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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Description of key information

Seven reliable chronic NOEC or EC10 values are selected for 3 annelid worm species, ranging from 130 mg Pb/kg dwv for hatching success of Dendrobaena rubida to 3000 mg Pb/kg dw for mortality of Eisenia fetida.
Similar toxicity tests are reported in different source documents (i.e. using the same organism, endpoint, soil and test conditions). For these cases, a geometric mean value is calculated. Two geometric mean values are calculated for tests with invertebrates.
• A geometric mean value is calculated based on 2 results for reproduction of Eisenia fetida in an OECD artificial soil (Spurgeon and Hopkin, 1995: NOECr = 608 mg/kg; Spurgeon et al., 1994: NOECr = 1822 mg/kg). The geometric mean is 1053 mg Pb/kg dw in the total risk approach.
• The second geometric mean value is calculated based on 2 results for reproduction of Eisenia fetida in a silt loam soil (Davies et al., 2002: NOECr = 400 mg/kg; Davies et al., 2003b: NOECr = 625 mg/kg). The geometric mean is 500 mg Pb/kg dw.
In total 5 NOEC or EC10 values for soft-bodied soil invertebrates are taken forward to the PNEC derivation.

Key value for chemical safety assessment

Additional information

Pyrochlore:

The overall chemical and physiological properties of pyrochlore are principally characterised by a degree of inertness because of the specific synthetic process (calcination at high temperatures, approximately 1000°C), rendering the substance to be of a unique, stable crystalline structure in which the majority of atoms are tightly bound and not prone to dissolution in environmental and physiological media. This has been shown in transformation/dissolution testing for antimony, in which dissolved Sb concentrations were below 27 µg/L (after 7 days at a loading of 0.1g/L) and 2 µg/L (after 28 days at a loading of 1 mg/L); thus implying a solubility of < 0.03% of antimony. Hence, Sb can be considered as not bioavailable and is not regarded concerning toxicological and environmental effects.

On the other hand, lead dissolution levels were much higher (>2.9 mg/L at a loading of 100 mg/L after 7 days at pH 6; 105 µg/L at a loading of 1 mg/L after 28 days at pH 6) and therefore have to be regarded concerning toxicological and environmental aspects. No substance-specific data on the toxicity of pyrochlore are available, so that instead read-across to lead oxide and sparingly soluble lead compounds was conducted

Lead:

Seven reliable chronic NOEC or EC10 values are selected for 3 annelid worm species, ranging from 130 mg Pb/kg dwv for hatching success of Dendrobaena rubida to 3000 mg Pb/kg dw for mortality of Eisenia fetida. Similar toxicity tests are reported in different source documents (i.e. using the same organism, endpoint, soil and test conditions). For these cases, a geometric mean value is calculated. Two geometric mean values are calculated for tests with invertebrates. • A geometric mean value is calculated based on 2 results for reproduction of Eisenia fetida in an OECD artificial soil (Spurgeon and Hopkin, 1995: NOECr = 608 mg/kg; Spurgeon et al., 1994: NOECr = 1822 mg/kg). The geometric mean is 1053 mg Pb/kg dw in the total risk approach. • The second geometric mean value is calculated based on 2 results for reproduction of Eisenia fetida in a silt loam soil (Davies et al., 2002: NOECr = 400 mg/kg; Davies et al., 2003b: NOECr = 625 mg/kg). The geometric mean is 500 mg Pb/kg dw. In total 5 NOEC or EC10 values for soft-bodied soil invertebrates are taken forward to the PNEC derivation.