WASTEWATER, HEALTH AND HUMAN WELLBEING
Securing safe water and reducing the unregulated discharge of wastewater are among the most important factors influencing world health. Unmanaged wastewater is a vector of disease, causing child mortality and reduced labour productivity, but receives a dispro- portionately low and often poorly targeted share of development aid and investment in developing countries. At least 1.8 million children under five years die every year due to water related disease, or one every 20 seconds (WHO, 2008).
THE BURDEN OF WATER ASSOCIATED DISEASE Infectious disease
Estimates of the global burden of water-associated human dis- eases provide a simple index hiding a complex reality. WHO estimates that worldwide some 2.2 million people die each year from diarrhoeal disease, 3.7 per cent of all deaths and at any one time over half of the world’s hospitals beds are filled with people suffering from water related diseases (UNDP 2006). Of the 10.4 million deaths of children under five, 17 per cent are attributed to diarrhoeal disease, i.e. an estimated 1.8 million under-fives die annually as a result of diarrhoeal diseases. For an estimated 88 per cent of diarrhoea cases the underlying cause is unsafe water, inadequate sanitation and poor hygiene. Moreover, it is estimated that 50 per cent of malnutrition is associated with repeated diar- rhoea or intestinal worm infections. Childhood malnutrition is at the root of 35 per cent of all global child mortality (WHO, 2008).
The burden of disease is about more than just mortality; it also takes into account the proportion of healthy life years lost. The Disability-Adjusted Life Year (DALY) is a time-based mea- sure of the burden on community health that combines years of life lost due to premature mortality and years of life lost due to periods of illness. Diarrhoeal diseases rank second in terms of global DALYs lost (see: Table 1).
It is difficult to tease out which fraction of the disease burden can be attributed to the poor management of wastewater. The role of wastewater in human ill-health can pass through one
40
Distribution of causes of death among children under five years and within neonatal period
HIV/AIDS
Non communicable diseases Measles Injuries
Malaria
Other infectous and parasitic diseases Diarrhoeal diseases
Neonatal deaths Acute respiratory infections
Prematurity, low birth weight
Birth asphyxia and birth trauma
Neonatal infections
Other
Other non-infectious Diarrhieal diseases Neonatal tetanus Congenital anomalies
05 10 15 20 Percentage Source: WHO, 2008.
Figure 15: Distribution of causes of death among children un- der five years and within the neonatal period, 2004 (Figure from WHO, 2008).
25 30 35 40
Water linked diseases Postneonatal diseases
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