technical guidance documents - Institute for Health and Consumer ...

MARINE RISK ASSESSMENT
environment by examining both the exposures resulting from discharges/releases of chemicals
and the effects of such emissions on the structure and function of the ecosystem. In the TGD for
the inland environment this is practically done by considering five environmental compartments,
namely the aquatic ecosystem, the terrestrial ecosystem, top predators, the functioning of
Sewage Treatment Plants (STP) and the atmosphere. The environmental compartments are
assessed at the local and the regional spatial scale by comparing the Predicted Environmental
Concentration (PEC) with the Predicted No Effect Concentration (PNEC) for the ecosystem
using data from representative species at different trophic levels for the particular environmental
compartment. Top predators are assessed by assuming an exposure through the food chain. The
assessment addresses the functioning of the ecosystem as determined by the survival and wellbeing
of all the species in the specific ecosystem. It is assumed that the protection of species
protects ecosystem structure and hence the ecosystem function. It addresses the survival and
well-being of species populations rather than an individual organism.
While this approach must clearly also apply to the marine environment, it must be recognised
that the concepts and methodologies for the inland environment have largely been developed
with the local and regional spatial scales in mind, rather than the potential for global impact.
There are, therefore, additional concerns for the risk assessment of the marine environment,
which may not be adequately addressed by the methodologies used for the inland environmental
risk assessment. These are:
a. the concern that hazardous substances may accumulate in parts of the marine environment
and that:
(i) the effects of such accumulation are unpredictable in the long-term;
(ii) that such accumulation would be practically difficult to reverse;
b. the concern that remote areas of the oceans should remain untouched by hazardous
substances resulting from human activity, and that the intrinsic value of pristine
environments should be protected.
Of these additional concerns (a) above may be seen as the main concern. This is characterised by
a spatial and temporal scale not covered by the inland risk assessment approach. It is a concern
that chemical substances which can be shown both to persist for long periods and bioaccumulate
in biota, can give rise to toxic effects after a greater time and at a greater distance than chemicals
without these properties. While this is also true for the freshwater environment, the additional
concern in the marine environment is that once the chemical has entered the open seas, any
cessation of emission will not necessarily result in a reduction in chemical concentration and
hence any effects become difficult to reverse. Equally, because of the long-term exposures and
long-life-cycle of many important marine species, effects may be difficult to detect at an early
stage.
To meet these concerns, which principally relate to substances that are considered as Persistent,
Bioaccumulative and Toxic (referred to as PBTs), or have other properties which give rise to a
similar level of concern, an assessment approach will be detailed that will give special
consideration to this new protection goal. In this context, the assessment of risk fulfils
specifically the purpose of determining what are the sources, routes and pathways to the marine
environment. This assessment will facilitate in the subsequent risk management decisions on
which measures are the most effective in order to reduce the levels.
The structure of this section on marine risk assessment basically follows the structure of the
inland environmental assessment. It starts with a section of exposure assessment where specific
issues are highlighted relating to marine partitioning processes and marine degradation and
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