matter of great importance. Air pollution Anthrophogenic Natural Oxygen un nitrogen compose 99 % of inhaled air. Unfortunately, we inhale also: Droplets of the Dust Very small amount of water other gases 2Pollutants spread rapidly and to far distances in the atmosphere Troposphere contain almost 95 % of the all air mass 3A AIIR R P PO OL LL LU UT TIIO ON N S SO OU UR RC CE ES S Both industrial processes and heating contributes to air pollution. Transport Air pollution comes from: vehicles Thermo-electro power-plants Factories Dry cleaning solvents Smoking 4Picnics Aviation 5 FiresSecondary pollutants (sulphur acid) are deriving in air from primary pollutants in chemical reaction between Primary pollutants (sulphur primary pollutant air compounds dioxide) come in air directly by natural or anthropogenic Primary processes CO CO 2 Secondary SO NO 2 hydrocarbons N NO O S SO O H HN NO O 2 2 3 3 3 3 S Su us sp pe en nd de ed d H SO H O participles 2 4 2 2 O 3 - 2- NO SO 3 4 salts Natural Pollution Stationary sources Anthropogenic Mobile 6Schematic drawing, causes and effects of air pollution: (1) greenhouse effect, (2) particulate contamination, (3) increased UV radiation, (4) acid rain, (5) increased ground 7 level ozone concentration, (6) increased levels of nitrogen oxides.A A Aiiir r r p p po o ollllllu u ut t tiiio o on n n Pollutants spread rapidly and to far distances in the atmosphere; therefore, the problem of atmospheric pollution should be dealt with on a global scale, and international cooperation is vital in this regard. Turbulence made by airplanes A Ai ir r m mo ov ve em me en nt t a an nd d t tu ur rb bu ul le en nc ce e t to o make easy dissipation of the pollutants Nowadays countless very harmful substances can enter the air of a work area or the atmosphere in the form of gas, vapour, aerosols or dust. Some of them return back on the Earth surface in a form of solid participles, drops of liquid or polluted rain. 8H H HIIIS S ST T TO O OR R RY Y Y O O OF F F A A AIIIR R R P P PO O OL L LL L LU U UT T TIIIO O ON N N The air pollution problem has been accompanying us already since the times the ancient people discovered fire. The ancient people’s health or even life were endangered by high concentrations of such pollutants as carbon monoxide (CO) released from incompletely burnt firewood and other compounds emitted during burning. Furthermore, the ancient Romans already knew about lead and mercury poisoning in mines. A Al lr re ea ad dy y i in n 1 12 27 73 3. . E Ed dw wa ar rd d I I, , t th he e k ki in ng g o of f E En ng gl la an nd d f fo or rb bi id d t to o b bu ur rn n l lo ow w q qu ua al li it ty y c co oa al l, , t to o reduce air pollution. Air pollution hazard has sharply increased since the development of Industrial Revolution and the mining industry. Edward I smoke tails from factory chimneys photo-chemical smog motor vehicles new hazardous substances (petrol with tetra-ethyl lead) 9A A Aiiir r r p p po o ollllllu u ut t ta a an n nt t ts s s In troposphere are thousands of air pollutants, but main air pollution comes from substances of the nine groups : 1. Carbon oxides (CO un CO ) 2 2. Sulphur oxides (SO un SO ) 2 3 3 3. . Ni Nit tr ro og ge en n o ox xiid de es s ( (N N O O, , N NO O u un n N NO O ) ) 2 2 2 2 4. Volatile organic substances methane (CH ), benzol (C H ), formaldehyde 4 6 6 (CH O), freon‘s 2 5. Dispersed solid participles dust, soot, pollen, asbestos, compounds of lead, arsenic, cadmium and other heavy metals, nitrates, sulphates, drops of liquid with sulphur acid, oil products, dioxins', polycyclic biphenyl's, pesticides 10A A Aiiir r r p p po o ollllllu u ut t ta a an n nt t ts s s 6. Photo-chemical oxidant’s - ozone (O ), peroxsil-nitrates, 3 - hydrogen peroxide (H O ), hydroxyl radical (OH ), aldehydes, which forms 2 2 in atmosphere under reaction between oxygen, nitrogen oxides and volatile hydrocarbons in presence of Sun radiation 222 7. Radioactive substances (radon (Rn ), 131 90 239 iodide (J ), strontium (Sr ), plutonium (Pu ) a an nd d o ot th he er r r ra ad di io oa ac ct ti iv ve e i is so ot to op pe es s, , w wh hi ic ch h c co om me es s i in n atmosphere in gaseous or dispersed form 8. Heat always to result, when one energy form converting into other, especially by burning fossil fuel in car’s engine, furnace of factory, thermo-electro plant, stove or fireplace 9. Noise , rises using transport vehicles, mechanisms in industry or building, devices for households (vacuum cleaner, radio, mower, etc). 11A A Aiiir r r p p po o ollllllu u ut t tiiio o on n n t t tr r re e en n nd d ds s s iiin n n t t th h he e e w w wo o or r rllld d d Considerable pollution source group is motor transport – as motor exhaust gases contain various harmful substances. The exhaust gas composition may differ depending on driving habits, engine operating conditions, fuel supply and quality. In the process of incomplete combustion of fuel hydrocarbons, they are transformed into carcinogenic substances – polyaromatic hydrocarbons. Although a range of air environmental protection measures are being implemented today, it is estimated that the losses incurred by the effects of polluted air on the human health – medical expenses, loss of working capacity – still amount to hundreds of millions of EUR’s per year just in the European Union War is one of the substantial air polluter To protect both workers and residents, several criteria (limit value) have been established in order to limit the maximum permissible concentrations of various harmful substances in the air. 12P Po ollllu ut tiio on n f fr ro om m W Wa ar r Agent Orange, rocket fuel, lead, mercury, petroleum, asbestos, countless carcinogenic solvents. This toxic stew settles into the soil in which we grow our food, seeps down into the water we drink and floats unseen in the air we breathe making us sick — terribly sick – and killing many of us, or leading to birth defects, cancer, miscarriages, and kidney and thyroid disease. More recently in Alaska, as a result of nuclear testing off that state’s coast, doctors say workers there will develop cancer at twice the rate as the general public. The Vietnamese Red Cross estimates that 150,000 children have birth defects caused by the U.S. military’s spraying of Agent Orange during the Vietnam war. 13Smog is a type of air pollution; the word "smog" is a combination of “smoke” and “fog”. Modern smog is a type of air pollution derived from emission from internal combustion engines and industrial fumes that react in the atmosphere with sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog. Smog is also caused by large amounts of coal burning in an area caused by a mixture of smoke, sulphur dioxide and other components. The term "smog" is generally attributed to Dr. Henry des Voeux in his 1905 paper, "Fog and Smoke" for a meeting of the Public Health Congress. Characteristic coloration for smog in California in the beige cloud bank behind Golden Gate Bridge. The brown coloration is due to the NO in the photochemical smog. 14 xP PH HO OT TO OC CH HE EM MI IC CA AL L S SM MO OG G Photochemical smog was first described in the 1950s. It is the result of chemical reaction of sunlight, nitrogen oxides and volatile organic compounds in the atmosphere. This mixture of air pollutants can include the following: aldehydes; nitrogen oxides, especially, nitrogen dioxide; peroxyacil nitrates; tropospheric ozone; volatile organic c co om mp po ou un nd ds s. . All of these chemicals are usually highly reactive and oxidizing. Photochemical smog is therefore considered to be a problem of modern industrialization. It is present in all modern cities, but it is more common in cities with sunny, warm, dry climates and a large number of motor vehicles. Because it travels with the wind, it can affect sparsely populated areas as well. Heavy smog in Moscow. Russia. 15 Domodedovo International Airport. 2010. H HE EA AL LT TH H E EF FF FE EC CT TS S B BY Y S SM MO OG G Smog is a serious problem in many cities and continues to harm human health. Ground level ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide are especially harmful for senior citizens, children, and people with heart and lung conditions such as emphysema, bronchitis and asthma. It can inflame breathing passages, decrease the lungs' working capacity, cause shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and it dries out the protective membranes of the nose and throat and i in nt te er rf fe er re es s w wi it th h t th he e b bo od dy y''s s a ab bi il li it ty y t to o f fi ig gh ht t i in nf fe ec ct ti io on n, , increasing susceptibility to illness. Hospital admissions and respiratory deaths often increase during periods when ozone levels are high. The USA EPA has developed an Air Quality Index to help explain air pollution levels to the general public: - eight hour average ozone mole fractions of 85 to 104 nmol/mol are described as "Unhealthy for Sensitive Groups", 105 nmol/mol 124 nmol/mol as "unhealthy" and 125 nmol/mol to 404 nmol/mol as "very unhealthy“, Highland Park Optimist Club wearing - the "very unhealthy" range for some other pollutants smog-gas masks at banquet, are: 355 μg m−3 - 424 μg m−3 for PM ; 15.5 10 Los Angeles, 1954. μmol/mol - 30.4 μmol/mol for CO and 0.65 μmol/mol - 1.24 μmol/mol for NO 2 16 .M MA AJ JO OR R S SM MO OG G I IN NC CI ID DE EN NT TS S I IN N T TH HE E U US SA A 1948, October, 30-31, Donora, PA: 20 died, 600 hospitalized, thousands more stricken. Lawsuits were not settled until 1951, 1953, November, New York: Smog kills between 170 and 260 people, 1954, October, Los Angeles: heavy smog shuts down schools and industry for most of the month, 1963, New York: blamed for 200 deaths, 1966, New York: blamed for 169 deaths. Smog in New York City as viewed from the World Trade Center in 1988 17P Ph ho ot to oc ch he em mi ic ca al l s sm mo og g 18P PH HO OT TO OC CH HE EM MIIC CA AL L S SM MO OG G – – A AR RE EA AS S A AF FF FE EC CT TE ED D Photochemical smog more frequently happening in places, where is sunny, hot and dry climate, as well as, heavy street traffic. Beijing air on a day after rain (left) and a smoggy day (right), August 2005. Characteristic smog cities are Los Angeles, Denver, Sidney, Mexico City, Toronto, Beijing, Manila, Ruhr Areas, Buenos Aires, however smog usually are in summer time. 19IIN ND DU US ST TR RIIA AL L S SM MO OG G Burning coal and heavy oil fractions with high content of sulphur compounds, a industrial smog take shape. Earlier its happened mainly in winter time. Industrial smog consist manly of sulphur dioxide, droplets of sulphur acid and solid participles. Claude Monet made several trips to London between 1899 and 1901, during which he painted views of the Thames and Houses of Parliament which show the sun struggling to shine through London's smog-laden atmosphere. 20D DIIS ST TR RIIB BU UT TIIO ON N O OF F T TH HE E P PO OL LL LU UT TIIO ON N IIN N A AIIR R Cooler air Cool air Normal distribution of pollution in air Warm air Cool air Warm inversion layer Thermal inversion and concentration of pollution in Cool air air 21Fog in Riga 22S So olliid d p pa ar rt tiic ciip plle es s b by y s siize ze Medium participles Small participles Big participles Sea salt dust Ash Soot Pigments of paint P Po ol ll le en n T To ob ba ac cc co o s sm mo ok ke e Cement dust Flour Coal dust Dust from metallurgy Photochemical smog Pollen by magnification Pesticides’ dust 0,001 0,01 0,1 1,0 10,0 100,0 Micrometers (μm) or microns 23D Diis st tr riib bu ut tiio on n o of f t th he e p po ollllu ut tiio on n iin n c ciit tiie es s Air pollution in urban territories are distributed not only by non-equal heating of the Earth surface by Sun, but by specific of the city planning and building – as result there take a shape “heat islands” too. Effect of the trees on air flows in cities Turbulence of the air flow in city’s streets with high, but regular structure 24A AC CIID DIIC C P PR RE EC CIIP PIIT TA AT TIIO ON N Burning coal or heavy oil fractions in air is emitted huge quantity of the sulphur dioxide (SO ), solid participles and nitric oxides. 2 For reduction of local pollution in Local pollution has been 50-60-ies of the 20 century has been built reduced, but in territories more and more higher chimneys, which before the wind pollution distribute pollution above thermal g gr ro ow wt th h r ra ap pi id dl ly y a an nd d p po ol ll lu ut te ed d i in nv ve er rs si io on n l la ay ye er r. . territories enlarged. Since 1950 global pollution with sulphur and nitrogen oxides increased threefold. 25N NA AT TU UR RA AL L P PH HE EN NO OM ME EN NA A A AN ND D A AI IR R P PO OL LL LU UT TI IO ON N The principal natural phenomena that contribute acid-producing gases to the atmosphere are emissions from volcanoes. Thus, for example, fumaroles from Laguna Caliente crater of Poas Volcano create extremely high amounts of acid rain and fog with acidity 2 of pH, clearing an area of any vegetation and frequently causing irritation to the eyes and lungs of inhabitants in nearby settlements. A Ac ci id d- -p pr ro od du uc ci in ng g g ga as ss se es s a ar re e c cr re ea at te ed d a al ls so o b by y b bi io ol lo og gi ic ca al l p pr ro oc ce es ss se es s t th ha at t o oc cc cu ur r o on n t th he e land, in wetlands, and in the oceans. The major biological source of sulphur containing compounds is dimethylsuphide. Nitric acid in rainwater is an important source of fixed nitrogen for plant life, and is also produced by electrical activity in the atmosphere such as lightning. Acidic deposits have been detected in glacial ice thousands of years old in remote parts of the globe. Soils of coniferous forests are naturally very acidic due to the shedding of needles and this phenomenon should not be confused with acid rain. 26H HU UM MA AN N A AC CT TIIV VIIT TY Y A AN ND D A AIIR R P PO OL LL LU UT TIIO ON N The principal cause of acid rain is sulphur and nitrogen compounds from human sources, such as electricity generation, factories, and motor vehicles. Coal power plants are one of the most polluting. The gases ca can n b be e ca car rr riie ed d h hu un nd dr re ed ds s o off ki killo om me ette er rs s iin n tth he e a attm mo osp sph he er re e before they are converted to acids and deposited. In the past, factories had short funnels to let out smoke but this caused many problems locally; thus, factories now have taller smoke funnels. However, dispersal from these taller stacks causes pollutants to be carried farther, causing widespread ecological damage. 27Coal-fueled power generating station in Ekibastuz, The Inco Superstack in Sudbury, Ontario, with a height Kazakhstan. Built in 1987, has installed capacity of of 380 metres, is the tallest chimney in Canada and the 1,000 MW and has the world's tallest flue gas stack Western hemisphere, and the second tallest at 419.7 metres freestanding chimney in the world 28C CH HE EM MI IC CA AL L P PR RO OC CE ES SS SE ES S In the gas phase sulphur dioxide is oxidized by reaction with the hydroxyl radical via an intermolecular reaction: · · SO + OH → HOSO 2 2 which is followed by: · · HOSO + O → HO + SO 2 2 2 3 In the presence of water, sulphur trioxide (SO ) is converted rapidly to sulphuric acid : 3 SO (g) + H O (l) → H SO (l) 3 2 2 4 N Ni it tr ro og ge en n d di io ox xi id de e r re ea ac ct ts s w wi it th h O OH H t to o f fo or rm m n ni it tr ri ic c a ac ci id d: : · NO + OH → HNO 2 3 When clouds are present, the loss rate of SO is faster than can be explained by gas 2 phase chemistry alone. This is due to reactions in the liquid water droplets. Hydrolysis: sulphur dioxide dissolves in water and then, like carbon dioxide, hydrolyses in a series of equilibrium reactions: SO (g) + H O ↔ SO ·H O 2 2 2 2 + − SO ·H O ↔ H + HSO 2 2 3 − + 2− HSO ↔ H + SO 3 3F Fo or rm ma at tiio on n o of f t th he e a ac ciid diic c p pr re ec ciip piit ta at tiio on n Wind Transformation on sulphur acid (H SO ) 2 4 and nitric acid (HNO ) 3 Soil dust and ammonia partly neutralize acidic salts Acidic droplets mixes with Sulphur dioxide Nitrogen oxide rain or snow producing acid (SO ) and nitrogen 2 (NO) precipitation F Fo or rm ma at ti io on n o of f s sa al lt ts s, , d di io ox xi id de e ( (N NO O ) ) 2 2 but sulphates and nitrates fall down Acid on surface fog City Ocean In lakes, especially in Farm more shallow, water become more acidic Water drops and solid participles fall down un surface quite soon, therefore “acid rains” are more regional, instead of continental or global problem. 30Processes involved in acid deposition (note that only SO and 2 NO play a significant role in acid rain). xH HO OW W A AC CIID DIIC C A AR RE E E EN NV VIIR RO ON NM ME EN NT T ? ? pH 0 In chemistry, pH is a measure of the Acidic Accumulator solution acidity or basicity of an aqueous solution. 1  gastric juice (1,0-3,0), 2 Acid fog (2,0- lemon juice (2,3)  vinegar, vine 3,5) 3  sparkling drinks  tomato juice 4  eel, trout (4,5)  coffee, bred, pike 5 Normal rain  Industrial areas and big cities  u ur ri in ne e ( (5 5, ,0 0- -7 7, ,0 0) ) w wa at te er r ( (5 5, ,0 0- -5 5, ,6 6) ) 6 6 c ch ha ar ra ac ct te er ri iz ze e r ra ai in n a ac ci id di it ty y a as s p pH H≈ ≈4 4  milk (6,6), saliva, salmon, molluscs 7  At very polluted places acidity can be Distilled water  blood (7,3-7,5), eggs  shampoo tenfold higher with pH≈3 8 Sea water (7,8- 8,3)  baking natron, phosphate  In some places, situated before the 9 detergents, chlorine bleach wind from big cities and active industrial  soap solution 10 territories, as well as on mountain  ammonia solution (10,5- 11 ranges and summits pH=2,3 11,9),  non-phosphate 12 detergents 13 Alkaline  cleaning fluid 14 32H HO OW W A AC CIID DIIC C A AR RE E E EN NV VIIR RO ON NM ME EN NT T ? ? Hydrangea Hydrangea macrophylla blossoms vary from pink to blue, according to a pH-dependent mobilization and uptake of soil aluminium into the plants. 33This chart shows that not all fish, shellfish, or the insects that they eat can tolerate the same amount of acid; for example, frogs can tolerate water that is more acidic (i.e., has a lower pH) than trout.H HO OW W A AC CIID DIIC C A AR RE E H HU UM MA AN N ? ? The pH of different cellular compartments, body fluids, and organs is usually tightly regulated in a process called acid-base homeostasis. The pH of blood is usually slightly basic with a value of pH 7.365. This value is often referred to as physiological pH in biology and medicine. Plaque (iekaisums) can create a local a ac ciid diic c e en nv viir ro on nm me en ntt tth ha att c ca an n r re es su ulltt iin n tooth decay (sairšana) by demineralisation. Enzymes and other proteins have an optimum pH range and can become inactivated or denatured outside this range. The most common disorder in acid-base homeostasis is acidosis, which means an acid overload in the body, generally defined by pH falling below 7.35. 35E EM MP PH HY YS SE EM MA A Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema, the tissues necessary to support the physical shape and function of the lungs are destroyed. It is included in a group of diseases called chronic obstructive pulmonary disease or COPD (pulmonary refers to the lungs). Emphysema is called an obstructive lung disease because the destruction of lung tissue around smaller sacs, called alveoli, makes these air sacs unable to hold their functional shape upon exhalation. It is often caused by long-term exposure to air pollution or smoking.C Co on ns se eq qu ue en nc ce es s o of f t th he e “ “a ac ciid d r ra aiin ns s” ” “ “A Ac ci id d r ra ai in ns s” ” induce chain of the undesirable effects on land, if pH5,1. Damage of monuments, buildings, metal constructions Wash out of soil Ca a an nd d K K c co om mp po ou un nd ds s, , w wh hi ic ch h are a nutrients for plants Wither away trees, especially, coniferous trees, which grow on mountain slopes, exposed to acid fog and acid clouds flows Small solid participles, mainly sulphates, form a mist in many industrial countries and regions 37Since 1998, Harvard University wraps some of the bronze and marble statues on its campus, such as this “Chinese Stele", with waterproof covers every winter, in order to protect them from erosion caused by acid rain Trees killed by acid rain. (or, actually, acid snow). 38C Co on ns se eq qu ue en nc ce es s o of f t th he e “ “a ac ciid d r ra aiin ns s” ” “ “A Ac ciid d r ra aiin ns s” ” induce the undesirable effects in water ecosystems, if pH5,5 Under acidification processes in the lakes non-toxic inorganic mercury substances transform into very toxic methyl-mercury, which dissolve in fats and can accumulate in fishes, therefore to cause real threats for people, who consume these poisoned creations. Fishes, water plants and microorganisms perish in the lakes and rivers. If pH to decline under 6, many fish species lose their ability for reproduction, but, if in water pH4,3, fish don’t live at all. 39E EX XT TE EN NS SIIO ON N O OF F R RE EG GIIO ON NS S W WIIT TH H “A “AC CIID DIIC C P PR RE EC CIIP PIIT TA AT TIIO ON N” ” Sensitive soils, Air pollution regions, Very potentially emissions arouse the problematic problematic regions “acid rains” regions 40“F “Fo or re es st ts s’’ d de ea at th h” ” a ar re ea as s iin n E Eu ur ro op pe e Damage of forests, % High (25%) Medium (15-25%) “Acid rains”, which originate in Low (15%) one country, can be transfer to Low other countries by wind. Medium Intensity levels of “acid rains” High Norway, Switzerland, Austria, Sweden, Netherland and Finland receive ¾ of “acid rains” from other countries. 41A AIIR R P PO OL LL LU UT TIIO ON N IIM MP PA AC CT T O ON N F FO OR RE ES ST T Emissions Reduced Dry air precipitation Acid rains High Strengthen sensitivity evaporation towards diseases Direct impact on and vermins leaves or needles ( (k ka ai it tē ēkļ kļi i) ) S St tr re en ng gt th he en n Reduced transpiration photo- Inadequacy synthetic- Damage of bark of activity Downfall water of the and Crown of tree nutrients the tree and Soil acidification needles Disappear soil decay microorganisms Release of toxic metal ions Washing out Difficulties to of acids and ingest Unaffected roots soil nutrients and perishing compounds water Lake Underground water 42A AIIR R M MO ON NIIT TO OR RIIN NG G IIN N L LA AT TV VIIA A Air monitoring in Latvia is carried out by Environment, geology and meteorology centre by using differential optical absorption spectrophotometric stations and devices. Regular air monitoring measure c co on nc ce en nt tr ra at ti io on n o of f s su ul lp ph hu ur r d di io ox xi id de e ( (S SO O ) ), , 2 2 nitric dioxide (NO ), ozone (O ), benzol 2 3 (C H ), solid participles PM and PM 6 6 10 2.5 Device for measurements of solid participles PM and 10 PM 2.5 43A AIIR R M MO ON NIIT TO OR RIIN NG G S ST TA AT TIIO ON NS S IIN N R RIIG GA A A AN ND D L LA AT TV VIIA A Rīga Latvia Riga air monitoring stations for traffic pollution air monitoring stations for background measurements air monitoring stations for industrial pollution 44A AIIR R M MO ON NIIT TO OR RIIN NG G S ST TA AT TIIO ON NS S IIN N L LA AT TV VIIA A,, 2 20 01 10 0 National monitoring programme, 2010. Air quality stations in cities Regional reference stations 45OPSIS Opsis AB is a global company that develops, manufactures and markets state-of-the-art, innovative systems for gas analysis and process control. Our goal is to provide our customers with the most advanced, reliable and cost-effective systems, regardless of applications. Systems are available for ambient air quality monitoring (AQM), continuous emissions monitoring (CEM) and process control. Several hundred systems are installed worldwide. By focusing on our customers’ requirements and on continuous research and development, Opsis continues to lead the way and set the standard in gas monitoring. A NEW CONCEPT Opsis was founded in 1985 when two Ph.D. students from the University of Lund, Sweden, took the concept of measuring gases with light and developed it into a commercially viable product. Svante Wallin and Leif Unéus developed the idea of measuring gases in air, by using light, to measure several gases simultaneously. Opsis is certified according to ISO 9001 quality system and ISO 14001 environmental quality system. 46Air Quality Modelling Software Data Acquisition, Validation & Presentation Data Management 47Products DOAS Technique The basis of the principle used by Opsis to identify and measure concentrations of different gases is scientifically well established: Differential Optical Absorption Spectroscopy (DOAS), which is based on Beer-Lambert’s absorption law. It states the relationship between the quantity of light absorbed and the number of molecules in the light path. Because every type of molecule, every gas, has its own unique absorption spectrum properties, or “fingerprint”, it is possible to identify and determine the concentrations of several different gases in the light path at the same time. DOAS is based on transferring a beam of light from a special source – a high-pressure xenon lamp – over a chosen path and then using advanced computer calculations to evaluate and analyse the light losses from molecular absorption along the path. The light from the xenon lamp is very intense, and includes both the visible spectrum and ultraviolet and infrared wavelengths. The light is captured by a receiver and conducted through an optical fibre to the analyser. The fibre allows the analyser to be installed away from potentially aggressive environments. The analyser includes a high-quality spectrometer, a computer and associated control circuits. The spectrometer splits the light into narrow wavelength bands using an optical grating. This can be adjusted so that an optimum range of wavelengths is detected. The light is transformed into electrical signals. A narrow slit sweeps past the detector at high speed, and a large number of instantaneous values are built up to form a picture of the spectrum in the relevant wavelength range. This scan is repeated a hundred times a second, and the registered spectra are accumulated in the computer’s memory while awaiting evaluation. The absorption spectrum just registered from the light path is compared with one calculated by the computer. The calculated spectrum consists of a well- balanced summation of the reference spectra for the analysis concerned. The computer proceeds by varying the size factors for each reference spectrum until it reaches the best possible match. From this the different gas concentrations can be calculated with high accuracy. 48N NO O 2 2 P PO OL LL LU UT TI IO ON N I IN N R R R RI I I IG G G GA A A A 49N NO O P PO OL LL LU UT TI IO ON N I IN N V VE EN NT TS SP PI IL LS S A AN ND D L LI IE EP PA AJ JA A 2 2 50A AIIR R P PO OL LL LU UT TIIO ON N IIN N R RIIG GA A 1 2 3 4 5 6 7 8 9 10 11 12 Months Sulphur Benzol Ozone Nitrogen dioxide dioxide 51 3 C Co on nc ce en ntr tra ati tio on n, , μ μg g/ /m mIIN ND DO OO OR R A AIIR R Q QU UA AL LIIT TY Y Air pollution is usually associated with the quality of outdoor urban air. However, the health of humans may be much more affected by air pollution in their living environment – dwelling and working premises. Specific structure In the rooms is limited of the pollutants In the rooms is slow dispersion of emitted down degradation of the pollution pollutants People of developed countries, especially, residents of cities, main part of life stay indoor 6% of time 5% of time CITY in car outside COUNTRY-FOLK DWELLER stay indoor 65% of 89% of time time indoor 52IIN ND DO OO OR R A AIIR R Q QU UA AL LIIT TY Y A common air filter, being cleaned with a vacuum cleaner Spider plants (Chlorophytum comosum) absorb some airborne contaminants 53IIM MP PO OR RT TA AN NC CE E O OF F T TH HE E V VE EN NT TIIL LA AT TIIO ON N V Ve en nt ti il la at ti io on n m mo od de es s: : Intensive ventilation – air exchange by force with devices Infiltration – limited non-control air exchange (through chink, opening, door, chimney) Natural ventilation – air exchange by natural flow through special openings Outflo w Inflow Outflo w Fresh air Air from rooms Natural ventilation, affected Balanced Natural ventilation flows by wind and chimney 54 ventilation systemS SIIC CK K B BU UIIL LD DIIN NG G S SY YN ND DR RO OM ME E Sick building syndrome (SBS) is a combination of ailments (a syndrome) associated with an individual's place of work (office building) or residence. A 1984 World Health Organisation report into the syndrome suggested up to 30% of new and re-modelled buildings worldwide may be linked to symptoms of SBS. Most of the sick building syndrome is related to poor indoor air quality . Causes of the syndrome : Microorganisms Dust Products of fuel (bacteria, fungi, viruses) Tobacco smoke combustion Noxious vapours by chemicals Outdoor (glue, paint, etc.) used in pollution Pollen building materials Building occupants complain of symptoms such as sensory irritation of the eyes, nose, throat; neural-toxic or general health problems; skin irritation; nonspecific hypersensitivity reactions; and odour and taste sensations. In most cases, SBS symptoms will be relieved soon after the occupants leave the particular room or zone. However, there can be lingering effects of various neurotoxins, which may not clear up when the occupant leaves the building. Particularly in sensitive individuals there can be long-term health effects. 55C CO ON NS SE EQ QU UE EN NC CE ES S O OF F T TH HE E IIN ND DO OO OR R P PO OL LL LU UT TIIO ON N IIN N T TH HE E W WO OR RL LD D Mortality, fatal cases per one million 0-10 10-50 50-100 100-200 200-300 300-400 400-610 No data 56T TH HA AN NK K Y YO OU U F FO OR R A AT TT TE EN NT TIIO ON N
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