Overview
This study determined acute LC50 values and chronic toxicity endpoints for palladium and platinum in spiked sediment using two standard freshwater benthic test organisms: the midge Chironomus riparius and the amphipod Hyalella azteca. Platinum was more acutely toxic than palladium in both species. Environmental sediment Pd concentrations from the literature (0.3-90.8 ng/g dw) are well below the chronic NOEC, suggesting current environmental exposures are sub-toxic to benthic invertebrates.
Key numbers
- Acute Pd LC50 in Hyalella azteca: 1192 +/- 356 ug/g dry weight (sediment)
- Acute Pd LC50 in Chironomus riparius: 209 +/- 44 ug/g dry weight (sediment)
- Acute Pt LC50 in Hyalella azteca: 289 +/- 28 ug/g dry weight (Pt more toxic than Pd)
- Acute Pt LC50 in Chironomus riparius: 84 +/- 7 ug/g dry weight
- Chronic Pd exposure in C. riparius: impacted survival, emergence, and female adult weight
- Chronic emergence time significantly higher vs control at all concentrations (29 to 705 ug/g dw)
- Environmental sediment Pd (from literature): 0.3-90.8 ng/g dw (well below NOEC)
- Nominal test concentrations: Pd 100-2000 ug/g dw (acute/chronic); Pt 50-500 ug/g dw
Methods (brief)
Sediment spiking protocol with Pd and Pt at multiple nominal concentrations. Acute 10-day tests with Chironomus riparius and Hyalella azteca. Chronic 28-day tests with C. riparius measuring survival, emergence timing, and adult weight. LOC/NOEC derived from chronic exposure endpoints. Environmental concentration comparison with published monitoring data.
Implications
This page makes the source discoverable for palladium evidence routing. Provides standard ecotoxicological benchmarks (LC50, chronic NOEC) for Pd and Pt in freshwater sediment, confirming that current environmental Pd concentrations in urban sediments are below thresholds for acute or chronic toxicity in benthic invertebrates.
Related evidence
Update history
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