Slooff W ; Bont PFH ; Hoop MAGT van den ; Janus JA ; Annema
JA
54 p
in Dutch
1993
Toon Nederlands
English Abstract Rare earth metals (RE) are not produced in the
Netherlands. However, the Netherlands import approximately 10% of the world
production of RE ; most manufactured products are exported. Important
applications are in catalysts, glass/ceramics, lighting and electronics.
Based on available information catalyst industry and artificial fertilizer
industry seem to be the most important sources of emissions. Available
information on both exposure and (no) effect levels for humans and
ecosystems are poor, both qualitatively and quantitatively. Based on
margins of safety, one may conclude that inhalatory exposure does not
present a risk to the general population in the Netherlands, but there is
insufficient information to indicate the risks related to oral exposure. In
this respect it is recommended to evaluate the influence of RE containing
artificial fertilizers on the RE concentrations in soil and agricultural
consumption products. Based on very limited information on the
ecotoxicological characteristics of RE, an indicative maximum tolerable risk
concentration (MTR) for RE of 0.1 - 1 mug.1-1 per "dissolved" element was
derived for surface water. This conservative range of the MTR estimate
overlaps the range of maximum concentrations that may be expected to occur
in the field. Taking into account the uncertainty in risk estimation it is
recommended to initiate both in depths studies on effects and
exposure.
