Table 1: Global burden of disease and the relative disease burden caused by diarrhoeal diseases (measured in DALYs), 2004 Disease or injury

Disability-adjusted life years, all age groups (millions)

1 2 3 4 5

Lower respiratory infections Diarrhoeal diseases

...

11 12

Unipolar depressive disorders Ischaemic heart disease HIV/AIDS

Tuberculosis Malaria

Source: WHO (2008)

94.5 72.8 65.5 62.6 58.5

34.2 34.0

Disability-adjusted life years, children 0–14 years (millions)

73.6 65.2 – –

8.5

3.4 32.4

6.2 4.8 4.3 4.1 3.8

2.2 2.2

Percentage of total DALYs, all age groups

of two transmission pathways; the faecal-oral pathway (i.e. disease-causing microbes originating from faecal contamina- tion make their way when water is ingested); or the ecosystem, where wastewater collects providing an ecological niche for the propagation of certain human diseases vectors. The latter group includes lymphatic filariasis, and in some parts of the world, for some vector species, West Nile infection; it does not, however, include malaria, as the anopheline vectors of this dis- ease generally do not breed in wastewater.

Non-communicable disease

Direct evidence of ill-health related to exposure to toxic com- pounds is harder to establish. This is because of complexities in the exposure pathways and the long-term effect of exposure to low doses over extended periods of time, during which other hazards and risks will complicate the picture. Pesticides and pesticide residues in agricultural run-off, heavy metals and toxic compounds in industrial waste, the group of persistent organic pollutants (which includes many first generation synthetic pes- ticides), endocrine disruptors and pharmaceutical and person care products all feature as confirmed, incriminated or suspect chemicals that pose health hazards.

ACCESS TO SANITATION

The connection between wastewater and human health is linked with access to sanitation and with human waste dispos- al. Adequate sanitation is expected to create a barrier between disposed human excreta and sources of drinking-water. Waste- water management is a key component of health risk manage- ment in this context.

Access to basic sanitation is part of the 2015 water and sanita- tion target under Millennium Development Goal 7: to halve, by 2015, the proportion of the population without sustainable access to safe drinking-water and basic sanitation. The WHO/ UNICEF Joint Monitoring Programme (JMP) is the formal mechanism to keep track of progress towards achieving these targets. Information up to 2006 showed 2.5 billion people lacked access to basic sanitation (WHO/UNICEF, 2008). The 2010 JMP report (WHO/UNICEF, in print) will report that fig- ure estimated to be 2.6 billion at the end of 2008. This means that, taking population growth into account the situation has remained stagnant and progress towards the sanitation target is off track.

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