CHAPTER 8 • Quality Status. Appropriate Monitoring and Legislation of the North Sea
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to marine systems, where they tend to accumulate. Any system based on controlling chemical contaminants individually is now outmoded and inappropriate for its purpose.
The following points summarize important ways in which we believe a chemicallyorientated pollution control system is proving inadequate:
Environmental Quality Standards. While the protocol by which EQSs are determined
is rigorous enough, too many assumptions have to be made in their application for them
to serve their purpose adequately. EQSs are sometimes based on insufficient data, or
are not revised to take account of new data. Others have not been set because the hazard posed was not recognized until the chemical was in widespread use and a common
contaminant (e.g. endocrine disrupters). The utility of EQSs depends crucially on the
relevance of laboratory-based short term toxicology data to the environment, which
for ma .. 'lY reasons has always been doubtful, except as a means of determining the relative toxicity of a group of compounds.
Relationship of chemical data to toxicological thresholds. The utility of any EQS
to its purpose hinges on the extent to which toxicological thresholds, determined from
short-term laboratory experiments, have relevance to the biological impact of the
chemical in the environment (see Section 8.3.3) for which in situ data are much more
relevant). Laboratory experiments typically do not take into account many of the factors known to be important in the environment in determining the health or susceptibility of the organism (sex, season, breeding condition, etc.), or the bioavailability of
the chemical in the experimental medium (turbidity, DOC concentration or complexing
capacity, salinity). Sensitivity of biota to toxic effects depends on the environment experienced by the biota, which is at variance to that used in standard toxicity tests. The
relevance of an EQS to pollution depends on how well it indicates the likelihood of a
biological impact in the environment. The use of short-term lethal thresholds to predict long-term sublethal effects assumes a constancy in the acute/sublethal toxicity ratio.
This is unjustified, since the ratio is low for narcotic toxicants and high for others that
have a specific mode of action (e.g. TBT).
Weight of numbers. The sheer number of chemical contaminants entering the environment, particularly synthetic organic chemicals, has become too much for a regulatory sys~em based on the control of individual contaminants. The effluent of the river
Rhine is now estimated to contain as many as 40 000 individual contaminants. The
problem of control is aggravated by the fact that some classes of chemicals are biologically active at concentrations of nanograms per litre, and many are persistent with halflives of years in the marine environment. The growing burden for those regulatory
authorities with responsibilities for monitoring listed chemicals under EC and UK legislation has become overwhelming. Many significant contaminants go unmonitored,
and the frequency and spatial definition of monitoring is inadequate for its purpose,
and delays between sampling and analysiS devalues the data. As it is, the chemicallybased legislation motivates monitoring; links to the biological significance of the data
are often overlooked.
Redundancy in chemical legislation. Some classes of contaminants for which there
is pollution legislation and a requirement to monit.or are now known to pose much less
161
to marine systems, where they tend to accumulate. Any system based on controlling chemical contaminants individually is now outmoded and inappropriate for its purpose.
The following points summarize important ways in which we believe a chemicallyorientated pollution control system is proving inadequate:
Environmental Quality Standards. While the protocol by which EQSs are determined
is rigorous enough, too many assumptions have to be made in their application for them
to serve their purpose adequately. EQSs are sometimes based on insufficient data, or
are not revised to take account of new data. Others have not been set because the hazard posed was not recognized until the chemical was in widespread use and a common
contaminant (e.g. endocrine disrupters). The utility of EQSs depends crucially on the
relevance of laboratory-based short term toxicology data to the environment, which
for ma .. 'lY reasons has always been doubtful, except as a means of determining the relative toxicity of a group of compounds.
Relationship of chemical data to toxicological thresholds. The utility of any EQS
to its purpose hinges on the extent to which toxicological thresholds, determined from
short-term laboratory experiments, have relevance to the biological impact of the
chemical in the environment (see Section 8.3.3) for which in situ data are much more
relevant). Laboratory experiments typically do not take into account many of the factors known to be important in the environment in determining the health or susceptibility of the organism (sex, season, breeding condition, etc.), or the bioavailability of
the chemical in the experimental medium (turbidity, DOC concentration or complexing
capacity, salinity). Sensitivity of biota to toxic effects depends on the environment experienced by the biota, which is at variance to that used in standard toxicity tests. The
relevance of an EQS to pollution depends on how well it indicates the likelihood of a
biological impact in the environment. The use of short-term lethal thresholds to predict long-term sublethal effects assumes a constancy in the acute/sublethal toxicity ratio.
This is unjustified, since the ratio is low for narcotic toxicants and high for others that
have a specific mode of action (e.g. TBT).
Weight of numbers. The sheer number of chemical contaminants entering the environment, particularly synthetic organic chemicals, has become too much for a regulatory sys~em based on the control of individual contaminants. The effluent of the river
Rhine is now estimated to contain as many as 40 000 individual contaminants. The
problem of control is aggravated by the fact that some classes of chemicals are biologically active at concentrations of nanograms per litre, and many are persistent with halflives of years in the marine environment. The growing burden for those regulatory
authorities with responsibilities for monitoring listed chemicals under EC and UK legislation has become overwhelming. Many significant contaminants go unmonitored,
and the frequency and spatial definition of monitoring is inadequate for its purpose,
and delays between sampling and analysiS devalues the data. As it is, the chemicallybased legislation motivates monitoring; links to the biological significance of the data
are often overlooked.
Redundancy in chemical legislation. Some classes of contaminants for which there
is pollution legislation and a requirement to monit.or are now known to pose much less