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

EFFECTS ASSESSMENT
As mentioned in the introduction, the substances discharged into the soil can not only affect the
soil organisms but also can influence soil functions. Substances that are hydrophilic and that are
readily eluted with the rainwater into the ground water as well as those that geo-accumulate and
those that are poorly degradable in soil should be considered with special care. If the substance is
a biocide directly applied/emitted to soil, then the methodology referred in the Technical Notes
for Guidance in support of Directive 98/8 concerning the placing of biocidal products on the
market is recommended (http://ecb.jrc.it/biocides/).
The terrestrial ecosystem comprises of an above-ground community, a soil community and a
groundwater community. In this section only effects on soil organisms exposed directly via pore
water and/or soil are addressed. It is recognised that the strategy described here must therefore
be regarded as provisional. However, reference is made to the strategy for the air compartment
(Section 3.7) and for bioaccumulation and secondary poisoning of birds and mammals
(Section 3.8). It is currently not possible to carry out effect assessment for the groundwater
community because no toxicity data are available. However, ecotoxicity tests with groundwater
fauna and microflora have been proposed by Notenboom and Boessenkool (1992) and Van
Beelen et al. (1990).
The strategy described below is based on several documents relating to terrestrial effects
assessment: OECD (1989), Stavola (1990), Samsøe-Petersen and Pedersen (1994), UBA (1993)
and Römbke et al. (1993).
3.6.2 Strategy for effects assessment for soil organisms
Standardised methods exist for the soil compartment but toxicity tests with terrestrial organisms
are not yet included in a base set. For new substances toxicity tests with plants and earthworms
can be requested at level 1. At level 2 there are, as yet, no specific additional requirements to
examine effects on soil organisms. For existing substances data will probably be scarce: for most
chemicals the data set will consist of results from short-term tests with for example earthworms
and plants. Long-term tests methods are available (e.g. springtails and earthworms) but results
from these tests are seldom available for existing substances. For biocides, toxicity tests with
terrestrial organisms may be required depending on product type and expected use.
The equilibrium partitioning method can be applied to aquatic data to identify a PNEC for soil
organisms. However, this method cannot replace toxicity data for soil organisms and should only
be considered as a screen for identifying substances requiring further testing.
In common with the aquatic compartment, the objective of the assessment is to identify
substances that present an immediate or delayed danger to the soil communities.
Soil is a complex and heterogeneous medium in which biological processes are occurring.
Microorganisms play an important role in degradation processes and the mineralisation of
organic matter, allowing nutrients to be re-cycled in the ecosystem. Soil invertebrates are
contributing to the recycling of elements and play a significant part in creating and maintaining a
good soil structure. Finally, plants are primary producers and provide food for all other
heterotrophic organisms. Consequently, the protection of the soil community requires protection
of all organisms playing a leading role in establishing and maintaining the structure and the
functioning of the ecosystem. The use of results from tests that represent different and significant
ecological functions in the soil ecosystem is therefore suggested.
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