HJ Holterman

• Wageningen University & Research

Background Pesticides can be transported from the site of application to homes via different routes and lead to exposure of residents, raising concerns regarding health effects. We built a deterministic model framework (OBOmod) to assess exposure of residents living near fields where pesticides are applied. Methods OBOmod connects five independent...

Background Application of pesticides in the vicinity of homes has caused concern regarding possible health effects in residents living nearby. However, the high spatiotemporal variation of pesticide levels and lack of knowledge regarding the contribution of exposure routes greatly complicates exposure assessment approaches. Objective The objective...

BACKGROUND Application of pesticides in the vicinity of homes has caused concern regarding possible health effects in residents living close by. However, the high spatiotemporal variation of pesticide levels and lack of knowledge regarding contribution of exposure routes greatly complicates exposure assessment approaches. OBJECTIVE To describe the...

Background: During the SARS-CoV-2 pandemic, there was shortage of the standard respiratory protective equipment (RPE). The aim of this study was to develop a procedure to test the performance of alternative RPEs used in the care of COVID-19 patients. Methods: A laboratory-based test was developed to compare RPEs by total inward leakage (TIL). We...

Four different methods for measuring droplet size distributions are evaluated: the Image Analysis VisiSizer technique, a stroboscopic imaging method developed in-house, phase Doppler particle analysis (PDPA), and laser diffraction (Malvern Spraytec). We find that the larger the droplets, the bigger the differences between the results obtained by th...

Downwind deposits and airborne emissions of spray drift after a pesticide application on flower bulb fields were computed using the IDEFICS spray drift model. The simulations closely followed real spray applications that took place on selected flower bulb fields. Spray deposits on the ground down to 5 m off the downwind field edge were determined....

Sideways and upward sprayed fruit and tree crops. Wageningen Research, Report WPR-564. 86 pp.; 28 fig.; 20 tab.; 107 ref. This report can be downloaded for free at https://doi.org/10.18174/448381 As part of the Dutch authorisation procedure for pesticides an assessment of the effects on aquatic organisms in surface water adjacent to agricultural fi...

An innovative model has been developed for downwind deposits of pesticides due to spray drift next to an orchard of pome fruit trees (apple, pear). The SPEXUS model (spray drift exposure for upward and sideways directed sprays) is an empirical model based on 20 years of experimental data of spray drift deposits for conventional cross-flow pesticide...

In spray drift experiments, measuring spray deposits far downwind may yield deposits values that approach or go below the level of detection. Particularly, when deposits are corrected for background concentrations of whatever origin, in principle values at or even below zero may result. A conventional way to deal with those data is to adjust them t...

For bed-grown crops, ideally the spray is applied evenly to the bed only, while no spray should be applied onto the paths between the beds. Usually these criteria cannot be fulfilled easily. The current study describes the development and use of a model to design adequate set-ups of nozzles on a sprayer boom optimized for bed-grown crops. Spray pat...

Spray applications in arable crops cause off-target spray deposits downwind from the treated field. Throughout several decades, many experiments have been carried out by many researchers to quantify these downwind spray deposits and their relation to sprayer settings, field conditions and environmental conditions. Still, there is a large variance i...

An innovative spray drift model is developed to describe downwind deposits of pesticides applied in an orchard of pome fruit trees (apple, pear). The empirical model is based on 20 years of experimental data of downwind deposits of spray drift for conventional cross-flow spray applications. The model reveals the major factors affecting downwind dep...

A spray drift model has been developed to describe downwind deposits of pesticides applied in an orchard of pome fruit trees (apple, pear). The empirical model is based on 20 years of experimental data of downwind deposits of spray drift for conventional cross-flow spray applications. The model reveals the major factors affecting downwind deposits:...

An innovative spray drift model for fruit orchards in the Netherlands has been developed recently. The model is implemented in an assessment model for the exposure of watercourses to deposits of pesticide spray drift for all water bodies next to fruit orchards in the Netherlands. The exposure assessment model accounts for a large number of spatiall...

This is the pre-edited version of the following article: Holterman, H. J., van de Zande, J. C., Massop, H. T. L., Boesten, J. J. T. I., & Huijsmans, J. F. M. (2016). Modelling the exposure of water bodies to spray drift for fruit growing in the Netherlands. 243-248. Paper presented at International Advances in Pesticide Application, Aspects of Appl...

Downwind off-target deposits of spray drift have been investigated for many years. For spray applications in fruit crops, such deposits are significantly higher than those for field crops, mainly due to different application techniques for these crop types. For field crops, various spray drift models have been described in literature. For fruit cro...

This report gives a summary of the outcome of the analyses of the spray drift data for boom sprayers from Germany and The Netherlands.

Stof, grof en fijn, wordt vooral via de ventilator van veehouderijbedrijven in de lucht gebracht en in het bijzonder via de ventilatoren van kippenstallen. Het is niet bekend hoe een emissiepluim van ventilator(en) van lengteventilatiesystemen eruit zien op korte afstand van de stal (tot 30 à 40 m). Wel is bekend dat een groenelement invloed heeft...

An empirical model has been developed for computing downwind deposits of spray drift after spray applications in fruit orchards. A database of downwind spray deposits from experiments during 20 years of field trials was used in regression analysis to show the relevant parameters: wind speed, wind direction, ambient temperature, growth stage (BBCH c...

The high variability of the total ammonia emission after manure application on agricultural land in the Netherlands can partly be linked to the application method, slurry characteristics and the meteorological conditions by statistical analysis of experimental results. Mechanistic models may improve the explanation of the high variability and bette...

Sensor gestuurde spuitsystemen waarmee door middel van een sensor kwantitatief een aantasting of hoeveelheid onkruid (biomassa) in het veld gemeten kan worden vragen om spuitsystemen met een variabele dosering. Eén methode om dat te realiseren is met een Pulse Width Modulation (PWM) techniek het debiet van de spuitdop te variëren. Dit PWM-systeem b...

Groenelementen dragen in potentie bij aan het verlagen van de concentraties fijnstof afkomstig uit stallen doordat fijnstof door het groenelement wordt afgevangen. Afvangst treedt alleen op als de emissies ook daadwerkelijk het groenelement instromen. De vorm, hoogte en afstand van het groenelement rondom de emissiebron hebben invloed op de fractie...

Micro and nanostructuring of greenhouse covering materials is investigated to increase the hemispherical transmittance and diffusivity. This is also applied to PV cells, to increase efficiency of light trapping. In theory, a two-side micro-V structured material can increase transmittance with 7%, while measurements show a loss of 6% compared to the...

Bomen en struiken in een houtwal, een groenelement, kunnen een bijdrage leveren aan het verlagen van de concentratie emissies in de lucht. Deze overkoepelende samenvattende rapportage geeft een integraal overzicht van de beschikbare informatie uit onderzoeken en publicaties, zowel Nederlands als internationaal, met medeneming van alle facetten, die...

Het Lozingenbesluit Open Teelt en Veehouderij (LOTV, nu Activiteitenbesluit Milieubeheer) bepaalt dat bij bespuitingen van een gewas met veldspuitapparatuur de buitenste strook bespoten moet worden met driftarme spuitdoppen. Uit de resultaten van druppelgroottemetingen wordt aangegeven of de in dit onderzoek onderzochte spuitdoppen, bij bepaalde dr...

De depositie van fijnstof op beplanting hangt af van veel factoren: de eigenschappen van de deeltjes, de eigenschappen van het botsingsoppervlak en van omgevingsfactoren. Recent onderzoek naar de depositie van kunstmatig fijnstof op een bomenrij laat zien dat deeltjes op de bomen terecht komen. Om deze resultaten te vertalen naar afvangpercentages...

As part of the Dutch authorisation procedure for pesticides an assessment of the effect on aquatic organisms in surface water adjacent to agricultural fields is required. So far, in the current Dutch authorisation procedure spray drift is the only source of exposure. For this reason a new exposure scenario was developed, which includes also input b...

De veehouderij en in het bijzonder de pluimveehouderij is een belangrijke bron van fijnstofdeeltjes, deeltjes kleiner dan 10 micrometer. Er staat behoefte aan technische maatregelen waarmee de pluimveehouderij de concentratie fijnstof in de buitenlucht kan verminderen. Een effectief middel, een bomenrij langs de stal plaatsen, roept onduidelijkhede...

In het kader van het KRW-project 'Samen werken aan een schone Maas' zijn metingen uitgevoerd aan verschillende doptypen uit de driftreductieklassen 50,75,90 en 95. Aan de hand van druppelgroottemetingen van de doptypen bij de aangegeven spuitdruk wordt met het driftmodel IDEFICS bepaald tot welke driftreductieklasse deze dopdrukcombinatie behoren b...

In this study we compare light trapping in hydrogenated amorphous silicon (a-Si:H) solar cells deposited directly onto polycarbonate (PC) at low temperature (< 130°C). To that end, we embossed PC substrates with 400 nm and 10 μm square based pyramids to induce light trapping based on diffraction and on geometric effects. As a comparison, we deposit...

Emissions of plant protection products (PPP) from covered structures to the air outside were estimated to support the European Food Safety Authority (EFSA) in the development of guidance on risk assessments for protected crops. Such emissions are mainly caused by loss of volatilised PPPs through the vents in the covered structures. The newly develo...

In this work we propose and study a light trapping scheme for thin film silicon solar cells that is based on geometrical light trapping (instead of textures optimized for light scattering), using periodically arranged pyramidal structures with dimensions larger than the effective wavelength of light. We studied the absorption behavior of amorphous...

Het Lozingenbesluit Open Teelt en Veehouderij bepaalt dat bij bespuitingen van een gewas met veldspuitapparatuur de buitenste strook bespoten moet worden met driftarme spuitdoppen. Uit de resultaten van druppelgrootte-metingen wordt aangegeven of de doppen, bij bepaalde drukken, volgens het Lozingenbesluit aangemerkt kunnen worden met de status dri...

We present a novel method to achieve light trapping in thin film silicon solar cells. Unlike the commonly used surface textures, such as Asahi U-type TCO, that rely on light scattering phenomena, we employ embossed periodically arranged micro-pyramidal structures with feature sizes much larger than the wavelength of visible light. Angular resolved...

The Cascade Project describes the modelling of spray drift and pesticide fate for a network of interconnected water bodies in a rural area. A first part of the project, the Cascade Drift Model, models the spatial and temporal distribution of deposits of spray drift onto surface waters in the mentioned rural area. Deposits of spray drift are compute...

Drift from the application of crop protection products can cause damage to neighboring crops, ecosystems and human health. In this report, estimations of spray drift with reference to Chinese agricultural systems are provided, based on data from literature and a modeling study. As knapsack sprayers make up the most important tool for pesticide appl...

Het Lozingenbesluit Open Teelt en Veehouderij bepaalt dat bij bespuitingen van een gewas met veldspuitapparatuur de buitenste strook bespoten moet worden met driftarme spuitdoppen. Uit de resultaten van druppelgrootte-metingen wordt aangegeven of de doppen, bij bepaalde drukken, volgens het Lozingenbesluit aangemerkt kunnen worden met de status dri...

In agriculture, spray drift research is carried out in field experiments and by computer simulation. Regarding the latter approach, accurate knowledge of the initial spray is required. Not only is the overall drop size distribution of the spray an important factor in the spraying process, but also its local variation within the spray cone below a n...

Het driftmodel IDEFICS is al vele jaren in gebruik voor het vaststelen van depositei van drift naast een bespoten perceel. Het model is gevalideerd voor deze depositie. Validatie voor de emissie naar de lucht ontbrak nog steeds. In de jaren 2004 en 2005 is een meetcampagne opgezet om IDEFICS ook te valideren voor de emissie van spuitmiddel naar de...

The scope of this investigation is the development of a new type of greenhouse with an integrated filter for rejecting near infrared radiation (NIR) and a solar energy delivery system. Cooled greenhouses are an important issue to cope with the combination of high global radiation and high outdoor temperatures. As a first measure, the spectral selec...

De Elektriciteit Leverende Kas of kortweg de ELKAS genoemd, levert warmte én elektriciteit. Bij de Elkas wordt elektriciteit opgewekt met teruggekaatst NIR-licht. PAR-licht komt wel in de kas en is beschikbaar voor plantengroei. In dit project is het Elkas principe uitgewerkt tot een werkend prototype waaraan daadwerkelijk elektriciteit- en warmtel...

Evaluatie van driftbeperkende effecten van diverse spuitdoppen(bijvoorbeeld druppelgrootte, spuithoek, bereik) met behulp van de IDEFICS drift model bij het toepassen van pesticiden op landbouwgewassen.

Risk methodologies are to be developed, validated, reviewed or improved for the protection goal: non-target plants. Improved estimates of spray drift deposition onto non-target plants and the effects on the plants are necessary to be evaluated for authorization of safe use.

Using PDA, a convenient method to measure the spectral characteristics of the spray below a nozzle is to scan that spray along a set of parallel lines in a horizontal plane. Data of such a measurement are processed in order to determine the 2D distribution of spectral characteristics in the plane of measurement. Essential parameters of the measurin...

The current study describes the development and use of a new expert model iDRIFT to estimate downwind deposits of spray drift for field sprayers. The expert model is presented as a versatile and easy-to-use software tool for both simple and advanced situations. Users can adjust various essential parameters at will, and the model responds instantly...

A summary is given of research within the field of application technology for crop protection products for the past 10years in The Netherlands. Results are presented for greenhouse, orchard, nursery tree and arable field spraying for the typical Dutch situation. Research predominantly focussed on the quantification of spray deposition in crop canop...

The scope of this investigation is the design and development of a new type of greenhouse with an integrated filter for rejecting near infrared radiation (NIR) and a solar energy delivery system. Cooled greenhouses are an important issue to cope with the combination of high global radiation and high outdoor temperatures. As a first measure, the spe...

In fruit growing high values of spray drift are found compared to arable field applications. In arable spraying drift reducing nozzles are certified for use as drift reducing measures. The nozzles which may potentially reduce drift in fruit growing are not jet classified as drift reducing nozzles, although they are available on the market. The deve...

The Cascade Project describes the modelling of spray drift and pesticide fate for a network of interconnected water bodies in a rural area. The present study concerns the first part of the proj ect, the Cascade Drift Module, which models the spatial and temporal distribution of deposits of spray drift onto surface waters in the mentioned rural area...

The use of pesticides still is required to maintain the high production level of agriculture in Europe. For many years pesticides are used in an increasingly sophisticated way, to improve effectiveness of the pesticide application as well as to minimize the hazards for non-target organisms and the environment. For field applications of sprays sever...

The scope of this investigation is the development of a new type of greenhouse with an integrated filter for rejecting near infrared radiation (NIR) and a s olar energy delivery system. Cooled greenhouses are an important issue to cope with the combination of high global r adiation and high outdoor temperatures. As a first measure, the spectral sel...

Binnen gemeenten doet zich vaak een discussie voor over de afstand van woningbouw tot gebieden met agrarische activiteiten, met name het toedienen van gewasbeschermingsmiddelen. Op dit moment wordt generiek een afstand van 50m gehanteerd tussen bebouwing en perceel. Om te onderzoeken of het mogelijk is deze afstand te verkleinen is een studie uitge...

In dit project is onderzocht wat de lichttransmissie is van verschillende uitvoeringen van Anti-reflectie-glas. Hierbij zijn de effecten van lichttransmissie onder grote invalshoeken bestudeerd en de effecten van condensatie tegen het gecoat glas en is het zelfreinigend vermogen onderzocht. Voor dit onderzoek is met proefopstellingen gewerkt en is...

Holterman H.J. Off-target dust deposition for two granule application techniques. Calculations based on the IDEFICS spray drift model. Agrotechnology & Food Innovations (A&F), Wageningen UR, Wageningen, The Netherlands. September 2004. 35 pp. English. Generally, spray drift during pesticide application is considered one of the major routes of conta...

In dit rapport wordt een studie beschreven over spuitdoppen van de merken Agrotop, Albuz, Lechler en TeeJet, die al op de lijst van driftarme doppen voorkomen. Deze studie handelt over de berekening van drift en driftreductie ten opzichte van een standaardbespuiting, op basis van berekeningen met het driftmodel IDEFICS. Vervolgens worden de onderzo...

Deze rapportage is een verslag van een laboratorium- en modelonderzoek naar het driftreducerend vermogen van een Pulstec spuitsysteem, toegepast op een veldspuit.

Deze rapportage is een verslag van het effect van het naar voren of achteren kantelen van spuitdoppen op de drift.

Summary The BCPC spray quality classification system utilises the Lurmark 31-03-F110 (F110/1.2/3.0) flat fan nozzle to discriminate the threshold between the classes of Fine and Medium spray. This reference nozzle has also now been used to classify the spray drift potential for other spray nozzle-pressure combinations. This paper discusses whether...

Voor landsdekkende berekeningen van de emissie van bestrijdingsmiddelen naar de lucht is het informatiesysteem bestrijdingsmiddelen (ISBEST) verbeterd. Hierbij is zoveel mogelijk gebruik gemaakt van bestaande methoden en kennis. Tabellen met de emissiefactor vanaf bodem en gewas en vanuit de kas voor circa 250 bestrijdingsmiddelen en tabellen met d...

Sampling sprays and spray deposits actually means collecting a large but finite number of drops of various sizes. Therefore, statistically, averaged spray volume and standard deviation are based on a binomial distribution. If sample size is too small, not only the coefficient of variation will be large, but also the average drop size in the sample...

A random-walk model, IDEFICS, is developed to describe downwind spray deposits from a conventional boom sprayer for chemical crop protection in agriculture. Cumulative spray deposits from a large number of individual drops are calculated downwind from the sprayed crop. The model basically is two-dimensional (2D), but near the nozzle a 3D approach i...

A random-walk model, IDEFICS, is described to compute downwind spray drift from conventional boom sprayers in chemical crop protection. Spray deposits are computed downwind from the sprayed crop field. The model basically is two-dimensional (2D), but close to the spray nozzle the model is 3D, incorporating driving speed and entrained air-currents b...

In this study rheological properties of aqueous solutions of mucin, albumin and mucin-albumin have been investigated in search for saliva substitutes. They were compared with commercially available saliva substitutes on the one hand and natural human saliva on the other hand. For the latter a few measurements on saliva are reported here in addition...

At the air-liquid interface of human saliva a protein layer is adsorbed. An apparatus is described with which a flow curve of this layer was measured. In the majority of samples the viscosity of the surface layer changed gradually and could be described by a power-law dependence on the shear rate. The zero-shear viscosity was 1–100 MPas. In some sa...

Saliva at rest separates in a bulk solution and a protein layer on top. The layer has been characterized ellipsometrically giving its thickness and density. Rheologically the layer and bulk were studied separately with linear and non-linear methods: harmonic shear experiments and flow curves. Thus a rheological framework resulted which was used for...