Pak. J. Bot., 42(5): 3547-3554, 2010.

FREE FULL TEXT PDF

SPATIAL ASSOCIATION OF ASTHMA AND VEGETATION IN KARACHI: A GIS PERSPECTIVE

IMRAN AHMED KHAN¹, MUDASSAR HASSAN ARSALAN¹, MUHAMMAD FAHEEM SIDDIQUI², SAMREEN ZEESHAN³ AND SYED SHAHID SHAUKAT²

Abstract: A number of evidences confirm that the prevalence of asthma varies from place to place due to a variety of factors. This study focuses on the vegetation and health concerns, and assesses the utility of Geographic Information Systems, to investigate the spatial correspondence between asthma and vegetation in Karachi. Natural land-cover has both advantages and disadvantages with respect to health. Sometimes naturally growing or introduced plants can be noxious like some plants that release allergenic pollen or spores so that plant related allergy and asthma may occur. GIS is an effective computer mapping and analytical tool that permits huge quantities of information to be analyzed and explored, GIS and its associated spatial analytical techniques have been used extensively to study public health issues in recent years. The ultimate purpose of this study is not merely to present data, but also to seek association between the prevalence of asthma and plant cover (vegetation) in Landhi and Korangi towns of Karachi city, Pakistan. The populations under study were the residents of the Landhi and Korangi towns of Karachi metropolis. The study was designed to the assessment of asthma prevalence and its relation with the existing vegetation within the study area. A questionnaire was developed to evaluate desired data using a stratified random sampling design with union councils serving as strata for obtaining data with a sampling intensity of 0.1 %. The executed sample frame was based on 987 questionnaires from randomly selected households and collected information about asthma and related issues, later GIS was used for classification of Landcover of the study area with a satellite image and tabulated vegetation cover areas of different union councils, and finally the relationship of asthma and the vegetation cover was evaluated using Microsoft Excel. The vegetation cover was found to have a significant positive correlation with asthma prevalence. Such a relationship can be attributed to several possible causes. The most important one is that some of the constituent plant species may have allergenic pollen. Previous studies have attributed asthma prevalence to urban life style, with its associated industrial emissions, occupational exposure and certain items of daily use that can cause allergy and consequently affect human health. However, this study provides a direct evidence of a connection existing between the vegetation cover with the prevalence of asthma.

¹Department of Geography, University of Karachi, Karachi 75270, Pakistan

²Laboratory of Dendrochronology and Plant Ecology of Pakistan, Department of Botany, Federal Urdu University of Arts, Science and Technology, Gulshan-e-Iqbal, Karachi, Pakistan

³Civil Hospital Karachi, Pakistan.

^*Corresponding authors E-mail: mfsiddiqui2007@yahoo.com; imranak32@hotmail.com