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Measurements of by-stander contamination during and post the application of pesticides relevant to arable crops in typical UK conditions: Part 2: Studies with a volatile formulation. - PS2008

Description
Field experiments will be conducted in which a volatile pesticide will be applied to seed bed conditions appropriate for the establishment of a winter cereal crop that would be typical in the UK. Measurements will be made of the potential pesticide contamination of adults and children in an area downwind of the pesticide application site both at the time of application and in a 72 hour period following the application.

The work will involve sampling in the following areas at the time of application:
(i) ground contamination in areas immediately adjacent to the treated area - to be assessed using flat strip collectors mounted at ground level : this to be representative of domestic premises or similar with a boundary immediately adjacent to a treated field area;
(ii) airborne droplets and vapour at a distance of 2.0 metres downwind of the edge of the treated area and deposition on adults and children as by-standers;
(iii) airborne droplets at 5.0 metres downwind of the treated area; and
(iv) at 8.0 metres downwind, airborne spray droplet profiles and deposition on adults and children as by-standers.

Following the application, measurements of vapour cocentrations leaving the treated area will be made over a 72 hour period. A sampling strategy will be used that accounts for an expected high loss rate immediately following the applicaion and will use suction samplers mounted at heights of 1.5 and 0.7 metres representing the breathing levels for adults and children respectively. The loss of vapour is expected to reduce with time and hence the period and frequency of sampling will increase with time following the application. Wind conditions during the post application period will be monitored continuously and the position of samplers around the treated area will be adjusted to maximise vapour capture.

Measurements will be made on a total of three occasions covering a range of conditions. Experiments will be conducted in September/October when soil temperatures are relatively high leading to high levels of evaporation and vapour loss. A spraying configuration will be used that is representative of commercial practice but selected to give relatively high levels of drift.

Results of the study will be analysed to give values for losses from the treated area both as droplets at the time of application and vapours from the treated soil surface. The implications for by-stander contamination will be analysed and compared with other available data.
Objective
Specific objectives relate to:

1. The planning and design of a field experiment to obtain data relating to the risk of by-stander contamination during and post the application of a volatile pesticide: agreeing this design with representatives of The Pesticides Safety Directorate;
2. Conducting the field experiment and obtaining the contaminated collectors used during the applications for analysis;
3. Monitoring airborne losses from treated areas for periods up to 72 hours following treatment;
4. Analysing the deposits on the collection surfaces and reference surfaces used during the experiment;
5. Interpreting the results obtained;
6. Reporting the findings to Defra and The Pesticides Safety Directorate.

Project Documents
• Final Report : Measurements of by-stander contamination during and post the application of pesticides relevant to arable crops in typical UK conditions: Part 2: Studies with a volatile formulation.   (2166k)
Time-Scale and Cost
From: 2005

To: 2006

Cost: £41,185
Contractor / Funded Organisations
Silsoe Spray Application Unit
Keywords
Application              
Crops              
Deposits              
Pest and Weed Control              
Pesticide use              
Pesticides              
Plants and Animals              
Residues              
Fields of Study
Pesticide Safety