Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
bioaccumulation: terrestrial
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented publication which meets basic scientific principles

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2005

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Earthworms were exposed to composted cattle manure contaminated with a range of concentration of either lead acetate or lead carbonate.
Relative Pb bioaccumulation rates in earthworms were compared over time (0, 20, 40 and 60 days).
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Lead carbonate
EC Number:
209-943-4
EC Name:
Lead carbonate
Cas Number:
598-63-0
Molecular formula:
CH2O3.Pb
IUPAC Name:
lead carbonate
Details on test material:
- Name of test material (as cited in study report): lead carbonate
- Molecular formula (if other than submission substance): Pb(CO3)2
Radiolabelling:
not specified

Test substrate

Vehicle:
not specified

Test organisms

Test organisms (species):
Lumbricus sp.
Details on test organisms:
TEST ORGANISM
- Common name: Earthworm
- Source: a local bait shop
- Age at test initiation (mean and range, SD): mature
- Weight at test initiation (mean and range, SD): 4-9 g

ACCLIMATION
- Acclimation period: 14 d
- Acclimation conditions: same as test

Study design

Total exposure / uptake duration:
>= 0 - <= 60 d
Total depuration duration:
2 d

Test conditions

Test temperature:
18 °C
Moisture:
20 %
Details on test conditions:
TEST SYSTEM
- No. of organisms per container (treatment): 12
- No. of replicates per treatment group: 4
- No. of replicates percontrol / vehicle control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- % sand: 72.5
- % silt: 21.8
- % clay: 5.7
- pH soil: 7.6
- Organic carbon (%): 1.9

Nominal and measured concentrations:
Nominal: 0, 100, 200 and 500 µg/g
Actual: 5.09, 171, 575 and 710 µg/g

Results and discussion

Any other information on results incl. tables

A significant Pb accumulation by earthworms was observed in the Pb(CO3)2 trial (lower than in PbAc).

The Pb concentration in the earthworm tissue increased with the duration of exposure, and also with the Pb concentration in the organic matter.

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
Pb(CO3)2 contamination produces significant Pb bioaccumulation. Yet Pb(CO3)2 may take longer (than PbAc) to equilibrate within the organic matter because of its lower solubility, and thus over time the Pb may become less and less bioavailable, resulting in a non-lihnear Pb bioaccumulation.