Urban areas are extremely complicated environmental settings, where health and well-being of an individual and population govern by a large number of bio-physical, socio-economical, and inclusive aspects. Featuring speedy growth and development, the urban areas of developing nations are confronting with burgeoning population. Urban environment is increasingly under pressure with the shortage in housing provision. A significant urban population resides in slums. Unsafe, unsecure, and unsanitary living conditions; lack of basic services; and exclusion from participation in developmental process continue to worsen the health and economic productivity of urban poor who could not afford formal housing. These informal settlers or slum dwellers are both medium and sufferer of environmental degradation. Inevitable parts of the cities as well as urban environment, the slums are one of the major challenges for urban environment planning and management. These vulnerable entities are anthropogenic environmental problem for the city in general and specifically for its inhabitants.
The world's population is becoming increasingly urbanized are a prominent feature of urbanization in the developing world, and two thirds of the world's megacities are located in developing countries .However, the relationship between the characteristics of megacities and the health of their residents is not always clear. Rapidly increasing populations in megacities have been linked to increased environmental pollution (deteriorating air, water, and soil quality), poor housing, high population density and crowding, and poor services such as water and sanitation. Within megacities, slum dwellers have been cited as a particularly vulnerable group. Although increased environmental pollution can plausibly be linked to adverse human health impacts, especially among slum dwellers, this relationship is confounded by the underlying poverty and lack of education of this group, which could independently lead to poor health and nutritional status.