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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study based on national standard and scientific principles, well documented, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Photo-induced toxicity of anthracene to green algae, Selenastrum capricornutum
Author:
Gala WR, Giesy JP
Year:
1992
Bibliographic source:
Arch. Environ. Contam. Toxicol. 23, 316-323 (1992)

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: EPA-600/9-78-018 (1978)
Principles of method if other than guideline:
Static test system with replenishment of TS losses, 12 h pre-incubation without irradiation:
using the technical protocol of Miller WE et al. 1978: The Selenastrum capricornutum Printz algal assay bottle test.
Experimental design, application, and data interpretation protocol. US EPA Corvallis, OR, EPA-600/9-78-018 (1978)
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Anthracene, from Sigma, grade III, purity 99.9 %

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
at the beginning of pre-incubation, and before and after each TS renewal

Test solutions

Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Dissolution of anthracene in acetonitrile (stock solution)
- Differential loading: yes, aliquots of the stock solution
- Controls: solvent control receiving the maximum acetonitrile amount corresponding to
that added together with the highest anthracene concentration
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetonitrile
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)):
=< 150 µL/100 mL (estimation)

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Strain: Printz
- Source (laboratory, culture collection): inhouse culture
- Age of inoculum (at test initiation): log-growth phase
- Method of cultivation: maintained at 21 +-1°C under continuous illumination,
photosynthetically active radiation, intensity 40 µE/(m2*sec)


Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
40 h
Remarks on exposure duration:
12 h pre-incubation (without UV) + 28 h with UV

Test conditions

Test temperature:
21 +- 1°C
pH:
7.5
Nominal and measured concentrations:
nominal: 7, 15, and 35 µg/L
analytical: first series: 1.4-5.0 / 4.9-6.4 / 12.7-16.0 µg/L (Report, Tab. 2)
second series: 1.4-4.9 / 4.7-6.0 / 12.4-15.8 µg/L (Reporet, Tab. 4)
[Note: calculated from measured initial values and terminal values before renewal (assuming first-order kinetics of elimination)]
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 250-mL Erlenmeyer flask, Pyrex (UV transparent), 100 mL test volume
- Aeration: no
- Renewal rate of test solution: no (but see renewal of test substance)
- Initial cells density: 10^5/mL
- Preincubation: 12 h (without UV exposure)
- Test duration: 28 h (with UV-A exposure, continuous radiation)

- "Toxicant renewal system" (anthracene in acetoinitrile):
every 12 h during pre-incubation
every 8 h during UV-A exposure

- Control end cells density:
- No. of vessels per concentration (replicates): 2- 3
- No. of vessels per control (replicates):
- No. of vessels per vehicle control (replicates): 2- 3



TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted medium (EPA-APP medium)


OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: no
- Photoperiod: continuous
- Light intensity and quality: RAR intensity 47 -53 µM/(m2*sec) / UV-A intensity (320 - 380 nm): 125 - 765 µW/cm2
Note: UV-B (280 - 320 nm) was explicitly removed from the spectrum because these wavelengths are toxic
to photosynthesising organisms!


EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- growth rate (cell count with hemocytometer) and carbon fixation (14CO2 incorporation)


TEST CONCENTRATIONS
- Spacing factor for test concentrations: approx. 2

Results and discussion

Effect concentrationsopen allclose all
Duration:
22 h
Dose descriptor:
NOEC
Effect conc.:
1.5 - 1.7 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Remarks:
test material
Basis for effect:
other: growth rate / CO2 incorporation after 22 / 24 h UV-A radiation
Duration:
22 h
Dose descriptor:
EC10
Effect conc.:
1.5 - 7.8 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Remarks:
test material
Basis for effect:
growth rate
Remarks:
after 22 h UV-A radiation
Duration:
22 h
Dose descriptor:
EC50
Effect conc.:
3.9 - 37.4 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Remarks:
test material
Basis for effect:
growth rate
Remarks:
after 22 h UV-A radiation
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
3.3 - 24 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Remarks:
test material
Basis for effect:
other: 14CO2 incorporation after 24 h UV-A radiation
Duration:
24 h
Dose descriptor:
EC10
Effect conc.:
1.7 - 3.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Remarks:
test material
Basis for effect:
other: 14CO2 incorporation after 24 h UV-A radiation
Details on results:
Anthracene, in the absence of UV-A radiation and at a mean exposure concentration of 19.4 µg/L, did not have any effect
on the growth rate of the alga. Anthraquinone had no adverse (phototoxic) effects.

The threshold for photo-induced toxicity of anthracene was 2.5 - 3 µg/L (NOEC - EC10) at UV-A intensities from 125 - ~400 µW/cm2.
At the highest UV-A intensity of 765 µW/cm2, the threshold was 1.5 µg/L.

[Note: UV-B (280 - 320 nm) was explicitly removed from the spectrum because these wavelengths are toxic by themselves
to photosynthesising organisms! (see other entry: Oris and Giesy 1984)]
Reported statistics and error estimates:
Analysis of variance (ANOVA) performed for each toxicity endpoint for each UV-A intensity.
Dunnett´s tes or Tukey´s test applied to mean responses of different anthracene treatments.
Probit analysis (Finney 1971) for deriving the EC values.

Any other information on results incl. tables

Effect of anthracene in combination with UV-A on growth rate and 14 CO2 incorporation

(including cell proliferation as well as photosynthetic activity) [data taken from Report, Tab. 3 and 5]

UV-A intensity [µW/cm2]

Growth rate

[cell density, 0 -22 h UV]

Carbon fixation
[14CO2, primary production,

0 -24 h UV]

EC50 [µg/L]

EC10 [µg/L]

EC50 [µg/L]

EC10 [µg/L]

765

3.9 (2.8-5.4)

1.5 (0.9-2.5)

3.3 (2.8-3.9)

1.7 (1.4-2.2)

410

6.6 (5.5-7.8)

2.5 (2.0-3.3)

5.9 (5.0-6.9)

2.7 (2.2-3.4)

406

5.3 (3.6-7.8)

2.3 (1.0-5.4)

4.9 (4.4-5.4)

2.2 (1.8-2.7)

218

12.1 (10.2-14.3)

8.7 (7.5-10.1)

8.1 (6.2-10.6)

2.5 (1.7-3.8)

125

37.4 (11.8-118.6)

7.8 (5.5-11.2)

24.0 (13.0-44.3)

3.9 (2.8-5.3)

Applicant's summary and conclusion