Summer Samples Research Articles

Monitoring metal patterns from urban and agrarian sites using the bumblebee Bombus terrestris as a bioindicator

Honeybees are well-established bioindicators for different types of pollutants. This study aims to establish another species of the Apidae family as a bioindicator, with a distinct behaviour and life cycle. The bumblebee Bombus terrestris was used as a bioindicator for 12 metals. Bumblebee hives were placed at sampling sites in and around the city of Aachen, Germany, and metal concentrations were assessed using ICP-MS. Metal concentrations were compared to those found in honeybees described in the literature. Spatial differences in metal patterns were investigated by comparing two land-use types: urban and agrarian. Seasonal differences were compared by taking samples in spring and summer. All analysed metals were detected above the detection limit and within or even above the concentration range found in honeybees. Significant spatial differences were found for the metalloid B and the metal Cd with higher concentrations at the agrarian sites than the urban sites. Significant seasonal differences were found for 8 metals: Fe, Zn, Cu, Ni, Cd, and As concentrations were higher in summer than in spring, while B and V concentrations were higher in spring. To categorise the results, we applied the honeybee contamination index (HCI) and adapted it to bumblebee purposes. According to the HCI, only one agrarian site showed a high contamination level. This study shows that bumblebees are suitable bioindicators for metals. The obtained data can serve as a first baseline in the establishment of additional monitoring studies or risk assessments.

Litter and soil properties under woody and non-woody vegetation types: Implication for ecosystem management in a mountainous semi-arid landscape

There are contrasting reports about whether and how vegetation types influence litter and soil properties. Accurate and comprehensive assessment of the complex relationship between vegetation types, litter and soil characteristics in semi-arid mountain landscapes is almost unknown. Thus, the purpose of this research was to study the effects of (1) Carpinus orientalis Miller., (2) Crataegus melanocarpa M.B., (3) Rhamnus pallasii Fisch. and C.A.Mey, (4) Agropyron longiaristatum Boiss, (5) Bromus tomentolus Bioss. and (6) Hordeum vulgare L. on litter properties and soil physical, chemical, biochemical and biological features in northern Iran. A sampling of the organic layer (litter) and mineral soil (30 × 30 cm) from a depth of 0–10 cm was done for all characteristics in the summer season and for soil microclimate and biological characteristics in the summer and fall seasons. A total of 90 litter samples, 90 soil samples in summer and 90 soil samples in fall (6 vegetation types × 2 seasons × 15 samples) were taken from the area and transferred to the laboratory. Results showed that the Carpinus improved litter properties, soil organic matter contents, total N and available nutrients (P, K, Ca and Mg) and enzyme activities (urease, acid phosphatase, arylsulfatase and invertase). In addition, the population of earthworm groups (epigeic, anecic, and endogeic), acarina, collembola, nematodes, protozoa (especially in the fall season) and bacteria and fungi (especially in the summer season) under Carpinus significantly increased. Data analysis demonstrated higher soil fertility and biological activities in the woody vegetation, which can be assigned to the higher litter input and nutrients. Overall, the findings of this study showed that woody vegetation, especially Carpinus, can improve soil properties at high altitudes of mountainous, semi-arid sites that are often considered as especially fragile and sensitive ecosystems.

In hot water: Interactions of temperature, nitrogen form and availability and photosynthetic and nitrogen uptake responses in natural Karenia brevis populations

During 2020–2021, an unusually prolonged bloom of the toxigenic dinoflagellate Karenia brevis persisted for more than 12 months along the Gulf coast of Florida, resulting in severe environmental effects. Motivated by the possibility that unusual nutrient conditions existed during summer 2021, the short-term interactions of temperature, nitrogen (N) forms (ammonium (NH4+), nitrate (NO3−), and urea) and availability on photosynthesis-irradiance responses and N uptake rates were examined in summer 2021 and compared to such responses from the earlier winter. Winter samples were exposed to temperatures of 15, 20, 25, 30 °C while summer samples were incubated at 15, 25, 30, 33 °C, representing the maximum range the cells might experience throughout the water column due to daytime surface heating or extreme weather events. Depending on thermal history of the cells, photosynthetic performance differed when cells were exposed to the same temperature, showing a capacity for thermal acclimation in this species. Although blooms generally do not persist throughout the summer, bloom biomass was remarkably higher in summer than during the winter. However, most of the photosynthetic parameters and N uptake rates, as well as total carbon (C) and N cell−1 were significantly lower in the summer populations, showing that the summer populations were photosynthetically and nutritionally stressed. When the summer cells were treated with urea, however, uptake rates and total C and N cell−1 were higher than with the other N substrates, especially in warmer waters, showing differential thermal responses depending on N forms.

Co-occurrence of toxic metals, bacterial communities and metal resistance genes in coastal sediments from Bohai bay

Sediment heavy metal contamination poses substantial risks to microbial community composition and functional gene distribution. Bohai Bay (BHB), the second-largest bay in the Bohai Sea, is subject to severe anthropogenic pollution. However, to date, there have been no studies conducted to evaluate the distribution of metal resistance genes (MRGs) and bacterial communities in the coastal sediments of BHB. In this study, we employed high-throughput sequencing based on 16S rRNA genes and real-time quantitative PCR (qPCR) to provide a comprehensive view of toxic metals, MRGs, and bacterial communities in BHB's coastal sediment samples across two seasons. We detected high levels of Cd in the summer samples and As in the autumn samples. The metal content in most autumn samples and all summer samples, based on ecological indices, indicated low ecological risk. Proteobacteria dominated all samples, followed by Desulfobacterota, Bacteroidota and Campilobacterota. Bacterial community variability was higher between autumn sampling sites but more stable in summer. We detected 9 MRG subtypes in all samples, with abundances ranging from 4.58 × 10−1 to 2.25 copies/16S rRNA copies. arsB exhibited the highest relative abundance, followed by acr3, czcA and arrA. The efflux mechanism is a common mechanism for sediment resistance to metal stress in Bohai Bay. Procrustes analysis indicated that bacterial community composition may be a determinant of MRGs composition in BHB sediments. Network analysis suggested that eight classes could be potential hosts for six MRGs. However, this type of correlation requires further validation. To summarize, our study offers preliminary insights into bacterial community and MRG distribution patterns in heavy metal-exposed sediments, laying the groundwork for understanding microbial community adaptations in multi-metal polluted environments and supporting ecological restoration efforts.

Сезонные изменения биологической ценности белков молока ослиц киргизской породы

Due to its protein component, donkey’s milk is a multifunctional product with a wide range of beneficial physiological properties. It is known for its antioxidant, anti-inflammatory, rejuvenating, antimicrobial, and antitumor effects. However, the milk of Kyrgyz donkeys has not received proper scientific attention in this respect. This study analyzed the seasonal amino acid profile and biological value of milk obtained from Kyrgyz donkeys.
 The donkeys belonged to the Kyrgyz breed and inhabited the highlands of the Chui Region, Republic of Kyrgyzstan. The sampling took place in April, July, and September. The amino acid composition of milk proteins was determined by capillary electrophoresis. The biological value of proteins was assessed by amino acid score, index of essential amino acids (Auxerre index), utility ratio of essential amino acids, and utility ratio of amino acid composition.
 The analysis revealed 18 amino acids, including eight essential ones. The total content of amino acids in the spring samples was 1840.07 mg/100 g. In the summer samples, this value peaked at 2037 mg/100 g; in autumn, it dropped to 1264.35 mg/100 g. The changes could be explained by the seasonal differences in the diet. The ratio of essential to non-essential amino acids approached 1:1. The milk also proved to contain arginine, which is an essential amino acid for a juvenile organism. In the spring samples, its content was 2.5 times as big as in the autumn ones. Leucine and isoleucine were responsible for 1/3 of the essential amino acids (322.60 ± 19.35 mg/100 g). The summer samples demonstrated the maximal content of some other essential amino acids, except for valine and tryptophan, which appeared to be the limiting essential amino acids for donkey’s milk in the autumn period. Total essential amino acids in the spring, summer, and autumn samples amounted to 54.24, 59.26, and 34.77 g/100 g, respectively, which exceeded the value for the reference protein (27.46 g/100 g).
 Kyrgyz donkey’s milk proteins were of high biological value, regardless of the season, which means that donkey’s milk can become part of new functional products.

Variations in the dairy wastewater properties and bacterial diversity of each unit in membrane-enclosed anaerobic lagoon treatment process in Heilongjiang Province

In order to meet the land use requirements of the treated wastewater from high density polyethylene (HDPE) membrane-enclosed anaerobic lagoons, the physical and chemical properties of the wastewater in an HDPE membrane-enclosed anaerobic lagoon were measured. The total nitrogen content (TN) in wastewater treated in membrane-enclosed anaerobic lagoons is 3165 and 1510 mg/L in winter and summer respectively. The wastewater can be used as liquid organic fertilizer, partly replacing chemical fertilizer. The safety dosage of the wastewater was 21.48 t/ha for rice and 9.54 t/ha for corn, respectively. Meanwhile, the wastewater has the characteristics of high salt (conductivity>16.0 mS/cm) and high organic matter content (COD>16,900 mg/kg). Therefore, the potential negative effects of the wastewater on soil salinity and pH should be assessed. 16S rRNA was used to investigate the bacterial population structure and assess potential biological risks of land use of the wastewater. The wastewater from lagoon has the least and the most bacterial abundance in summer and winter, respectively. The bacterial diversity of wastewater samples from lagoon is the most. 21 and 24 phyla were detected in winter and summer samples respectively. Clostridium is the absolute dominant bacteria in the summer water samples and the absolute dominant bacteria is Trichococcus in winter water samples. Several animal and plant bacterial pathogens such as Campylobacter, Corynebacterium, Facklamia and Erysipelothrix can be detected in the wastewater samples. More than 70% of pathogenic bacteria such as Campylobacter, Facklamia, Erysipelothrix and Acholeplasma can be removed by lagoon in summer, but only about 99% of Corynebacterium is still in the lagoon (XYH). While more than 60% of Corynebacterium, Facklamia and Erysipelothrix are not removed in winter. So the biological risk of land use of anaerobic pond wastewater needs to be considered.

Effect of seasonal temperature shifts on body homeostasis, biochemical parameters and chemical composition of green ormer (Haliotis tuberculata) in the Northern Adriatic.

Seasonal responses of green ormer in terms of antioxidant capacity and lipid peroxidation, proximate and fatty acid tissue composition, trace and macro elements concentrations over the seasons were studied in relation to temperature shifts in the Northern Adriatic Sea. Overall antioxidative defenses (SOD, TBARS, TAS, LDH) varied significantly (p<0.001) according to seasons (primarily spring and summer). The proportions of overall SFA were highest in summer. The proportions of MUFA increased in autumn, with significant differences between genders in spring and summer, and spring, summer and autumn for C18:1n7 and C20:4n6. The only fatty acid lacking significant variation between seasons was C22:5n3. Significant overall differences were observed in summer vs. winter samples for As, Ba, Co, Ni, Mn, Pb, Sb, and Se content in soft tissues, however, gender variations were not significant. The data obtained in the study are of utmost importance for the management of this under-investigated species.

COMPARISON OF MICROBIOLOGICAL PROPERTIES OF TURKISH TRADITIONAL RAW MEATBALLS IN WINTER AND SUMMER

Raw meatball (çiğ köfte) is a popular food consumed fondly in Türkiye. The lack of being cooked and the constant hand contact during production and sale increase the risk of product contamination. This can cause food poisoning and pose a danger to public health. This study aims to determine the microbiological quality of raw meatballs sold in Çorum, Turkey. For this purpose, a total of 40 samples were studied in winter (n = 20) and summer (n = 20) months. Samples were analyzed for pH, total aerobic mesophilic bacteria, yeast-mold, E. coli, coliform, Enterobacteriaceae, Enterococcus, and Staphylococcus/Micrococcus. The pH value of raw meatball samples was 4.64-5.35 in the winter, and in summer, it was determined as 4.65–5.09. The total aerobic mesophilic bacteria, yeast-mold, coliform, Enterobacteriaceae, Enterococcus, Staphylococcus/Micrococcus count results of samples in summer and winter periods were determined respectively as

Predicting photooxidant concentrations in aerosol liquid water based on laboratory extracts of ambient particles

Abstract. Aerosol liquid water (ALW) is a unique reaction medium, but its chemistry is poorly understood. For example, little is known of photooxidant concentrations – including hydroxyl radicals (⚫OH), singlet molecular oxygen (1O2*), and oxidizing triplet excited states of organic matter (3C*) – even though they likely drive much of ALW chemistry. Due to the very limited water content of particles, it is difficult to quantify oxidant concentrations in ALW directly. To predict these values, we measured photooxidant concentrations in illuminated aqueous particle extracts as a function of dilution and used the resulting oxidant kinetics to extrapolate to ALW conditions. We prepared dilution series from two sets of particles collected in Davis, California: one from winter (WIN) and one from summer (SUM). Both periods are influenced by biomass burning, with dissolved organic carbon (DOC) in the extracts ranging from 10 to 495 mg C L−1. In the winter sample, the ⚫OH concentration is independent of particle mass concentration, with an average value of 5.0 (± 2.2) × 10−15 M, while in summer ⚫OH increases with DOC in the range (0.4–7.7) × 10−15 M. In both winter and summer samples, 3C* concentrations increase rapidly with particle mass concentrations in the extracts and then plateau under more concentrated conditions, with a range of (0.2–7) × 10−13 M. WIN and SUM have the same range of 1O2* concentrations, (0.2–8.5) × 10−12 M, but in WIN the 1O2* concentration increases linearly with DOC, while in SUM 1O2* approaches a plateau. We next extrapolated the relationships of oxidant formation rates and sinks as a function of particle mass concentration from our dilute extracts to the much more concentrated condition of aerosol liquid water. Predicted ⚫OH concentrations in ALW (including mass transport of ⚫OH from the gas phase) are (5–8) × 10−15 M, similar to those in fog/cloud waters. In contrast, predicted concentrations of 3C* and 1O2* in ALW are approximately 10 to 100 times higher than in cloud/fogs, with values of (4–9) × 10−13 M and (1–5) × 10−12 M, respectively. Although ⚫OH is often considered the main sink for organic compounds in the atmospheric aqueous phase, the much higher concentrations of 3C* and 1O2* in aerosol liquid water suggest these photooxidants will be more important sinks for many organics in particle water.

Study of traffic-related pollution and its treatment with a particular focus on microplastics in tunnel wash and road runoff water.

Treatment of tunnel wash runoff water and road runoff water before it reaches the environment is recommended to limit the negative consequences of traffic-related pollution. The efficiency of existing water treatment systems to remove traffic-related microplastic (MP) has not been sufficiently documented. Expanding the knowledge about traffic-related MP and documenting the treatment efficiency of MP in road tunnel wash water (TWW) and road runoff (RRW) treatment systems were the objectives of the presented project. TWW from the Tåsen tunnel, Norway, and RRW from the Fossbekken sedimentation pond were investigated in summer and winter situations. Six commonly available polymer types, tire rubber tread particles (TRP), and road marking paints (RMP) were analyzed in the selected samples. About 0.12 and 0.26 μg/L of polymers were identified in winter and summer TWWs. Significantly higher tire rubber and road marking paint concentrations were identified in the winter sample compared to summer sample. Suspended particle concentration in the Fossbekken RRW treatment pond effluent was lower in the summer than in the winter sample. About 0.002 and 0.0008 μg/L polymer masses were identified in winter and summer samples, respectively. TRP in the winter and summer samples were 0.7 and 0.2 μg7/L, and 13.4 μg/L RMP was found in the winter sample, while it was only 0.008 μg/L in the summer sample.

Impact of fossil and non-fossil fuel sources on the molecular compositions of water-soluble humic-like substances in PM2.5 at a suburban site of Yangtze River Delta, China

Abstract. Atmospheric humic-like substances (HULIS) affect the global radiation balance due to their strong light absorption at the ultraviolet wavelength. The potential sources and molecular compositions of water-soluble HULIS at a suburban site in the Yangtze River Delta from 2017 to 2018 were discussed, based on the results of the radiocarbon (14C) analysis and combining the Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) technique in this study. The 14C results showed that the averaged non-fossil-fuel source contributions to HULIS were 39 ± 8 % and 36 ± 6 % in summer and winter, respectively, indicating significant contributions from fossil fuel sources to HULIS. The Van Krevelen diagrams obtained from the FT-ICR-MS results showed that the proportions of tannin-like and carbohydrate-like groups were higher in summer, suggesting significant contribution of HULIS from biogenic secondary organic aerosols (SOAs). The higher proportions of condensed aromatic structures in winter suggested increasing anthropogenic emissions. Molecular composition analysis on the CHO, CHON, CHOS, and CHONS subgroups showed relatively higher intensities of high O-containing macromolecular oligomers in the CHO compounds in summer, further indicating stronger biogenic SOA formation in summer. High-intensity phenolic substances and flavonoids, which were related to biomass burning and polycyclic aromatic hydrocarbon (PAH) derivatives indicating fossil fuel combustion emissions, were found in winter CHO compounds. Besides, two high-intensity CHO compounds containing condensed aromatic ring structures (C9H6O7 and C10H5O8) identified in the summer and winter samples were similar to those from off-road engine samples, indicating that traffic emissions were one of the important fossil fuel sources of HULIS at the study site. The CHON compounds were mainly composed of nitro compounds or organonitrates with significantly higher intensities in winter, which were associated with biomass burning emissions, in addition to the enhanced formation of organonitrates due to high NOx in winter. However, the high-intensity CHON molecular formulas in summer were referring to N-heterocyclic aromatic compounds, which were produced from the atmospheric secondary processes involving reduced N species (e.g., ammonium). The S-containing compounds were mainly composed of organosulfates (OSs) derived from biogenic precursors, namely long-chain alkane and aromatic hydrocarbon, which illustrate the mixed sources of HULIS. Generally, different policies need to be considered for each season due to the different seasonal sources (i.e., biogenic emissions in summer and biomass burning in winter for non-fossil-fuel sources, traffic emissions and anthropogenic SOA formation in both seasons, and additional coal combustion in winter). Measures to control emissions from motor vehicles and industrial processes need to be considered in summer. Additional control measures on coal power plants and biomass burning should be applied in winter. These findings add to our understanding of the interaction between the sources and the molecular compositions of atmospheric HULIS.

Assessment of aflatoxin M1 in raw milk samples of some dairy animals from Sohag City, Egypt

PurposeThe purpose of this study was to determine the incidence and concentrations of aflatoxin M1 (AFM1) in raw buffalo milk samples obtained from four different seasons: winter, spring, summer and autumn in Sohag City, upper Egypt, and compared the determined findings against the several regulations regarding AFM1 that have been legislated by the European Union, US Food and Drug Administration and Egyptian Regulations.Design/methodology/approachSimultaneous determination of aflatoxins in raw buffalo milk samples trailed in different seasons, in Sohag City, Egypt. The aflatoxin that has been included in this survey is AFM1. Milk samples were obtained from February to October 2021. The enzyme-linked immunosorbent assay was used as a methodology technique.FindingsThe results of AFM1 presented the highest frequency of occurrence, with a detected incidence of 85.5% in winter samples, 64.2% in spring samples, 78.5% in summer samples and 78.5% in autumn samples. The positive samples showed concentration range levels of AFM1 between 0.0 and 0.9 µg/kg (12 samples) in winter samples, 0.03 and 1.2 µg/kg in spring milk samples (9 samples), 0.06 and 0.8 µg/kg in summer milk samples (11 samples) and lasted with 0.028 and 0.9 µg/kg in autumn milk samples (11 samples). The percentage of AFM1samples exceeded the maximum residues limit of Egyptian Standard Regulation 2010/7136 last updated, 78%, 57%, 100% and 64% in the four examined seasons, respectively.Originality/valueThe residue levels of AFM1 obtained in the investigated samples represented a serious concern about the health risk of consumers. Milk is introduced to the diet plan all over the people units especially the offspring ones as it is a complete food that contains a lot of important nutrients. So it is worth to set a regular schedule for monitoring and inspection of dairy products for aflatoxin residues.

Winter-time pollution in Central European cities shifts the 208Pb/207Pb isotope ratio of atmospheric PM2.5 to higher values: Implications for lead source apportionment

Atmospheric lead pollution has adverse health effects on humans. Identification of anthropogenic Pb sources is thus crucial for understanding of pollution-related risks and for formulation of efficient abatement strategies. We analyzed concentrations and isotope ratios of Pb in fine air-borne particulate matter (PM2.5) in three Central European cities. Aerosol sampling in 12-h intervals was performed during summer and winter in Hradec Králové, Olomouc and Brno, regional centers of highly industrialized Czech Republic, each with a population of more than 90 thousand. Lead analysis was complemented with concentration measurements of Zn, Cu, Cd, As, Sb, and S. Trace element and PM2.5 concentrations were higher in winter than in summer in all studied cities, on average by 47%. The overall mean concentration of PM2.5 in urban air was 21 μg m−3, similar to that in Bern (Switzerland) and Vienna (Austria). Across the sites, 206Pb/207Pb ratios ranged from 1.142 to 1.178 in summer and from 1.143 to 1.173 in winter. The mean 206Pb/207Pb ratios were statistically indistinguishable in all three studied cities (1.165 in Hradec Králové, 1.163 in Olomouc, and 1.160 in Brno). In the 206Pb/207Pb vs.208Pb/207Pb graph, Pb isotope composition of summer samples formed a straight line, whereas Pb isotope composition of winter samples was shifted toward higher 208Pb/207Pb ratios. A Pb isotope inventory of regional pollution sources indicated that winter-time Pb pollution was not caused solely by household heating and increased electricity production in coal-burning power plants. Recycling of industrial Pb originating from Variscan ores and waste incineration could have shifted the 208Pb/207Pb ratio of PM2.5 to higher values, however, such sources do not emit more Pb in winter than in summer. Remobilization of legacy alkyl-Pb from gasoline additives and Pb emissions from current unleaded gasoline and diesel could have shifted both Pb isotope ratios to lower values.

Epidemiology of sperm DNA fragmentation in a retrospective cohort of 1191 men.

The scientific and clinical communities now recognize that sperm DNA integrity is crucial for successful fertilization, good embryo development, and offspring quality of life. Despite the apparent unanimity, this criterion is rarely evaluated in clinical practice. We evaluated the sperm DNA fragmentation index of nearly 1200 sperm samples and its connections based on the patient's age, body mass index, the season of sperm collection, geographical location, medical history, and addictive behaviors. A cohort of 1503 patients who were referred to the Royan Institute between July 2018 and March 2020 was examined. Only 1191 patient records with demographic data, complete semen analysis, and DNA fragmentation index measurements were included in the final cohort. Documents were classified, incorporated into statistical models, and analyzed. The results confirmed previous findings that the sperm DNA fragmentation index was significantly higher in aging men. The sperm DNA fragmentation index and high DNA stainability levels were significantly higher in spring and summer samples than in those of other seasons. No correlation was found between semen DNA fragmentation index and patient body mass index, although the study cohort was significantly overweight. Contrary to what might be expected, we observed that the sperm DNA fragmentation index was higher in rural than in urban patients. Intriguingly, epileptic patients exhibited significantly higher sperm DNA fragmentation index levels. Age is the factor that is most strongly associated with sperm DNA fragmentation index levels. Our analysis of 1191 samples indicates that between the ages of 19 and 59, the sperm DNA fragmentation index increases by an average of 2% each year. Intriguingly, from an epidemiological perspective, the warm season (spring/summer) is associated with a higher sperm DNA fragmentation index in the study population, possibly due to the deleterious effect of temperature on sperm quality. Some neurological diseases, such as epilepsy, are associated with decreased sperm DNA integrity. This observation could be related to the iatrogenic effects of associated therapies. In the study cohort, body mass index did not appear to be correlated with the DNA fragmentation index.

Tracing the fate of microplastic in wastewater treatment plant: A multi-stage analysis of treatment units and sludge

Microplastic (MP) pollution is ubiquitous in the environment presenting a global problem for both scientists and the general public. One of the major pathways of MPs entering the natural environment is through wastewater treatment plants (WWTPs). Once MPs reach the natural environment, they are posing threat to aquatic ecosystems and public health. The aim of this study is to investigate the concentration, morphology, and composition of MPs in different treatment units of a WWTP. Sampling included different points across WWTP in the water and sludge lines. Pre-treatment of the samples consists of advanced Fenton oxidation, and alkaline and enzymatic digestion followed by density separation. Once the particles were isolated, their morphology and size were studied using a stereoscopic and optical microscope followed by final confirmation with ATR-FTIR and micro-FTIR spectroscopy. Microplastic particle concentrations exhibit significant reductions as water undergoes treatment in the WWTP. For summer sampling, concentrations decreased from 351 MP/L (influent) to 35 MP/L (primary clarifier), 32 MP/L (biological reactor), and 13 MP/L (2.3 MP/L) (secondary clarifier). Similarly, winter sampling showed reductions from 403 MP/L (influent) to 159 MP/L (primary clarifier), 178 MP/L (biological reactor), and 26 MP/L (5.6 MP/L) (secondary clarifier). Removal efficiency of WWTP is high and exceeds 96%. The most abundant morphology is fibers followed by fragments and films. Polymers such as PE, synthetic cellulose, PP, PVC, PE-PP, PEEA, PA, acrylamide, and PES are widely detected in different units of WWTP. The number of MPs that are avoided from being emitted into the environment through direct water discharge was estimated to be 9.1 × 1012 MP/year. Removed MPs tend to accumulate in the sludge that is used for agricultural purposes although it should be managed as waste properly, avoiding the transition of MPs pollutants to terrestrial ecosystems adding to the number of MPs that will inevitably end up in receiving water bodies through direct WWTP effluent discharge that was set in 5.1 × 1010 MP/year in the studied WWTP.

Mineral organic carbon interactions in dry versus wet tundra soils

Mineral organic carbon interactions (aggregation, organo-mineral associations and organo-metallic complexes) enhance the protection of organic carbon (OC) from microbial degradation in soils. The northern circumpolar permafrost region stores between 1,440 and 1,600 Pg OC of which a significant portion is already thawed or about to thaw in coming years. In the light of this tipping point for climate change, any mechanism that can promote OC stabilization and hence mitigate OC mineralization and greenhouse gas emissions is of crucial interest. Here, we study interactions between metals (Fe, Al, Mn and Ca) and OC in the moist acidic tundra ecosystem of Eight Mile Lake, near Healy, AK, USA. We collected thirteen cores (124 soil samples) in late summer 2019 with shallow and deep active layers (45 to 109 cm deep) and varying water table depths. We find that between 6% and 59% of total OC in Eight Mile Lake tundra soils is mineral-associated (mean 20%), in organo-mineral associations (association between poorly crystalline oxides and OC) and in organo-metallic complexes (associations between Fe, Mn, Al, Ca polyvalent cations and organic acids). We find that total Fe and Mn concentrations can be used as good proxies to assess the reactive pool of these metals able to form associations with OC, i.e., poorly crystalline oxides or metals complexed with OC. We observe that in the active layer, mineral OC interactions are mostly as organo-metallic complexes with Fe cations, with an accumulation at the water table level acting as a soil redox interface. In waterlogged soils with a water table level above surface, no such accumulation of OC-Fe complexes is found due to the absence of a redox interface below soil surface. In the permafrost layer, we find that a combination of complexed metals and poorly crystalline Fe oxides act as reactive phases towards OC. Knowing that upon permafrost thaw tundra soils will become wetter or drier, the assessment of mineral-bound OC in drier or wetter tundra soils is a needed step to better constrain the changes in the proportion of non-protected OC more likely to contribute to C emissions from tundra soils.

Environmental DNA clarifies impacts of combined sewer overflows on the bacteriology of an urban river and resulting risks to public health

There is no reference of microbiological water quality in the European Union's Water Framework Directive, adapted into English law, and consequently microbial water quality is not routinely monitored in English rivers, except for two recently designated bathing water sites. To address this knowledge gap, we developed an innovative monitoring approach for quantitative assessment of combined sewer overflow (CSO) impacts on the bacteriology of receiving rivers. Our approach combines conventional and environmental DNA (eDNA) based methods to generate multiple lines of evidence for assessing risks to public health. We demonstrated this approach by investigating spatiotemporal variation in the bacteriology of the Ouseburn in northeast England for different weather conditions in the summer and early autumn of the year 2021 across eight sampling locations that comprised rural, urban, and recreational land use settings. We characterized pollution source attributes by collecting sewage from treatment works and CSO discharge at the peak of a storm event. CSO discharge was characterized by log10 values per 100 mL (average ± stdev) of 5.12 ± 0.03 and 4.90 ± 0.03 for faecal coliforms and faecal streptococci, and 6.00 ± 0.11 and 7.78 ± 0.04 for rodA and HF183 genetic markers, for E. coli and human host associated Bacteroides, respectively, indicating about 5 % sewage content. SourceTracker analysis of sequencing data attributed 72–77 % of bacteria in the downstream section of the river during a storm event to CSO discharge sources, versus only 4–6 % to rural upstream sources. Data from sixteen summer sampling events in a public park exceeded various guideline values for recreational water quality. Quantitative microbial risk assessment (QMRA) predicted a median and 95th percentile risk of 0.03 and 0.39, respectively, of contracting a bacterial gastrointestinal disease when wading and splashing around in the Ouseburn. We show clearly why microbial water quality should be monitored where rivers flow through public parks, irrespective of their bathing water designation.

Including environmental covariates clarifies the relationship between endangered Atlantic salmon (Salmo salar) abundance and environmental DNA

AbstractCollecting environmental DNA (eDNA) as a nonlethal sampling approach has been valuable in detecting the presence/absence of many imperiled taxa; however, its application to indicate species abundance poses many challenges. A deeper understanding of eDNA dynamics in aquatic systems is required to better interpret the substantial variability often associated with eDNA samples. Our sampling design took advantage of natural variation in juvenile Atlantic salmon (Salmo salar) distribution and abundance along 9 km of a single river in the Province of New Brunswick (Canada), covering different spatial and temporal scales to address the unknown seasonal impacts of environmental variables on the quantitative relationship between eDNA concentration and species abundance. First, we asked whether accounting for environmental variables strengthened the relationship between eDNA and salmon abundance by sampling eDNA during their spring seaward migration. Second, we asked how environmental variables affected eDNA dynamics during the summer as the parr abundance remained relatively constant. Spring eDNA samples were collected over a 6‐week period (12 times) near a rotary screw trap that captured approximately 18.6% of migrating smolts, whereas summer sampling occurred (i) at three distinct salmon habitats (9 times) and (ii) along the full 9 km (3 times). We modeled eDNA concentration as a product of fish abundance and environmental variables, demonstrating that (1) with inclusion of abundance and environmental covariates, eDNA was highly correlated with spring smolt abundance and (2) the relationships among environmental covariates and eDNA were affected by seasonal variation with relatively constant parr abundance in summer. Our findings underscore that with appropriate study design that accounts for seasonal environmental variation and life history phenology, eDNA salmon population assessments may have the potential to evaluate abundance fluctuations in spring and summer.

Flavor profile of "Dao Ban Xiang" (a traditional dry-cured meat product in Chinese Huizhou cuisine) at different processing stages in winter and summer.

"Dao Ban Xiang" is a famous traditional Chinese dry-cured meat product. This study aimed to comparatively analyze the difference in the volatile flavor information of "Dao Ban Xiang" produced in winter and summer. In this study, we determine the physical and chemical properties, free amino acids (FAAs), free fatty acids (FFAs), and volatile compounds in the four processing stages of samples in winter and summer. The content of FAAs decreased significantly during the curing period in winter while increasing steadily in summer. The content of total FFAs increased in both winter and summer, and polyunsaturated fatty acids (PUFAs) decreased significantly in summer. The characteristic compound in winter samples is hexanal, nonanal, and (E)-2-octenal, which may mainly come from the degradation of FAAs, while the characteristic compound in winter samples is hexanal, nonanal, and (E)-2-nonenal, which may mainly be derived from the oxidation of FFAs. This study extends our knowledge on flavor from traditional cured meat products at different processing stages in different seasons and could be useful for the standardization of the traditional and regional meat products.

Assessment of the water quality of Bartın Kışla (Kozcağız) Dam by using geographical information system (GIS) and water quality indices (WQI)

This study was conducted to evaluate the water quality of the Kışla (Kozcagiz) Dam located in the province of Bartın in the Western Black Sea Region of Turkey. Water samples were collected monthly from 5 stations for a year and analyses were conducted using 27 water quality parameters. The quality of the dam and the water quality parameters were evaluated using different indices in comparison to the limits determined according to the standards set by the World Health Organization (WHO) and Turkey Surface Water Quality Regulation (SWQR). Water quality index (WQI), organic pollution index (OPI), sodium adsorption ratio (SAR), magnesium adsorption ratio (MAR), permeability index (PI), and metal pollution index (MPI) were calculated and spatial assessment of pollution was made seasonally by making use of the geographic information system (GIS). A piper diagram was used in determining the facies of the water. The types of Ca2+-Mg2+-HCO3- predominated in the dam water. Moreover, statistical analyses were used in order to determine if there was a significant difference between the parameters. WQI results generally indicate that the water quality was good in all seasons; however, only in the autumn, sampling points S1 (101.58), S2 (100.59), S4 (102.31), and S5 (102.12) showed poor water characteristics. According to the OPI results, while winter and spring yielded good water quality, summer samples were lightly polluted and autumn samples were moderately polluted. Given SAR results, it can be stated that the water of Kışla Dam could be used as irrigation water. Considering the standards specified by WHO and SWQR, the parameters generally exceeded the threshold values, but the water hardness value was much higher than 100mg L-1 specified in SWQR as very hard water. The principal component analysis (PCA) results showed that the pollution sources were anthropogenic. Thus, for the dam water to not be affected by the increasing pollutant factors, it should be continuously monitored, and attention should be paid to the irrigation methods used in agricultural activities.