Cesium fluoroaluminate

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption, other

Remarks:

monitoring data in water and sediment

Type of information:

other: Calculation of Kp values based on environmental field data

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Kp-values are based on reliable field data of concentration levels in water and sediment; no standard guideline test was conducted to generate Kp-values. Kp-values are calculated based on the hypothesis that equilibrium exists between the baseline levels in water and in sediment.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

2005

Report date:

2005

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Evaluation of high quality environmental geochemical data for Europe, which is provided by the Forum of European Geological Surveys (FOREGS), with respect to cesium (Cs) concentrations in stream water and stream sediment. Baseline levels of cesium in water and sediment were determined in 728 paired sample locations. Assuming equilibrium between both environmental compartments, site-specific partitioning coefficients (Kp) were derived.

GLP compliance:

no

Type of method:

other: field data of baseline levels in water and sediment

Media:

sediment

Test material

Test material information

Constituent 1

Reference substance name:

Caesium

EC Number:

231-155-4

EC Name:

Caesium

Cas Number:

7440-46-2

Molecular formula:

Cs

IUPAC Name:

cesium

Details on test material:

naturally occuring cesium

Radiolabelling:

no

Study design

Test temperature:

environmental relevant temperatures

Batch equilibrium or other method

Analytical monitoring:

yes

Details on sampling:

FOREGS:
-The FOREGS sampling grid was based on GTN grid cells developed for Global Geochemical Baseline mapping. This grid divides the entire land surface into 160 km x 160 km cells covering an area of 4,500,000 km2.
- Sampling methodology, preparation and analysis are described by Salminen et al. (2005).
- A total of 807 stream water samples and 888 sediment samples were processed in the FOREGS-program, including 740 paired samples, i.e. samples with the same coordinates for the sampling location of stream water and sediment that are summarised below. However, Cs concentrations in 12 stream water samples (3 from Albania and 9 from Switzerland) were excluded from the analysis, resulting in a total of 728 paired samples summarised below.
- High quality and consistency of the obtained data were ensured by using standardised sampling methods and by treating and analysing all samples in the same laboratory of each country.

Results and discussion

Partition coefficients

Key result

Phase system:

sediment-water

Type:

log Kp

Value:

5.7 L/kg

Remarks on result:

other: European 50th percentile log Kp

Results: Batch equilibrium or other method

Adsorption and desorption constants:

The monitoring stream water and sediment data show that Cs concentrations of sediments range from 0.5 to 68 mg/kg, while dissolved Cs concentrations in the water column of European stream waters range from 0.001 to 24.30 µg/L, showing a comparable higher portion of cesium to be present in sediments under envionmental conditions. Regarding the partitioning of cesium in the water column, stream water/sediment partition coefficients range from 123.463 to 47,000,000 L/kg. Since FOREGS sampled on a grid aiming to equally represent geochemical baseline concentrations across Europe, the 50th percentile log Kp for cesium across Europe was determined to be 5.70 L/kg.

Any other information on results incl. tables

Table 1: Concentrations of cesium in sediment and water and resulting partition coefficients

	Concentration		Concentration		Partitioning (Kp)		Log Kp
Parameter	Cs (sediment)		Cs (water)		Cs (sed / water)		Cs (sed / water)
#	740	728	740		740	728	740	728
	mg/kg		µg/L		L/kg		L/kg
Min	0.50		0.001		123.46		2.09
Max	68.00		24.30		47,000,000.00		7.67
Mean	5.24	5.20	0.07		1,107,788.54	1,104,103.92	5.68
STD	6.26918881	6.22	0.94	0.95	2,380,009.74	2,380,688.15	0.61
5th percentile	2	2.00	0.001		43,478.26	43,816.43	4.64
Median	3	3.00	0.01		500,000.00		5.70
90 th percentile	10	10.00	0.05		2,333,333.33	2,255,555.56	6.37	6.35
95th percentile	15	15.00	0.09		3,341,666.67	3,000,000.00	6.52	6.48

¹Values from Switzerland and Albania are not included.

Table 2: Country-specific stream water/sediment partition coefficients (given as log Kp in L/kg)

Country	# of data	Area (km2)	Min	Max	Mean	5th P	50th P	90th P	95th P
AL	3	28.75	5.70	6.85	6.44	5.81	6.78	6.83	6.84
AT	20	83.88	3.85	6.48	5.54	4.48	5.67	6.19	6.35
BE	5	32.55	4.96	6.12	5.65	5.07	5.70	6.04	6.08
CH	9	41.29	4.58	5.85	5.29	4.65	5.47	5.65	5.75
CZ	10	78.87	4.66	6.43	5.62	4.88	5.60	6.13	6.28
DE	66	357.12	3.87	7.13	5.60	4.58	5.70	6.30	6.30
DK	0	43.10	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.
EE	11	45.23	5.22	6.70	5.84	5.23	5.78	6.30	6.50
ES	83	504.65	4.47	7.34	5.93	4.67	6.00	6.78	6.97
FI	63	338.14	4.68	6.40	5.53	5.07	5.48	6.00	6.00
FR	118	543.97	4.33	6.59	5.62	4.83	5.61	6.31	6.43
GR	26	131.96	4.57	6.70	6.03	5.25	6.30	6.30	6.53
HR	10	56.54	5.52	6.90	6.36	5.77	6.30	6.85	6.88
IE	10	70.27	4.34	6.30	5.79	4.91	5.88	6.23	6.27
IT	45	301.34	2.09	6.60	5.31	3.86	5.52	6.14	6.44
LT	14	64.59	5.48	6.30	5.92	5.56	5.94	6.22	6.25
LV	7	65.30	5.82	6.00	5.90	5.82	5.82	6.00	6.00
NL	9	41.526	5.22	6.12	5.51	5.25	5.46	5.71	5.92
NO	58	323.76	4.26	6.78	5.38	4.61	5.34	6.00	6.30
PL	56	312.69	4.63	6.60	5.93	5.08	6.00	6.48	6.48
PT	19	92.35	5.05	7.67	6.17	5.29	6.20	6.82	7.07
SE	20	449.96	4.42	6.30	5.02	4.47	4.96	5.53	5.64
SK	15	49.03	4.18	6.40	5.79	4.81	6.00	6.22	6.27
SL	4	20.25	6.22	6.54	6.34	6.23	6.30	6.47	6.51
UK	59	219.33	3.54	6.56	5.69	4.89	5.82	6.18	6.30

Applicant's summary and conclusion

Conclusions:

Reliable baseline levels of cesium in pristine water/sediment samples were determined in 728 samples. Sampling and analytical procedures are considered adequate and resulted in reliable data. Assuming equilibrium between the typical concentration in water and sediment, relevant log Kp-values were generated. Data are therefore considered useful for the determination of a relevant log Kp for the sediment compartment. Since FOREGS sampled on a grid aiming to equally represent geochemical baseline concentrations across Europe, the 50th percentile concentrations of cesium across Europe were 3 mg/kg sediment and 0.01 mg/L stream water, respectively, yielding a log Kp for cesium across Europe of 5.70.