Dodecaaluminium trimolybdenum dodecaoxide

Bioaccumulation: terrestrial

Description of key information

The available evidence shows the absence of aluminium biomagnification across  trophic levels both in aquatic and terrestrial food chains. The existing information suggests not only that aluminium does not biomagnify, but rather that it tends to exhibit biodilution at higher trophic levels in the food chain. More detailed information can be found in the attached document (White paper on waiving for secondary poisoning for Al & Fe compounds final report 02-02-2010. pdf).
BCF/BAF (Mo): 0.2 to 4 (dry weight basis) in plants, and 0.4 to 3.4 (dry weight basis) for earthworms

Additional information

No data on terrestrial bioaccumulation are available for aluminium molybdenum oxide. However, there are reliable data available for different analogue substances.

The environmental fate pathways and ecotoxicity effects assessments for aluminium metal and aluminium compounds as well as for molybdenum metal and molybdenum compounds is based on the observation that adverse effects to aquatic, soil- and sediment-dwelling organisms are a consequence of exposure to the bioavailable ion, released by the parent compound. The result of this assumption is that the ecotoxicological behaviour will be similar for all soluble aluminium and molybdenum substances used in the presented ecotoxicity tests. As aluminium molybdenum oxide has shown to be only slightly soluble in water (pH 4.5, 7d) and poorly soluble in ecotoxicity test media (pH 7.5-8.5, 96h), it can be assumed that under environmental conditions in aqueous media, the components of the substance will be present in a bioavailable form only in minor amounts (Mo) or hardly, if at all (Al). Within this dossier all available data from soluble and insoluble aluminium and molybdenum substances are taken into account and used for the derivation of ecotoxicological and environmental fate endpoints, based on the aluminium ion and molybdenum ion. All data were pooled and considered as a worst-case assumption for the environment. However, it should be noted that this represents an unrealistic worst-case scenario, as under environmental conditions the concentration of soluble Al³⁺and MoO₄^2-ions released from aluminium molybdenum oxide is negligible (Al) or low (Mo), respectively.

Aluminium

The available evidence shows the absence of aluminium biomagnification across trophic levels both in aquatic and terrestrial food chains. The existing information suggests not only that aluminium does not biomagnify, but rather that it tends to exhibit biodilution at higher trophic levels in the food chain. More detailed information can be found in the attached document (White paper on waiving for secondary poisoning for Al & Fe compounds final report 02-02-2010.pdf).

Molybdenum

Mo concentration ranges in environmental matrices have been compiled. The data includes concentrations of Mo in the environmental compartments, excluding geogenic enriched areas, and at moderate levels below Mo concentrations causing a toxic effect.

This data suggests that Mo is not significantly concentrated from soil to plants, or soil invertebrates with bioconcentration factors (BCF) or bioaccumulation factors (BAF) of < 5, and that there is no further significant increase in concentration from diet to mammals or birds, even including organs such as kidney or liver (diet tissue concentration ratios <10 and even <1 for muscle tissue). This suggests that biomagnification of Mo, if any, is not significant in the terrestrial compartment and foodchain.

Eisler (1989) made a more exhaustive compilation of environmental concentrations of Mo. That review concluded equally that Mo concentrations in plants, mosses and wildlife tissues (liver and kidney included) are well below 10 mg/kg dry weight, excluding legumes (e.g. clover) that contain up to 28 mg/kg dry weight. Legumes –N2 fixing plants - require higher levels of Mo as the latter element is required for the proper functioning of the enzymes nitrate reductase and nitrogenase.