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EC number: 231-970-5 | CAS number: 7782-91-4
Bioaccumulation: aquatic / sediment
Administrative data
Link to relevant study record(s)
Description of key information
Data that were retrieved, suggest that molybdenum bioconcentration through the food chain is negligible: whole body internal concentrations remain below 1 mg/kg at concentration levels up to several mg/L. Reported whole-body BAFs vary more than 2 orders of magnitude, but there is a distinct inverse relationship between exposure concentration and BAF, i.e., decreasing BAFs with increasing Mo-levels in the water column.
Key value for chemical safety assessment
Additional information
Regardless of the exposure concentration, Mo-levels in livers of fish ranged from <0,019 to 14.9 mg/kg wet weight , with a median value of 0.45 mg/kg wet weight, and a 90thpercentile of 1.71 mg/kg wet weight. Mo-levels in muscle samples were markedly lower, i.e., ranging from 0.01 to 7.59 mg/kg wet weight, with a median value of 0.043 mg/kg wet weight, and a 90thpercentile of 0.924 mg/kg wet weight. Median Mo-level in the muscle tissue is one order of magnitude lower than the median Mo-level in liver samples.
The current data set comprises around thirty values that represent whole body Mo-levels in fish (based on wet weight). Values are situated between 0.012 and 14.3 mg/kg wet weight, with a median Mo-concentration of 0.22 mg/kg wet weight. Few values below detection limit were not included as the detection limit of <0.5 mg/kg wet weight was greater than the median value. Assuming that levels in these fish were equal to 0.5 mg/kg wet weight, a median value of 0.31 mg/kg wet weight is obtained. The 90thpercentile of Mo-concentration in whole body samples was 3.00 mg/kg wet weight.
Median levels for other organs like bone, brain, intestines, kidneys, skin, spleen and stomach, were 0.185, 0.028, 0.064, 0.1184, 0.071, 0.092 and 0.041 mg/kg wet weight, respectively. For the gill only few data points were identified, ranging from 0,016 to 5.94 mg/kg wet weight.
Limited information on transfer of Mo through the food chain indicates that molybdenum does not biomagnify in aquatic food chains.
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