Report from the Sub-comittee on the environment and health

International cooperation
146
be illustrated in <strong>the</strong> following, using pesticide pollution of groundwater
as an example.
In 1997, a conference was held, under <strong>the</strong> OECD, on risk indicators for
pesticides with a view to measuring trends in <strong>the</strong> risks associated with
<strong>the</strong> use of pesticides. Indicators have been developed for different
purposes, one of which is to assess national risk reductions and identify
those pesticides that contribute most to <strong>the</strong> total risk. Since <strong>the</strong> indicators
used differ in <strong>the</strong>ir structure, pesticides can in some cases be indexed
differently. It was also pointed out that a number of indicators would be
preferable to a single indicator because <strong>the</strong>re are no satisfactory methods
for combining different types of risk for each pesticide. The OECD
working group Pesticide Forum is now continuing work on <strong>the</strong>
development of risk indicators for pesticides on <strong>the</strong> basis of <strong>the</strong>
conference’s recommendations. The results of this work were presented
at a workshop in June 1999.
Under <strong>the</strong> EU, work started in 1998 on a project called Concerted Action
on Pesticide Environmental Risk Indicators (CAPER). The purpose of
<strong>the</strong> project is to compare eight different indicators for <strong>the</strong> environmental
effects of pesticides. The eight indicators have been developed for
decision-support systems, for example, and for comparison of farming
systems. Most of <strong>the</strong>se indicators have not yet been published. It should
be noted that, in EU contexts, too, <strong>the</strong>re is a need to recognise <strong>the</strong> extent
to which ranking models can be used to identify <strong>the</strong> most
environmentally harmful pesticides (Lindhardt et al. 1998).
8.1.1 Risk of groundwater pollution
There are several methods for calculating indices that allow ranking of
pesticides with respect to <strong>the</strong> load on <strong>the</strong> groundwater. Table 8.1 shows
<strong>the</strong> methods that are relevant for Danish conditions and <strong>the</strong> parameters
and data used in <strong>the</strong>m.
Table 8.1
Methods of ranking <strong>the</strong> potential of pesticides for leaching to groundwater. The methods are listed in
order of increasing complexity and data requirements. The table also shows <strong>the</strong> types of parameters
used in <strong>the</strong> methods.
Method Dose Degradation Adsorpti
on
in soil
Soil
parameters
Water transport Spatial
variation
in <strong>the</strong> soil
GUS index x x
Hasse diagram x (x) x
AF index x x x x
Dutch point system x (x) x x x
Yardstick method (x) x x x x
Fuzzy expert model x x x (x) (x) (x) (x)
Expert assessment x x x x (x) (x) (x)
Deterministic models x x x x x x (x)
Stochastic models x x x x x x x
GUS index
Climat
e
The GUS index was developed by <strong>the</strong> California Department of Food and
Agriculture (Gustafson 1989). It is a very simple index for <strong>the</strong> risk of
leaching to <strong>the</strong> groundwater. The index is based only on <strong>the</strong> inherent
properties of <strong>the</strong> active ingredient. It divides pesticides into three