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Occurrence and distribution of PAHs in stranded dolphin tissues from the Northwestern Mediterranean Full text
2023
Dron, Julien | Wafo, Emmanuel | Boissery, Pierre | Dhermain, Frank | Bouchoucha, Marc | Chamaret, Philippe | Lafitte, Daniel
There are few cetacean tissue-specific polycyclic aromatic hydrocarbon (PAH) concentration studies in the Mediterranean, despite this region is among the most subjected to chemical contamination. PAH analyses were conducted in different tissues of striped dolphins (Stenella coeruleoalba, N = 64) and bottlenose dolphins (Tursiops truncatus, N = 9) stranded along the French Mediterranean coastline from 2010 to 2016. Comparable levels were measured in S. coeruleoalba and T. trucantus (1020 and 981 ng g−1 lipid weight in blubber, 228 and 238 ng g−1 dry weight in muscle, respectively). The results suggested a slight effect of maternal transfer. The greatest levels were recorded by urban and industrial centers, and decreasing temporal trends were observed in males muscle and kidney, but not in other tissues. As a conclusion, the elevated levels measured could represent a serious threat to dolphins populations in this region, particularly by urban and industrial centers.
Show more [+] Less [-]Sponge organic matter recycling: Reduced detritus production under extreme environmental conditions Full text
2023
Maggioni, Federica | Bell, James J. | Pujo-pay, Mireille | Shaffer, Megan | Cerrano, Carlo | Lemonnier, Hugues | Letourneur, Yves | Rodolfo-metalpa, Riccardo
Sponges are a key component of coral reef ecosystems and play an important role in carbon and nutrient cycles. Many sponges are known to consume dissolved organic carbon and transform this into detritus, which moves through detrital food chains and eventually to higher trophic levels via what is known as the sponge loop. Despite the importance of this loop, little is known about how these cycles will be impacted by future environmental conditions. During two years (2018 and 2020), we measured the organic carbon, nutrient recycling, and photosynthetic activity of the massive HMA, photosymbiotic sponge Rhabdastrella globostellata at the natural laboratory of Bouraké in New Caledonia, where the physical and chemical composition of seawater regularly change according to the tide. We found that while sponges experienced acidification and low dissolved oxygen at low tide in both sampling years, a change in organic carbon recycling whereby sponges stopped producing detritus (i.e., the sponge loop) was only found when sponges also experienced higher temperature in 2020. Our findings provide new insights into how important trophic pathways may be affected by changing ocean conditions.
Show more [+] Less [-]On-field high-resolution quantification of the cobalt fraction available for bio-uptake in natural waters using antifouling gel-integrated microelectrode arrays Full text
2023
Layglon, Nicolas | Creffield, Sébastien | Bakker, Eric | Tercier-waeber, Mary-lou
We report the optimization, characterization, and validation of Adsorptive Square Wave Cathodic Stripping Voltammetry on antifouling gel-integrated microelectrode arrays for autonomous, direct monitoring of cobalt(II) metal species. Detection is accomplished by complexation with an added nioxime ligand. The limit of detection established for a 90 s accumulation time was 0.29 ± 0.01 nM in freshwater and 0.27 ± 0.06 nM in seawater. The microelectrode array was integrated in a submersible probe to automatically dose the complexing agent nioxime and realize an integrated sensing system. For the first time ever, the potentially bioavailable Co(II) fraction was determined in La Leyre River-Arcachon Bay continuum, enabling to evaluate the potential ecotoxicological impact of freshwater-carried Co(II) in the Arcachon Bay. The measured potentially bioavailable Co(II) concentrations were hazardous for aquatic biota along the continuum. The electrochemical Co(II) data were compared to ICP-MS data in various fractions to determine spatial Co(II) speciation.
Show more [+] Less [-]Integument colour change : Tracking delayed growth of Oppia nitens as a sub-lethal indicator of soil toxicity Full text
2023
Jegede, Olukayode O. | Fajana, Hamzat O. | Adedokun, Adedamola | Najafian, Keyhan | Lingling, Jin | Stavness, Ian | Siciliano, Steven D.
Growth is an important toxicity end-point in ecotoxicology but is rarely used in soil ecotoxicological studies. Here, we assessed the growth change of Oppia nitens when exposed to reference and heavy metal toxicants. To assess mite growth, we developed an image analysis methodology to measure colour spectrum changes of the mite integument at the final developmental stage, as a proxy for growth change. We linked the values of red, green, blue, key-black, and light colour of mites to different growth stages. Based on this concept, we assessed the growth change of mites exposed to cadmium, copper, zinc, lead, boric acid, or phenanthrene at sublethal concentrations in LUFA 2.2 soil for 14 days. Sublethal effects were detected after 7 days of exposure. The growth of O. nitens was more sensitive than survival and reproduction when exposed to copper (EC50growth = 1360 mg/kg compared to EC50reproduction = 2896 mg/kg). Mite growth sensitivity was within the same order of magnitude to mite reproduction when exposed to zinc (EC50growth = 1785; EC50reproduction = 1562 mg/kg). At least 25% of sublethal effects of boric acid and phenanthrene were detected in the mites but growth was not impacted when O. nitens were exposed to lead. Consistent with previous studies, cadmium was the most toxic metal to O. nitens. The mite growth pattern was comparable to mite survival and reproduction from previous studies. Mite growth is a sensitive toxicity endpoint, ecologically relevant, fast, easy to detect, and can be assessed in a non-invasive fashion, thereby complimenting existing O. nitens testing protocols.
Show more [+] Less [-]Microplastic appraisal of soil, water, ditch sediment and airborne dust: The case of agricultural systems Full text
2023
Lwanga, Esperanza Huerta | Van Roshum, Ilse | Munhoz, Davi R. | Meng, Ke | Rezaei, Mahrooz | Goossens, Dirk | Bijsterbosch, Judith | Alexandre, Nuno | Oosterwijk, Julia | Krol, Maarten | Peters, Piet | Geissen, Violette | Ritsema, Coen
Although microplastic pollution jeopardizes both terrestrial and aquatic ecosystems, the movement of plastic particles through terrestrial environments is still poorly understood. Agricultural soils exposed to different managements are important sites of storage and dispersal of microplastics. This study aimed to identify the abundance, distribution, and type of microplastics present in agricultural soils, water, airborne dust, and ditch sediments. Soil health was also assessed using soil macroinvertebrate abundance and diversity. Sixteen fields were evaluated, 6 of which had been exposed to more than 5 years of compost application, 5 were exposed to at least 5 years of plastic mulch use, and 5 were not exposed to any specific management (controls) within the last 5 years. We also evaluated the spread of microplastics from the farms into nearby water bodies and airborne dust. We found 11 types of microplastics in soil, among which Light Density Polyethylene (LDPE) and Light Density Polyethylene covered with pro-oxidant additives (PAC) were the most abundant. The highest concentrations of plastics were found in soils exposed to plastic mulch management (128.7 ± 320 MPs.g-1 soil and 224.84 ± 488 MPs.g-1 soil, respectively) and the particles measured from 50 to 150 μm. Nine types of microplastics were found in water, with the highest concentrations observed in systems exposed to compost. Farms applying compost had higher LDPE and PAC concentrations in ditch sediments as compared to control and mulch systems; a significant correlation between soil polypropylene (PP) microplastics with ditch sediment microplastics (r2 0.7 p 0.05) was found. LDPE, PAC, PE (Polyethylene), and PP were the most abundant microplastics in airborne dust. Soil invertebrates were scarce in the systems using plastic mulch. A cocktail of microplastics was found in all assessed matrices.
Show more [+] Less [-]Effects of microplastics and chlorpyrifos on earthworms (Lumbricus terrestris) and their biogenic transport in sandy soil Full text
2023
Ju, Hui | Yang, Xiaomei | Osman, Rima | Geissen, Violette
Although microplastics (MPs) are ubiquitous in agricultural soil, little is known about the effects of MPs combined with pesticides on soil organisms and their biogenic transport through the soil profile. In this study, we conducted mesocosm experiments to observe the effects of microplastics (polyethylene (LDPE-MPs) and biodegradable microplastics (Bio-MPs)) and chlorpyrifos (CPF) on earthworm (Lumbricus terrestris) mortality, growth and reproduction, as well as the biogenic transport of these contaminants through earthworm burrows. The results showed that earthworm reproduction was not affected by any treatment, but earthworm weight was reduced by 17.6% and the mortality increased by 62.5% in treatments with 28% Bio-MPs. Treatments with 28% LDPE-MPs and 7% Bio-MPs combined with CPF showed greater toxicity while the treatment with 28% Bio-MPs combined with CPF showed less toxicity on earthworm growth as compared to treatments with only MPs. The treatments with 1250 g ha−1 CPF and 28% Bio-MPs significantly decreased the bioaccumulation of CPF in earthworm bodies (1.1 ± 0.2%, w w−1), compared to the treatment with CPF alone (1.7 ± 0.4%). With CPF addition, more LDPE-MPs (8%) were transported into earthworm burrows and the distribution rate of LDPE-MPs in deeper soil was increased. No effect was observed on the transport of Bio-MPs. More CPF was transported into soil in the treatments with LDPE-MPs and Bio-MPs, 5% and 10% of added CPF, respectively. In addition, a lower level of the CPF metabolite 3,5,6-trichloropyridinol was detected in soil samples from the treatments with MPs additions than without MP additions, indicating that the presence of MPs inhibited CPF degradation. In conclusion, Bio-MPs caused significant toxicity effects on earthworms and the different types of MPs combined with CPF affected earthworms differently, and their transport along the soil profile. Thus, further research is urgently needed to understand the environmental risks of MPs and MP-associated compounds in the soil ecosystem.
Show more [+] Less [-]On the probability of ecological risks from microplastics in the Laurentian Great lakes Full text
2023
Koelmans, A.A. | Redondo Hasselerharm, P.E. | Mohamed Nor, N.H. | Gouin, T.
The Laurentian Great Lakes represent important and iconic ecosystems. Microplastic pollution has become a major problem among other anthropogenic stressors in these lakes. There is a need for policy development, however, assessing the risks of microplastics is complicated due to the uncertainty and poor quality of the data and incompatibility of exposure and effect data for microplastics with different properties. Here we provide a prospective probabilistic risk assessment for Great Lakes sediments and surface waters that corrects for the misalignment between exposure and effect data, accounts for variability due to sample volume when using trawl samples, for the random spatiotemporal variability of exposure data, for uncertainty in data quality (QA/QC), in the slope of the power law used to rescale the data, and in the HC5 threshold effect concentration obtained from Species Sensitivity Distributions (SSDs). We rank the lakes in order of the increasing likelihood of risks from microplastics, for pelagic and benthic exposures. A lake-wide risk, i.e. where each location exceeds the risk limit, is not found for any of the lakes. However, the probability of a risk from food dilution occurring in parts of the lakes is 13–15% of the benthic exposures in Lakes Erie and Huron, and 8.3–10.3% of the pelagic exposures in Lake Michigan, Lake Huron, Lake Superior, and Lake Erie, and 24% of the pelagic exposures in Lake Ontario. To reduce the identified uncertainties, we recommend that future research focuses on characterizing and quantifying environmentally relevant microplastic (ERMP) over a wider size range (ideally 1–5000 μm) so that probability density functions (PDFs) can be better calibrated for different habitats. Toxicity effect testing should use a similarly wide range of sizes and other ERMP characteristics so that complex data alignments can be minimized and assumptions regarding ecologically relevant dose metrics (ERMs) can be validated.
Show more [+] Less [-]Removal Study of Hazardous Thiols Pollution by Tributylammonium Halochromates (VI) / Silica, (C4 H9) 3 NH + [CrO3 X]- , (X=F, Cl): as an Oxidizing Agent Full text
2023
OICC Press Authors | Mohammad Kazem Mohammadi
Oxidative coupling of thiols to the corresponding symmetrical disulfides were performed in the presence of silica gel supported tributylammonium fluorochromate(VI), (TriBAFC), and tributylammonium chlorochromate(VI), (TriBACC). Silica gel supported TriBAFC and TriBACC are versatile reagents for the effective and selective oxidation of organic substrates, in particular of thiol, under mild conditions. Disulfides are also key intermediates in a wide variety of organic synthetic routes. Considerable improvements are observed in the presence of the absorbent and making the work-up much more convenient. The nature of the solvent does not appear to be particularly critical. Hydrocarbons, benzene, ethers and chlorinated hydrocarbons are equally effective, the practical choice being oriented by the solubility of the products and the desired reaction temperature. The IR spectra of TriBAFC and TriBACC are similar to that of other fluoro and chlorochromates, TriBAFC and TriBACC are soluble in water, dimethylformamide, acetonitrile, acetone and dichloromethane; they are only sparingly soluble in benzene, carbon tetrachloride, chloroform and hexane.
Show more [+] Less [-]Risk analysis of ammonia release in food refrigeration Using FTA technique and fuzzy logic Full text
2023
Leila Asghariazim
The purpose of this research is to analyze the risk of ammonia release in the cold storage of one of the large food companies in Mashhad. This is an applied research that was done using FTA technique and fuzzy logic. Fuzzy logic was used to weight experts' opinions (Delphi panel). In this study, to model the consequences and calculate the collective risk using the DNV PHAST 7.2 software, the most critical conditions that have the greatest possible contribution to the release of ammonia were, respectively: lack of proper and planned maintenance; Pressure increase and failure and defects in gaskets. Also, the results showed that the rate of death, toxicity and explosion is directly related to the distance. On the other hand, the maximum amount of possible losses in the event of an explosion will be in the winter season and at a distance of 14.26 meters, and finally, 95% of the losses due to the blast wave will occur at a distance of 13.54 meters and 99% of deaths of people up to a radius of 38.89 meters, also 50% of the deaths of people from the radius of 38.89 meters to the radius of 124.93 meters, and 10% of the deaths of people from the radius of 124.93 meters to the radius of 178.53 meters, also 1 percent of deaths from the radius of 178.53 meters to the radius of 234.05 meters.
Show more [+] Less [-]Long-term and microstructural studies of soft clay stabilization using municipal solid waste and Nano-MgO as an Eco-Friendly Method Full text
2023
Ali Ohadian | Navid Khayat | Mehdi Mokhberi
This study provides a practical solution to manage non-hazardous waste and aid the environment. The largest group of non-hazardous waste is called municipal solid waste (MSW) which can be effectively used as an alternative material in civil projects. In this research, as an alternative to traditional modification methods of soil which causes global warming, the soft clay (Clay) was chemically modified by four different percentages of MSW in soil dimensions (15%, 25%, 35%, 45%) in 28 and 120 days. The optimum percentage of MSW addition (15%) to the Clay at the curing age of 28 days increased the unconfined compressive strength (UCS) and California bearing ratio (CBR) by 1.28 and 3.34 times, respectively. Given that higher percentages of MSW reduce the UCS and CBR in the specimens, four percentages of Nano-MgO, i.e., 0.25, 0.5, 0.75, and 1% were used for stabilization. The specimens containing optimum percentages of MSW (15%, 25%) and stabilized with 1% Nano-MgO could improve UCS and CBR 2.34 and 5.59 times, respectively that results had better durability over 120-days which can be attributed to the CBR testing condition. The cause of the increase in UCS and CBR was investigated using microstructural analysis for 120 days of curing. The specimen with high durability approved the cement bond formation with Anorthite & Dolomite minerals. In conclusion, using optimum MSW and Nano-MgO effectively solved the Clay problems in suitable conditions and allowed higher percentages of MSW to be removed from the environment.
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