Journal article
Toxic metals in the atmosphere in Lahore, Pakistan
The Science of the total environment, Vol.408(7), pp.1640-1648
2010
DOI: 10.1016/j.scitotenv.2009.12.022
PMID: 20080284
Abstract
Aerosol mass (PM 10 and PM 2.5) and detailed elemental composition were measured in monthly composites during the calendar year of 2007 at a site in Lahore, Pakistan. Elemental analysis revealed extremely high concentrations of Pb (4.4 μg m − 3 ), Zn (12 μg m − 3 ), Cd (0.077 μg m − 3 ), and several other toxic metals. A significant fraction of the concentration of Pb (84%), Zn (98%), and Cd (90%) was contained in the fine particulate fraction (PM 2.5 and smaller); in addition, Zn and Cd were largely (≥ 60%) water soluble. The 2007 annual average PM 10 mass concentration was 340 μg m − 3 , which is well above the WHO guideline of 20 μg m − 3 . Dust sources were found to contribute on average (maximum) 41% (70%) of PM 10 mass and 14% (29%) of PM 2.5 mass on a monthly basis. Seasonally, concentrations were found to be lowest during the monsoon season (July–September). Principle component analysis identified seven factors, which combined explained 91% of the variance of the measured components of PM 10. These factors included three industrial sources, re-suspended soil, mobile sources, and two regional secondary aerosol sources likely from coal and/or biomass burning. The majority of the Pb was found to be associated with one industrial source, along with a number of other toxic metals including As and Cr. Cadmium, another toxic metal, was found at concentrations 16 times higher than the maximum exposure level recommended by the World Health Organization, and was concentrated in one industrial source that was also associated with Zn. These results highlight the importance of focusing control strategies not only on reducing PM mass concentration, but also on the reduction of toxic components of the PM as well, to most effectively protect human health and the environment.
Details
- Title: Subtitle
- Toxic metals in the atmosphere in Lahore, Pakistan
- Creators
- Erika von Schneidemesser - Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 North Park Street, Madison, WI, 53706, USAElizabeth A Stone - Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 North Park Street, Madison, WI, 53706, USATauseef A Quraishi - Institute of Environmental Engineering and Research, University of Engineering and Technology, G.T. Road, Lahore 54890, PakistanMartin M Shafer - Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 North Park Street, Madison, WI, 53706, USAJames J Schauer - Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 North Park Street, Madison, WI, 53706, USA
- Resource Type
- Journal article
- Publication Details
- The Science of the total environment, Vol.408(7), pp.1640-1648
- Publisher
- Elsevier B.V
- DOI
- 10.1016/j.scitotenv.2009.12.022
- PMID
- 20080284
- ISSN
- 0048-9697
- eISSN
- 1879-1026
- Grant note
- DOI: 10.13039/100000200, name: United States Agency for International Development; DOI: 10.13039/501100004681, name: Higher Education Commission, Pakistan; DOI: 10.13039/100000209, name: National Academy of Sciences
- Language
- English
- Date published
- 2010
- Academic Unit
- Chemistry; Chemical and Biochemical Engineering
- Record Identifier
- 9983985816402771
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