Lanthanum oxide

Monitoring data

Administrative data

Endpoint:

monitoring data

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented publication which meets basic scientific principles

Data source

Reference

Reference Type:

publication

Title:

Levels of rare earth elements in dutch drinking water and its sources. Determination by inductively coupled plasma mass spectrometry and toxicological implications. A pilot study.

Author:

de Boer, J.L.M. et al.

Year:

1996

Bibliographic source:

Wat. Res. 30(1): 190-198

Materials and methods

Principles of method if other than guideline:

The determination of rare earth elements (REE) in water samples using inductively coupled plasma mass spectrometry was evaluated with respect to selection of isotopes, detection limits, precision, matrix effects, and spectral interferences. The method was applied to raw and drinking water samples of 18 groundwater stations and two surface water stations, and to samples taken from the rivers Rhine and Meuse and from Lake IJsselmeer.

GLP compliance:

no

Type of measurement:

background concentration

Media:

other: drinking water and surface water

Test material

Test material information

Constituent 1

Reference substance name:

Rare Earth Elements (REE)

IUPAC Name:

Rare Earth Elements (REE)

Details on test material:

- Name of test material (as cited in study report): rare earth elements (REE), analysed as Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu
(Gd-Lu)

Study design

Details on sampling:

Samples were taken from 20 drinking water stations and from the rivers Rhine and Meuse. Fifteen stations used groundwater for the preparation of drinking water and two stations used surface water. At the remaining three stations groundwater was pumped after infiltration of surface water. At one of these stations infiltration was applied of Rhine water after a prepurification step, at a second one bank infiltration from the River Noord (a side-arm of the River Rhine) and at a third station infiltration of water from a canal after prepurification by coagulation with aluminium salts. The water of the canal itself was also sampled.
For each station an unfiltered and filtered sample was analyzed as well as the final product (no filtration).

Results and discussion

Concentration

Concentration 1

Country:

Netherlands (the)

Location:

river Meuse

Substance or metabolite:

other: element La

Conc.:

0.228 µg/L

Concentration 2

Country:

Netherlands (the)

Location:

river Rhine

Substance or metabolite:

other: element La

Conc.:

0.513 µg/L

Concentration 3

Country:

Netherlands (the)

Location:

Lake Ijsselmeer

Substance or metabolite:

other: element La

Conc.:

< 0.01 µg/L

Remarks on result:

other: detection limit

Any other information on results incl. tables

At 8 of the 22 locations sampled (4 of the 15 "true" groundwater stations) REE (with the exception of Y) at concentration levels above the detection limits were found in the raw unfiltered water (only results for La shown here):

Location	type	pH	total carbon	La (ng/L)
Station 1	raw	7.05	71	1729
	raw filtered			1004
	endproduct	7.92	85	199
Station 2	raw	7.04	60	7653
	raw filtered			5603
	endproduct	7.89	86	8693
Station 3	raw	6.13	21	2269
	raw filtered			2292
	endproduct	7.91	65	1749
Station 4	raw	5.44	15	13063
	raw filtered			13186
	endproduct	7.78	165	26
Station 5	raw	6.89	85	235
	raw filtered			197
	endproduct	8.04	110	27
canal	raw	7.4	90	757
	raw filtered			220
Station 6	raw	8.07	142	405
	raw filtered			5
	endproduct	7.95	137	8
Meuse	raw			228
Rhine	raw			513

The filtration step during the sampling procedure reflects the ratio of dissolved REE/particle-bound plus particulate REE.

At a pH of 5.44 and 6.13 the REE are totally dissolved and even at a pH of 7.04-7.05 about 50% of the amount of REE can be present in the dissolved form even for higher concentrations of REE.

The REE in groundwater could effectively be removed by aeration followed by filtration over a carbonate-based mineral. When the treatment procedure was limited to addition of sodium hydroxide or calcium hydroxide no reduction of REE concentrations was observed.

Range of background values of REE in Dutch sandy topsoils of nature reserves (Edelman and de Bruin, 1986): 3.16 -14 µg La/g.

Taken into account limited toxicological effect studies concerning REEs indicative admissible drinking water concentrations (iAC) were calculated by adding relevant safety factors (iAC for La: 2µg/L).