2-ethylhexanoic acid, molybdenum salt

Monitoring data

Administrative data

Endpoint:

monitoring data

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Reliable ambient monitoring data were collected from various national and international environmental agencies. Main data were generated in the GEMAS-project. Methodology and procedures for data analyses were in line with the guidance given by ECHA (European Chermicals Agency) and with the methodology that was followed in existing compulsory and voluntary risk assessments for some other metals (e.g., Zn, Cu, Ni, Pb)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: ECHA, 2008. RIP 3.2: Guidance on information requirements and chemical safety assessment. Chapter R.16: Environmental Exposure Estimation

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EC, 2003. Technical Guidance Document in support of Commission Directive 93/67/EEC on risk assessment for new notified substances and Commission Regulation (EC) No 1488/94 on risk assessment for existing substances. Part II: Environment.

GLP compliance:

no

Type of measurement:

other: ambient concentration levels

Media:

soil

Test material

Test material information

Constituent 1

Reference substance name:

Molybdenum

EC Number:

231-107-2

EC Name:

Molybdenum

Cas Number:

7439-98-7

Molecular formula:

Mo

IUPAC Name:

molybdenum

Details on test material:

no Mo-compounds added to soil; determination of ambient levels in the environment

Results and discussion

Details on results:

The regional (EU) ambient reasonable-worst-case concentration of molybdenum in european grazing land is 1.04 mg/kg dry wt.
The regional (EU) ambient reasonable-worst-case concentration of molybdenum in european agricultural land is 0.86 mg/kg dry wt.

Any other information on results incl. tables

Table 1 represents the country-specific 50th and 90th percentiles of Mo-levels in soil samples taken from grazing land and agricultural land.

Country-specific RWC-ambient Mo-levels in grassland soils ranged from 0.33 mg/kg dry wt (Lithuania) to 3.26 mg/kg dry wt (Croatia) (difference of a factor of 9.9). The median RWC-ambient PEC value for Europe is 1.04 mg/kg dry wt. The lowest values (<1.0 mg/kg dry wt) were mainly situated in Eastern/Central Europe (e.g., Baltic countries, Hungary, Czech Republic, Germany, Denmark. Countries with relatively higher RWC-ambient PEC (i.e., >30 mg/kg) were mainly situated in Southern Europe (e.g., Greece, Croatia, Italy, Cyprus, Montenegro, Macedonia).

In general the same trends that were found in grassland soils were also observed in agricultural soils: the lowest RWC-ambient PECs (i.e., below 1 mg Mo/kg) were observed in Eastern/Central Europe (e.g., Baltic States, Bulgaria, Hungary, Poland, Ukraine). Higher levels (> 1 mg/kg) were more typical for the Northern part of Europe (e.g., Scandinavian countries, British Islands) and some Mediterranean countries (e.g., Italy, Spain, Croatia). A difference of a factor of 7.1 was determined between the lowest (0.31 mg Mo/kg in Lithuania) and highest (2.19 mg Mo/kg; Sweden) country-specific RWC-ambient PEC. The typical value for Europe was 0.86 mg Mo/kg.

Table 1: Country-specific RWC-ambient PEC of molybdenum in grazing land and agricultural land

Country	RWC-ambient PEC for grazing land	RWC-ambient PEC for agricultural land
	mg/kg dry wt
Austria	1.23	1.41
Belgium	0.93	0.73
Bosnia-Herzegowina	0.94	1.15
Bulgaria	0.68	0.55
Croatia	3.26	2.03
Cyprus	1.25	1.67
Czech Republic	0.64	0.69
Denmark	0.45	0.37
Estonia	0.40	0.42
Finland	1.18	1.47
France	0.93	0.98
Germany	0.85	0.73
Greece	1.21	1.00
Hungary	0.55	0.54
Ireland	1.95	1.29
Italy	1.37	1.37
Latvia	0.35	0.35
Lithuania	0.33	0.31
Macedonia	2.34	1.03
Montenegro	2.35	0.57
The Netherlands	0.59	0.42
Norway	1.85	1.47
Poland	0.46	0.39
Portugal	0.72	0.71
Switzerland	2.36	1.00
Slovakia	1.16	0.70
Slovenia	1.14	1.30
Spain	1.25	1.09
Serbia	0.55	0.45
Sweden	1.84	2.19
Ukraine	0.57	0.56
United Kingdom	1.22	1.29
Median for Europe	1.04 mg/kg dry wt	0.86 mg/kg dry wt

The GEMAS-data set is the most robust and most recent data set for Europe which describes molybdenum concentration levels in two different types of soil: agricultural and grassland soils. The derived values of 1.04 mg/kg dry wt and 0.86 mg/kg dry wt for grazing land and agricultural land, respectively, are therefore put forward as the most relevant and reliable concentrations levels for molybdenum in European soils.

Ambient molybdenum concentrations for the terrestrial compartment were also determined with other available data sets. Based on these data the regional RWC-ambient PEC concentrations were situated between 0.45 mg/kg (Spain) and 5.78 mg/kg (Sweden). One should take in mind that the regional RWC-ambient PEC for arable soils was below the detection limit for four countries. Taking countries outside Europe into account, relevant Mo-levels in soil were situated between 0.2 and 9.5 mg/kg dry wt. All of these values are in line with the molybdenum concentration levels that were generated with the GEMAS data set.

Applicant's summary and conclusion

Conclusions:

Based on the monitoring data that were collected for different EU-countries, reliable regional RWC-ambient PEC of 0.86 and 1.04 mg/kg dry wt have been derived for agricultural soils and grazing land soils, respectively.