Cerium

Toxicity to other aquatic organisms

Administrative data

Endpoint:

toxicity to other aquatic vertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study does not comply with the specific testing guideline but the documented results are sufficient to be accepted.

Data source

Reference

Reference Type:

publication

Title:

Toxicity of sixty-three metals and metalloids to hyalella azteca at two levels of water hardness

Author:

Borgmann, U., Couillard, Y., Doyle, P., Dixon, G.

Year:

2004

Bibliographic source:

Environmental Toxicology and Chemistry, Vol. 24, No. 3. pp. 641-652, 2005

Materials and methods

Principles of method if other than guideline:

The toxicity of cerium metal was measured in one-week exposures using the freshwater amphipod Hyalella azteca in both Lake Ontario (Canada) and soft water (10% Lake Ontario). Cerium was added as an atomic absorption standard and LC50 values were measured at 48h.

Test material

Test material information

Constituent 1

Reference substance name:

Cerium

EC Number:

231-154-9

EC Name:

Cerium

Cas Number:

7440-45-1

Molecular formula:

Ce

IUPAC Name:

cerium(3+)

Test solutions

Vehicle:

yes

Details on test solutions:

Atomic absorption standard of cerium containing 1g metal/L and preserved in 2% HCl.

Test organisms

Test organisms (species):

other: Fresh water amphipod "Hyalella azteca" (Crustacea)

Details on test organisms:

Test with young Hyalella azteca, including feeding.
The initial age of the test animals was 1 to 11 days at the start of the test.
Feeding during test: a piece of 2,5x2,5cm cotton gauze and 2,5mg Tetra-Min (Ulrich Baensch, Melle, Germany) fish food flakes were added at the beginning to each incubator, followed by addition of 15 young Hyalella Test containers were not aerated during the test. An additional 2,5mg of food was provided midweek.
Required amount: 15 Hyalella

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

1 wk

Test conditions

Hardness:

Tap (Lake Ontario, Canada) water: hardness 124mg/L
Soft water composed of 90% Milli-Q (Millipore, Bedford, MA, USA) deionized water and 10% tap (Lake Ontario, Canada) water: hardness 18mg/L

Test temperature:

Incubator at 24-25°C

pH:

7.37 - 8.46

Details on test conditions:

A one-week test with young Hyalella, including feeding. This 7-day test sis considered to be an acute test.
16:8 h light:dark photoperiod.

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

1 wk

Dose descriptor:

LC50

Effect conc.:

131 µg/L

Nominal / measured:

nominal

Conc. based on:

other: atomic absorption standard in 2% HCl

Basis for effect:

mortality

Remarks on result:

other: 88-197

Effect concentrations 2

Duration:

1 wk

Dose descriptor:

LC50

Effect conc.:

32 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: atomic absorption standard in 2% HCl

Basis for effect:

mortality

Remarks on result:

other: 14-70

Effect concentrations 3

Duration:

1 wk

Dose descriptor:

LC50

Effect conc.:

651 µg/L

Nominal / measured:

nominal

Conc. based on:

other: atomic absorption standard in 2% HCl

Basis for effect:

mortality

Remarks on result:

other: 521-813

Details on results:

LC50 = 131 µg/L in soft water nominal
LC50 = 32 µg/L in soft water measured
LC50 = 651 µg/L in tap water nominal

Any other information on results incl. tables

Ammonia does not appear to have contributed noticeably to toxicity.

The LC50s in tap water usually were either similar to (0.6-2.5-fold) those in soft water, or slightly higher (2.5-10-fold).

In this study, multiple tests were conducted, at only one or a few concentrations of cerium metal were included in each test. The data were then pooled and analyzed as if they had all been obtained from a single test. This provides an approximate guide to data reliability.

Applicant's summary and conclusion

Conclusions:

The toxicity of cerium metal to Hyalella was determined in one-week tests in both Lake Ontario (tap) and soft (10% tap) water. The LC50s for Hyalella correlate strongly with three-week LC50s and three-week EC 50S for reproduction in D. magna.