Spray Drift of Pesticides Arising from Aerial Application in Cotton

Woods, N.; Craig, Ian; Dorr, G. J.; Young, Brian

doi:10.2134/jeq2001.303697x

Cited by 65 publications

(38 citation statements)

References 9 publications

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“…air) or to the fate and movement between media. Examples of the first type are the dispersion of particles and movement through air, which can be modelled by AgDRIFT [77] and Gaussian models [78], soil erosion and sedimentation of runoff [79] and leaching of water-soluble fractions into the soil profile, e.g. Pesticide Root-Zone Model (PRZM) [80] and others [81].…”

Section: Exposure Assessmentmentioning

confidence: 99%

Environmental Risk Assessment of Agrochemicals — A Critical Appraisal of Current Approaches

Sánchez‐Bayo¹,

Tennekes²

2015

Toxicity and Hazard of Agrochemicals

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This chapter provides insights into the difficulties and challenges of performing risk evaluations of agrochemicals. It is a critical review of the current methodologies used in ecological risk assessment of these chemicals, not their risks to humans. After an introduction to the topic, the current framework for ecological risk assessment is outlined. Two types of assessments are typically carried out depending on the purpose: i) regulatory assessments for registration of a chemical product; and ii) ecological assessments, for the protection of both terrestrial and aquatic ecosystems, which are usually site-specific. Although the general framework is well established, the methodologies used in each of the steps of the assessment are fraught with a number of shortcomings. Notwithstanding the subjectivity implicit in the evaluation of risks, there is scepticism in scientific circles about the appropriateness of the current methodologies because, after so many years of evaluations, we are still incapable of foreseeing the negative consequences that some agrochemicals have in the environment. A critical appraisal of such methodologies is imperative if we are to improve the current assessment process and fix the problems we face today. The chapter reviews first the toxicity assessment methods, pointing to the gaps in knowledge about this essential part of the process and suggesting avenues for further improvement. Deficiencies in the current regulations regarding toxicity testing are discussed, in particular the effect of the time factor on toxicity and the issue of complex mixtures.

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Section: Exposure Assessmentmentioning

confidence: 99%

Environmental Risk Assessment of Agrochemicals — A Critical Appraisal of Current Approaches

Sánchez‐Bayo¹,

Tennekes²

2015

Toxicity and Hazard of Agrochemicals

View full text Add to dashboard Cite

show abstract

“…proximity to pesticides at distances < 1 mi (1,609 m). Yet some dispersion studies suggest that pesticides are measurable only at considerably smaller distances of ≤ 500 m from the application site (Chester and Ward 1984;Frost and Ware 1970;MacCollom et al 1986;Woods et al 2001). Thus, exposure misclassification may occur if the drift range of an applied pesticide is considerably less than one 1 mi.…”

Section: Historical Pesticide Exposure In California Using Pesticide mentioning

confidence: 99%

“…Pesticides applied from the air or ground have been observed to drift from their intended treatment sites, with measurable concentrations detected in the air and in plants and animals several hundred meters away (Chester and Ward 1984;Currier et al 1982;Frost and Ware 1970;MacCollom et al 1986;Woods et al 2001). Herbicides transported downwind can cause unintended damage to crops (Byass and Lake 1977), and acute pesticide poisonings have been observed in communities downwind from agricultural fields after applications (Ames et al 1993).…”

mentioning

confidence: 99%

Historical pesticide exposure in California using pesticide use reports and land-use surveys: an assessment of misclassification error and bias.

Rull

Ritz

2003

Environ Health Perspect

104

102

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We used California's Pesticide Use Report (PUR) and land-use survey data to conduct a simulation study evaluating the potential consequences of misclassifying residential exposure from proximity to agricultural pesticide application in health effect studies. We developed a geographic model linking the PUR with crop location data from land-use surveys to assess the impact of exposure misclassification from simpler exposure models based solely on PUR or land-use data. We simulated the random selection of population controls recruited into a hypothetical case-control study within an agricultural region. Using residential parcel data, we derived annual exposure prevalences, sensitivity, and specificity for five pesticides and relied on the PUR plus land-use model as the "gold standard." Based on these estimates, we calculated the attenuation of prespecified true odds ratios (ORs), assuming nondifferential exposure misclassification. True ORs were severely attenuated a) when residential exposure status was based on a larger geographic area yielding higher sensitivity but low specificity for exposure, in contrast to relying on a smaller area and increasing specificity; b) for less frequently applied pesticides; and c) with increasing mobility of residents among the study population. Considerable effect estimate attenuation also occurred when we used residential distance to crops as a proxy for pesticide exposure. Finally, exposure classifications based on annual instead of seasonal summaries of PUR resulted in highly attenuated ORs, especially during seasons when applications of specific pesticides were unlikely to occur. These results underscore the importance of increasing the spatiotemporal resolution of pesticide exposure models to minimize misclassification.

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“…The recent data provided by Woods et al (2001) compares the drift profiles generated by oil versus water based aerial spraying methods. There was good agreement between the data and the outputs from both AgDRIFT (evaporating) and GDS model (non evaporating) models.…”

Section: Effect Of Droplet Evaporationmentioning

confidence: 99%

The GDS model—a rapid computational technique for the calculation of aircraft spray drift buffer distances

Craig

2004

Computers and Electronics in Agriculture

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A model for predicting the required spray drift buffer distance for a specified off target deposition level is described. The GDS model is based upon Gaussian diffusion and sedimentation of particles originating from an elevated instantaneous line source. Aircraftinduced near wake effects are ignored. Agreement between aircraft wake models FSCBG,AgDRIFT and the GDS model is reasonable for downwind distances greater than 50m. The model has the advantage over Lagrangian models in that it is faster computationally and can readily provide real time prediction in the cockpit over large distances (3 km). A sensitivity analysis has been performed on the model to elucidate the effects of the primary parameters on spray drift. The model has proved useful in the determination of spray drift buffer distances for regulatory purposes and in the development of appropriate spray drift management systems for aerial spraying. Further research work is required to refine the model to better account for air stability effects, collector type, evaporation and crop canopy.

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Spray Drift of Pesticides Arising from Aerial Application in Cotton

Abstract: from the masts was cut into 2-m sections and the dye was (1978), Akesson and Yates (1974, p. 92-98), Riley and extracted from 2-m sections of the string using 10 mL of Wiesner (1989), Richardson et al. (1995), and the U.S.isopropanol solvent. Dye concentration was measured using

Cited by 65 publications

References 9 publications

Environmental Risk Assessment of Agrochemicals — A Critical Appraisal of Current Approaches

Environmental Risk Assessment of Agrochemicals — A Critical Appraisal of Current Approaches

Historical pesticide exposure in California using pesticide use reports and land-use surveys: an assessment of misclassification error and bias.

The GDS model—a rapid computational technique for the calculation of aircraft spray drift buffer distances

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