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The extensive application of carbon nanomaterials (CNMs) has attracted increasing studies concerned about its environmental impact. These studies focus on single exposure to CNMs, but repeated exposures with relatively low concentration are more likely to occur under actual exposure scenario. In this study, we studied the metabolic functional and structure of soil microorganism community under single and repeated exposures to multiwalled carbon nanotubes (MW), graphene (GR), and fullerene (C 60 ) by Biolog EcoPlates and high-throughput sequencing. Our findings revealed that repeated exposures to CNMs significantly increase the metabolic activity and diversity of the soil microbial community as compared with single exposure. Principal component and similarity analysis not only indicated that GR exerted a stronger effect on soil microbial diversity among three exposures compared to C 60 and MW, but also revealed that the metabolic activity of the soil microbial community was more affected by the exposure scenarios of CNMs than the type of CNMs. These findings elucidated the effect of CNMs under different exposure scenarios on soil microorganism community, providing a new perspective on the risk assessment of nanomaterials.

Aflatoxins (AFs), ochratoxin A (OTA), citrinin (CIT), fumonisin B 1 (FB 1 ), zearalenone (ZEN), and deoxynivalenol (DON) are mycotoxins that may contaminate diets, especially in low-income settings, with potentially severe health consequences. This study investigates the exposure of 439 pregnant women in rural Bangladesh to 35 mycotoxins and their corresponding health risks and links their exposure to certain foods and local stimulants. Overall, 447 first-morning urine samples were collected from pregnant women between July 2018 and November 2019. Mycotoxin biomarkers were quantified by DaS-HPLC–MS/MS. Urinary concentration of frequently occurring mycotoxins was used to estimate dietary mycotoxin exposure. Median regression analyses were performed to investigate the association between the consumption of certain foods and local stimulants, and urinary concentration of frequently occurring mycotoxins. Only in 17 of 447 urine samples (4%) were none of the investigated mycotoxins detected. Biomarkers for six major mycotoxins (AFs, CIT, DON, FB 1 , OTA, and ZEN) were detected in the urine samples. OTA (95%), CIT (61%), and DON (6%) were most frequently detected, with multiple mycotoxins co-occurring in 281/447 (63%) of urine samples. Under the lowest exposure scenario, dietary exposure to OTA, CIT, and DON was of public health concern in 95%, 16%, and 1% of the pregnant women, respectively. Consumption of specific foods and local stimulants—betel nut, betel leaf, and chewing tobacco—were associated with OTA, CIT, and DON urine levels. In conclusion, exposure to multiple mycotoxins during early pregnancy is widespread in this rural community and represents a potential health risk for mothers and their offspring.

Pharmaceuticals pose a major threat to the marine environment, and several studies have recently described their negative effects on marine organisms. Pharmaceutical compounds are constantly being released into aquatic ecosystems, and chronic exposure, even at low concentrations, may have a major impact on marine organisms. The purpose of the present study is to evaluate the biological changes induced by one of the most widely used pharmaceuticals—paracetamol—in the blue mussel Mytilus edulis , after a long-term exposure at environmentally relevant concentrations. We present our data alongside and in comparison with results from a previous short-term exposure, to demonstrate the significance of exposure period on the effects of paracetamol in adult blue mussels. After 24 days of laboratory exposure, seven potential target genes were selected to examine toxicological effects in mussels’ gonads and possible disruptive effects on reproductive processes. The results show the modulation of some important reproduction-related genes: estrogen receptor-2 ( ER2 ), vitelline envelope zona pellucida domain-9 ( V9 ), and vitellogenin ( VTG ). Variations in mRNA expression of four other genes involved in apoptosis ( HSP70 , CASP8 , BCL2 , and FAS ) are also highlighted. Histopathological alterations caused by paracetamol, together with neutral red retention time response in mussels’ hemocytes, are presented herein. Overall, this study highlights the exacerbated effects of low concentration of paracetamol after chronic exposure, similar to the damage induced by higher concentrations in a short exposure scenario, thus emphasizing the importance of length of exposure period when studying the effects of this substance. Additionally, this study also discusses the potential of paracetamol to inflict several major changes in the reproductive system of mussels and thus possibly affect the survival of populations.

Streams and their riparian zones are connected by spatial flows of organic matter and constitute a model example of a meta‐ecosystem. Fluxes of leaf litter from the riparian zone to the stream are a major energy source in stream food webs. Leaf litter can enter the stream vertically, falling from the tree and into the stream, or laterally, washing into the stream after a period of exposure in the terrestrial ecosystem. The latter can contribute up to 23% to the total amount of litterfall entering streams. To determine if decomposition, microbial and invertebrate colonization of lateral litter inputs are similar to those of vertical inputs, we assessed leaf decomposition of alder, poplar and a 1:1 mixture of the two species in three scenarios across a gradient of terrestrial:aquatic exposures. Overall, decomposition was explained by a negative exponential model and decreased with the increase in the period of terrestrial exposure in all cases. Invertebrate colonization tended to decrease with the increase in the period of terrestrial exposure, but total invertebrate richness and biomass were more affected by litter type than by the exposure scenario, attaining higher values in the mixture than in the species alone. As the length of exposure in the terrestrial ecosystem increased, in‐stream decomposition rates of leaf litter decreased. Comparing leaf species treatments, alder decomposition rates were faster than poplar and the alder–poplar mixture. The richness of the aquatic hyphomycete community colonizing leaf litter after submergence decreased, and sporulation rates were strongly inhibited with an increasing terrestrial exposure period. While fungi colonizing leaf litter exposed only in the stream invested in rapid reproduction, fungi colonizing litter with prior terrestrial exposure built up more biomass. We conclude that the path taken by the litter fluxes has important effects on the functioning of the receiving ecosystem. Studies relying only on the fate of freshly abscissed leaf litter (vertical inputs) may not present a complete picture of the decomposition process in streams and may have been overestimating the overall richness and reproductive activity of the aquatic hyphomycetes colonizing leaf litter. Resumo Os ribeiros e as suas áreas ripícolas estão ligados por fluxos espaciais de matéria orgânica e constituem um dos melhores exemplos de meta‐ecossistemas. Os fluxos de folhada provenientes da zona ripícola são a principal fonte de energia dos ribeiros de baixa ordem. Nas regiões temperadas, as entradas laterais, constituídas por detritos que chegam à água depois de um período de exposição no ecossistema terrestre, podem constituir até 23% da quantidade total da matéria orgânica de origem alóctone. Para determinar se a decomposição, a colonização microbiana e a colonização por invertebrados dos detritos que entram lateralmente são semelhantes aos das entradas verticais, estudámos a decomposição de folhas de amieiro, choupo e uma mistura 1:1 das duas espécies em três cenários num gradiente de exposição terrestre‐aquática. A decomposição global foi explicada por um modelo exponencial negativo e diminuiu com o aumento do período de exposição terrestre em todos os casos. A colonização por invertebrados diminuiu tendencialmente com o aumento do período de exposição terrestre, mas tanto a riqueza como a biomassa foram mais afetadas pelo tipo de detritos que pela exposição, atingindo valores mais elevados na mistura que nas espécies isoladas O efeito da exposição terrestre nas taxas de decomposição aquáticas dependeu da espécie, com o amieiro decompondo‐se mais rapidamente e o choupo e a mistura decompondo‐se mais lentamente com o aumento do período de exposição terrestre. A riqueza dos hifomicetes aquáticos que colonizaram as folhas após a submersão diminuiu e as taxas de esporulação foram fortemente reduzidas pela exposição terrestre. Enquanto os fungos que colonizaram as folhas expostas apenas na água investiram em rápida reprodução, os fungos que colonizaram as folhas com exposição terrestre prévia acumularam mais biomassa. Concluímos que a via tomada pelos fluxos de detritos tem efeitos importantes no ecossistema recetor. Os estudos efetuados apenas com folhas senescentes (entradas verticais) podem não apresentar uma imagem completa do processo de decomposição nos rios e podem ter sobrestimado a riqueza e a atividade reprodutiva dos hifomicetes aquáticos que colonizam os detritos. A free Plain Language Summary can be found within the Supporting Information of this article. A free Plain Language Summary can be found within the Supporting Information of this article.

Slovene press has recently expressed concern for the health of children who ingest playground sand contaminated with lead. However, current assessments may be overestimating the health risk, as they assume that human body absorbs the whole amount of a contaminant. The aim of our study was to see how much lead in sand intended for playground sandboxes in Slovenia really is absorbed and what health risk it may present. To do that, we ran bioaccessibility tests to simulate metabolism and see how digestion affects lead levels. Our results show low bioaccessibility of lead from sand (0.01- 36.84 %). Taking into account lead bioaccessibility, we ran several scenarios of sand ingestion in children and established that in general the risk is negligible, except for pica behaviour with extremely high (20 g) ingestion of sand with highly mobilised lead (2.69 μg g-1). Further research should assess real-life exposure to lead from playground sand in children and perhaps update these preliminary bioaccessibility data. V zadnjem obdobju so se v Sloveniji pojavili številni pomisleki o varnosti mivke, ki je namenjena za otroške peskovnike. Ocena tveganja otrok, ki so izpostavljeni svincu temelji na predpostavki, da je celotna količina toksične kovine biološko dostopna. Zato je bil namen raziskave analizirati biološko dostopnost svinca v mivki, ki je namenjen za peskovnike otroških igrišč. Z simulacijo prebavnega trakta smo analizirali vpliv prebavnih sokov za izplavljanje svinca iz mivke. Rezultati kažejo na majhno biodostopnost svinca v mivki (0,01-36,84 %) slovenskih proizvajalcev. Na podlagi biološke dostopnosti smo simulirali različne scenarije vnosa in ugotovili, da je tveganje zanemarljivo, razen v primeru pica sindroma (zaužitje 20 g mivke) ter ob predpostavki največje dokazane biološke dostopnosti (2,69 μg g-1). Raziskave v prihodnosti bodo vključevale realno izpostavljenost otrok svincu iz peskovnikov in bodo morda nadgradile preliminarno raziskavo.

So far, the majority of in vitro toxicological experiments are conducted after an acute 24 h treatment that does not represent a realistic human chemical exposure. Recently, new in vitro approaches have been proposed to study the chemical toxicological effect over several days in order to be more predictive of a representative exposure scenario. In this study, we investigated the genotoxic potential of chemicals (direct or bioactived clastogen, aneugen and apoptotic inducer) with the γH2AX and pH3 biomarkers, in the human liver-derived HepaRP cell line. We used different treatment durations, with or without a three-day recovery stage (release period), before genotoxicity measurement. Data were analysed with the Benchmark Dose approach. We observed that the detection of clastogenic compounds (notably for DNA damaging agents) was more sensitive after three days of repeated treatment compared to one or three treatments over 24 h. In contrast, aneugenic chemicals were detected as genotoxic in a similar manner whether after a 24 h exposure or a three-day repeated treatment. Globally, the release period decreases the genotoxicity measurement substantially. For DNA damaging agents, after high concentration treatments, γH2AX induction was always observed after a three-day release period. In contrast, for DNA topoisomerase inhibitors, no effect could be observed after the release period. In conclusion, in the HepaRP cell line, there are some important differences between a one-day acute and a three-day repeated treatment protocol, indicating that different cell treatment procedures may differentiate chemical genotoxic mechanisms of action more efficiently.

Background Exposure to pesticides with its associated effects prenatally and in early childhood has not received much attention. There is little scientific data on this aspect in Tanzania therefore this study was meant to contribute to the deficit in the subject. Method A cross-sectional study was conducted to a sample of 286 participants of mother to child pair, whereby 172 and 114 were exposed and non-exposed respectively. Mothers who had been working in tomato sprayed farms were exposed and mothers who had not been working in the tomato sprayed farms were un-exposed. Child aged 0–6 years was chosen from each mother sampled but only one child found to be the youngest with the classified age was enrolled. Malawi child development Tool (M-DAT) was employed to assess the child level of development, height, and weight of the children were collected and analyzed by the WHO anthropometric calculator. A checklist and questionnaire were used to observe and assess maternal exposure. Bivariate and Multivariate analysis were conducted to assess the relationship between various factors of exposure. Results Overall 15% of the children examined were not well developed and the most used pesticides were those posing neuro-development effects. On the bivariate analysis model, mothers who worked while pregnant were more likely to have a child with neuro-developmental effect OR=5.8(1.29–26.3). On multivariate analyses adjusted for age of the mother, variables which remain in the model were a distance from home [AOR=9.4(4.2–20.5)], and working while pregnancy [AOR=5.8(1.29–26.3)] other were removed due to collinearity effect. None of confounders had a potential significant effect but only nutrition seems to be the effect modifier [AOR=7.8(1.29–36.3)] when analyzed with working while pregnancy. Conclusions The findings from this study have indicated that maternal pesticide exposure among farmworker residents in the SAGCOT area has a potential association with child developmental effect.

Caffeine (CAF) has been considered an emerging environmental contaminant and its presence indicator of anthropogenic contamination. This study evaluated the effects of environmental concentrations of CAF (0, 0.5, 1.5, and 300 μg. L −1 ) on the behaviour of adult zebrafish ( Danio rerio ) after 7 days of exposure. The components of feeding, locomotion, boldness (new tank test), sociability (schooling test), and aggression (mirror test) were analysed. Growth rate and weight were investigated as complementary measures. CAF (0.5, 1.5, and 300 μg. L −1 ) reduced exploratory behaviour in zebrafish, increased feeding latency time (1.5, and 300 μg. L −1 ), and decreased growth rate and fish weight (300 μg. L −1 ). CAF also induced aggressive behaviour (0.5, 1.5, and 300 μg. L −1 ) and decreased appetence to the shoal (sociability) (0.5, and 1.5 μg. L −1 ). This study showed that low doses of CAF can induce behavioural effects in zebrafish that may have significant long-term impacts on vital ecological functions.

In the European Union, more than 100,000 man-made chemical substances are awaiting an environmental risk assessment (ERA). Simultaneously, ERA of these chemicals has now entered a new era requiring determination of risks for physiologically diverse species exposed to several chemicals, often in mixtures. Additionally, recent recommendations from regulatory bodies underline a crucial need for the use of mechanistic effect models, allowing assessments that are not only ecologically relevant, but also more integrative, consistent and efficient. At the individual level, toxicokinetic-toxicodynamic (TKTD) models are particularly encouraged for the regulatory assessment of pesticide-related risks on aquatic organisms. In this paper, we first briefly present a classical dose-response model to showcase the on-line MOSAIC tool, which offers all necessary services in a turnkey web platform, whatever the type of data analyzed. Secondly, we focus on the necessity to account for the time-dimension of the exposure by illustrating how MOSAIC can support a robust calculation of bioaccumulation metrics. Finally, we show how MOSAIC can be of valuable help to fully complete the EFSA workflow regarding the use of TKTD models, especially with GUTS models, providing a user-friendly interface for calibrating, validating and predicting survival over time under any time-variable exposure scenario of interest. Our conclusion proposes a few lines of thought for an easier use of modelling in ERA.

Over the last 10 years, there has been a plethora of experimental studies estimating the potential of microplastic particles (MPs) to exert toxic effects in the environment, many specifically focusing on their postulated capacity to enhance the transfer of environmental pollutants into organisms after ingestion. Obviously, there is little to no consensus on appropriate experimental design, which is mainly owing to the novelty, the interdisciplinarity of the subject, and the complexity of parameters involved. This results in fundamental discrepancies regarding the materials applied, the approach for spiking MPs with pollutants, and the exact exposure scenario. Aiming for a non-chemist audience and providing illustrative, representative, and comparative examples, this review first outlines the theoretical essentials of processes involved in sorption. Also, it discusses the implications for designing experimental approaches using MPs and interpreting the results obtained under consideration of their relevance for environmental conditions. It may help to improve the interpretation of studies on MP toxicity already published, while also calling experimenters’ attention to various aspects important to consider when designing and performing environmentally relevant experiments with MPs.