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Environmental fate & pathways

Bioaccumulation: terrestrial

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Administrative data

Endpoint:
bioaccumulation: terrestrial
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2005-04-28 to 2005-07-07
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well conducted study to GLP

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2005
Reference Type:
publication
Title:
Unnamed
Year:
2005

Materials and methods

Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
Carrots were grown in the presence of radiolabelled C14-17 chlorinated paraffin (52% chlorinated) and the accumulation in the roots at intervals up to 70 days was compared with the soil concentrations.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): C14-17 chlorinated paraffin ( 52% chlorinated)
- Substance type: technical product
- Analytical purity: no data
- Impurities (identity and concentrations): no data on the absence/presence of a stabiliser.
- Composition of test material, percentage of components: C14-17 chlorinated paraffin.
- Lot/batch No.:no data
- Storage condition of test material: no data
Other
- Name of test material (as cited in study report): chlorinated n-pentadecane-8-14C (52.48% chlorinated)
- Radiochemical purity (if radiolabelling): no data
- Specific activity (if radiolabelling): 39.2 MBq/g (1.06 mCi/g)
- Locations of the label (if radiolabelling): 8-14C
- Expiration date of radiochemical substance (if radiolabelling): no data
- Stability under test conditions: no data
- Storage condition of test material: frozen in container it was received in

Test substance: defined in the report as test material (chlorinated paraffin (52% chlorinated, C14-17)) mixed with radiolabelled material (chlorinated n pentadecane-8-14C)
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):none used
Radiolabelling:
yes

Sampling and analysis

Details on sampling:
- Sampling intervals/frequency for test organisms: days 42, 50, 60 and 70- Sampling intervals/frequency for test medium samples: days -57, -2, 28 and 70- Sample storage conditions before analysis: no data- Details on sampling and analysis of test organisms and test media samples -Test organism: Samples were partially dried (65oC), cut into small sections (<1 g) and combusted to 14CO2. -Test media: soil from day -57 was extracted twice with acetone and the total radioactivity in the extracts determined. : soil from day -2 was extracted twice with hexane, ethyl acetate and dichloromethane and the total radioactivity in the 6 extracts determined. Samples of the residual soil were combusted to 14CO2 : soil from days 28 and 70 was air-dried by ball milling and samples combusted to 14CO2.

Test substrate

Vehicle:
yes
Details on preparation and application of test substrate:
- Method of mixing into soil (if used): Samples of stock solution of test substance (medium-chain chlorinated paraffin and 14C-labelled n-pentadecane) in acetone were mixed with dried sewage sludge (175 g) and the spiked sludge mixed with the required amount of soil on an inclined roller, rotating at 21 rpm, for 1 hour. The soil and spiked sludge were divided into 2 portions for mixing and the two mixed portions combined.- Controls: a solvent control was used prepared from acetone-only spiked sludge.- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone- Evaporation of vehicle before use: yes

Test organisms

Test organisms (species):
other: Daucus carota
Details on test organisms:
TEST ORGANISM- Common name: Carrot- Source: Suttons Seeds Torbay, Devon

Study design

Total exposure / uptake duration:
70 d
Total depuration duration:
0 d

Test conditions

Test temperature:
20 ± 2oC nominal (19.6 to 21.4oC : measured 3 times/week)
pH:
6.6-7.3
TOC:
2%
Moisture:
no data
Details on test conditions:
TEST SYSTEM- Test container (material, size):Polypropylene container 570x360x160 mm- Amount of soil or substrate: 35 kg dry weight- No. of organisms per container (treatment): 127 seeds/treatment- No. of replicates per treatment group: 1- No. of replicates per control / vehicle control: 1SOURCE AND PROPERTIES OF SUBSTRATE (if soil)- Composition (if artificial substrate): 50% Surrey loam/50% gravel + nutrients- pH water: no data- pH soil: 6.6-7.3- Organic carbon (%): 2.0 (after sludge addition)- Moisture (%): 7.46 (before use)- Maximum water holding capacity (in % dry weight): no data- Stability and homogeneity of test material in the medium: no dataOTHER TEST CONDITIONS- Adjustment of pH: no data- Photoperiod: 16 h light: 8 h dark- Light intensity: 17,500 lux nominal (14200-18440 lux measured )VEHICLE CONTROL PERFORMED: yes
Nominal and measured concentrations:
Nominal soil concentration (mg/kg dry weight) : 1 and 10Measured concentrations (mg/kg dry weight) : Day -57 (after soil spiking): 1 and 13 Day -2 : 0.95 and 5 Day 28 : <0.47 and 5.8 Day 70 : <0.43 and 3.9

Results and discussion

Bioconcentration factor
Type:
BSAF
Value:
0.045
Basis:
whole body w.w.
Calculation basis:
other: mean of values on days 50, 60 and 70
Remarks on result:
other: Calculated from radioactivity measurements at 10 mg/kg dose level; C14-17 chlorinated paraffin (52% chlorinated)
Kinetic parameters:
no data
Metabolites:
not investigated
Details on results:
Carrot root weight (g) : 0.96, 5.06, 10.69, 20.97 and 37.36 on days 42, 50, 60, 70 and 81 respectivelyCarrot root test substance concentration (mg/kg wet wt): 0.38, 0.25, 0.20, 0.13 on days 42, 50, 60 and 70 respectivelyMean bioaccumulation factor : 0.088, 0.058, 0.046 and 0.030 on days 40, 50, 60 and 70 respectively
Reported statistics:
mean ± standard deviation

Any other information on results incl. tables

Four plants were sampled at each time points from each treatment (solvent control, 1 and 10 mg/kg dry wt soil). Carrot root weight is the mean of the 12 carrots sampled at each time. Carrot root test substance concentration is the mean of 4 carrots exposed to 10 mg/kg test substance. At the 1 mg/kg nominal exposure level, carrot root concentrations were too low to calculate bioaccumulation factors.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
The mean bioaccumulation factor (BAF) for a C14-17 chlorinated paraffin (52% chlorinated) from soil by the roots of carrot (Daucus carota) was calculated to be 0.045, based on the relative concentration of radioactivity in soil and carrot root on days 50 to 70.
Executive summary:

The bioaccumulation of a C14-17 chlorinated paraffin (52% chlorinated), radiolabelled with chlorinated [8-14C] n-pentadecane, from soil by the roots of carrot (Daucus carota) has been investigated at nominal concentrations of test substance of 1.0 and 10.0 mg/kg dry wt of soil, over a period of 70 days.

At the higher nominal concentration (10.0 mg/kg dry wt soil) the measured soil concentration of radioactivity fell from 13.0 mg/kg dry wt of soil on spiking (day -57) to 5.0 mg/kg dry wt of soil at the start of the study (day -2), however, no further significant decline was seen up to the end of the study on day 70. Thus a mean measured value of 4.9 mg/kg dry wt was used to calculate bioaccumulation factors. The mean root concentration of radioactivity in carrots exposed to soil containg 10.0 mg/kg dry wt declined steadily from 0.38 mg equivalent of test substance/kg on the first sampling day (day 42) to 0.13 mg equivalent/kg at the end of the exposure (day 70). At this higher exposure level, the bioaccumulation factor, based on wet weight of soil, declined from 0.088 on day 42 to 0.030 on day 70. The mean value from days 50 to 70, when root weight was greater than 5.0 g, was 0.045. As the concentrations of radioactivity in many of the soil and carrot samples were below the level of quantitation (LOQ) at the lower concentration level (1 mg/kg dry wt soil), bioaccumulation factors were not calculated from this data.