Registration Dossier

Environmental fate & pathways

Additional information on environmental fate and behaviour

Currently viewing:

Administrative data

Endpoint:
additional information on environmental fate and behaviour
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable publication which meets basic scientific principles

Data source

Reference
Reference Type:
publication
Title:
Environmental Fate of Five Radiolabeled Coal Conversion By-Products Evaluated in a Laboratory Model Ecosystem
Author:
Lu P-Y, Metcarf RL, and Carlson EM
Year:
1978
Bibliographic source:
Environ Health Perspect 24, 201-208

Materials and methods

Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
The distribution of various polycyclic (hetero)aromatic substances radiolabeled with tritium was determined over time (33 days) in a laboratory terrestrial-aquatic model ecosystem consisting of Sorghum leaves and salt marsh caterpillars on one side and plankton, alga, daphnia, and snail complemented with mosquito larvae and fish on the other side.
GLP compliance:
not specified
Type of study / information:
The amount of test compound measured as radioactivity in different environmental compartments and trophic organisms (water, alga, snail, mosquito, fish) was determined. Biotransformation intermediate products were identified. No overall mass balance could be established. The biomagnification as well as biodegradability potential were estimated.
In addition, partition coefficients and water solubility were determined using the radioactive test substances.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): anthracene
- 3H-labeled test substance was prepared by a modification of the method of Hilton and O'Brian (1964, J Agr. Food Chem 12, 236).
0.16 mL of T2O was mixed with P205 and BF3 gas to form an active T3PO4-BF3 complex as active medium
which was reacted with 60 mg of pure unlabeled compound.
- Analytical purity: no data
- Radiochemical purity (if radiolabelling): 99.9%
- Specific activity (if radiolabelling): 149.95 mCi/mMol
- Locations of the label (if radiolabelling): randomly labeled with tritium

Results and discussion

Any other information on results incl. tables

Tritium in the aqueous phase reached a maximum of 0.2342 ppm after 14 days and declined to 0.1198 ppm after 33 days.

The overall distribution and fate of tritium labeled compounds in different environmental/trophic constituents is shown in the following table (anthracene equivalents in ppm).

 

Environmental fate of 3H-anthracene in the laboratory model ecosystem (after 33 d) (report, Tab. 2)

 

Water

Alga
(Oedogonium)

Snail
(Physa)

Mosquito
(Culex)

Fish
(Gambusia)

Unextractable 3H

0.04527

1.8020

2.2910

0.3036

1.3721

Total extractable 3H

0.09786

0.5715

3.3333

0.4464

0.7456

Unknown I

---

0.0353

---

---

---

     Anthracene

0.00035

0.2345

0.7610

0.2209

0.3603

Unknown II

0.0123

0.0239

0.2923

0.0322

0.0100

    Anthrone (9-oxo-9,10-dihydroanthracene)

0.00017

0.0152

0.1700

0.0003

0.2032

     Unknown III

0.00110

0.0155

0.3147

0.0088

0.0153

    Anthranol

(9 -OH-anthracene)

0.00977

0.0312

0.6240

0.0308

0.0547

    Polar extractables

0.03997

0.2159

1.1713

0.1434

0.1021

The parent compound anthracene amounted to 4.1% of total tritium in alga (EM = 670), to 22.8% in snail (EM = 2714), to 49.5% in mosquito (EM = 631), and to 48.3% in fish (EM = 1029). 

The relative percentages of degradation products (related to total extractable 3H of each organism) are shown in the following table:

Anthracene [%]

Anthranol [%)

Anthrone [%]

Polar [%]

Alga

41.0

5.46

2.66

37.77

Snail

22.8

18.72

5.10

35.14

Mosquito

49.8

6.90

23.07

32.12

Fish

48.3

7.34

7.34

13.68

 

The extractable radioactivity accounted for ...

  • 75.9 % of the total radioactivity in alga,
  • 40.7 % of the total radioactivity in snail,
  • 40.4 % of the total radioactivity in mosquito, and
  • 64.7 % of the total radioactivity in fish.

The results indicate that anthracene tends to be bioaccumulated. Phenols formed by microsomal hydroxylation are more easily eliminated, and thus do not accumulate. The further oxidation product, anthrone, likewise tends to bioaccumulate, as it shows similar biomagnification as anthracene in this model system.

Using radioactive test substance, the partition coefficient was determined to be 8135 (logPow = 3.91). Water solubility at 25° C was 74 µg/L.

Applicant's summary and conclusion

Conclusions:
The distribution and the fate of 3H-labeled carbazole was investigated in a laboratory terrestrial-aquatic model ecosystem consisting of Sorghum leaves, salt marsh caterpillars, plankton, alga, daphnia, snail, mosquito larvae, and fish for a complete food chain.
Tritium in the aqueous phase reached a maximum of 0.1246 ppm after 14 days and declined to 0.0433 ppm at the end of the experiment after 33 days. The parent compound carbazole amounted to 10.1% of total tritium in alga (EM = 49), to 12.3% in snail (EM = 134), to 26.8% in mosquito (EM = 112), and to 29.3% in fish (EM = 125) (EM = concentration of parent compound in the organism/concentration of parent compound in the water). Unextractable tritium was relatively high in all the organisms and comprised 43.9% of total tritium in alga, 72.7% in snail, 81.8% in mosquito, and 53.9% in fish indicating that transformation of carbazole was intense.
Results suggest that the bioaccumulation potential of native cabazole is limited.