Black carbon aerosols in urban air in South Asia

We report data from a yearlong (2006–2007) study of black carbon concentrations ([BC]) measured at 5-min intervals with an Aethalometer in Karachi, Pakistan. Daily mean [BC] varied from about 1 to 15 μg m^?3. However, short-term spikes exceeding 40 μg m^?3 were common, occurring primarily during the morning and evening rush-hour periods. The [BC] values were highest during November through February, ～10 μg m^?3, and lowest during June through September, ～2 μg m^?3. Diurnal, seasonal, and day-of-the-week trends are discussed. It is demonstrated that these trends are strongly affected by meteorological patterns. A simple expression is applied to the concentration profiles to separate the effects of meteorological conditions and elucidate the underlying emissions patterns. Daily emissions varied from 14,000 to 22,000 kg of BC per day. When integrated over the year emissions for Karachi Proper were estimated at 6.7 kilometric tons per year and emissions for greater Karachi were 17.5 kilometric tons per year. Folding in the populations of each area yields BC emissions of 0.74 and 1.1 kg per person per year, respectively. Applying the model to previously collected data at Lahore, Pakistan yields emissions during November–January that are around a factor of two higher than those in Karachi, but because the BC measurements in Lahore covered only three months, no estimates of annual emissions were attempted. Given the large populations of these cities the local health impact from PM alone is expected to be severe but because of the high [BC] emissions the impact on the global climate may be equally significant.     

Environmental factors and its influence on human health in BRICS: implications for human development

Environmental Science and Pollution Research - BRICS economies are facing severe environmental issues that exert a detrimental impact on human health. The analysis intends to examine the impact of...     

Development of baseline (air quality) data in Pakistan

During 2003–2004, SUPARCO, the Pakistan Space and Upper Atmosphere Research Commission has conducted a year long baseline air quality study in country’s major urban areas (Karachi, Lahore, Quetta, Rawalpindi, Islamabad and Peshawar). The objective of this study was to establish baseline levels and behavior of airborne pollutants in urban centers with temporal and spatial parameters. This study reveals that the highest concentrations of CO were observed at Quetta (14 ppm) while other pollutants like SO₂ (52.5 ppb), NO _x (60.75 ppb) and O₃ (50 ppb) were higher at Lahore compared to other urban centers like Karachi, Peshawar etc. The maximum particulate (TSP) and PM10 levels were observed at Lahore (996 ug/m³ and 368 ug/m³ respectively), Quetta (778 ug/m³, 298 ug/m³) and in Karachi (410 ug/m³, 302 ug/m³). In all major cities the highest levels were recorded at major intersections and variations were directly correlated with traffic density. These pollutants showed highest levels in summer and spring while lowest were observed in winter and monsoon. A data bank has been generated for future planning and air pollution impact studies.     

Measuring the association of environmental,corporate, financial,and social CSR: evidence from fuzzy TOPSIS nexus in emerging economies

Environmental Science and Pollution Research - The purpose of this research is to measure the combing impact of corporate social responsibility on company performance and to conduct a comparative...     

Characterization of cytotoxicity of airborne particulates from urban areas of Lahore

A number of species (organic and inorganic) in airborne particulates cause the toxicity to living being. The potential of in vitro test methods were explored for toxicity assessment of trace toxic elements (inorganic species) present in ambient air on human being (lungs). A year long sampling of airborne particles (PM_2.5) was carried (April 2008 to March 2009) in Lahore, Pakistan. A total of thirty nine samples were collected on 47 mm Zefluor Teflon filter membranes and each was analysed to characterize for the elements: Sb, As, Be, Cd, Cr, Co, Pb, Mn, Hg using ICP-MS in water extract and total acid digestate. The samples cytotoxicity was also established using lung derived cells and MTS colorimetric assays. This generated dose response curves and IC₅₀ values for the elemental mixtures identified on the Teflon filter membrane. The results indicated that even at low concentrations airborne elemental mixtures displayed an additive toxic effect.     

Integrating biophysical and socioeconomic information for prioritizing watersheds in a Kashmir Himalayan lake: a remote sensing and GIS approach

Dal Lake, a cradle of Kashmiri civilization has strong linkage with socioeconomics of the state of Jammu and Kashmir. During last few decades, anthropogenic pressures in Dal Lake Catchment have caused environmental deterioration impairing, inter-alia, sustained biotic communities and water quality. The present research was an integrated impact analysis of socioeconomic and biophysical processes at the watershed level on the current status of Dal Lake using multi-sensor and multi-temporal satellite data, simulation modelling together with field data verification. Thirteen watersheds (designated as ‘W1–W13’) were identified and investigated for land use/land cover change detection, quantification of erosion and sediment loads and socioeconomic analysis (total population, total households, literacy rate and economic development status). All the data for the respective watersheds was integrated into the GIS environment based upon multi-criteria analysis and knowledge-based weightage system was adopted for watershed prioritization based on its factors and after carefully observing the field situation. The land use/land cover change detection revealed significant changes with a uniform trend of decreased vegetation and increased impervious surface cover. Increased erosion and sediment loadings were recorded for the watersheds corresponding to their changing land systems, with bare and agriculture lands being the major contributors. The prioritization analysis revealed that W5?>?W2?>?W6?>?W8?>?W1 ranked highest in priority and W13?>?W3?>?W4?>?W11?>?W7 under medium priority. W12?>?W9?>?W10 belonged to low-priority category. The integration of the biophysical and the socioeconomic environment at the watershed level using modern geospatial tools would be of vital importance for the conservation and management strategies of Dal Lake ecosystem.     

Application of the SO4(2-)/Se tracer technique to study SO2 oxidation in cloud and fog on a time scale of minutes

We have demonstrated the use of Se as a tracer to quantitatively determine in situ SO4(2-) production from SO2 oxidation in clouds and fogs. Until now, it has not been possible to study the kinetics of SO2 oxidation because the aerosol sampling interval for Se determination was limited to 2 h or longer. Here we report results of 5-min aerosol measurements carried out at Lahore, Pakistan, during January 9-11, 2001, using new methodology for Se analysis coupled with hydride generation and ICP-MS detection. These improvements will enable the tracer technique to determine in situ SO4(2-) production in clouds and fogs on a time scale of several minutes and possibly 1 min. The method may prove useful for kinetic studies of in-cloud SO2 oxidation and in the study of other phenomena such as atmospheric mixing, cloud drop lifetimes, and aerosol formation that occur on the time scale of a few minutes.     

Trichoderma harzianum: a green sorbent for Pb(II) uptake from aqueous solutions

This investigation describes the use of specially cultivated, nonliving biomass of Trichoderma harzianum as a biosorbent for the batch removal of Pb(II) from a stirred system under different experimental conditions. The metal removal depended upon pH, sorbent particle size, initial Pb(II) concentration, shaking speed, and sorption time. The optimal experimental conditions for the removal of Pb(II) by T. harzianum with an initial metal concentration of 100 mg L^?1 were obtained at a particle size of 53 μm, a pH of 4.5, a shaking speed of 200 rpm, and a contact time of 720 min. The results were analyzed in terms of adsorption isotherms and kinetic models. The Freundlich isotherm model and pseudo second-order model fitted well in the data. T. harzianum proved to be a good biomaterial for accumulating Pb(II) from aqueous solutions (q = 460 mg g^?1).     

Comparative assessment of respiratory and other occupational health effects among elementary workers

Objective. This study was conducted to assess hazards faced by elementary workers. Methods. A questionnaire survey and a respiratory function test (spirometry) were carried out on 150 respondents. Results. Major hazards identified related to sharp objects, heavy weight lifting, thermally harsh conditions, working at height, whole body vibration, chemicals, pathogens, increased noise levels and confined space entry. Workers suffered from upper and lower respiratory disorder symptoms, digestive problems, optical and musculoskeletal issues, etc. Spirometric measurement showed obstructive lung disorders to be highest among construction workers (CW) (48%) followed by sanitation workers (SW) (32%) and solid waste pickers (SWP) (28%). Restrictive lung pattern was dominant among SW (56%) followed by SWP (46%) and CW (42%). The observed FEV₁/FVC in diseased SWP, SW and CW ranged from 51 to 96%, from 52 to 98% and from 31 to 99% respectively while observed mean FEV₁ was 2.15, 1.79 and 1.70 L, respectively. Conclusion. The study findings show that occupational exposure can significantly influence respiratory system impairment and contribute to other ailments among elementary workers. The study recommends use of appropriate protective equipment and regular medical examination for early recognition of any health risk so that timely interventions for effective management may be undertaken.     

An assessment of air quality in Karachi,Pakistan

An atmospheric pollution survey was carried out at 13 sites in Karachi, Pakistan, simultaneously from 0600 h to 2100 h for 15 consecutive days in May 1990 which also included meteorological measurements. The monitoring sites were included along the prevailing wind patterns in Karachi. Carbon monoxide levels in the ambient air were found to reach 9–10 ppm along the busy urban streets whereas CO₂ level exceeded 370 ppm in these areas. Our survey indicates that NO₂ levels were exceeding U.S. ambient air quality standards. Maxmum NO₂ concentrations were observed (0.3–0.5 ppm) during the daytime from 0600 h to 2100 h. The surface ozone maximum around noon at the inland sites reached the levels of 40 ppb and 50 ppb respectively compared to upwind coastal Sites 1 level of 25 ppb. The Pb concentrations were approximately 3- to 7-fold higher than average, which corresponded well to urban air. Fossil fuel SO₄ (excess) and NO₃ were apportionally based on the assumption that these two anions were present as (NH₄)₂SO₄, and NH₄NO₃ in the aerosols. In the eastern part of the city atmospheric sulphate (SO₄) shows the combustion of coal as its source from the vicinity and downwind of a steel manufacturing plant.