Brevetoxins (PbTx) are a well-recognized group of neurotoxins associated with harmful algal blooms, and specifically recurrent "Florida Red Tides," in marine waters that are linked to impacts on... Show moreBrevetoxins (PbTx) are a well-recognized group of neurotoxins associated with harmful algal blooms, and specifically recurrent "Florida Red Tides," in marine waters that are linked to impacts on both human and ecosystem health including well-documented "fish kills" and marine mammal mortalities in affected coastal waters. Understanding mechanisms and pathways of PbTx toxicity enables identification of relevant biomarkers to better understand these environmental impacts, and improve monitoring efforts, in relation to this toxin. Toward a systems-level understanding of toxicity, and identification of potential biomarkers, high-resolution magic angle spinning nuclear magnetic resonance (HRMAS NMR) was utilized for metabolic profiling of zebrafish (Danio rerio) embryos, as an established toxicological model, exposed to PbTx-2 (the most common congener in marine waters). Metabolomics studies were, furthermore, complemented by an assessment of the toxicity of PbTx-2 in embryonic stages of zebrafish and mahi-mahi (Coryphaena hippurus), the latter representing an ecologically and geographically relevant marine species of fish, which identified acute embryotoxicity at environmentally relevant (i.e., parts-per-billion) concentrations in both species. HRMAS NMR analysis of intact zebrafish embryos exposed to sub-lethal concentrations of PbTx-2 afforded well-resolved spectra, and in turn, identification of 38 metabolites of which 28 were found to be significantly altered, relative to controls. Metabolites altered by PbTx-2 exposure specifically included those associated with (1) neuronal excitotoxicity, as well as associated neural homeostasis, and (2) interrelated pathways of carbohydrate and energy metabolism. Metabolomics studies, thereby, enabled a systems-level model of PbTx toxicity which integrated multiple metabolic, molecular and cellular pathways, in relation to environmentally relevant concentrations of the toxin, providing insight to not only targets and mechanisms, but potential biomarkers pertinent to environmental risk assessment and monitoring strategies. Show less
Riverine ecosystems can be conceptualized as ‘bioreactors’ (the riverine bioreactor) which retain and decompose a wide range of organic substrates. The metabolic performance of the riverine... Show moreRiverine ecosystems can be conceptualized as ‘bioreactors’ (the riverine bioreactor) which retain and decompose a wide range of organic substrates. The metabolic performance of the riverine bioreactor is linked to their community structure, the efficiency of energy transfer along food chains, and complex interactions among biotic and abiotic environmental factors. However, our understanding of the mechanistic functioning and capacity of the riverine bioreactor remains limited.We review the state of knowledge and outline major gaps in the understanding of biotic drivers of organic matter decomposition processes that occur in riverine ecosystems, across habitats, temporal dimensions, and latitudes influenced by climate change.We propose a novel, integrative analytical perspective to assess and predict decomposition processes in riverine ecosystems. We then use this model to analyse data to demonstrate that the size-spectra of a community can be used to predict decomposition rates by analysing an illustrative dataset. This modelling methodology allows comparison of the riverine bioreactor's performance across habitats and at a global scale.Our integrative analytical approach can be applied to advance understanding of the functioning and efficiency of the riverine bioreactor as hotspots of metabolic activity. Application of insights gained from such analyses could inform the development of strategies that promote the functioning of the riverine bioreactor across global ecosystems. Show less
Large filter-feeding animals are potential sentinels for understanding the extent of microplastic pollution, as their mode of foraging and prey mean they are continuously sampling the environment.... Show moreLarge filter-feeding animals are potential sentinels for understanding the extent of microplastic pollution, as their mode of foraging and prey mean they are continuously sampling the environment. However, there is considerable uncertainty about the total and mode of exposure (environmental vs trophic). Here, we explore microplastic exposure and ingestion by baleen whales feeding year-round in coastal Auckland waters, New Zealand. Plastic and DNA were extracted concurrently from whale scat, with 32 ± 24 (mean ± SD, n = 21) microplastics per 6 g scat sample detected. Using a novel stochastic simulation modeling incorporating new and previously published DNA diet information, we extrapolate this to total microplastic exposure levels of 24,028 (95% CI: 2119, 69,270) microplastics per mouthful of prey, or 3,408,002 microplastics (95% CI: 295,810, 10,031,370) per day, substantially higher than previous estimates for large filter-feeding animals. Critically, we find that the total exposure is four orders of magnitude more than expected from microplastic measurements of local coastal surface waters. This suggests that trophic transfer, rather than environmental exposure, is the predominant mode of exposure of large filter feeders for microplastic pollution. Measuring plastic concentration from the environment alone significantly underestimates exposure levels, an important consideration for future risk assessment studies. Show less
Following the 2010 Deepwater Horizon oil spill, extensive research has been conducted on the toxicity of oil and polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment. Many studies... Show moreFollowing the 2010 Deepwater Horizon oil spill, extensive research has been conducted on the toxicity of oil and polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment. Many studies have identified the toxicological effects of PAHs in estuarine and marine fishes, however, only recently has work begun to identify the combinatorial effect of PAHs and abiotic environmental factors such as hypoxia, salinity, and temperature. This study aims to characterize the combined effects of abiotic stressors and PAH exposure on the cardiac transcriptomes of developing Fundulus grandis larvae. In this study, F. grandis larvae were exposed to varying environmental conditions (dissolved oxygen (DO) 2, 6 ppm; temperature 20, 30 °C; and salinity 3, 30 ppt) as well as to a single concentration of high energy water accommodated fraction (HEWAF) (∑PAHs 15 ppb). Whole larvae were sampled for RNA and transcriptional changes were quantified using RNA-Seq followed by qPCR for a set of target genes. Analysis revealed that exposure to oil and abiotic stressors impacts signaling pathways associated with cardiovascular function. Specifically, combined exposures appear to reduce development of the systemic vasculature as well as strongly impact the cardiac musculature through cardiomyocyte proliferation resulting in inhibited cardiac function and modulated blood pressure maintenance. Results of this study provide a holistic view of impacts of PAHs and common environmental stressors on the cardiac system in early life stage estuarine species. To our knowledge, this study is one of the first to simultaneously manipulate oil exposure with abiotic factors (DO, salinity, temperature) and the first to analyze cardiac transcriptional responses under these co-exposures Show less
It is increasingly recognized that the ubiquity of convenient single-use plastic has resulted in a global plastic pollution challenge, with substantial environmental and health consequences.... Show moreIt is increasingly recognized that the ubiquity of convenient single-use plastic has resulted in a global plastic pollution challenge, with substantial environmental and health consequences. Physical, chemical, and biological processes result in plastic weathering, with eventual formation of debris in the micro to nano size range. There is an increasing awareness that plastic fragments are dispersed in the air and can be inhaled by humans, which may cause adverse effects on the respiratory system and on other systems. Urban environments are often characterized by high concentrations of fine airborne dust from various sources. To date, however, there is limited information on the distribution, shape, and size of microplastics in the air in urban and other environments. In this article, we review and discuss our current understanding of the exposure characteristics of airborne plastic debris in urbanized areas, focusing on concentration, size, morphology, presence of additives and distributions of different polymers. The natural and extend data are compiled and compared to laboratory-based analyses to further our understanding of the potential adverse effects of inhaled plastic particles on human health. (C) 2020 Elsevier B.V. All rights reserved. Show less
Weger, L.A. de; Molster, F.; Raat, K. de; Haan, J. den; Romein, J.; Leeuwen, W. van; ... ; Hiemstra, P.S. 2020
Allergic rhinitis caused by pollen exposure is one of the most common allergic diseases. Therefore monitoring pollen levels in ambient air is an important tool in research and health care. Most... Show moreAllergic rhinitis caused by pollen exposure is one of the most common allergic diseases. Therefore monitoring pollen levels in ambient air is an important tool in research and health care. Most European monitoring stations collect airborne pollen at rooftop levels for measurements in the larger surrounding of the sampling station, and not in the direct environment of sensitized subjects. Here we present the development and evaluation of a por table pollen sampler, called "Pollensniffer", that was designed to collect pollen in the immediate environment of allergic subjects. Validation of the Pollensniffer against the standard volumetric pollen sampler showed for most pollen types high correlations between the number of pollen collected by those two devices (Spearman's Correlation Coefficient > 0.8); the Pollensniffer appeared to collect on average 5.8 times more pollen per hour than the static sampler. Pollen monitoring was performed using this Pollensniffer at street level at 3 different locations in the city of Leiden during 22 weeks in 2017 and 21 weeks in 2018, during three 15-min periods a day and at one day in the week. The results showed that the pollen levels for birch and grass pollen can significantly differ from location to location and per time of day. Furthermore, the Pollensniffer measurements at street level showed that birch and grass pollen grains were detected 1 1/2 and 2-3 weeks, respectively, before detection at rooftop level. The street measurements show that allergic subjects can encounter varying pollen levels throughout the city and that they can be exposed to grass and birch pollen and may experience hay fever symptoms, even before the sampler at rooftop level registers these pollen. (C) 2020 The Authors. Published by Elsevier B.V Show less
It is increasingly recognized that the ubiquity of convenient single-use plastic has resulted in a global plastic pollution challenge, with substantial environmental and health consequences.... Show moreIt is increasingly recognized that the ubiquity of convenient single-use plastic has resulted in a global plastic pollution challenge, with substantial environmental and health consequences. Physical, chemical, and biological processes result in plastic weathering, with eventual formation of debris in the micro to nano size range. There is an increasing awareness that plastic fragments are dispersed in the air and can be inhaled by humans, which may cause adverse effects on the respiratory system and on other systems. Urban environments are often characterized by high concentrations of fine airborne dust from various sources. To date, however, there is limited information on the distribution, shape, and size of microplastics in the air in urban and other environments. In this article, we review and discuss our current understanding of the exposure characteristics of airborne plastic debris in urbanized areas, focusing on concentration, size, morphology, presence of additives and distributions of different polymers. The natural and extend data are compiled and compared to laboratory-based analyses to further our understanding of the potential adverse effects of inhaled plastic particles on human health. Show less
According to ISO 14046 the quantification of the water scarcity footprint (WSFP) of hydropower reservoirs has to consider (1) the evaporation of water from the surface of the reservoir, (2) the... Show moreAccording to ISO 14046 the quantification of the water scarcity footprint (WSFP) of hydropower reservoirs has to consider (1) the evaporation of water from the surface of the reservoir, (2) the baseline evaporation of water of the same area before the reservoir has been built, and (3) the water scarcity index of the location of the reservoir on a spatially and temporally explicit level.When a reservoir has a storing function, e.g., for irrigation in the dry season, monthly water scarcity indexes have to be used in order to calculate the WSFP, since storage in wet seasons and release in dry seasons can counteract water scarcity and lead to a reduction of overall water scarcity in the watershed.This paper builds on previous research regarding detailed hydropower modeling and extends the water scarcity assessment to include and advance new methods for identifying sensitivities in monthly WSFP of hydropower due to the choice of impact assessment methods. We applied the global analysis to 1473 hydropower plants covering >100 countries, and added a detailed assessment for a subset of important power plants to discuss the limitations of global assessments. We thereby provide the most complete WSFP of global hydropower with state-of-the-art methods, assess the robustness of the global model and different methodological choices, and provide new monthly average AWARE CFs on watershed level.The results show that water scarcity can often be mitigated if the net evaporation is compensated by the storage effects. The two water scarcity metrics applied lead to larger differences than expected, since the monthly dynamics of dams can lead to stronger differences than the differences in the applied water scarcity factors. The new insights help to better understand the WSFP of hydropower and its uncertainties. Show less
Paulin, M.J.; Remme, R.P.; Hoek, D.C.J. van der; Knegt, B. de; Koopman, K.R.; Breure, A.M.; ... ; Nijs, T. de 2020
Organic–inorganic perovskite solar cells (PSCs) are promising candidates as photovoltaic cells. Recently, they have attracted significant attention due to certified power conversion efficiencies... Show moreOrganic–inorganic perovskite solar cells (PSCs) are promising candidates as photovoltaic cells. Recently, they have attracted significant attention due to certified power conversion efficiencies exceeding 23%, low–cost engineering, and superior electrical/optical characteristics. These PSCs extensively utilize a perovskite–structured composite with a hybrid of Pb-based nanomaterials. Operation of them may cause the release of Pb-based nanoparticles. However, limited information is available regarding the potential toxicity of Pb-based PSCs on various organisms. This study conducted a battery of in vitro and in vivo toxicity bioassays for three quintessential Pb-based PSCs (CH3NH3PbI3, NHCHNH3PbBr3, and CH3NH3PbBr3) using progressively more complex forms of life. For all species tested, the three different perovskites had comparable toxicities. The viability of Caco–2/TC7 cells was lower than that of A549 cells in response to Pb-based PSC exposure. Concentration–dependent toxicity was observed for the bioluminescent bacterium Vibrio fischeri, for soil bacterial communities, and for the nematode Caenorhabditis elegans. Neither of the tested Pb-based PSCs particles had apparent toxicity to Pseudomonas putida. Among all tested organisms, V. fischeri showed the highest sensitivity with EC50 values (30 min of exposure) ranging from 1.45 to 2.91 mg L-1. Therefore, this study recommends that V. fischeri should be preferably utilized to assess.PSC toxicity due to its increased sensitivity, low costs, and relatively high throughput in a 96–well format, compared with the other tested organisms. These results highlight that the developed assay can easily predict the toxic potency of PSCs. Consequently, this approach has the potential to promote the implementation of the 3Rs (Replacement, Reduction, and Refinement) principle in toxicology and decrease the dependence on animal testing when determining the safety of novel PSCs. Show less
