conditions with regard to, among others, working and living conditions, pollutants, discrimination, exploitation, income, occupational safety, and legal and social security. All these factors substantially increase the risks of ill-health among people engaged in the informal sector. Using the perspective of urban ecology, we propose to include ecosystem services (ESS) and urban fabric. For example, urban expansion facilitates the loss of regulating ESS (e.g. water retention during the monsoon season) and provisioning ESS (e.g. local food production). The study of GRIFFITHS ET AL. (2010) makes it obvious that the widespread practice of earth in-filling in low lying, (i.e. temporally inundated) areas, for building ground construction is increasing in pace in Dhaka. The loss in provisioning and regulating ESS fosters deteriorating living conditions and increases environmental risks, particularly the risk of flooding (CALDWELL 2004; GRIFFITHS ET AL. 2010). Due to poverty, such negative effects are most prominent in the marginal settlements (BURKART ET AL. 2008). Furthermore, Dhaka’s expansion has been constrained by the surrounding tributary rivers of the Ganges-Brahmaputra Basin resulting in extreme densification of urban areas. Dense urban areas can be identified through their impervious urban fabric; this has manifold consequences for the urban ecosystem, including increased surface runoff or urban heat island effect (ALBERTI 2009), thus indirectly affecting urban health. We further propose including meso- and microclimate issues, such as the urban heat island effect, which is directly connected to the urban fabric. BURKART & ENDLICHER (2009) for example, found that cardiovascular mortality in urban areas of Bangladesh showed a secondary maximum during the hot season. This underscores the relevance of the urban heat island, as well as the increased vulnerability of
IHDP Update Issue 1, 2011
Photos: UN Photo, and IFPRI
44 Human Health and Global Environmental Change