Aquatic and sediment ecotoxicity data of difenoconazole and its potential environmental risks in ponds bordering rice paddies.

Difenoconazole has a widespread agricultural use to control fungal diseases in crops, including rice. In edge-of-field surface waters the residues of this lipophilic fungicide may be toxic to both pelagic and benthic organisms. To allow an effect assessment we mined the regulatory and open literature for aquatic toxicity data.

Species Sensitivity Distributions of Benthic Macroinvertebrates in Fludioxonil-Spiked Sediment Toxicity Tests.

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.

Open Science in regulatory environmental risk assessment.

A possible way to alleviate the public skepticism toward regulatory science is to increase transparency by making all data and value judgments 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 in strengthening Open Science initiatives in regulatory environmental risk assessment (ERA). In this discussion paper, we argue that the benefits associated with Open Science in regulatory ERA far outweigh its perceived risks.

Sediment toxicity of the fungicide fludioxonil to benthic macroinvertebrates -evaluation of the tiered effect assessment procedure.

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 tubifex, the insects Chironomus riparius and Caenis horaria, the crustaceans Hyalella azteca and Asellus aquaticus and the bivalves Corbicula fluminalis and Pisidium amnicum. Toxicity estimates were expressed in terms of total concentration of dry sediment as well as in pore water concentration.

Is the Effect Assessment Approach for Fungicides as Laid Down in the European Food Safety Authority Aquatic Guidance Document Sufficiently Protective for Freshwater Ecosystems?

In Europe, the European Food Safety Authority 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 [SSDs]), and tier-3 (model ecosystem studies) approaches. In the present study, the protectiveness of such a tiered approach was evaluated for fungicides. Acute and chronic RACs for tier-1 and tier-2B (SSDs) were calculated using toxicity data for standard and additional test species, respectively.

Exposure pattern-specific species sensitivity distributions for the ecological risk assessments of insecticides.

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 exposure of pesticides in the field is often characterised by a variable exposure regime.

Exposure and effects of sediment-spiked fludioxonil on macroinvertebrates and zooplankton in outdoor aquatic microcosms.

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 pelagic macroinvertebrates and zooplankton. Besides blank control and solvent control systems the experiment had six different treatment levels (1.

Prospective Environmental Risk Assessment for Sediment-Bound Organic Chemicals: A Proposal for Tiered Effect Assessment.

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 procedure for organic chemicals in sediment, with a focus on the applicable European regulations and the underlying data requirements.

Ecological Recovery Potential of Freshwater Organisms: Consequences for Environmental Risk Assessment of Chemicals.

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.

Analysing chemical-induced changes in macroinvertebrate communities in aquatic mesocosm experiments: a comparison of methods.

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 analysed with univariate statistics have been proposed.

Acute tier-1 and tier-2 effect assessment approaches in the EFSA Aquatic Guidance Document: are they sufficiently protective for insecticides?

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 based on threshold concentrations from micro/mesocosm studies (ETO-RAC). A lower-tier RAC was considered as sufficiently protective, if less than the corresponding ETO-RAC.

Impact of imidacloprid on life-cycle development of Coccinella septempunctata in laboratory microcosms.

Long-term effects of a single application of imidacloprid on ladybird beetle, Coccinella septempunctata L., were studied in indoor laboratory microcosms, starting with the 2nd instar larvae of C. septempunctata but covering the full life cycle.

Assessing effects of the fungicide tebuconazole to heterotrophic microbes in aquatic microcosms.

Aquatic ecological risk assessment of fungicides in Europe under Regulation 1107/2009/EC does not currently assess risk to non-target bacteria and fungi. Rather, regulatory acceptable concentrations based on ecotoxicological data obtained from studies with fish, invertebrates and primary producers (including algae) are assumed to be protective to all other aquatic organisms. Here we explore the validity of this assumption by investigating the effects of a fungicide (tebuconazole) applied at its "non-microbial" HC5 concentration (the concentration that is hazardous to 5% of the tested taxa) and derived from acute single species toxicity tests on fish, invertebrates and primary producers (including algae) on the community structure and functioning of heterotrophic microbes (bacteria and aquatic fungi) in a semi-field study, using novel molecular techniques.

Toxic effects of hexaflumuron on the development of Coccinella septempunctata.

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.

Priorities to improve the ecological risk assessment and management for pesticides in surface water.

This article deals with prospective and retrospective ecological risk assessment (ERA) procedures for pesticides in surface waters as carried out under European legislation (Regulation 1107/2009/EC; Directive 2009/128/EC; Directive 2000/60/EC). Priorities to improve the aquatic risk assessment and management of pesticides are discussed on basis of the following 5 theses: 1) the management of the environmental risks of pesticides in surface water requires an appropriate implementation of feedback mechanisms between prospective and retrospective ERA, 2) an appropriate ERA cannot be carried out without well-defined specific protection goals, described in terms of focal vulnerable populations and related exposure assessment goals, 3) the interaction between the assessment of exposure and eco(toxico)logical effects in ERA is at a lower level of sophistication than either assessment of exposure or assessment of effects in the field, 4) there is insufficient experimental proof that, in prospective ERA, the chronic effect assessment procedures accurately predict long-term population- and community-level impacts, and 5) multiple stress by pesticides in aquatic ecosystems cannot be ignored in ERA, but in individual water bodies, toxicity usually is dominated by a limited number of substances.

Acute toxicity tests with Daphnia magna, Americamysis bahia, Chironomus riparius and Gammarus pulex and implications of new EU requirements for the aquatic effect assessment of insecticides.

Threshold concentrations for treatment related effects of 31 insecticides, as derived from aquatic micro-/mesocosm tests, were used to calibrate the predictive value of the European Tier-1 acute effect assessment on basis of laboratory toxicity tests with Daphnia magna, Chironomus spp., Americamysis bahia and Gammarus pulex. The acute Tier-1 effect assessment on basis of Daphnia (EC(50)/100) overall was protective for organophosphates, carbamates and most pyrethroids but not for neonicotinoids and the majority of insect growth regulators (IGRs) in the database.

Effects of the fungicide metiram in outdoor freshwater microcosms: responses of invertebrates, primary producers and microbes.

The ecological impact of the dithiocarbamate fungicide metiram was studied in outdoor freshwater microcosms, consisting of 14 enclosures placed in an experimental ditch. The microcosms were treated three times (interval 7 days) with the formulated product BAS 222 28F (Polyram®). Intended metiram concentrations in the overlying water were 0, 4, 12, 36, 108 and 324 μg a.

Development of a framework based on an ecosystem services approach for deriving specific protection goals for environmental risk assessment of pesticides.

General protection goals for the environmental risk assessment (ERA) of plant protection products are stated in European legislation but specific protection goals (SPGs) are often not precisely defined. These are however crucial for designing appropriate risk assessment schemes. The process followed by the Panel on Plant Protection Products and their Residues (PPR) of the European Food Safety Authority (EFSA) as well as examples of resulting SPGs obtained so far for environmental risk assessment (ERA) of pesticides is presented.

Macroinvertebrate responses to insecticide application between sprayed and adjacent nonsprayed ditch sections of different sizes.

Under typical agricultural use of an insecticide, it is likely that only part of an edge-of-field drainage ditch will be directly contaminated by spray drift. The response, including recovery, of aquatic macroinvertebrates in sprayed ditch sections may be affected by immigration of organisms from adjacent nonsprayed ditch sections, but also the population dynamics in nonsprayed sections (refuges) may be affected by nearby contaminated patches (known as action at a distance). Experimental ditches were used to study the influence of the presence of nearby refuges on the responses of macroinvertebrates in ditch sections directly sprayed with the insecticide lufenuron, and vice versa.

Fungicide risk assessment for aquatic ecosystems: importance of interspecific variation, toxic mode of action, and exposure regime.

The risk assessment of fungicides in Europe uses information from ecotoxicity studies performed on vertebrates, invertebrates, and primary producers, but not nontarget fungi. But which toxicity data should be used to assess risk and how important are modes of action and exposure regimes? A data set was compiled comprising acute single-species toxicity data for 42 fungicides, semifield data for 12 fungicides, and covering seven toxic modes of action and different exposure regimes. Most fungicides were general biocides and data from all taxonomic groups were used to construct species sensitivity distributions (SSDs) and assess risk.

Impact of a benzoyl urea insecticide on aquatic macroinvertebrates in ditch mesocosms with and without non-sprayed sections.

The long-term response, including recovery, of aquatic macroinvertebrates to short-term insecticide exposure may be affected by the presence of uncontaminated refuges in the stressed ecosystem. Experimental ditches were used to study the influence of non-sprayed ditch sections regarding the ecotoxicological effects on and the recovery of macroinvertebrates following treatment with the insecticide lufenuron. The treatment regimes differed in the proportion of the ditch (0, 33, 67, and 100% of surface area) that was sprayed to reach a lufenuron concentration of 3 microg/L in the water column of the sprayed ditch section.

Effects of the pyrethroid insecticide gamma-cyhalothrin on aquatic invertebrates in laboratory and outdoor microcosm tests.

The sensitivity of a range of freshwater lentic invertebrates to gamma-cyhalothrin (GCH), a single enantiomer of the synthetic pyrethroid lambda-cyhalothrin, was assessed in single species laboratory tests and an outdoor multi-species ecosystem test. The most sensitive species in the laboratory single species tests with GCH was Chaoborus obscuripes (96 h EC(50): 3.8 ng/l).