Nsibande, SADabrowski, James Mvan der Walt, EVenter, AForbes, PBC2016-06-272016-06-272015-06Nsibande SA, Dabrowski JM, van der Walt E, Venter A and Forbes PBC. 2015. Validation of the AGDISP model for predicting airborne atrazine spray drift: a South African ground application case study. In: Chemosphere, 138, pp 454-4610045-6535http://www.sciencedirect.com/science/article/pii/S0045653515007122http://hdl.handle.net/10204/8602Copyright 2015. Due to copyright restrictions, the attached PDF file only contains the abstract of the full text item. For access to the full text item, please consult the publisher's websiteAir dispersion software models for evaluating pesticide spray drift during application have been developed that can potentially serve as a cheaper convenient alternative to field monitoring campaigns. Such models require validation against field monitoring data in order for them to be employed with confidence, especially when they are used to implement regulatory measures or to evaluate potential human exposure levels. In this case study, off-target pesticide drift was monitored during ground application of a pesticide mixture to a sorghum field in South Africa. Atrazine was used as a drift tracer. High volume air sampling onto polyurethane foam (PUF) was conducted at six downwind locations and at four heights at each sampling point. Additional data, including meteorological information, required to simulate the spray drift with the AGDISP® air dispersion model was collected. The PUF plugs were extracted by a plunger method utilizing a hexane:acetone mixture with analysis by GC-NPD (94.5% recovery, 3.3% RSD, and LOD 8.7pg). Atrazine concentrations ranged from 4.55ngL(-1) adjacent to the field to 186pgL(-1) at 400m downwind. These results compared favourably with modeled output data, resulting in the validation of the model up to 400m from the application site for the first time. Sensitivity studies showed the importance of droplet size distribution on spray drift, which highlighted the need for good nozzle maintenance. Results of this case study indicate that the model may provide meaningful input into environmental and human health risk assessment studies in South Africa and other developing countries.enAtrazineSpray driftAir dispersion modelingPolyurethane foamPUFPesticidesAGricultural DISPersal modelAGDISPArticleNsibande, S., Dabrowski, J. M., van der Walt, E., Venter, A., & Forbes, P. (2015). Validation of the AGDISP model for predicting airborne atrazine spray drift: a South African ground application case study. http://hdl.handle.net/10204/8602Nsibande, SA, James M Dabrowski, E van der Walt, A Venter, and PBC Forbes "Validation of the AGDISP model for predicting airborne atrazine spray drift: a South African ground application case study." (2015) http://hdl.handle.net/10204/8602Nsibande S, Dabrowski JM, van der Walt E, Venter A, Forbes P. Validation of the AGDISP model for predicting airborne atrazine spray drift: a South African ground application case study. 2015; http://hdl.handle.net/10204/8602.TY - Article AU - Nsibande, SA AU - Dabrowski, James M AU - van der Walt, E AU - Venter, A AU - Forbes, PBC AB - Air dispersion software models for evaluating pesticide spray drift during application have been developed that can potentially serve as a cheaper convenient alternative to field monitoring campaigns. Such models require validation against field monitoring data in order for them to be employed with confidence, especially when they are used to implement regulatory measures or to evaluate potential human exposure levels. In this case study, off-target pesticide drift was monitored during ground application of a pesticide mixture to a sorghum field in South Africa. Atrazine was used as a drift tracer. High volume air sampling onto polyurethane foam (PUF) was conducted at six downwind locations and at four heights at each sampling point. Additional data, including meteorological information, required to simulate the spray drift with the AGDISP® air dispersion model was collected. The PUF plugs were extracted by a plunger method utilizing a hexane:acetone mixture with analysis by GC-NPD (94.5% recovery, 3.3% RSD, and LOD 8.7pg). Atrazine concentrations ranged from 4.55ngL(-1) adjacent to the field to 186pgL(-1) at 400m downwind. These results compared favourably with modeled output data, resulting in the validation of the model up to 400m from the application site for the first time. Sensitivity studies showed the importance of droplet size distribution on spray drift, which highlighted the need for good nozzle maintenance. Results of this case study indicate that the model may provide meaningful input into environmental and human health risk assessment studies in South Africa and other developing countries. DA - 2015-06 DB - ResearchSpace DP - CSIR KW - Atrazine KW - Spray drift KW - Air dispersion modeling KW - Polyurethane foam KW - PUF KW - Pesticides KW - AGricultural DISPersal model KW - AGDISP LK - https://researchspace.csir.co.za PY - 2015 SM - 0045-6535 T1 - Validation of the AGDISP model for predicting airborne atrazine spray drift: a South African ground application case study TI - Validation of the AGDISP model for predicting airborne atrazine spray drift: a South African ground application case study UR - http://hdl.handle.net/10204/8602 ER -