The world and its geo-bio spheres is an integrated system – a system of interrelated components and elements of which none can be segregated. The two most profound components of this system are the environment and human beings. There exists a web of linkages between the two wherein sustainability holds a critical position. For sustaining the ‘good’ health of people, a sustainable environment is as indispensable as oxygen to the body.
Urban health is of concern for two reasons: (1) the large numbers of persons involved, and (2) the fact that the population density of an area changes the potential for both public health problems and solutions. In the 21st century, cities are so ubiquitous and their impact so pervasive that it is difficult to ignore the role of cities when considering any aspect of health. As growing numbers of people live in cities, urban population health contributes to global population health.
A current hot potato is the state of human health in the rapidly growing city of Delhi as well as its deteriorating environment. Whilst the city’s population has grown majestically from 1.74 million (1951) to 16.75 million (2011) on 1,483 sq.km of land, it counts the density of 11,297 persons per sq.km. In response to the needs of thriving urbanization and globalization, there is massive vehicularization and land use alterations. The pervious landscape is replaced with impervious concrete and asphalt that affect the albedo and run-off characteristics of the land surface, thus significantly impacting the local and regional land-atmosphere energy exchange processes.
Increases in anthropogenic heat discharge, decreases in surface evaporation, changes in thermal characteristics, and increasing air pollution have disrupted the radiation balance. Hence, urban areas generally act as islands of elevated temperature relative to the areas surrounding them, which is commonly known as the ‘urban heat island’ (UHI) effect (Singh et al., 2011; Lo & Quattrochi; Stone et al., 2014; Oke, 1982). The higher temperatures in the city brought about by UHI have adversely affected air quality and have also increased heat stroke incidences. Consequently, cities that are centers of opportunity have translated to grave risk zones. While the best health services are expected to be available and accessible in these centers of excellence, the worst environmental threats affecting human health and wellbeing are also offered by the city.
High degrees of heat and air pollution can cause stress and heat stroke especially for people with cardiovascular and respiratory disorders (Piver et al., 1999). Respiratory system diseases, minor skin and eye problems, and cancer cases and heart diseases have seen exponential rise in the past decade as counterblast to environmental changes. Studies reveal that nearly 40,000 Indians experience early death due to air pollution every year, of which 7,500 are from the national capital of Delhi. It is alarming to note that 8.6% of mortality cases in India (2009) were due to diseases of the respiratory system where pneumonia and asthma were major killers (Ministry of Home Affairs, 2009). A temporal analysis from 1991 to 2009 suggests that nearly 3,000 deaths occur annually due to diseases of the respiratory system in Delhi alone.
The relationship between air pollution and its impacts has been highlighted by scholars as warning signals. Using mortality data, Cropper et al. (1997) established that there is positive relationship between particulate pollution and daily non-traumatic deaths from respiratory and cardiovascular problems. Jayaraman and Nidhi (2008) concluded that there is high correlation between particulates and chronic respiratory symptoms. RSPM levels were found to be strongly correlated with lower respiratory tract illness by Siddique et al. (2010). Commonly found diseases include dry and wet cough, wheezing, whistling sounds while breathing, pain in the lungs and breathlessness, sinusitis, rhinitis, sneezing, sore throat, common cold, pulmonary emphysema, cancer, eye burning, acute bronchitis, bronchitis, chronic and unspecified emphysema, asthma, headache, damage to skin, and diseases of the circulatory system. Of particular note, males are more vulnerable than females, and children and the elderly are the most affected as their immunity is much lower. There are also seasonal variations in respiratory illness. Researchers point out that winters are most severe and harsh on human health whilst the monsoon season is the mildest.
If health is a multi-dimensional concept involving physical, psychological, and social components, then how can urban environments be solely responsible for ill-health? Despite the influences of dietary habit, lifestyle, stress, occupation, and other socio-economic-cultural factors, environment remains supreme. The degree of influence that our immediate surroundings have, however, is mediated by factors of lifestyle and socio-cultural contexts. There is differential vulnerability on the basis of age, gender, immunity, and other factors that play a vital role in health. The level of contact to harmful environments and the duration of exposure determine the state of human health.
Reflections on these complex side-effects for health persuade us to choreograph city growth in an alternative manner so as to minimize unforeseen repercussions. Behavioural changes can have a butterfly effect on the urban environment. These include carpooling, abiding by laws and rules, and educating drivers on air pollution and the optimum use of fuel and urban amenities. Besides this, greening roofs, lawns, walls and terraces, and the planting of indigenous pollutant tolerant tree species like Mangiferaindica (Mango), Ficus religiosa (Peepal), Azadiracta indica (Neem), Acacia Arabic (Babool), can give positive results. This must be accompanied with strict policy norms on the cutting of trees, land use changes, fuel use, and vehicle and industrial pollution control laws to be implemented by the state. The right to safe environmental surroundings is the right of all citizens of the nation and hence sustainable urban development can only be achieved collectively.
Singh, R.B., Grover, A., Zhan, J. Inter-seasonal variations of surface temperature in the urbanized environment of Delhi using Landsat thermal data, Energies 2014, 7, 1811–1828.
Lo, C.P., Quattrochi, D.A. Land-use and land-cover change, urban heat island phenomenon, and health implications: A remote sensing approach, Photogramm. Eng. Remote Sens. 2003, 69,1053–1063.
Stone, B., Hess, J.J. and Frumkin, H. Urban form and extreme heat events: are sprawling cities more vulnerable to climate change than compact cities?, Environmental Health Perspectives, 2010, 118, 1425-1428.
Oke, T.R. The energetic basis of the urban heat island. Quarterly Journal of the Royal Meteorology Society, 1982, 108, 1-24.
Piver, W.T., Ando, M., Ye, F. and Portier, C.J. Temperature and air pollution as risk factors for heat stroke in Tokyo, July and August1980-1995. Environmental Health Perspectives, 107, 911-916.
Ministry of Home Affairs, 2009, Report on Medical certification of Cause of death, Office of the Registrar General & Census Commissioner, Government of India
Jayaraman, G., Nidhi Air pollution and associated respiratory morbidity in Delhi, Health care and management science, 2008, 11, 132-138.
Siddique, S., Benerjee, M., Ranjan Ray, M., Lahiri, T. Air pollution and its impact on lung function of children in Delhi, the capital city of India, Water Air Soil Pollut, 2010, 212, 89–100
Cropper, M.L., Simon, N.B., Alberini, A., Sharma, P.K. The health effects of air pollution in Delhi, India, 1997, Policy Research Working Paper 1860, The World Bank, 1-40.
R.B. Singh is the Vice President at International Geographical Union (IGU), Member of IUGG-IGU Joint National Committee, Indian National Science Academy (INSA) and Springer Series Editor: Advances in Geographical and Environmental Sciences. He is presently the head of Department of Geography, Delhi School of Economics, University of Delhi, India. He specializes in environment and ecology, disaster management and remote sensing and GIS.
Aakriti Grover is an Assistant Professor of Geography at the Swami Shraddhanand College, University of Delhi. She is also a research scholar at the Department of Geography, Delhi School of Economics, University of Delhi, India. Her research interests include urban environment and urban health.
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