Biology Reference
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national or regional levels with this approach designed to allow countries
to adapt standards and monitoring according to local environmental, social,
economic and cultural conditions to determine legislative and regulatory
frameworks. For example, it is unlikely to be an efficient use of resources
for developing countries to spend scarce resources on determining stan-
dards and monitoring for substances with minor implications for public
health.
Microbial contamination is considered to pose the greatest threat to health
in both developing and developed countries, with fecally derived pathogens
being the principal concern.
1
The WHO Guidelines comment that the pres-
ence of pathogens in water can vary rapidly and by the time pathogen pres-
ence is detected many people may have been exposed. The WHO therefore
advocate that monitoring alone is not sufficient and should be incorporated
into a wider Water Safety Framework (WSF) and adoption of Water Safety
Plans (WSPs), implementing multiple barriers from catchment to consumer
to deliver sufficient protection (see
Figs 3.1
and
3.2
). So far there have been few
studies that have assessed the impact of WSPs on water safety, though those
that have, have been supportive.
3
A full discussion of WSF and WSPs is
beyond the scope of this topic, and the reader is referred to the WHO guide-
lines
1
for more detail as well as topics published by the WHO.
Health
targets
Acceptable
risk
Basic control approaches
Water quality
objectives
Other management
objectives
Define measures and interventions
(requirements, specifications)
based upon objectives
Assess
environmental
exposure
Assessment
of risk
Define key risk points and
audit procedures for overall
system effectiveness
Public
health
status
Define analytical verifications
(process, public health)
Figure 3.1
Schematic showing the WSF: expanded framework. Source:
Reproduced
from Figure 1.2 in Ref.
2
, originally from Figure 3.4 from (Bartram et al. 2001).
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