Aerosol size distribution and mass concentration measurements in various cities of Pakistan

Abstract

During March and April 2010 aerosol inventories from four large cities in Pakistan were assessed in terms of particle size distributions (N), mass (M) concentrations, and particulate matter (PM) concentrations. These M and PM concentrations were obtained for Karachi, Lahore, Rawalpindi, and Peshawar from N concentrations using a native algorithm based on the Grimm model 1.109 dust monitor. The results have confirmed high N, M and PM concentrations in all four cities. They also revealed major contributions to the aerosol concentrations from the re-suspension of road dust, from sea salt aerosols, and from vehicular and industrial emissions. During the study period the 24 hour average PM(10) concentrations for three sites in Karachi were found to be 461 μg m(-3), 270 μg m(-3), and 88 μg m(-3), while the average values for Lahore, Rawalpindi and Peshawar were 198 μg m(-3), 448 μg m(-3), and 540 μg m(-3), respectively. The corresponding 24 hour average PM(2.5) concentrations were 185 μg m(-3), 151 μg m(-3), and 60 μg m(-3) for the three sites in Karachi, and 91 μg m(-3), 140 μg m(-3), and 160 μg m(-3) for Lahore, Rawalpindi and Peshawar, respectively. The low PM(2.5)/PM(10) ratios revealed a high proportion of coarser particles, which are likely to have originated from (a) traffic, (b) other combustion sources, and (c) the re-suspension of road dust. Our calculated 24 hour averaged PM(10) and PM(2.5) concentrations at all sampling points were between 2 and 10 times higher than the maximum PM concentrations recommended by the WHO guidelines. The aerosol samples collected were analyzed for crustal elements (Al, Fe, Si, Mg, Ca) and trace elements (B, Ba, Cr, Cu, K, Na, Mn, Ni, P, Pb, S, Sr, Cd, Ti, Zn and Zr). The averaged concentrations for crustal elements ranged from 1.02 ± 0.76 μg m(-3) for Si at the Sea View location in Karachi to 74.96 ± 7.39 μg m(-3) for Ca in Rawalpindi, and averaged concentrations for trace elements varied from 7.0 ± 0.75 ng m(-3) for B from the SUPARCO location in Karachi to 17.84 ± 0.30 μg m(-3) for Na at the M. A. Jinnah Road location, also in Karachi.

Traffic ‐and Industry‐Related Air Pollution Exposure Assessment in an Asian Megacity

“…Generally, the average values were higher in the morning but were comparatively low in the noon and evening timings. The results were compared with other studies [50] showing that the values were higher than for Lahore and Karachi, but lower than that of Peshawar and Rawalpindi. The observed values at all the sites were also higher than the Pak-EPA safety limits.…”

“…Al, Ba, Ca, Cr, Cu, Fe, Pb, Mg, Mn, K, Na, Ti, and Zn [57] In total, 129 samples were collected from an urban site in Lahore (near two airports) with 6 h of sampling from November 2005 to January 2006 Na, Mg, Al, K, Ca, Cr, Mn, Fe, Co, Ni, Zn, As, Cd, and Pb [89] In total, 96 samples from an urban site and 79 samples from a rural site were collected from November 2002 to April 2003 with sampling duration of 12 h on day time basis Na, K, Fe, Mn, Pb, Cr, Zn, and Co [94] In total, 61 samples from an urban site and 44 samples from a rural site were collected from ) [50] but was much higher than for international cities such as Bangkok (60 ng m ). [34] Awan et al [43] analyzed Cd, Pb, and Zn from 48 TSP samples both quantitatively and qualitatively by FAAS and XRF, respectively.…”

“…The Pb contents were found higher in comparison to other reports [31] from the study area. [50] Usage of Pb-rich fuel was proposed as a main source of emission. For comparison, a summary of recent studies conducted in different areas of Pakistan with special reference to elemental profile is provided in Table 4.…”

“…Zn, Cu, Pb, and Cd [50] From outdoor and indoor environment of Wah Cantt (prime industrial area) during October 2008 to May 2009 with frequency of two to three samples per week Cd, Co, Cr, Cu, Fe, Mn, Pb, Sb, and Zn [55] In total, 215 samples were collected from typical urban area of Islamabad on 24-h basis during June 2005 to May 2006…”

“…The leaded petroleum fractions and battery manufacturing were regarded as major sources of emission. The average Pb [77] From Northern Pakistan during January, April, July, and October of 2006 PM2.5 [79] From Islamabad (around official buildings and industrial estate) during 2007-2011 and from Lahore (residential area), Peshawar (road site), and Quetta (high traffic area) during 2007-2008 PM2.5 [80] From major industrial area of Peshawar and samples were collected during first 20 days of April 2011 PM2.5 and PM10 [81] From indoor environment of 15 households located in Lahore with sample collection during different seasons from March 2012 to January 2013 with sampling duration of 72 h PM2.5 [114] From indoor and outdoor environment of an educational institute located at a high-traffic site in Lahore with sampling duration of 24 h for each sample PM2.5 [83] From an educational institution located at Khanspur during summer (May) and winter (December) for sampling duration of 24 PM1, PM2.5, PM4, PM10, and PM total [84] From a tourist spot located in Shogran for sampling duration of 24 h PM1, PM2.5, PM4, PM10, and PM total [85] From indoor environment of houses having different floor structures located in Gujranwala PM1, PM2.5, PM4, and PM10 [86] In total, 25 samples were collected from an urban site influenced by road transport located in Lahore during March of 2010 PM10 and TSP [87] From indoor and outdoor environment of various industrial and residential sites located in the metropolitan city of Lahore during December 2001 to January 2002 with sampling duration of 8-24 h SPM [47] From Karachi (urban site), Lahore (Residential site), Rawalpindi (densely populated commercial site), and Peshawar (road site) during March and April of 2010 PM2.5 and PM10 [50] From a typical urban area (having adjoining small scale industrial setup accompanied by high traffic burdens) located in Lahore with sample collection every sixth day from 12 January 2007-19 January 2008 PM 2.5, PM10, and PM10-2.5 [88] In total, 129 samples were collected from an urban site in Lahore (near two airports) with 6 h of sampling from November 2005 to January 2006 PM2.5 [89] From 33 urban sites located in six cities (Karachi, Lahore, Quetta, Rawalpindi, Islamabad, and Peshawar) with duration of 24 h per sample from 2003 to 2004 PM10 and TSP [32] From a busy road site in Karachi with sampling duration of 6 h and two sites in Islamabad (having industrial and rural areas) with sampling duration of 24 h from 10 December 1998-08 January 1999 TSP [48] www.advancedsciencenews.com www.clean-journal.com Table 4. Summary of some recent studies conducted in Pakistan with special reference to elemental profile.…”