Mecoprop

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:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Leaching of phenoxylalkanoic acid herbicides from farmland.

Author:

Felding G.

Year:

1995

Bibliographic source:

The Science of the Total Environment 168: 11-18.

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The content of phenoxyalkanoic acid herbicides were measured over a 2-year period in drainage water from three clayey soils in Denmark.

GLP compliance:

not specified

Type of measurement:

concentration at contaminated site

Media:

ground water

Test material

Test material information

Constituent 1

Reference substance name:

Mecoprop

EC Number:

230-386-8

EC Name:

Mecoprop

Cas Number:

7085-19-0

Molecular formula:

C10H11ClO3

IUPAC Name:

2-(4-chloro-2-methylphenoxy)propanoic acid

Test material form:

not specified

Study design

Details on sampling:

- Geographic coordinates: Suitable sites for study had the following requirements: a flat, temporarily saturated clayey soil which had been sprayed with 2,4-D, dichlorprop, MCPA, and the test material. These criteria led to the selection of three fields all situated on a glacier deposit, one in south Zealand (Gyldenholm, 55°21'N 11°28' E), one in north Lolland (Blans, 54°51'N 11°27'E) and one in north east Falster (Falkerslev, 54°51'N 12°02'E).
At three sites each field, soil from the upper 140 cm of the soil profile was sampled with a soil auger. The content of organic carbon in the plough layer was about 1 %.
- Known emission sources near sampling site: Applications of the test material at the three sites:
Blans (test material ester): 1.644 kg a.i./ha (Autumn 1986), 1.250 kg a.i./ha (Spring 1990)
Falkerslev (test material ester): 1.918 kg a.i./ha (Spring 1985)
Falkerslev (test material salt): 1.500 kg a.i./ha (Spring 1989)
Gyldenholm (test material ester): 0.840 kg a.i./ha (Autumn 1987), 0.336 kg a.i./ha (Autumn 1989), 0.384 kg a.i./ha (Autumn 1990)
- Sampling: Water samples were collected from three stainless steel sampling tubes at each site. The water was sampled between 1 and 1.25 m below the soil surface. When the soil became saturated in winter, water samples were collected from the tubes.
The water samples were analysed for the parent phenoxyalkanoic acids.

Results and discussion

Concentration

Country:

Denmark

Location:

Falkerslev

Substance or metabolite:

substance

Conc.:

0.34 µg/L

Remarks on result:

other: maximum conc recorded

Details on results:

The total number of water samples was 65

pH and nitrate content of water samples:
- The pH of the water sampled at Blans varied from 6.7 to 7.8 and the nitrate content varied from 25 to 100 mg/L.
- At Falkerslev, pH varied from 6.9 to 7.9 and the nitrate content varied from 10 to 50 mg/L.
- At Gyldenholm, pH varied from 6.8 to 7.9 and the nitrate content varied from 10 to 100 mg/L.

Analysed level of test material in water samples:
- Blans: The test material formulated as an ester was used at locality Blans in autumn 1986. The hydrolysed compound was only seen in very low concentrations (0.014 - 0.040 µg/L) with the exception of the water sampled in February 1990. In spring 1990, test material (ester) was used again; water samples taken in December 1990 showed a very low content of the hydrolysed compound.
- Falkerslev: In spring 1985, the test material formulated as an ester was applied at Falkerslev. Water samples taken in November 1988 showed only a low concentration of test material acid (0.082 µg/L). The test material formulated as a salt was applied in April 1989; water sampled in December 1990 contained up to 0.344 µg/L of test material acid. Four months later, the test material concentration was low again.
- Gyldenholm: In autumn 1987, 1989 and 1990, the test material formulated as an ester was applied at Gyldenholm. Test material acid was not found in the water samples during this period.

Concentrations above 0.1 µg/L:
- Three out of the four water samples contained test material in concentrations > 0.1 µg/L derived from the spring treatment at Falkerslev.

Any other information on results incl. tables

Concentration of the Test Material.

Location	Sampling Date	Tube	Concentration µg/L
Blans	19 December 1988	1	NR
		2	NA
		3	NA
	13 February 1989	1	NA
		2	NR
		3	NR
	20 December 1989	1	NR
		2	< 0.01
		3	< 0.01
	23 January 1990	1	< 0.02
		2	NR
		3	NR
	27 February 1990	1	0.14 (0.13; 0.14)
		2	< 0.02
		3	< 0.02
	15 November 1990	1	NR
		2	NR
		3	NR
	11 December 1990	1	0.02 (0.02; 0.03)
		2	0.01 (0.01; 0.02)
		3	0.04 (0.04; 0.04)
	28 February 1991	1	0.04 (0.04; 0.04)
		2	NR
		3	NR
	13 March 1991	1	NR
		2	NR
		3	NR
Falkerslev	24 November 1989	1	0.08 (0.08; 0.09)
		2	< 0.02
		3	< 0.02
	16 January 1989	1	NR
		2	NR
		3	NR
	01 March 1989	1	NR
		2	NR
		3	NR
	12 December 1989	1	NR
		2	NR
		3	NR
	23 January 1990	1	NR
		2	NR
		3	NR
	26 February 1990	1	NR
		2	NR
		3	NR
	11 December 1990	1	0.34 (0.34; 0.35)
		2	0.09 (0.09; 0.09)
		3	0.06 (0.06; 0.06)
	28 February 1991	1	0.13 (0.13; 0.14)
		2	0.03 (0.03; 0.03)
		3	0.21 (0.20; 0.22)
	13 March 1991	1	< 0.004
		2	< 0.004
		3	0.021 (0; 0.02)
Gyldenholm	25 January 1989	1	NR
		2	NR
		3	NR
	06 March 1989	1	NR
		2	NA
		3	NR
	10 January 1990	1	NR
		2	NR
		3	NR
	05 March 1990	1	NR
		2	NR
		3	NR
	09 November 1990	1	NR
		2	NR
		3	NR

95 % Confidence limits in parentheses.

NA: Not analysed

NR: No response.

<: There is a response but it is below the detection limit. 

Applicant's summary and conclusion

Conclusions:

The herbicide content in 17 out of 65 water samples was above 0.1 µg/L which is the maximum residue limit for drinking water in Europe. Application of the test material in the autumn did not cause the expected leaching. The highest concentrations for  2,4-D, dichlorprop, MCPA and the test material were 0.24, 0.30, 0.29 and 0.34 µg/L, respectively.

Executive summary:

The content of the phenoxyalkanoic acid herbicides 2,4-D, dichlorprop, MCPA, and the test material was measured over a 2-year period in drainage water from three clayey soils in Denmark. The herbicide content in 17 out of 65 water samples was above 0.1 µg/L which is the maximum residue limit for drinking water in Europe. Application of the test material in the autumn did not cause the expected leaching. The highest concentrations for 2,4-D, dichlorprop, MCPA and the test material were 0.24, 0.30, 0.29 and 0.34 µg/L, respectively.