Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Study period:
February 2010
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline followed. Study well conducted.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
2007
Reference Type:
study report
Title:
Unnamed
Year:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: USEPA(2002) Methods for measuring the acute toxicity of effluents and receiving waters to freshwater organisms. Cincinnati, Ohio, U.S. Environmental Protection Agency
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Pb

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Ceriodaphnia dubia
Details on test organisms:
- Test organisms originate from Aquatic Biosystems and maintained in dechlorinated tapwater at 26°C
- For all tests, a mass culture was started and maintained for 3 days. All mass cultures were fed with a combination of YCT and algae
- Test organisms were < 24 h old before testing

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
5.8 mg/L See for details the table below.


Test temperature:
25°C
See for details the table below.
pH:
5.71See for details the table below.
Nominal and measured concentrations:
pH Nominal Pb (µg/L) Measured Pb (µg/L)
5.71 0, 5, 10, 20, 40, 80 0, 3, 9, 17, 36, 76
6.78 0, 25, 75, 150, 300, 600 1, 18, 52, 127, 271, 569
7.18 0, 250, 350, 500, 700, 1000 0, 282, 371, 596, 820, 1161
7.27 0, 100, 200, 400, 800, 1600 0, 41, 100.7, 241.0, 746, 1740.8
7.32 0, 1000,2000, 3000, 4000, 5000 3, 985, 2153, 2879, 4030,5911
7.43 0, 300, 400, 500, 600, 700 0, 157, 256, 315, 421, 440
7.44(H=121.8) 0, 400, 800, 1200, 1600, 2000 0, 261, 641, 1096, 1386, 1707
7.44 0, 400, 800, 1200, 1600, 2000 0, 355, 723, 1097, 1584, 1851
7.48 0, 50, 150, 300, 600, 1000 0, 345, 704, 1019, 1379, 1732
7.49 0, 300, 600, 900, 1200, 1500 0, 203, 615, 1069, 1398, 1569
7.58 0, 200, 350, 500, 650, 800 0, 180, 373, 477, 575, 907
7.8 (H=40.5) 0, 200, 400, 600, 800, 1000 0, 219, 483, 819, 1004, 1303
7.8 0, 400, 600, 800, 1000, 1200 0, 491, 801, 1129, 1481, 1695
7.89 0, 200, 400, 600, 800, 1000 0, 101, 236, 404, 566, 802
7.96 0, 400, 800, 1200, 1600, 2000 0, 279, 504, 921, 1236, 1344
8.06 0, 300, 600, 900, 1200, 1500 0, 389, 798, 1152, 1576, 1876
8.15 0, 200, 400, 600, 800, 1000 0, 345, 704, 1019, 1379, 1732
8.15(H=103.2) 0, 400, 1200, 2000, 3500, 6000 0, 271, 888, 1571, 3039, 5026
8.2 0, 400, 800, 1000, 1200, 1600 0, 416, 772, 1081, 1164, 1547
8.23 0, 300, 600, 900, 1200, 1500 0, 355, 742, 1102, 1518, 1890
8.36 0, 50, 100, 200, 400, 800, 1600, 3200, 6400 2, 35, 72, 170, 91, 120, 227, 186, 182
8.58 0, 500, 1000, 2000, 4000, 8000 1, 378, 1039, 1722, 3048, 6369
Details on test conditions:

- 5 individuals/20 mL polyethylene cups
- 4 replicates were used for testing

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
LC50
Effect conc.:
>= 28.8 - <= 3 115.8 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Basis for effect:
mortality
Remarks on result:
other: 5.71
Reported statistics and error estimates:
All acute tests were assessed for LC50 values using Maximum Likelihood Probit or Trimmed Spearman Karber method

Any other information on results incl. tables

LC values compared to the various water parameters:

pH Hardness Na+ K+ Ca2+ Mg2+ Cl- SO42- CO2 DOC 48h-LC50 (µg/L)
6.78 5.8 81 60 32 26 72 19 n.d. 104 28.8
5.71 16.4 78 55 106 58 408 21 n.d. 50 73.56
7.27 38.1 640 65 295 86 767 71   216 100.12
8.36 227.8 1475 181 1152 1126 936 492 n.d. 137 107.7
7.18 15.7 108 47 99 58 115 20 n.d. 622 290.33
7.43 244.4 1411 67 2302 142 1078 1528 555 321 318.74
7.96 50.4 2168 74.3 400 104 1385 133 857 214 383.79
7.58 46.1 1260 64.4 315 146 1063 85 506 213 394.78
7.8 40.5 1179 58.3 256 149 887 63 714 228 424.76
7.44 74.4 735 49.7 614 130 1110 90 587 242 432.77
7.48 32.1 2164 59.3 216 106 2066 119 428 216 446.43
7.89 99.7 2477 110 701 297 2198 204 n.d. 415 531.9
7.8 53.1 1216 66 361 170 1012 75 793 266 547.47
8.06 43.7 2937 69.3 295 142 1445 108 1715 228 571.28
7.49 35.5 1256 54.8 221 134 861 63 621 171 590.94
7.44 121.8 792 51.4 1088 130 1110 90 587 242 596.83
8.23 39.4 2944 58.4 289 105 928 70 2175 199 764.73
8.2 50 2823 74.4 396 104 1485 96 1326 233 779.17
8.15 97.3 2535 110 673 302 2152 215 n.d. 897 963.9
8.58 225.5 401 58 2157 98 393 3824 n.d. 653 995.7
7.32 27.8 230 87 218 60 250 25 n.d. 1467 1179.6
8.15 103.2 4034 282 796 242 3391 368 n.d. 1298 3115.8

Applicant's summary and conclusion

Conclusions:
Increasing DOC or pH decreases the toxicity of lead in invertebrates significantly due to a decrease of the bioavailability of the lead ion. Changing the hardness or concentrations of Na+, K+ or Mg2+ had no additional significant effect on toxicity expressed as the 96h-LC50 for C. dubia. The lowest and the highest 48h-LC50 differed by three orders of magnitude (range: 30 - 3100 µg/L).
Executive summary:

In a study according to guideline US EPA (2002), 22 individual reliable acute toxicity data points for one specie Ceriodaphnia dubia were summarized in this data point:

After exposures were conducted under static conditions and for different pH and hardness values, the acute toxicity values (48h-LC50) for Ceriodaphnia dubia varied between 28.8 µg dissolved Pb/L (at pH 6.8, a DOC of 104 mg/L and hardness of 5.8 mg CaCo3/L) and 3115.8 µg dissolved Pb/L (at pH 8.15, a DOC of 1298 mg/L and hardness of 103.2 mg/L).