Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
biodegradation in soil
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The testing methodology is well described Acceptable, well-documented publication which meets basic scientific principles

Data source

Reference
Reference Type:
publication
Title:
Phosphate-induced lead immobilization from different lead minerals in soils under varying pH conditions
Author:
Xinde Cao, Lena Q. Ma, SatyaP. Singh, Qixing Zhou
Year:
2008
Bibliographic source:
Environmental pollution 152, 184-192

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Dissolution behaviour of Pb in soils at different pH
GLP compliance:
not specified
Test type:
laboratory

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:
λ²-lead(2+) carbonate

Study design

Oxygen conditions:
not specified
Soil classification:
not specified
Soil propertiesopen allclose all
Soil no.:
#1
Soil type:
sandy loam
% Clay:
>= 0 - <= 10.9
% Silt:
>= 0 - <= 10.9
% Sand:
89.1
% Org. C:
2.96
pH:
>= 7.57 - <= 7.59
CEC:
4.7 other: cmoles/Kg
Soil no.:
#2
Soil type:
sandy loam
% Clay:
>= 0 - <= 13.5
% Silt:
>= 0 - <= 13.5
% Sand:
86.5
% Org. C:
5.09
pH:
>= 7.2 - <= 7.22
CEC:
6.7 other: cmoles/Kg
Duration of test (contact time)open allclose all
Soil No.:
#1
Duration:
2 wk
Soil No.:
#2
Duration:
2 wk
Initial test substance concentrationopen allclose all
Soil No.:
#1
Initial conc.:
7.7 mg/kg soil d.w.
Based on:
not specified
Soil No.:
#2
Initial conc.:
5 550 mg/kg soil d.w.
Based on:
not specified
Experimental conditionsopen allclose all
Soil No.:
#1
Temp.:
room temp.
Humidity:
40%
Soil No.:
#2
Temp.:
room temp.
Humidity:
40%

Results and discussion

% Degradationopen allclose all
Soil No.:
#1
% Degr.:
0.03
Parameter:
other: pH = 7
Sampling time:
3 h
Soil No.:
#1
% Degr.:
1.29
Parameter:
other: pH = 5
Sampling time:
3 h
Soil No.:
#1
% Degr.:
51
Parameter:
other: pH=3
Sampling time:
3 h
Soil No.:
#2
% Degr.:
0.03
Parameter:
other: pH=7
Sampling time:
3 h
Soil No.:
#2
% Degr.:
0.8
Parameter:
other: pH = 5
Sampling time:
3 h
Soil No.:
#2
% Degr.:
38.4
Parameter:
other: pH = 3
Sampling time:
3 h
Transformation products:
not specified
Evaporation of parent compound:
not specified
Volatile metabolites:
not specified
Residues:
not specified

Applicant's summary and conclusion

Conclusions:
In the study, lead carbonate was found slightly soluble in soil at neutral pH, but much more soluble at acidic pH. However, using Phosporus can easily form an insoluble form.