Evaluation of Watershed‐Scale Simulations of In‐Stream Pesticide Concentrations from Off‐Target Spray Drift

Winchell, Michael; Pai, Naresh; Brayden, Benjamin H.; Stone, Chris; Whatling, Paul; Hanzas, John P.; Stryker, J.

doi:10.2134/jeq2017.06.0238

Cited by 11 publications

(4 citation statements)

References 25 publications

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“…Drift or point‐source‐driven events (e.g., spillage on hard surfaces during filling or wash‐off from rinsing spraying equipment, unreported or misuse of the product) can be a major problem for SEAWAVE–QEX performance. In this context, an uncalibrated mechanistic model such as SWAT can provide more confident results, which has the additional advantage of obtaining a rigorous understanding of the chemical entry paths and can be set up to account for drift (Winchell, Pai, et al, 2018). A model framework combining a statistical approach (e.g., SEAWAVE–QEX) with an uncalibrated mechanistic model (e.g., SWAT as parameterized in Winchell et al, 2017) could leverage the advantages of both approaches.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of SEAWAVE–QEX in a high agricultural intensity catchment in Belgium

Rathjens¹,

Miguez²,

Winchell³

et al. 2022

Integr Envir Assess & Manag

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Pesticide surface water monitoring data have rarely been used as the only quantitative measure of exposure because the available monitoring data for most pesticides has not been considered robust enough for direct use in pesticide exposure assessments due to infrequent sampling. The cost of daily sample collection and analysis prohibits frequent sampling for most monitoring programs. In this context, a common question raised in assessments is how likely peak concentrations (i.e., annual maxima) may be missed if sampling intervals are longer than daily. The US Geological Survey developed the statistical model "seasonal wave with streamflow adjustment and extended capability" (SEAWAVE-QEX) to address the need to estimate infrequently occurring pesticide concentrations, such as annual maximum daily concentrations, for sites with nondaily monitoring data. This study compares the results of two postprocessing methods and evaluates the capability of SEAWAVE-QEX to estimate annual maximum concentrations of three commonly used herbicides and one metabolite in a catchment in Belgium. The study concludes that the appropriateness of using SEAWAVE-QEX to estimate annual maximum concentrations depends on pesticide characteristics and use and that the model can be particularly sensitive to nonflow correlated exposure events (e.g., point source contributions or drift).

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Section: Discussionmentioning

confidence: 99%

Evaluation of SEAWAVE–QEX in a high agricultural intensity catchment in Belgium

Rathjens¹,

Miguez²,

Winchell³

et al. 2022

Integr Envir Assess & Manag

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“…Given the variety of exposure scenarios that result from chlorpyrifos use worldwide and that surface water monitoring methodologies designed to characterize impacts on aquatic receptors at biologically relevant time scales are largely logistically and fiscally intractable, recent developments in ecohydrologic modeling show promise in estimating continuous pesticide concentrations in surface water at the watershed scale and beyond (Janney & Jenkins, 2019; Winchell et al, 2018; Zhang et al, 2018). Model estimates of daily pesticide surface water concentrations evaluated with surface water monitoring can provide field estimates of the magnitude and frequency of acute exposures and allow estimates of TWA chronic exposures for comparison with bioassay results.…”

Section: Discussionmentioning

confidence: 99%

Multi‐ and Trans‐Generational Effects on Daphnia Magna of Chlorpyrifos Exposures

Maggio

Jenkins

2022

Enviro Toxic and Chemistry

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Chlorpyrifos, a broad‐spectrum neurotoxic organophosphate insecticide, is subject to atmospheric and hydrolytic transport from application sites to aquatic ecosystems. Across the landscape, concentrations in surface water can vary spatially and temporally according to seasonal use practices. Standardized bioassays can provide a screening‐level understanding of aquatic receptor acute and chronic toxicity. However, these bioassays do not address ecologically relevant exposure patterns that may impact fitness and survival within and across generations. The aim of the present study was to evaluate the utility of a second‐tier, screening‐level methodology employing Daphnia magna multi‐ and transgenerational bioassays spanning four generations to investigate the effect of variable chronic chlorpyrifos exposure. The multigenerational assay consisted of continuous chlorpyrifos exposure across four consecutive 21‐day bioassays using progeny from the previous assay for each successive generation. In the transgenerational assay, only the parent (F0) generation was exposed. For both assays, survival and reproduction were assessed across treatments and generations. Results indicated that (1) following continuous chlorpyrifos exposure at ecologically relevant concentrations to four generations of D. magna, the highest treatment showed an apparent tolerance response for both survival and reproductive success in the F3 generation, and (2) chlorpyrifos exposure to the F0 generation did not result in treatment effects in the unexposed F1, F2, and F3 generations in the apical endpoints of survival and reproduction. Employing a suite of acute and chronic bioassays, including chronic exposures spanning multiple generations, allows for a more robust screening‐level evaluation of the potential impact of chlorpyrifos on aquatic receptors for variable periods of exposure. Environ Toxicol Chem 2022;41:1054–1065. © 2021 SETAC

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“…Another study, which was conducted at the watershed level (Winchell et al ), investigated the impact of incorporating several site‐specific parameters in a stepwise approach (i.e., annual application data, field‐scale application data, observed wind direction and speed, and stream geometry) as refined modeling inputs from a screening‐level approach. The resulting concentrations were compared to observed field data, and the greatest model improvements were associated with the wind speed and wind direction parameters (Winchell et al ).…”

Section: Discussionmentioning

confidence: 99%

Impact of Wind Speed and Direction and Key Meteorological Parameters on Potential Pesticide Drift Mass Loadings from Sequential Aerial Applications

Desmarteau

Ritter

Hendley³

et al. 2019

Integr Envir Assess & Manag

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Pesticide spray drift is potentially a significant source of exposure to off‐target, adjacent aquatic habitats. To estimate the magnitude of pesticide drift from aerial or ground applications, regulatory agencies in North America, Europe, and elsewhere rely on spray drift models to predict spray drift deposition for risk assessments. Refined assessments should ultimately depend on best‐available data for exposure modeling. However, when developing lower tier “screening” assessments designed to indicate whether further refinement is needed, regulators often make conservative assumptions with a resulting increased level of uncertainty in estimating environmental exposure or risk. In the United States, it is generally accepted that, to ensure conservative regulatory assessments, it is reasonable to assume that the wind speed might be 4.47 m/s (10 miles per hour [mph]), the relative humidity and temperature are highly conducive to drift, and the wind is blowing directly toward a receiving water for any given single spray event in a season. However, what is the probability these conditions will all co‐occur for each of 4 sequential spray events spaced a week apart (common practice for insecticides)? The refined approach in the present study investigates this question using hourly meteorological data sets for 5 United States Environmental Protection Agency (USEPA) standard crop scenarios to understand how real‐world data can reduce unnecessary uncertainty for sequential applications. The impact of wind speeds, temperatures, relative humidity, and wind direction at different times of day on annual drift loadings has been examined using a stepwise process for comparison with corresponding regulatory default loading estimates. The impacts on drift estimates were significant; interestingly, the time of day of the applications impacted variability more than did the selected crop scenario. When all these real‐world factors were considered, estimated 30‐y total drift loads ranged from 2% to 5% greater than the default estimate (2 of 30 cases due to high afternoon wind speeds) to 51% to 86% reductions (25 of 30 cases) with an overall average reduction of 63%. Integr Environ Assess Manag 2020;16:197–210. © 2019 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

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Evaluation of Watershed‐Scale Simulations of In‐Stream Pesticide Concentrations from Off‐Target Spray Drift

Cited by 11 publications

References 25 publications

Evaluation of SEAWAVE–QEX in a high agricultural intensity catchment in Belgium

Evaluation of SEAWAVE–QEX in a high agricultural intensity catchment in Belgium

Multi‐ and Trans‐Generational Effects on Daphnia Magna of Chlorpyrifos Exposures

Impact of Wind Speed and Direction and Key Meteorological Parameters on Potential Pesticide Drift Mass Loadings from Sequential Aerial Applications

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