Worker Re-Entry Exposure within the Framework of the BROWSE Project Kim Doan Ngoc Informa Life Sciences CIR 2013 congress 4 – 5 September 2013, Barcelona, Spain
Overview of the presentation Introduction to BROWSE Introduction to BROWSE Overview of worker model Overview of worker model Software Software Example outputs Example outputs Indoor volatilisation Indoor volatilisation
The BROWSE project = Bystanders, Residents, Operators and WorkerS Exposure models for plant protection products (PPPs) supported by: Start End Jan 2011 Dec 2013 Now project partners:
The main objective is to develop improved exposure models available transparancy data improved gender and stakeholder exposure regional differences input models Sustainable Use Directive Regulation 1107/2009
The main output is a user-friendly software tool WP1 WP2 software tool WP3 tools and guidance in support of regulation 1107/2009 WP5 WP6 risk indicators and web platform on training materials
Each model has a set of priority scenarios Operator Boom sprayer Mixing and loading (l/s) Orchard sprayer Hand-held sprayer Residents and bystanders Boom sprayer Orchard sprayer Hand-held sprayer
A worker exposure scenario is a combination of a crop group and a task outdoor indoor harvesting harvesting fruiting orchard fruit vegetables harvesting harvesting grapes ornamentals
Inhalation, dermal and oral exposure are taken into account residue inhalation in air exposure residue dermal absorbed application on crop exposure amount oral exposure
Overview of the presentation Introduction to BROWSE Overview of worker model Software Example outputs Indoor volatilisation
The conceptual model starts from the application modelled by application PEARL-OPS volatilisation initial deposit and dispersion on crop deposit on crop concentration in air at re-entry at re-entry contact with crop hand-to-mouth contact inhalation inhalation oral exposure dermal exposure exposure absorbed amount
Dermal exposure is the result of contact with residue on the crop Expressed by transfer coefficient Two options available • User input • User input • EFSA guidance • Default based on survey data • (Distribution based on literature) Contact Residue Duration Clothing/PPE Expressed by DFR Predefined options available • User input Coverage • Modelled by PEARL-OPS Migration factors
Inhalation exposure results from inhalation of contaminated air Modelled by PEARL-OPS Substance properties Application rate Crop properties Meteorological data Concentration air Breathing rate Duration User input From Exposure Factors Handbook Intensity activity Gender
Hand-to-mouth contact leads to oral exposure Modelled by dermal exposure module Exposure hands Contact Duration Defined by: ► Fraction of hand in contact with mouth ► Hand-to-mouth transfer efficiency ► Number of contacts
The PEARL-OPS model uses meteorological data to create a distribution Meteorological data of 5 years 5 locations in 3 EU zones Simulates one application every week in period April-September Distribution of 120 data points Acute exposure: averaged over a single day Longer term exposure: averaged over longer period � Daytime working period taken into account
In case of acute exposure, the target output is averaged over a single day Target output re-entry interval re-entry interval 8 a.m.–6 p.m. 8 a.m.–6 p.m. Time 14/04 21/04 application next application: residue is first set to zero
In case of longer term exposure, the target output is averaged over a longer assessment period Target ouput longer term assessment period 8 a.m.–6 p.m. Time 14/04 21/04 next application: residue is first set to zero application
The modules are combined in the software to estimate the different exposure routes
Overview of the presentation Introduction to BROWSE Overview of worker model Software Example outputs Indoor volatilisation
The software Dynamic process conceptual model coding WP2 developing algorithms developing and testing iteration bug fixing and adapting features validation finished model checking algorithms and working software tool results Will be available on the website for download: www.browseproject.eu
The Assessment screen shows inputs which are common across all models
The Worker screen shows inputs which are specific for the worker model
Overview of the presentation Introduction to BROWSE Overview of worker model Software Example outputs Indoor volatilisation
The estimated exposure levels seem to be in the same range as the currently used models Harvesting of grapes U.S. EPA table grapes U.S. EPA wine grapes EUROPOEM longer term BROWSE 75th percentile acute longer term BROWSE median acute 0 0,05 0,1 0,15 0,2 Absorbed amount (mg/kg BW/d)
The estimated exposure levels seem to be in the same range as the currently used models Harvesting of orchard fruit U.S. EPA EUROPOEM longer term BROWSE 75th percentile acute longer term BROWSE median acute 0 0,05 0,1 0,15 Absorbed amount (mg/kg BW/d)
The estimated exposure decreases as the re-entry interval increases Harvesting of orchard fruit Re-entry interval = 0 day Re-entry interval = 1 day Re-entry interval = 6 days 0 0,05 0,1 0,15 0,2 Absorbed amount (mg/kg BW/d)
The estimated exposures are highest in the northern zone for a moderately volatile substance Harvesting of orchard fruit southern zone - Spain longer term acute central zone - Germany northern zone - Denmark 0 0,05 0,1 0,15 Absorbed amount (mg/kg BW/d)
Dermal exposure is the most important exposure route Harvesting of orchard fruit Contribution to total exposure Northern Central Southern zone zone zone Dermal 99,3 99,2 99,1 Inhalation 0,0 0,1 0,2 Ingestion 0,7 0,7 0,7
The exposure increases as the vapour pressure decreases Harvesting of orchard fruit high Vp longer term medium acute Vp low Vp 0 0,1 0,2 0,3 0,4 Absorbed amount (mg/kg BW/d)
Overview of the presentation Introduction to BROWSE Overview of worker model Software Example outputs Indoor volatilisation
The volatilisation model for indoor scenarios is under development Model development vapour pressure temperature comparison ventilation rate greenhouse type Greenhouse experiments vegetable greenhouses measure air concentration after application
Two types of sampling units and sorption tubes were used inside crop outside crop 1 small sampling unit 2 large sampling units ORBO 42-L tubes ORBO 42-L tubes
Two products were applied to a tomato crop in a single tank mixture Applied products Scala (pyrimethanil) Single substance Corbel (fenpropimorf) Mixture Application rate 14 1,2 0,032 g/m² 12 1 10 0,8 Sprayer type 8 spray trolley 0,6 6 0,4 4 0,2 2 0 0 Fenpropimorph Pyrimethanil Concentration in air (ng/m³)
Different sampling heights and sampling periods are considered Pump set-up 2 heights: 1,5 and 2,5 m small 24 m Ventilation unit large windows closed units only leakage losses 30 m Sampling periods Day 0: consecutive periods of 15, 30, 60 and 120 min Day 1-4: sampling periods of 120 min during morning and afternoon
The highest levels are measured approximately 1 hour after application Fenpropimorf measured at aisle Breathing height 25 25 Concentration Crop height (µg/m³) 20 20 15 10 15 5 0 10 0 1 2 3 4 5 0 0 20 40 60 80 Hours
The volatilisation experiments also help with identifying and confirming the most important factors Temperature in general: afternoon > morning Vapour pressure fenpropimorph > pyrimethanil Location in greenhouse centre > aisle Sampling height no pattern could be observed
Conclusions Exposure estimates seem to be reasonable Model seems to react properly when changing inputs More testing and validation is needed The indoor volatilisation module is still under development
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