Pollution can be defined as an undesirable change in the physical, chemical or biological characteristics of the air, water or land that can affect health, survival or activities of humans or other organisms. Air pollution is a serious problem in many developing countries especially for those in the process of rapid industrialization, urbanization with increasing populations. Air pollution is a serious problem in Karachi, Lahore, Rawalpindi and Peshawar and many other cities of Pakistan, which are usually characterized with high ambient concentrations of particulate pollutants. Regular monitoring of ambient air quality is still not systematic in Pakistan. All the available information is based on random and short-term sampling conducted to assess the concentrations of various pollutants.

1. * Khan Alam & ** Hussain Majid *Department of Geography and Geology, University of Salzburg **Department of Bio-Physics University of Salzburg Measurement of aerosol size distribution, PM concentration and lung deposition calculation at different cities of Pakistan

7. Direct radiative forcing by aerosols (Direct effect) Solar radiation absorbed (Warming) Solar radiation scattered to space (Cooling) Absorbing aerosols Scattering aerosols e.g. Black carbon, mineral dust e.g. Sulphates, nitrates, organics Most aerosols both absorb and scatter!

8. Indirect aerosol effect (I) Few aerosols Low droplet concentration Less reflective cloud Numerous aerosols High droplet concentration More reflective cloud (Cooler climate)

9. Indirect aerosol effect (II) Smaller droplets Lower Precipitation rate Clouds are longer lived and retain higher liquid water content

18. Results

19. Particle number and mass size distributions

20. Mass variation in different cities

21. PM concentrations

22. Particulate matter concentration Min.= minimum, Max.= maximum, Avg.= average No Site TSP(µg/m 3 ) PM 10 (µg/m 3 ) PM 2.5 (µg/m 3 ) PM 1.0 (µg/m 3 ) Min. Max. Avg. Min. Max. Avg. Min Max. Avg. Min. Max. Avg. 1. Peshawar 3467 92399 21924 119 1751 618 38 337 189 28 281 129 2. Rawalpindi 6907 82461 27131 216 1037 489 70 300 159 45 261 121 3 Lahore 3482 23896 6759 146 284 204 64 98 76 47 60 52 4. Karachi Suparco 2372 11508 5941 126 399 270 51 289 151 32 216 114 Saddar 5522 38765 14438 284 860 462 115 320 197 79 267 155 Sea View 794 11223 2308 74 127 93 51 84 64 33 48 38

23. Chemical Analysis Site Al Ca Cu Fe K Mg Na S Si Zn B Ba Cr Mn Ni P Sr Ti Zr Peshawar 7385 34569 688 8650 2676 4044 5314 2650 3062 1454 20 48 556 199 561 365 110 205 75 Pindi 10766 74955 4984 15026 7437 5981 13249 4413 21809 5032 155 152 787 375 1475 958 296 580 93 Lahore 9521 20675 657 8244 2866 3233 5531 5420 3323 1637 50 100 218 205 360 414 72 207 32 Karachi Suparco 4188 13442 273 3390 1211 1241 2384 2683 1486 757 7 27 156 96 230 133 47 75 11 Saddar 19916 74385 1146 16867 8574 7299 17839 9045 7547 2834 78 180 501 471 545 1557 243 527 42 Sea View 5571 17954 938 7344 1995 2589 11252 5469 1022 1638 21 79 616 162 474 248 58 103 23

24. WHO AIR QUALITY GUIDELINES 2000 Compound Guideline [ u g m -3 ] Averaging Time Carbon monoxide 100 000 15 min 60 000 30 min 30 000 1 hour 10 000 8 hours Nitrogen dioxide 200 1 hour 40 1 year Ozone 120 8 hours Sulphur dioxide 500 10 min 125 24 hours 50 1 year Lead 0.5 1 year 2006 100 20

33. Tracheaobronchial (TB) Trachea direct air into the lung Bronchial tree is the first part of the lung. This part directs air in the lung Each branch in the tree split into 2 part Bronchial tree can be divide into 5 segment that use to characterize the lung airway Head airway (HA) Air and aerosol enter from here and used to remove dust and other particles from entering the respiratory Humidify the air before entering the lung Separate out food to digestive system Human lung structure Parent Branch Major daughter Minor daughter Bifurcation Trachea Bronchial Tree Mouth Pharynx Larynx Nose

34. Alveolar or Pulmonary (AV) Alveoli are located at the end of the bronchial tree Gas exchange occur at the Alveoli If particle deposit in this region it can directly enter the blood stream alveoli Alveolar duct Alveolar entrance rings 100µm 100µm Alveoli

36. Deposition Mechanisms Involved Major: Minor: Diffusion Sedimentation Impaction Interception Electrostatic Naso-pharyngeal: impaction, sedimentation, electrostatic (particles > 1 μm) Tracheo-bronchial: impaction, sedimentation, diffusion (particles < 1 μm) Pulmonary: sedimentation, diffusion (particles < 0.1 μm)

37. Diffusion Cause by Brownian motion Diffusion is the deposition mechanism for small particles. Diffusion depends increases with decreasing particle size and flow rate. More deposition occurs in the alveoli region because longer residence time and smaller airway.

39. Impaction Particle cannot follow the trajectory due to its inertia and hit the wall called impaction. Impaction increases with particle size and flow rate. This type of deposition occur through out the lung. This is important, especially in the head airway where most of the large particles are screened out Impaction occurs mostly in the upper generation airways due to high velocity

43. Deposition patterns of 0.25-10 µm particles under light exercise breathing condition (V T = 500 mL, t = 4s) for three different days at Karachi, Sadar near a road crossing Deposition is normalized to the number of particles entering the trachea. Particle deposition in lung

44. Deposition patterns of 0.25-10 µm particles under light exercise breathing condition (V T = 500 mL, t = 4s) for two different days at Rawalpindi, near a road crossing Deposition is normalized to the number of particles entering the trachea. Particle deposition in lung (cont..)

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