Report from the Sub-comittee on the environment and health

Uncertainties and
variations
162
A = ecotoxicologically set zero effect level for aquatic organisms using a
safety factor. 0.1µg/L = <strong>the</strong> limit value for pesticides given in <strong>the</strong>
Drinking Water Directive (µg/L = microgramme per litre).
(Figure text:
Effekt = Effect
Laveste effektniveau for akvatiske dyr og planter = Lowest effect level
for aquatic organisms and plants
Lavest effektniveau for mennesker = Lowest effect level for humans
Økotoksikologisk risikovurdering = Ecotoxicological risk assessment
Humantoksikologisk risikovurdering = Human-toxicological risk
assessment
Koncentration i vand = Concentration in water)
2) A zero value approach
In <strong>the</strong> zero value approach, basis is set by uncertainties, random
variations and possible erroneous assessments, including insufficient data
or a direct lack of knowledge, and greater importance is attached to a
general recognition of <strong>the</strong> fact that data, documentation and/or concrete
knowledge must always, scientifically, be regarded as deficient. From a
desire for a “zero concentration or dose”, requirements can be made
concerning insignificant, possibly ‘immeasurable’ content/doses/loads
etc. for exposed individuals, populations and/or environments. This is
illustrated in figure 8.2.
Effekt
0,1 µg/L NELA NELB NELC Dosis
“Nulværdi”
A B C
Figure 8.2
The zero value approach with a fixed, low limit. A, B and C refer to
individual pesticides with different toxicity. The curves can be <strong>the</strong> lowest
toxic dose/effect curves for humans: NELA, NELB and NELC = lowest
effect level for A, B and C, respectively. 0,1µg/L = <strong>the</strong> limit value for
pesticides given in <strong>the</strong> Drinking Water Directive (µg/L = microgramme
per litre).
(Figure text:
Effekt = Effect
Nulværdi = Zero value
Dosis = Dose)
Operationalisation of <strong>the</strong> approaches must accordingly be linked to <strong>the</strong>
assessment of documentation and data, including – particularly, <strong>the</strong> lack
of material and data, which can be concretised to a number of variations
and uncertainties comprising: