Real-time particle monitoring of pesticide drift from an axial fan airblast orchard sprayer

Real-Time Monitoring of Spray Drift from Three Different Orchard Sprayers

“…Only the one-minute meteorological data that met our inclusion criteria was included in our analyses: wind speeds at least 1.0 m/s, air temperature 5-35 °C, relative humidity 0-100%, and wind blowing in 135° arc towards our sample field (wind rose direction from 281-360 ° or 0-56 °). One-minute Dylos PNCs for each bin (0.5 μm ≤ b 1 < 1.0 μm, 1.0 μm ≤ b 2 < 2.5 μm, 2.5 μm ≤ b 3 < 10.0 μm, and b 4 ≥ 10.0 μm) were adjusted for changes in ambient PNC using a fifth percentile, eight-minute rolling average of PNC (Blanco et al, 2018;Brantley et al, 2014;Bukowiecki et al, 2002) ( . These adjusted oneminute PNCs for each bin (b) were converted to particle mass concentrations (PMC) using an assumed aerosol density (ρ) of 1 μg/m 3 and each bin's geometric mean diameter (d), except for the largest bin where the lowest size cut was used (d 1 = 0.71 μm, d 2 = 1.58 μm, d 3 = 5.00 μm and d 4 = 10.00 μm).…”

“…We briefly summarize our study design, which has been described previously (Blanco et al, 2018;Kasner et al, 2018), and provide further details about the unique aspects of this particular study. This research took place during June and September of 2016 in a modern research orchard operated by Washington State University.…”

“…The AEZ for airblast applications and other spray applications using fine or very fine size droplets (volume median diameter less than 294 μm) is 100 ft (30 m) (US EPA, 2016). Still, studies have found significantly higher pesticide drift and particulate matter (PM) levels past 100 ft during airblast applications relative to background concentrations (Blanco et al, 2018;Frank et al, 1994;Kasner et al, 2018;Salyani and Cromwell, 1992), suggesting that this current AEZ does not fully protect individuals from pesticide drift.…”

“…Our recent study appears to be the only one that has used low-cost, real-time monitors (Dylos DC 1100, Dylos Corporation) to characterize spray drift (Blanco et al, 2018). Validation studies using Dylos DC1100 have found high correlations between these relatively new real-time optical particle monitors and three well-characterized reference instruments: the Grimm 1.109 (Grimm Technologies Inc.), APS 3321 (TSI Inc.) and FMPS 3091 (TSI Inc.) (Manikonda et al, 2016).…”

“…This study was nested in a larger study that measured micronutrient drift using accepted methods of passive sampling for spray drift characterization (Kasner et al, 2018). Our past work described a novel method of drift characterization using real-time particle monitors during AFA sprayer applications (Blanco et al, 2018). The purpose of this study was to characterize the spray drift potential of three airblast sprayers (AFA, MFT and DAT) in an effort to evaluate whether modern tower sprayers (MFT and DAT) have the potential to reduce occupational pesticide drift exposures at different locations in a neighboring orchard field.…”