Karsten Schlich

• Fraunhofer Institute for Molecular Biology and Applied Ecology

Maintaining constant exposure concentrations during ecotoxicological studies while testing rapidly degradable substances is a challenge. To achieve stable concentrations during exposure, flow‐through systems are used. To assess the impact of substances on higher aquatic plants, the 14‐day macrophyte water–sediment Myriophyllum spicatum growth inhib...

In environmental risk assessment of substances, the 14-day growth inhibition test following the OECD test guideline 239 is employed to assess toxicity in the macrophyte Myriophyllum spicatum as a representative for dicotyledonous aquatic plants. Currently, this test evaluates physiological parameters and does not allow the identification of the mod...

Recently a number of publications have drawn attention to various concerns related to the reliability and relevance of data published in the peer-reviewed literature with respect to the quality of ecotoxicological effects data for microplastic particles (MPs) (de Ruitjer et al., 2020 and Mehinto et al., 2022). An important observation from these st...

The potential effects of microplastic particle exposure on environmental organisms has sparked intense research activities. Various studies have been conducted, however on a limited set of mostly pristine polymer materials. In parallel to the ongoing research activities, it is discussed to include non-natural polymers into the registration process...

Background Advanced/innovative materials are an undefined group of nano- and micro-particles encompassing diverse material compositions, structures and combinations. Due to their unique properties that enable specific functions during applications, there are concerns about unexpected hazards to humans and the environment. In this study, we provide...

The freshwater algae and cyanobacteria growth inhibition test (OECD test guideline 201) is frequently used to assess the ecotoxicity of chemicals or particles. A central issue is the measurement of algal growth by quantifying algal biomass over time. Chlorophyll fluorescence measurements are recommended for the testing of particles. The analysis of...

In the environmental risk assessment of substances, toxicity to aquatic plants is evaluated using, among other methods, the 7 dayLemna sp. growth inhibition test following the OECD TG 221. So far, the test is not applicable for short-term screening of toxicity, nor does it allow evaluation of toxic modes of action (MoA). The latter is also complica...

The increasing use of antibacterial silver nanomaterials (AgNM) in consumer products leads to their release into sewers. High amounts of AgNM become retained in sewage sludge, which causes their accumulation in agricultural soils when sewage sludge is applied as fertilizer. This increase in AgNM arouses concerns about toxicity to soil organisms and...

The current environmental hazard assessment is based on the testing of the pristine substance. However, it cannot be excluded that (nano)pharmaceuticals are excreted into sewage during the use phase followed by entry into wastewater treatment plants (WWTPs). Sorption to sewage sludge or release via effluent can result in modified ecotoxicological e...

The increasing use of antibacterial silver nanomaterials (AgNMs) in consumer products leads to their release into sewers. High amounts of AgNMs become retained in sewage sludge, which causes their accumulation in agricultural soils when sewage sludge is applied as fertilizer. This increase in silver arouses concerns about toxicity to soil organisms...

Adequate functioning of a sewage treatment plant (STP) is essential to protect the downstream aquatic environment (ECHA 2017), and information on the degradability of chemicals and their toxicity to activated sludge microorganisms is required. An environmental realistic higher tier test is a STP simulation test as described in OECD 303A (2001) whic...

Engineered nanomaterials (ENMs) based on CeO2 and TiO2 differ in their effects on the unicellular green alga Raphidocelis subcapitata but these effects do not reflect the physicochemical parameters that characterize such materials in water and other test media. To determine whether interactions with algae can predict the ecotoxicity of ENMs, we stu...

Fate and impact of cerium dioxide nanomaterials (CeO2 NM) in soil remains uncertain. Most of the recent environmental studies used high doses of CeO2 NM in short-term laboratory experiments and stated soil as large sink for NM. Recent studies covering the life cycle of plants found evidence for particle uptake in crop plants, and triggered concern...

Silver nanomaterials (AgNMs) are released into sewers and consequently find their way to sewage treatment plants (STPs). The AgNMs are transformed en route, mainly into silver sulfide (Ag2S), which is only sparingly soluble in water and therefore potentially less harmful than the original AgNMs. Here we investigated the toxicity and fate of differe...

Background Increasing amounts of engineered nanoparticles (NPs) in wastewater can reach the aquatic environment by passing through the sewage treatment plant (STP). NPs can induce ecotoxicological effects due to their specific chemical properties. However, their bioavailability and toxicity are potentially influenced by transformation processes cau...

Nanoenabled products (NEPs) have numerous outdoor uses in construction, transportation or consumer scenarios, and there is evidence that their fragments are released in the environment at low rates. We hypothesized that the lower surface availability of NEPs fragment reduced their environmental effects with respect to pristine nanomaterials. This h...

Silver nanoparticles (AgNPs) are efficiently converted during the wastewater treatment process into sparingly soluble silver sulfides (Ag2S). In several countries, sewage sludge is used as a fertilizer in agriculture. The bioavailability of sulfidized silver to the terrestrial isopod Porcellio scaber was investigated. Sewage sludge containing trans...

Manufactured nanomaterials (NMs) are being developed in many different variations such as size, shape, crystalline structure and surface modifications. To avoid the testing of each single nanomaterial variation, grouping and read-across strategies for nanomaterials similar to classical chemicals are discussed. Grouping and read-across aim to identi...

Sewage sludge is repeatedly applied as fertilizer on farmland due to its high nutrient content. This may lead to a significant increase of silver nanomaterials (AgNM) in soil over years. Therefore, our aim was to investigate the ecotoxicity and fate of AgNM under environmentally relevant conditions in outdoor lysimeters over 25 months. Two AgNM con...

The use of silver nanoparticles (AgNPs) in consumer products such as textiles leads to their discharge into wastewater and consequently to a transfer of the AgNPs to soil ecosystems via biosolids used as fertilizer. In urban wastewater systems (e.g., sewer, wastewater treatment plant [WWTP], anaerobic digesters) AgNPs are efficiently converted into...

Regulatory ecotoxicity testing of chemicals is of societal importance and a large effort is undertaken at the OECD to ensure that OECD test guidelines (TGs) for nanomaterials (NMs) are available. Significant progress to support the adaptation of selected TGs to NMs was achieved in the context of the project MARINA (http://www.marina-fp7.eu/) funded...

Nanomaterials enter the terrestrial environment via the repeated application of sludge to soils over many years. The goal of this investigation was to compare the effects of CuO and Ag nanomaterials on soil microorganisms after a single application and after repeated applications ultimately resulting in the same test concentrations. The effect on s...

Engineered nanomaterials (ENMs) are marketed as a substance or mixtures and are additionally used due to their active agent properties in products such as pesticides or biocides, for which specific regulations apply. Currently, there are no specific testing strategies for environmental fate and effects of ENMs within the different regulations. An e...

Based on the increased utilization of nanosilver (silver nanomaterials=AgNM) as antibacterial agent, there is the strong need to assess the potential environmental implication associated with its new application areas. In this study an exemplary environmental risk assessment (ERA) of AgNM applied in textiles was performed. Environmental exposure sc...

a b s t r a c t We investigated the effects of silver nanomaterials (AgNMs) on five well-characterized soils with distinct physicochemical properties using two standardized test systems. The carbon transformation test (OECD 217) showed minimal sensitivity whereas the ammonia oxidizing bacteria test (ISO 15685) showed extreme sensitivity over 28 day...

Background: The procedure described in The Organisation for Economic Co-operation and Development (OECD) test guideline (TG) 216 is used to assess the effects of chemicals on microbial nitrogen transformation in soil, and the results are considered in regulatory risk assessments. We investigated the suitability of this method to characterize the ef...

Increased use of nanomaterials in everyday products leads to their environmental release and therefore, the information need on their fate and behaviour. Nanomaterials have to be suspended with high repeatability and comparability for studies on environmental effects. They also have to be well characterised with a focus on the state of agglomeratio...

http://www.ttl.fi/en/publications/Electronic_publications/Nanosafety_in_europe_2015-2025/Documents/nanosafety_2015-2025.pdf

Silver nanoparticles (AgNPs) are widely believed to be retained in the sewage sludge during sewage treatment. The AgNPs and their derivatives, however, re-enter the environment with the sludge and via the effluent. AgNP were shown to occur in surface water, while evidence of a potential toxicity of AgNPs in aquatic organisms is growing. This study...

Silver nanoparticles (AgNPs) are widely used in many fields of application and consumer products due to their antibacterial properties. The aim of this study was to prepare a hazard assessment for one specific AgNP in soil, incorporated via sewage sludge (the sewage sludge pathway). The effects of pristine AgNPs on microorganisms, plants and earthw...

The widespread use of silver nanoparticles (Ag-NPs), for example, in textiles and cleaning products, means that they are likely to reach the environment via biosolids or the effluent from wastewater treatment plants. The aim of the present study was to determine the ecotoxicity of Ag-NPs in the earthworm reproduction test using Eisenia andrei. In a...

Background The increasing use of nanotechnology means that nanomaterials will enter the environment. Ecotoxicological data are therefore required so that adequate risk assessments can be carried out. In this study, we used a standardized earthworm reproduction test with Eisenia andrei to evaluate three types of TiO2 nanoparticles (NM-101, NM-102, N...

Background: In terrestrial ecotoxicological tests, the availability and ecotoxicity of solid nanomaterials may depend on the application technique. We compared five spiking procedures using solid uncoated TiO2 and Ag nanoparticles in standardized OECD tests with earthworms, plants and soil microflora: dry spiking of soil by applying soil or silica...

Purpose Little is known about the ecotoxicity of nanomaterials and there are no specific guidelines for sample preparation and testing. We set out to establish whether the method used to prepare TiO2 dispersions had a significant impact on aquatic ecotoxicity. We also followed the formation of agglomerates during the incubation period. Methods We a...