Theo C M Brock

Theo C M Brock
Wageningen University & Research | WUR · Wageningen Enviromental Research

Dr

About

260
Publications
55,460
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Introduction
Theo Brock is an aquatic ecologist and expert in environmental risk assessment for pesticides, who recently retired from Wageningen Environmental Research (Wageningen University and Research Centre). As a volunteer he still is connected to Wageningen UR to support his current activities in a working group of the European Food Safety Authority
Additional affiliations
January 1992 - present
Wageningen University & Research
Position
  • Senior research scientist aquatic ecology and ecooxicology

Publications

Publications (260)
Article
Information from effects of pesticides in sediments at an ecosystem level, to validate current and proposed risk assessment procedures, is scarce. A sediment-spiked outdoor freshwater microcosm experiment was conducted with fludioxonil (lipophilic, non-systemic fungicide) to study exposure dynamics and treatment-related responses of benthic and pel...
Article
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A conceptual framework was developed by a working group of the Scientific Committee of the European Food Safety Authority (EFSA) to guide risk assessors and risk managers on when and how to integrate ecological recovery and resilience assessments into environmental risk assessments (ERA). In this commentary we advocate that a systems approach is re...
Article
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In Europe, the EFSA Aquatic Guidance Document describes the procedures for the derivation of Regulatory Acceptable Concentrations (RACs) for pesticides in edge‐of‐field surface waters on the basis of Tier‐1 (standard test species), Tier‐2 (geometric mean and species sensitivity distributions) and Tier‐3 (model ecosystem studies) approaches. In the...
Article
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28-Day sediment-spiked laboratory toxicity tests with eight benthic macroinvertebrates and the lipophilic fungicide fludioxonil were conducted to verify the proposed tiered sediment effect assessment procedure as recommended by the European Food Safety Authority (EFSA). The test species were the oligochaetes Lumbriculus variegatus and Tubifex tubif...
Article
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The fungicide fludioxonil, given its physicochemical properties, potentially accumulates and persists in sediments. Fludioxonil has a widespread agricultural use to control various fungal diseases. Its residues may cause toxic effects to benthic aquatic fauna, thereby impacting ecosystem service functions of aquatic ecosystems. To assess the potent...
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This final report evaluates the training courses delivered under the contract NP/EFSA/SCER/2018/01. The courses are to explain the basics of how to conduct environmental risk assessments (ERA’s) with a particular focus on (1) living organisms, i.e. the deliberate commercial release into the environment of Genetically Modified Organisms (GMO’s), or...
Preprint
Full-text available
In China, the fungicide fludioxonil, that accumulates and persists in sediments, has a widespread agricultural use to control various fungal diseases. Its residues may cause toxic effects to benthic aquatic fauna, thereby impacting ecosystem service functions of aquatic ecosystems. To assess the potential environmental effects of fludioxonil in the...
Technical Report
Full-text available
Mysid shrimps such as the marine Americamysis bahia have become a subject of interest in ecotoxicological research as they appear to react rather more sensitive to exposure to plant protection products than previously tested freshwater macroinvertebrates. Although it is curious that in the freshwater risk assessment of plant protection products a m...
Preprint
In China, the fungicide fludioxonil, that accumulates and persists in sediments, has a widespread agricultural use to control various fungal diseases. Its residues may cause toxic effects to benthic and pelagic aquatic fauna, thereby impacting ecosystem service functions of aquatic ecosystems.To assess the environmental risks of fludioxonil, sedime...
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Full-text available
A possible way to alleviate the public skepticism towards regulatory science is to increase transparency by making all data and value judgements used in regulatory decision‐making accessible for public interpretation, ideally early‐on in the process, and following the concepts of Open Science. This paper discusses the opportunities and challenges i...
Article
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Mathematical models within the GUTS (= General Unified Threshold models of Survival) framework translate time‐variable chemical exposure information into expected survival of animals. GUTS models are species‐ and compound‐specific and explicitly describe the internal exposure dynamics in an organism (toxicokinetics) and the related damage and effec...
Article
When entering aquatic ecosystems, hydrophobic organic chemicals like the fungicide fludioxonil partition to the sediment compartment where they pose potential risks to benthic invertebrates. To assess the ecological risk for sediment-dwelling invertebrates, nematodes are a suitable organism group, as they are abundantly present and possess key posi...
Article
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In the higher tiers of pesticide risk assessment, the Species Sensitivity Distribution (SSD)concept is often used to establish the effect threshold defined as the concentration protecting 95% of the species (Hazardous Concentration 5%, HC5). The toxicity data included in SSDs are normally established using a constant exposure regime. However, the e...
Article
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Highlights • 9 recommendations digest recent developments in regulatory environmental risk assessment. • Efforts are necessary to make the translation of ecotoxicology into regulatory decisions more open and transparent. • They require concerted and sustained action from a variety of sectors and stakeholders. • Better evidence will lead to bette...
Article
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Abstract This guidance document is intended to assist the applicant in the preparation and the presentation of an application, as foreseen in Article 7.6 of Regulation (EC) No 1831/2003, for the authorisation of additives used in animal nutrition. It specifically covers the assessment of the safety for the environment. Draft endorsed by the FEEDAP...
Article
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TKTD models are species‐ and compound‐specific and can be used to predict (sub)lethal effects of pesticides under untested (time‐variable) exposure conditions. Three different types of TKTD models are described, viz., (i) the ‘General Unified Threshold models of Survival’ (GUTS), (ii) those based on the Dynamic Energy Budget theory (DEBtox models),...
Article
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The EFSA Panel on Plant Protection Products and their Residues reviewed the guidance on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessment. The inclusion of aged sorption is a higher tier in the groundwater leaching assessment. The Panel based its review on a test with three substances taken fro...
Article
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Following a request from the European Commission, the EFSA Panel on Plant Protection Products and their Residues (PPR Panel) prepared a scientific opinion to provide a comprehensive evaluation of pesticide residues in foods for infants and young children. In its approach to develop this scientific opinion, the EFSA PPR Panel took into account, amon...
Article
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Following a request from EFSA, the Panel on Plant Protection Products and their Residues developed an opinion on the science to support the potential development of a risk assessment scheme of plant protection products for amphibians and reptiles. The coverage of the risk to amphibians and reptiles by current risk assessments for other vertebrate g...
Article
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This final report evaluates the training courses delivered under the contract OC/EFSA/SCER/2014/02- Lot 1. Two types of specialised training courses were delivered: a training course addressing uncertainty in EFSA’s scientific assessments and a training course on Environmental Risk Assessment. Both trainings were evaluated as very good by the parti...
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In 2013, EFSA published a comprehensive systematic review of epidemiological studies published from 2006 to 2012 investigating the association between pesticide exposure and many health outcomes. Despite the considerable amount of epidemiological information available, the quality of much of this evidence was rather low and many limitations likely...
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In 2013, EFSA published a literature review on epidemiological studies linking exposure to pesticides and human health outcome. As a follow up, the EFSA Panel on Plant Protection Products and their residues (PPR Panel) was requested to investigate the plausible involvement of pesticide exposure as a risk factor for Parkinson's disease (PD) and chil...
Article
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EFSA is committed to assess and communicate the risks occurring in the food and feed chain from farm to fork and to provide other forms of scientific advice. This work, carried out by EFSA since its inception, has resulted in the adoption of thousands of scientific assessments. EFSA is obliged to re-assess past assessments in specific regulatory co...
Article
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Following a request from EFSA, the Panel on Plant Protection Products and their Residues developed an opinion on the science behind the risk assessment of plant protection products for in-soil organisms. The current risk assessment scheme is reviewed, taking into account new regulatory frameworks and scientific developments. Proposals are made for...
Article
Chemical contaminants released into the in the environment may have adverse effects on (non-target) species, populations and communities. The return of a stressed system to its pre-disturbance or other reference state, i.e. the ecological recovery, may depend on various factors related to the affected taxon, the ecosystem of concern and the type of...
Article
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Regulatory policies in many parts of the world either recognize the utility of, or mandate, that all available studies be considered in Environmental/Ecological Hazard and Risk Assessment (ERA) of chemicals, including studies from the peer-reviewed literature. Consequently, a vast array of different studies and data types need to be considered. The...
Article
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Maintaining a healthy environment and conserving biodiversity are major goals of environmental protection. A challenge is that protection goals outlined in legislation are often too general and broad to be directly applicable for environmental risk assessment (ERA) performed by EFSA. Therefore, they need to be translated into specific protection go...
Technical Report
Full-text available
The EFSA performs environmental risk assessment (ERA) for single potential stressors such as plant protection products, genetically modified organisms and feed additives, and for invasive alien species that are harmful to plant health. This ERA focusses primarily on the use or spread of such potential stressors in an agricultural context, but also...
Technical Report
Full-text available
EFSA performs environmental risk assessments (ERAs) for single potential stressors such as plant protection products, genetically modified organisms and feed additives and for invasive alien species that are harmful for plant health. In this risk assessment domain, the EFSA Scientific Committee recognises the importance of more integrated ERAs cons...
Article
Full-text available
EFSA performs environmental risk assessments (ERAs) for single potential stressors such as plant protection products, genetically modified organisms and feed additives and for invasive alien species that are harmful for plant health. In this risk assessment domain, the EFSA Scientific Committee recognises the importance of more integrated ERAs cons...
Article
Full-text available
A broadly accepted framework for prospective environmental risk assessment (ERA) of sediment-bound organic chemicals is currently lacking. Such a framework requires clear protection goals, evidence-based concepts that link exposure to effects and a transparent tiered-effect assessment. In this paper, we provide a tiered prospective sediment ERA pro...
Article
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We investigated the appropriateness of several methods, including those recommended in the Aquatic Guidance Document of the European Food Safety Authority (EFSA), for the derivation of chronic Tier-1 Regulatory Acceptable Concentrations (RACs) for insecticides and aquatic organisms. The insecticides represented different chemical classes (organopho...
Article
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The prospective aquatic Environmental Risk Assessment (ERA) of pesticides is generally based on the comparison of predicted environmental concentrations in edge-of-field surface waters with regulatory acceptable concentrations derived from laboratory and/or semi-field experiments with aquatic organisms. New improvements in mechanistic effect modell...
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This case study of the SETAC workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field water bodies. A standard EU risk assessment for an ex...
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Accounting for ecosystem services helps to translate broad policy protection goals into specific operational ones for environmental risk assessments
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The EFSA Panel on Plant Protection Products and their Residues (PPR Panel) was tasked to revise the Guidance Document (GD) on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev. 4 (final), 17 October 2002). This scientific opinion of the PPR Panel is the second of three requested deliverables within this mandate. The scie...
Article
Full-text available
The European Food Safety Authority (EFSA) asked the Panel on Plant Protection Products and their Residues to prepare a scientific opinion on the Food and Environment Research Agency guidance proposal ‘Guidance on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessments’. The Panel concluded that the...
Article
Full-text available
Mesocosm experiments that study the ecological impact of chemicals are often analysed using the multivariate method 'Principal Response Curves' (PRCs). Recently, the extension of generalised linear models (GLMs) to multivariate data was introduced as a tool to analyse community data in ecology. Moreover, data aggregation techniques that can be anal...
Article
Full-text available
Following a request from the European Food Safety Authority, the Panel on Plant Protection Products and their Residues developed an opinion on the science to support the development of a risk assessment scheme of plant protection products for non-target arthropods. The current risk assessment scheme is reviewed, taking into consideration recent wor...
Article
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The Panel has interpreted the Terms of Reference by carrying out a stepwise evaluation of the BEEHAVE simulation model with a view to assessing its suitability for use in a regulatory context and for risk assessment of multiple stressors at the landscape level. The EFSA opinion on good modelling practice was used to evaluate the model and its docum...
Article
Background: The objective of this paper is to evaluate whether the acute tier-1 and tier-2 methods as proposed by the Aquatic Guidance Document recently published by the European Food Safety Authority (EFSA) are appropriate for deriving regulatory acceptable concentrations (RACs) for insecticides. The tier-1 and tier-2 RACs were compared with RACs...
Article
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In the European registration procedure for pesticides, microcosm and mesocosm studies are the highest aquatic experimental tier to assess their environmental effects. Evaluations of microcosm/mesocosm studies rely heavily on no observed effect concentrations (NOECs) calculated for different population-level endpoints. Ideally, a power analysis shou...
Article
The aim of the conducted work was to assess whether populations effects and recovery times increase when a population of a vulnerable aquatic invertebrate is exposed to concentrations of one or multiple pesticides. The two sets of pesticide combinations are typical for orchard and tuber crops in The Netherlands. Exposure concentrations were predict...
Article
Full-text available
The Panel has interpreted the Terms of Reference as a stepwise analysis of issues relevant to both the development and the evaluation of models to assess ecological effects of pesticides. The regulatory model should be selected or developed to address the relevant specific protection goal. The basis of good modelling practice must be the knowledge...
Article
Full-text available
Sediment toxicity tests play an important role in prospective risk assessment for organic chemicals. This review describes sediment toxicity tests for microorganisms, macrophytes, benthic invertebrates, and benthic communities. Current approaches in sediment toxicity testing are fragmentary and diverse. This hampers the translation of single-specie...
Article
Full-text available
Studying the toxic risk of pesticide exposure to ladybird beetles is important from an agronomical and ecological perspective since larval and adult ladybirds are dominant predators of herbivorous pest insects (e.g., aphids) in various crops in China. This article mainly deals with the long-term effects of a single application of the insect growth...
Technical Report
Full-text available
EFSA’s Panel on Plant Protection Products and their Residues (PPR) was tasked to revise the Guidance Document (GD) on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev.4 (final), 17 October 2002). This Guidance of the PPR Panel is the first of three requested deliverables within this mandate. It has its focus on tiered a...
Article
Full-text available
EFSA's Panel on Plant Protection Products and their Residues (PPR) was tasked to revise the Guidance Document (GD) on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev.4 (final), 17 October 2002). This Guidance of the PPR Panel is the first of three requested deliverables within this mandate. It has its focus on tiered a...