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Performance of a novel magnetic solid-phase-extraction microsphere and its application in the detection of organic micropollutants in the Huai River, China Texte intégral
2019
Solid phase extraction has been increasingly applied for the detection of organic micropollutants (OMPs). However, time-consuming and high-cost disadvantages also limit the widespread use of this method, especially for the extraction of large-volume field water samples. In this study, a gas chromatography-mass spectrometry (GC-MS) method based on the magnetic microsphere (M150) solid-phase-extraction (MSPE) was established to investigate the OMPs in source water throughout the whole Huai River. In brief, the results demonstrated that the extraction efficiency of the M150 was superior to that of C₁₈ and HLB for the selected OMPs, including species of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), phthalate esters (PAEs) and nitrobenzenes (NBs), and the method detection limits of M150 for these OMPs were comparable to those of C₁₈ and HLB. The optimized conditions of extraction and elution were the 100 mg/L dosages of microspheres, extraction time of 60 min and pH of 2, and the eluent with a similar polarity, hydrophobicity and molecular structure to the OMPs rendered higher elution efficiencies. A total of 21 types of OMPs affiliating to PAHs, OCPs, PAEs and NBs were detected by the established method, with the total concentrations of 505–2310 ng/L in source water of the Huai River. Spatial differences of the OMPs were also observed, demonstrating the link between pollutant profiles and geographical locations. This study provides an alternative to enrich OMPs in filed water samples, and it reveals pollutant profiles of source water throughout the whole Huai River.
Afficher plus [+] Moins [-]Microplastics in municipal mixed-waste organic outputs induce minimal short to long-term toxicity in key terrestrial biota Texte intégral
2019
(Danielle Peta),
Sustainable alternatives to landfill disposal for municipal mixed wastes represents a major challenge to governments and waste management industries. In the state of New South Wales (NSW) Australia, mechanical biological treatment (MBT) is being used to reduce the volume and pathogen content of organic matter isolated from municipal waste. The product of this treatment, a compost-like output (CLO) referred to as mixed waste organic output (MWOO), is being recycled and applied as a soil amendment. However, the presence of contaminants in MWOO including trace organics, trace metals and physical contaminants such as microplastic fragments has raised concerns about potential negative effects on soil health and agriculture following land application. Here, we used multiple lines of evidence to examine the effects of land application of MWOO containing microplastics in three soils to a variety of terrestrial biota. Treatments included unamended soil, MWOO-amended soil and MWOO-amended soil into which additional high-density polyethylene (HDPE), polyethylene terephthalate (PET), or polyvinyl chloride (PVC) microplastics were added. Tests were conducted in soil media that had been incubated for 0, 3 or 9 months. Addition of microplastics had no significant negative effect on wheat seedling emergence, wheat biomass production, earthworm growth, mortality or avoidance behaviour and nematode mortality or reproduction compared to controls. There was also little evidence the microplastics affected microbial community diversity, although measurements of microbial community structure were highly variable with no clear trends.
Afficher plus [+] Moins [-]Early life exposure to triphenyl phosphate: Effects on thyroid function, growth, and resting metabolic rate of Japanese quail (Coturnix japonica) chicks Texte intégral
2019
Guigueno, M.F. | Head, J.A. | Letcher, R.J. | Karouna-Renier, N. | Peters, L. | Hanas, A.M. | Fernie, K.J.
Triphenyl phosphate (TPHP; CAS # 115-86-6), a commonly used plasticizer and flame retardant, has been reported in wild birds and identified as a potential high-risk chemical. We exposed Japanese quail (Coturnix japonica) by in ovo injection, and once hatched, orally each day for 5 days to safflower oil (controls) or TPHP dissolved in vehicle at low (5 ng TPHP/g), mid (50 ng TPHP/g), or high (100 ng TPHP/g) nominal TPHP doses. The low TPHP dose reflected concentrations in wild bird eggs, with mid and high doses 10x and 20x greater to reflect potential increases in environmental TPHP concentrations in the future. Despite no effects on mRNA expression in thyroid-related genes, TPHP exposure enhanced thyroid gland structure in high TPHP males, but in females, suppressed thyroid gland structure and activity (all TPHP females), and circulating free triiodothyronine (high TPHP females only). Consistent with thyroidal changes, and compared to controls, mid and high TPHP chicks experienced significantly reduced resting metabolic rate (≤13%) and growth (≤53%); mid TPHP males and high TPHP females were significantly smaller. The observed thyroidal effects and suppressed growth and metabolic rate of the quail chicks suggest that TPHP may adversely affect the health of wild birds.
Afficher plus [+] Moins [-]Ingestion of microplastics by nematodes depends on feeding strategy and buccal cavity size Texte intégral
2019
Fueser, Hendrik | Mueller, Marie-Theres | Weiss, Linette | Höss, Sebastian | Traunspurger, W. (Walter)
Microplastics are hardly biodegradable and thus accumulate rather than decompose in the environment. Due to sedimentation processes, meiobenthic fauna is exposed to microplastics. Within the meiofauna, nematodes are a very abundant taxon and occupy an important position in benthic food webs by connecting lower and higher trophic levels. However, the key determinants of the uptake of microplastics by freshwater nematodes are still unknown. To investigate the bioaccessibility of microplastics for nematodes, we performed single- and multi-species ingestion experiments in which the ability of seven nematode species (six bacterial and one fungal feeder), diverse in their buccal cavity morphology (1.3–10.5 μm), to ingest fluorescence-labelled polystyrene (PS) beads along with their natural diet was examined. Applied beads sizes (0.5, 1.0, 3.0 and 6.0 μm), exposure time (4, 24 and 72 h) and concentration (3 × 10⁶ PS beads ml⁻¹ and 10⁷ PS beads ml⁻¹) were varied. Ingested beads were localized and quantified via fluorescence microscopy in the nematodes. In contrast to fungal-feeding nematode species with a stylet, bacterial-feeding species ingested 0.5- and 1.0-μm PS beads with up to 249 and 255 beads after 24 h, respectively. Microplastics ≥0.5 μm could only be ingested and transported into the gastrointestinal tract, if the buccal cavities were considerably (>1.3 times) larger than the beads. At concentrations of 10⁷ PS beads ml⁻¹ ingestion rates were influenced by exposure time and PS bead concentration. In case of a known microplastic size distribution in the environment, predictions on the potential ingestion for nematode communities can be made based on the feeding type composition and the size of their buccal cavities.
Afficher plus [+] Moins [-]Composition of dissolved organic matter controls interactions with La and Al ions: Implications for phosphorus immobilization in eutrophic lakes Texte intégral
2019
Du, Yingxun | Zhang, Qiaoying | Liu, Zhengwen | He, Hu | Lürling, Miquel | Chen, Musong | Zhang, Yunlin
Applications of aluminium (Al) salt or lanthanum (La) modified bentonite (LMB) have become popular methodologies for immobilizing phosphorus (P) in eutrophic lakes. The presence of humic substances, has been shown to inhibit this form of treatment due to the complexation with La/Al. However, the effects of other dissolved organic matter (DOM), especially that derived from phytoplankton (the dominant source in eutrophic lakes) are unknown. In this study, the interaction with La/Al of Suwannee River Standard Humic Acid Standard II (SRHA) and algae-derived DOM (ADOM) were investigated and compared. Differed to SRHA which was dominated by polyphenol-like component (76.8%, C1-SRHA), majority in ADOM were protein-like substance, including 41.9% tryptophan-like component (C2-ADOM) and 21.0% tyrosine-like component (C3-ADOM). Two reactions of complexation and coprecipitation were observed between SRHA/ADOM and La/Al. Complexation dominated at low metal inputs less than 10 μM and coprecipitation was the main reaction at higher metal inputs. For ADOM, the tryptophan-like component (C2-ADOM) was the important component to react with metal. The reaction rate for C2-ADOM with La were about two-third of that for C1-SRHA, indicating that the influence of C2-ADOM was significant during the P immobilization by La/Al-based treatment in eutrophic lakes. The P removal data in the presence of ADOM confirmed the significant inhibition of ADOM. In addition, based on the composition of coprecipitates and relatively biodegradable character of tryptophan-like substances (C2-ADOM), the coprecipitation of ADOM was assumed to reduce the stability of precipitated P in eutrophic lakes. The release of P from the potential biodegradation of the coprecipitates and thus the possible decline of the performance of P immobilization by La/Al-based treatments is an important work in the future.
Afficher plus [+] Moins [-]Short-term associations between daily mortality and ambient particulate matter, nitrogen dioxide, and the air quality index in a Middle Eastern megacity Texte intégral
2019
Amini, Heresh | Trang Nhung, Nguyen Thi | Schindler, Christian | Yunesian, Masud | Hosseini, Vahid | Shamsipour, Mansour | Hassanvand, Mohammad Sadegh | Mohammadi, Younes | Farzadfar, Farshad | Vicedo-Cabrera, Ana M. | Schwartz, Joel | Henderson, Sarah B. | Künzli, Nino
There is limited evidence for short-term association between mortality and ambient air pollution in the Middle East and no study has evaluated exposure windows of about a month prior to death. We investigated all-cause non-accidental daily mortality and its association with fine particulate matter (PM₂.₅), nitrogen dioxide (NO₂), and the Air Quality Index (AQI) from March 2011 through March 2014 in the megacity of Tehran, Iran. Generalized additive quasi-Poisson models were used within a distributed lag linear modeling framework to estimate the cumulative effects of PM₂.₅, NO₂, and the AQI up to a lag of 45 days. We further conducted multi-pollutant models and also stratified the analyses by sex, age group, and season. The relative risk (95% confidence interval (CI)) for all seasons, both sexes and all ages at lag 0 for PM₂.₅, NO₂, and AQI were 1.004 (1.001, 1.007), 1.003 (0.999, 1.007), and 1.004 (1.001, 1.007), respectively, per inter-quartile range (IQR) increment (18.8 μg/m³ for PM₂.₅, 12.6 ppb for NO₂, and 31.5 for AQI). In multi-pollutant models, the PM₂.₅ associations were almost independent from NO₂. However, the RRs for NO₂ were slightly attenuated after adjustment for PM₂.₅ but they were still largely independent from PM₂.₅. The cumulative relative risks (95% CI) per IQR increment reached maximum during the cooler months, including: 1.13 (1.06, 1.20) for PM₂.₅ at lag 0–31 (for females, all ages); 1.17 (1.10, 1.25) for NO₂ at lag 0–45 (for males, all ages); and 1.13 (1.07, 1.20) for the AQI at lag 0–30 (for females, all ages). Generally, the RRs were slightly larger for NO₂ than PM₂.₅ and AQI. We found somewhat larger RRs in females, age group >65 years of age, and in cooler months. In summary, positive associations were found in most models. This is the first study to report short-term associations between all-cause non-accidental mortality and ambient PM₂.₅ and NO₂ in Iran.
Afficher plus [+] Moins [-]Atrazine induced transgenerational reproductive effects in medaka (Oryzias latipes) Texte intégral
2019
Cleary, Jacob A. | Tillitt, Donald E. | Vom Saal, Frederick S. | Nicks, Diane K. | Claunch, Rachel A. | Bhandari, Ramji K.
Atrazine is presently one of the most abundantly used herbicides in the United States, and a common contaminant of natural water bodies and drinking waters in high-use areas. Dysregulation of reproductive processes has been demonstrated in atrazine exposed fish, including alteration of key endocrine pathways on hypothalamic-pituitary-gonadal (HPG) axis. However, the potential for atrazine-induced transgenerational inheritance of reproductive effects in fish has not been investigated. The present study examined the effects of early developmental atrazine exposure on transgenerational reproductive dysregulation in Japanese medaka (Oryzias latipes). F0 medaka were exposed to atrazine (ATZ, 5 or 50 μg/L), 17α-ethinylestradiol (EE2, 0.002 or 0.05 μg/L), or solvent control during the first twelve days of development with no subsequent exposure over three generations. This exposure overlapped with the critical developmental window for embryonic germ cell development, gonadogenesis, and sex determination. Exposed males and females of the F0 generation were bred to produce an F1 generation, and this was continued until the F2 generation. Sperm count and motility were not affected in F0 males; however, both parameters were significantly reduced in the males from F2 Low EE2 (0.002 μg/L), Low ATZ (5 μg/L), and High ATZ (50 μg/L) lineages. Fecundity was unaffected by atrazine or EE2 in F0 through F2 generations; however, fertilization rate was decreased in low atrazine and EE2 exposure lineages in the F2 generation. There were significant transgenerational differences in expression of the genes involved in steroidogenesis and DNA methylation. These results suggest that although early life exposure to atrazine did not cause significant phenotypes in the directly exposed F0 generation, subsequent generations of fish were at greater risk of reproductive dysfunction.
Afficher plus [+] Moins [-]A spatio-temporally weighted hybrid model to improve estimates of personal PM2.5 exposure: Incorporating big data from multiple data sources Texte intégral
2019
Ben, YuJie | Ma, FuJun | Wang, Hao | Hassan, Muhammad Azher | Yevheniia, Romanenko | Fan, WenHong | Li, Yubiao | Dong, ZhaoMin
An accurate estimation of population exposure to particulate matter with an aerodynamic diameter <2.5 μm (PM₂.₅) is crucial to hazard assessment and epidemiology. This study integrated annual data from 1146 in-home air monitors, air quality monitoring network, public applications, and traffic smart cards to determine the pattern of PM₂.₅ concentrations and activities in different microenvironments (including outdoors, indoors, subways, buses, and cars). By combining massive amounts of signaling data from cell phones, this study applied a spatio-temporally weighted model to improve the estimation of PM₂.₅ exposure. Using Shanghai as a case study, the annual average indoor PM₂.₅ concentration was estimated to be 29.3 ± 27.1 μg/m³ (n = 365), with an average infiltration factor of 0.63. The spatio-temporally weighted PM₂.₅ exposure was estimated to be 32.1 ± 13.9 μg/m³ (n = 365), with indoor PM₂.₅ contributing the most (85.1%), followed by outdoor (7.6%), bus (3.7%), subway (3.1%), and car (0.5%). However, considering that outdoor PM₂.₅ makes a significant contribution to indoor PM₂.₅, outdoor PM₂.₅ was responsible for most of the exposure in Shanghai. A heatmap of PM₂.₅ exposure indicated that the inner-city exposure index was significantly higher than that of the outskirts city, which demonstrated that the importance of spatial differences in population exposure estimation.
Afficher plus [+] Moins [-]The effect of major cations on the toxicity of cadmium to Folsomia candida in a sand-solution medium analyzed by biotic ligand modeling Texte intégral
2019
Ardestani, Masoud M. | van Gestel, Cornelis A.M.
The aim of this study was to assess the effect of major cations (Ca²⁺, Mg²⁺, Na⁺, K⁺, and H⁺) on cadmium toxicity to the springtail Folsomia candida. Survival of the animals was determined after seven days exposure to different cadmium concentrations in an inert sand-solution medium, in different experimental setups with modification of the cation concentrations. Among the cations tested, Ca²⁺ and Mg²⁺ had protective effects on the toxicity of cadmium to the springtails while Na⁺, K⁺, and H⁺ showed less competition with free cadmium ions for binding to the uptake sites of the collembolans. Toxicity predicted with a biotic ligand model agreed well with the observed values. Calculated conditional binding constants and the fraction of biotic ligands occupied by cadmium to show 50% effects were similar to values reported in the literature. The results emphasize the important role of solution chemistry in determining metal toxicity to soil invertebrates.
Afficher plus [+] Moins [-]Unveiling resistome profiles in the sediments of an Antarctic volcanic island Texte intégral
2019
Centurion, V.B. | Delforno, T.P. | Lacerda-Júnior, G.V. | Duarte, A.W.F. | Silva, L.J. | Bellini, G.B. | Rosa, L.H. | Oliveira, V.M.
The Deception Island, located in Maritime Antarctica, is a volcanic island with geothermal activity and one of the most visited by tourists. However, the extent of the anthropogenic impact remains largely unknown and the factors shaping the resistance/tolerance mechanisms in the microbiomes from Whalers Bay ecosystems have never been investigated. In this context, this study aimed to reveal the resistome profiles of Whalers Bay sediments and correlate them with environmental factors. Samples were collected at four sites during the summer 2014/2015 along a transect of 27.5 m in the Whalers Bay sediments. DNA isolated from sediment samples was sequenced using the Illumina HiSeq platform. Bioinformatic analyses allowed the assembly of contigs and scaffolds, prediction of ORFs, and taxonomic and functional annotation using NCBI RefSeq database and KEGG orthology, respectively. Microorganisms belonging to the genera Psychrobacter, Flavobacterium and Polaromonas were shown to dominate all sites, representing 60% of taxonomic annotation. Arsenic (As), copper (Cu) and iron (Fe) were the most abundant metal resistance/tolerance types found in the microbiomes. Beta-lactam was the most common class related to antibiotics resistance/tolerance, corroborating with previous environmental resistome studies. The acridine class was the most abundant amongst the biocide resistance/tolerances, related to antiseptic compounds. Results gathered in this study reveal a repertoire of resistance/tolerance classes to antibiotics and biocides unusually found in Antarctica. However, given the volcanic nature (heavy metals-rich region) of Deception Island soils, this putative impact must be viewed with caution.
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