5,7-dichloro-4-(4-fluorophenoxy)quinoline;quinoxyfen (ISO)

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:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Principles of method if other than guideline:

Exposure monitoring was carried out to investigate the presence of Quinoxyfen residues in non-target areas close to the point of application, and following repeated use. The monitoring subsequently provided realistic exposure data under typical field conditions compared to that generated by the conservative PEC (predicted environmental concentration) approach.

GLP compliance:

no

Remarks:

Good Agricultural Practice is followed

Type of measurement:

other: Exposure monitoring

Media:

other: Soil, sediment and water

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

124495-18-7

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Test substance name: Quinoxyfen

Results and discussion

Concentration

Concentration 1

Key result

Country:

Germany

Location:

Northeim, Lehrte and Kraichgau

Substance or metabolite:

other: Test substance residue

Conc.:

> 2.1 - < 19.1 other: µg/kg

Remarks on result:

other: Soil samples taken before application in 2005

Concentration 2

Key result

Country:

Germany

Location:

Northeim, Lehrte and Kraichgau

Substance or metabolite:

substance

Remarks:

Further sampling before and after the test substance applications in 2005

Conc.:

> 9.5 - < 204.1 other: µg/kg

Remarks on result:

other: Additional loading in 2005 (Test substance soil concentrations at field scale)

Remarks:

Additional loading was below the nominal predicted environmental concentration of 208 µg/kg

Concentration 3

Key result

Country:

Germany

Location:

Northeim, Lehrte and Kraichgau

Substance or metabolite:

substance

Remarks:

Further sampling before and after the test substance applications in 2006

Conc.:

> 59 - < 182.1 other: µg/kg

Remarks on result:

other: Additional Loading in 2006 (Test substance soil concentrations at field scale)

Remarks:

below the nominal predicted environmental concentration of 208 µg/kg

Concentration 4

Key result

Country:

Germany

Location:

Northeim, Lehrte and Kraichgau

Substance or metabolite:

substance

Remarks:

Test substance sediment concentrations at field scale

Conc.:

< 0.33 other: µg/kg

Remarks on result:

other: With the exception of one site where a concentration of 0.49 µg/kg was found.

Remarks:

Sediment concentrations below the LOQ (<0.33 µg/kg)

Concentration 5

Key result

Country:

Germany

Location:

Northeim, Lehrte and Kraichgau

Substance or metabolite:

substance

Remarks:

Test substance sediment concentrations at area scale

Remarks on result:

other: As a result of greater distances between test substance treated areas and the area scale monitoring sites, sediment concentrations were lower than those seen at field scale, with values only around or below the LOQ.

Applicant's summary and conclusion

Conclusions:

Test substance soil concentrations at field scale:
- Positive findings of low level test substance residues (2.1-19.1 µg/kg) in soil samples taken before application in 2005 confirmed the historical use of test substance at the test sites.
- Further sampling before and after the test substance applications in 2005 and 2006 demonstrated that the additional loading (9.5 204.1 µg/kg in 2005, and 59-182.1 µg/kg in 2006) was below the nominal PECs of 208 µg/kg (significantly so in some cases).
Test substance sediment concentrations at field scale:
- With the exception of one site (where a concentration of 0.49 µg/kg was found), the historical use of test substance resulted in sediment concentrations below the LOQ (<0.33 µg/kg).
- Increases in sediment concentrations were generally low following the test substance applications in 2005 and 2006 (<1 µg/kg), and the results showed no trend towards accumulation. Furthermore, the measured concentrations were below the nominal PECSEC of 3.5 µg/kg.
Test substance sediment concentrations at area scale:
- As a result of greater distances between test substance treated areas and the area scale monitoring sites, sediment concentrations were lower than those seen at field scale, with values only around or below the LOQ.
- No significant or meaningful increases in sediment concentration were seen, and there was no trend towards accumulation.
- Short range transport and dry or wet deposition of volatilised or soil-bound test substance entering via dust or run-off, drainage or erosion during storm events seems not to be an important pathway at the area scale.

Executive summary:

Exposure monitoring has been carried out over two years (2005 and 2006) to investigate the presence of test substance residues in non-target areas close to the point of application and following repeated use in representative cereal-growing regions of Germany.

Three monitoring regions (Northeim, Lehrte and Kraichgau) were selected to cover the different environmental conditions found in cereal-growing areas of Germany. The regions were selected according to the following criteria: historical use and future use (at least during 2005 and 2006) of test substance can be assured; close relationship between target areas (test substance treated) and non-target areas (stagnant or slow moving edge-of-field water bodies); slope of the landscape to capture possible run-off events into the edge-of-field water bodies); and location of the water bodies in the major downwind drift direction (if possible).

In each region, two different types of monitoring were carried out, i.e., field scale and area scale. The field scale monitoring was designed to quantify residues in soil that had potentially resulted from the long-term (up to 10 years prior to 2005) use of test substance, and the additional loading produced by the applications made in 2005 and 2006. In addition, aquatic sediment samples were taken from the edge-of-field water body in order to quantify historical exposure caused by spray drift, run-off and erosion, and to quantify the additional loading produced by the applications made in 2005 and 2006. In contrast, the area scale monitoring represented a wider scale since the water bodies chosen were not in direct neighborhood to treated fields, but were located downwind from cereal-growing areas with similar test substance application patterns to the farms at field scale. One possible entry into these water bodies is through dry or wet deposition of volatilized test substance, or soil-bound test substance entering via dust or run-off, drainage or erosion during storm events. At area scale, only aquatic sediment was sampled.

Test substance was used at field scale according to GAP, and in spring 2005 and 2006 the target areas at field scale were applied once with test substance at 250 g a.i./ha according to label recommendations. Four sampling occasions were established as follows were prior to application in spring; approximately 1 week after application; after crop harvest; and in autumn. The same sampling scheme was used for both years of the experimental period (2005 and 2006).

At field scale, soil cores (10 cm depth) were taken at each sampling occasion from each site. For each site, one randomized soil sample was produced from 20 individual soil cores to give one sample for test substance analysis. At both field and area scale, sediment at the boundary layer (5 cm depth) was taken at each sampling occasion from each site. As before, one randomized sediment sample was produced to give one sample for test substance analysis. The soil and sediment samples were air-dried and sieved (<2 mm), and then extracted and analyzed in accordance with a standard LC-MS/MS method (LOD 0.05-0.11 µg/kg; LOQ 0.16-0.33 µg/kg).

The results showed that test substance soil concentrations at field scale were: positive findings of low level test substance residues (2.1-19.1 µg/kg) in soil samples taken before application in 2005 confirmed the historical use of test substance at the test sites. Further sampling before and after the test substance applications in 2005 and 2006 demonstrated that the additional loading (9.5-204.1 µg/kg in 2005, and 59-182.1 µg/kg in 2006) was below the nominal PECs of 208 µg/kg (significantly so in some cases).

Test substance sediment concentrations at field scale: With the exception of one site (where a concentration of 0.49 µg/kg was found), the historical use of test substance resulted in sediment concentrations below the LOQ (<0.33 µg/kg) and increases in sediment concentrations were generally low following the test substance applications in 2005 and 2006 (<1 µg/kg), and the results showed no trend towards accumulation. Furthermore, the measured concentrations were below the nominal PEC_SED of 3.5 µg/kg.

Test substance sediment concentrations at area scale, as a result of greater distances between test substance treated areas and the area scale monitoring sites, sediment concentrations were lower than those seen at field scale, with values only around or below the LOQ. No significant or meaningful increases in sediment concentration were seen, and there was no trend towards accumulation. Short range transport and dry or wet deposition of volatilized or soil-bound test substance entering via dust or run-off, drainage or erosion during storm events seems not to be an important pathway at the area scale.