Sedimentation Method Research Articles

Quality and fertilizing ability of frozen-thawed porcine sperm separated using a migration sedimentation method.

We evaluated the quality and fertilizing ability of frozen-thawed porcine sperm that were selected using a commercially available device (MIGLIS, Menicon Life Science) consisting of three parts: an outer lid, an inner lid, and a tube. Firstly, to determine an adequate concentration of caffeine for separation, frozen-thawed sperm were incubated with different concentrations of caffeine (0, 1, 2.5, 5, and 10 mM) in a MIGLIS device. To determine the appropriate incubation time for separating sperm in the MIGLIS device, frozen-thawed sperm were incubated with 2.5 mM caffeine for 5, 10, 15, or 20 min. To evaluate the fertilization and embryo development of oocytes fertilized with frozen-thawed sperm separated into two regions (outer and inner) in the MIGLIS device, the separated sperm from the three boars was used to fertilize invitro-matured oocytes and cultured invitro for 7 days. Sperm quality parameters of sperm collected from the inner tube after incubation with 2.5 mM caffeine were superior to sperm incubated without caffeine. Moreover, sperm collected from the inner tube after incubation for 10 min had a higher progressive motility. The rate of blastocyst produced from spermatozoa collected from the inner tube after incubation with 2.5 mM caffeine for 10 min significantly increased compared to that produced from spermatozoa from the outer tube, regardless of the boar. In conclusion, sperm sorting using the MIGLIS device may be useful for separating high-quality sperm after incubation with 2.5 mM caffeine for 10 min to improve blastocyst formation.

Effect of an extraoral scavenging device on eliminating droplets and aerosols generated in ultrasonic supragingival scaling: A randomised clinical trial.

Ultrasonic scaling is extensively applied as part of the initial therapy for periodontal diseases, which has been restricted since the outbreak of the COVID-19 pandemic due to droplets and aerosols generated by ultrasonic devices. An extraoral scavenging device (EOS) was designed for diminishing droplets and aerosols in dental clinics. The objective of this study is to evaluate the effect of EOS on eliminating droplets and aerosols during ultrasonic supragingival scaling. This single-blinded, randomised controlled clinical trial enrolled 45 patients with generalised periodontitis (stage I or II, grade A or B) or plaque-induced gingivitis. The patients were randomly allocated and received ultrasonic supragingival scaling under three different intervention measures: only saliva ejector (SE), SE plus EOS and SE plus high-volume evacuation (HVE). The natural sedimentation method was applied to sample droplets and aerosols before or during supragingival scaling. After aerobic culturing, colony-forming units (CFUs) were counted and analysed. Compared with the level before treatment, more CFUs of samples throughout treatment could be obtained at the operator's chest and the patient's chest and the table surface when using SE alone (p < 0.05). Compared with the SE group, the SE + EOS group and the SE + HVE group obtained decreasing CFUs at the operator's chest and the patient's chest (p < 0.05), while no significant difference was determined between these two groups. The EOS effectively eliminated splatter contamination from ultrasonic supragingival scaling, which was an alternative precaution for nosocomial contamination in dental clinics.

Settling velocity of atmospheric particles in seawater: Based on hydrostatic sedimentation method using video imaging techniques

When atmospheric particles deposit to the ocean, their settling velocities and residence times associated are critical for their effects on oceanic ecosystems. We developed a hydrostatic sedimentation method using video imaging techniques to track particles of 5–20 μm in diameter falling into seawater and determine the particle settling velocities in relation to their diameter, shape, organic matter contained, and seawater salinity. The measured settling velocities varied from 0.025 to 0.41 mm/s. Irregular particle shape and organic matter contained in particles also, however, reduced the values. The settling velocities were decelerated by the dissolution process of particle in seawater. Combined with the experimental results, a formula for calculating the settling velocity formulae for atmospheric particles was estimated. Using this equation, the residence time of particles is estimated to be less than one month in continental shelf sea and more than 100 days in the oceans.

Two millennia of climate change, wildfires, and caribou hunting in west Greenland

Changing climatic conditions is a perpetual circumstance for mankind. In this study, we investigate local environmental and climatic changes near Kangerlussuaq, west Greenland. Our reconstruction is based on a lake sediment core and methods include chemical proxies and a palynological analysis. The investigated site is located 15 km from the Aasivissuit Inuit summer hunting ground, which has been in use for caribou hunting for more than 2000 years. The presented climatic reconstruction covers the time from c. 560 CE to present time. We identify three distinct periods of climate regimes: From c. 560–1100 CE conditions were stable, warm and humid, and summer temperatures were 1.5–2°C warmer than today. 1100–1600 was a period of cooler and very arid conditions with more sea ice, corresponding to the Neoglacial cooling. In this period, we detect two wildfire events and subsequent temporary caribou abandonment of the area. From 1600 to present we find increasingly warmer conditions with more precipitation and less extensive sea ice cover, gradually approaching today’s climate regime in Kangerlussuaq. We review the existing literature regarding the Aasivissuit summer hunting ground, which was first used concurrently with the detected cooling. Despite climatic deterioration, the hunting ground was regularly in use throughout the Neoglacial and onwards, with peak hunting intensity in the early 1700s. The detected wildfires and reindeer abandonment are interpreted to be localized events at the coring site and did not affect the hunting ground. Our findings highlight the resilience of the Inuit hunters to climatic changes as well as the advantages and limitations of local environmental reconstructions.

Real-time and high-sensitive colorimetric sensor based on photonic crystal for amniotic fluid identification

In this study, we proposed a pH-responsive photonic crystal hydrogel sensor (PCHs) to conveniently and accurately recognize the amniotic fluid from urine of parturient women, which was constituted by three-dimensional polymethyl acrylamide (PMMA) array and optimized hydrogel. PMMA array was self-assembled by 180 nm monodispersed nanoparticles with vertical sedimentation method. The functional hydrogel containing N-acryloyl phenylalanine (APA), acrylamide (AM) and N, N'-methylene bis(acrylamide) (BIS) as co-monomer and crosslinking agent respectively, was photo-polymerized by the precursor under 365 nm UV light. This hydrogel significantly shrank or swelled corresponding to the acidity and alkalinity of the aqueous solution, which resulted in both the reflection peak position (λmax) of the prepared sensor and its structural color changing with the pH value. The λmax of PCHs redshifted from 514 nm to 606 nm in 60 s while the pH value of testing solution increased from 4.5 to 8.0, which exactly covered the pH value of amniotic fluid and urine. Correspondingly, its structure color gradually changed from pale-green to red ensuring their naked-eye determination. Furthermore, an extremely high sensitivity as 26.3 nm/pH of Δλmax was obtained which was linearly related to pH value. The prepared sensor possessed steady accuracy and extraordinary sensitivity compared with the pH test strip which was generally used in amniorrhexis diagnosis nowadays besides the advantages of the low cost, simple operation, rapid response and visual detection mode. The reliability of this PCHs was further confirmed by the real sample detection which relative standard deviation was below 5.0 %, suggesting its potential clinical applications.

Purification of Iranian bentonite for organoclay synthesis for use in clay–polymer composites

Abstract Polymer-based composites modified with organoclay are economically beneficial candidates for a variety of applications. Different types of impurities accompany montmorillonite phases in various bentonites, which impact the quality and cost of organoclays and final composites. To obtain organoclays for clay composite applications, eight Iranian raw bentonites from different geographical locations were selected as the candidates and characterized by X-ray diffraction (XRD). Sample IB was chosen due to its high purity and lower cristobalite content than the other samples. It was purified by centrifugation or sedimentation methods using a sodium hexametaphosphate (NaHMP) dispersant. The cation-exchange capacity (CEC) was measured for bentonite before and after purification by sedimentation, and it showed a significant increase from 6.944 to 12.128 eq g–1, confirming successful purification. Organoclays were prepared using purified bentonite (sedimentation method) with two surfactants (cetyltrimethylammonium bromide and octadecylamine), and the amount of octadecylamine was optimized. Purified bentonite and organoclay were characterized by XRD, scanning electron microscopy (SEM) and X-ray fluorescence. The results indicate that most of the impurities were removed after purification, and the interlayer space of organoclays increased to 35 Å in the optimized sample prepared with an amount of octadecylamine that was twice the CEC in purified bentonite. The prepared organoclay was used to improve low-density polyethylene (LDPE) polymer properties. The clay–polymer composite properties were studied by field emission SEM, thermogravimetric analysis and tensile strength tests. The organoclay was fully dispersed in the LDPE matrix and in the sample with 5 wt.% of organoclay, where Ti (the temperature at which 10% of the sample is decomposed) and T50% (the midpoint of degradation) were 17°C and 13°C greater than those of polyethylene, respectively. Additionally, the sample residue with 5 wt.% of organoclay at 600°C was 43.4%. The tensile strength of polyethylene increased from 8.67 to 9.03 MPa in the sample with 4 wt.% of organoclay.

Underestimated single-aliquot quartz OSL ages of Late-Pleistocene sediments due to the dominance of medium component

Optically stimulated luminescence (OSL) dating technique has increasingly been employed to establish chronologies for coastal deposits since the Late Pleistocene. However, the commonly used single-aliquot quartz OSL dating method may yield inaccurate ages due to factors such as partial bleaching, luminescence characteristics, and the age limit of quartz. In this study, taking the Yangtze River Delta (YRD) as an example, single-aliquot and single-grain OSL dating using varying grain-sized quartz and K-feldspar were cross-checked to establish appropriate dating method for Late-Pleistocene sediments in coastal areas. The quartz OSL signals of the upper 24 m Holocene sediments were dominated by the fast component, and the ages obtained through OSL and AMS 14C ages agree. Conversely, the lower 24–91 m section, representing the last glacial-interglacial cycle, reveals a notable underestimation of quartz OSL ages, with a maximum underestimation of 250%, attributed to the influence of signal components. For samples within the dating limit of quartz (less than 70 ka), the single-grain method effectively mitigates the issue associated with the signal component. Single-grain K-feldspar technique proves valuable for accurately determining the age of those older sediments exceeding 70 ka. Through cross-checking between different OSL dating methods, sediments initially attributed to marine isotope stage (MIS) 3 (36–60 ka) are re-identified as deposited during MIS 5 (80–130 ka). This study highlights the necessity of assessing the variability in luminescence characteristics before applying a single OSL dating protocol to all samples from different sedimentary facies within a single core.

Evaluation of Heavy Metals in Roadside Soil of Tumfure Main Market, Gombe State

Heavy metal pollution has been a problem of concern in soil ecology in recent decades. This study evaluated the physico-chemical characteristics and heavy metal contents in roadside soil samples of Tumfure main market, Gombe, Nigeria. The soil samples were collected from six different sampling points with a control sample each by handpicking, this was followed by oven-drying, ground to fine grain, and then sieved using a 2 mm mesh sieve. The pH, electrical conductivity and bulk density were carried out on the soil samples, sieve and sedimentation method were used to determine the soil texture. The soil samples were weighed and digested using mixture of HCl and HNO3. The contents (mg/kg) of four metals (cadmium, copper, lead and zinc) were estimated using Atomic Absorption Spectrophotometer (AAS). Among the metals analyzed, the contents of Cd, Cu and Pb were not detected while the content of Zn (23.454 - 36.026) was found to be within the desirable permissible limits by the World Health Organization (WHO) and European Regulatory Standards (EURS) whose prevalence is to be considered non-toxic in unpolluted soils.

Recommended centrifuge method: Specific grain size separation in the

The isolation of specific grain size classes of lithogenic samples and biogenic carbonate from the <63 µm fraction (i.e. clay and silt) of marine sediment is often a prerequisite to further pre-treatments and/or analytical measurements for palaeoceanographic studies. Established techniques employed have included sieving, settling and micro-filtration (and/or a combination of these). However, these methods often use significant amounts of bulk sediment (often up to ∼3 g) and/or require considerable amounts of time during sediment processing (ranging from 48 h to 3 weeks) to isolate a size specific class for further analyses. Here, we build on previous approaches to isolate three grain size classes (e.g. <2 µm, clay; 2–10 µm, fine silt; and 10–63 µm, coarse silt) from the <63 µm fraction of marine sediment with the aid of a centrifuge at varying revolutions per minute using Stokes’ Law. We show the utility of our approach using two common sediment types dominated by (i) lithogenic and (ii) biogenic carbonate (specifically coccoliths) components of marine sediment cores. Our method reduces the amount of sample material required to 1–2 g to provide an isolated clay fraction (or other targeted size fraction) and decreases the sample processing time (to ∼1 hour) to enable high throughput of analysis, when compared to previous techniques for palaeoceanographic proxy measurements.•We recommend a more straightforward grain size isolation method for lithogenic sediment and biogenic carbonate sediment types•Isolating commonly targeted grain size fractions for palaeoceanographic studies using a centrifuge

Corrosion Behaviour of Al/(TiB2 + -Al3Ti)-Based Functional Grade Metal Matrix Composite by Sedimentation Method

Corrosion Behaviour of Al/(TiB2 + -Al3Ti)-Based Functional Grade Metal Matrix Composite by Sedimentation Method

Retrospective study on occurrence of bovine gastrointestinal parasitic infections in different regions of Haryana

The production and reproduction of livestock is hampered by the presence of gastrointestinal (GI) parasitic infections. The effect of parasites ranges from anorexia, loss of body condition, anaemia, diarrhoea, protein losing enteropathy and loss of body condition apart from aforementioned direct and indirect effects on the animals leads to huge economic losses to livestock owners. In the present study, a total of 1669 faecal samples from cattle (n=550) and buffaloes (n=1119) with the history of diarrhoea or digestive disturbances were processed for presence of parasitic infections at different disease investigation laboratories (Ambala, Bhiwani, Mahendragarh and Rohtak) of Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana from July 2021 to June 2022. All the faecal samples were processed by floatation and sedimentation methods for detection of parasitic eggs and the results revealed that 29.6% cattle and 34.7% buffaloes were positive for GI parasites. Buxtonella sulcata (17.7%), Amphistomes (5.2%), and Strongyles (6.9%) were the major parasites observed in cattle and buffaloes. The occurrence of parasitic infection was significantly higher (P&lt;0.05) in Rohtak followed by Bhiwani, Ambala and the least in Mahendragarh district of Haryana. However, no significant difference (P&gt;0.05) between the cattle and buffaloes of geographical regions was observed. Further, analysis of month, season and age influences on prevalence of GI parasites were found to have no significant impact (P&gt;0.05). Overall, this study helps to assess the parasitic load within the study region and helps to further devise control strategies against the parasites of bovines.

Gastrointestinal parasite infections and associated factors in fighting bulls over 7 years of monitoring in Southern Thailand.

Indigenous beef cattle engaged in bullfighting in Southern Thailand represent a distinctive and valuable breed. Gastrointestinal (GI) parasites, which are recognized as important pathogens, have a negative impact on the overall health and physical performance of these fighting bulls. This study aimed to estimate the prevalence of GI parasitic infections and identify factors associated with these infections in a fighting bull population in Southern Thailand. Fecal samples (n = 4,244) from fighting bulls were submitted to the Laboratory and Diagnostic Centre of the Teaching Animal Hospital, Faculty of Veterinary Science, Rajamangala University of Technology Srivijaya. We examined the samples using simple flotation and centrifugal sedimentation methods. Individual animal profiles and demographic data were collected. The overall prevalence of GI parasitic infections was 93.2%. Nine GI parasites were identified as Paramphistome spp. [PP]. being the most prevalent (93.2%), and the highest annual prevalence occurred in 2019 (97.9%). The infection rates of various parasite species were significantly related to the years of study, geographic area, season, and age group (p < 0.05). The prevalence of parasitic infection was higher on the west coast (98.6%) than on the east coast (98.0%). PP, Eurytrema spp., Strongyles spp., and Buxtonella spp. infections differed significantly among the seven provinces of Southern Thailand (p < 0.05). The prevalence of GI parasitic infections was higher during the rainy season (98.5%) than during the summer (97.7%). Bulls aged 7.0-7.9 years and 8.0-8.9 years had the highest parasite infection rate (99.2%) compared with those aged 8.0-8.9. GI parasitic infections continue to be a significant health concern among fighting bulls in Southern Thailand. Regular epidemiological investigations are crucial for developing effective preventive programs and control strategies and providing basic knowledge for bull farmers.

Helminths of captive and free-ranging populations of the mountain gazelle (Gazella gazella): Evidence from faecal examination.

Understanding parasite diversity in wild and captive animal populations has critical implications for both individual animal health and ecosystem dynamics in a broader sense. In mountain gazelles (Gazella gazella), the gastrointestinal helminth community is poorly understood, limiting our efforts in the conservation of this endangered bovid species. This species has only two remaining populations in the world, including the isolated northernmost population in Türkiye. To identify and compare the diversity and prevalence of gastrointestinal helminths in captive and free-ranging populations of mountain gazelles in Hatay, Türkiye, and to assess potential zoonotic risks. In total, 105 fresh faecal samples, 45 individual samples and 60 faecal samples, representing 16 pools, from both captive and free-ranging populations were collected and analysed using Fulleborn flotation, Benedek sedimentation and Bearman-Wetzel methods faecal flotation methods, including the McMaster technique to determine the severity of infection. We detected 12 helminth taxa in our examination of faecal samples, including gastrointestinal nematodes, lungworms and trematodes. Parasites from the Trichostrongyloidea family demonstrated variable hatching stages and rates, potentially influenced by ambient conditions. We also detected one protozoan among the samples. Our results revealed a higher diversity of parasites in free-ranging populations compared to captive ones. This study underscores the necessity for regular parasitological surveillance in both captive and free-ranging wildlife populations for effective conservation management. It also contributes to the 'One Health' perspective by highlighting the potential zoonotic risks posed by parasites in wild ruminants. Our results have implications for the conservation and management of the mountain gazelle.

Geo-helminths on leafy vegetables sold in Ogidi market, Idemili north local government area, Anambra state, Nigeria

Consumption of contaminated vegetables is a way through which people get infected with parasites. This study was carried out to determine the prevalence of Geo-helminth parasites that contaminate leafy vegetables sold in Ogidi market, Anambra state. The markets investigated were Oye Ogidi, Ekenweje and Nkwo Ogidi and vegetables were procured directly from the rural farmers who brought the vegetables to the markets which were examined in the laboratory for the presence of parasites using sedimentation method. Chi square was used to test for relationships at 95% confidence interval (p&lt;0.05). Geo-helminth parasites observed were ova of Ascaris lumbricoides, Trichuris trichuria, Hookworm and larvae of Strongyloides stercoralis with an overall prevalence of 56%. There was statistical significance on the parasites and vegetables sold in the three markets (X2= 0.00; P&lt;0.05). Ascaris lumbricoides had the highest prevalence rate of 25.6%, while Hookworm had the least prevalence rate of 7.6%. The vegetable that had the highest contamination rate was Scent leaf (16.6%), while Uziza had the least contamination rate (5.3%) but there was no significance relationship in the prevalence of parasites and vegetables (X2=0.57; P&gt;0.05). Ekenweje market had the highest contamination rate (7.1%), while Oye Ogidi had the least contamination rate (4.9%) but there was no significant relationship between the parasites and the markets (X2=0.98; P&gt;0.05). These findings may have important implications for global food safety and emphasize the importance of leafy vegetables in public health through transmission of Geo-helminth parasites to humans in Nigeria. Individuals and local health authorities should improve the sanitary conditions in the areas where the vegetables are cultivated and consumed. Therefore, proper treatment of wastewater used in the irrigation of vegetables, and improvement of sanitary facilities in our markets and among vegetable vendors are recommended.

Optimized combination of zero-valent iron and oxygen-releasing biochar as cathodes of microbial fuel cells to enhance copper migration in sediment

Membrane-less single-medium sediment microbial fuel cells (single-SMFC) can remove Cu2+ from sediment through electromigration. However, the high mass transfer resistance of the sediment and amount of oxygen at the cathode of the SMFC limit its Cu2+ removal ability. Therefore, this study used an oxygen-releasing bead (ORB) for slow oxygen release to increase oxygen at the SMFC cathode and improve the mass transfer property of the sediment. Resultantly, the copper removal efficiency of SMFC increased significantly. Response surface methodology was used to optimize the nano zero-valent iron (nZVI)-modified biochar as the catalyst to enhance the ability of the modified ORB (ORBm) to remove Cu2+ and slow release of O2. The maximum Cu2+ removal (95 %) and the slowest O2 release rate (0.41 mg O2/d·g ORBm) were obtained when the CaO2 content and ratio of nZVI-modified biochar to unmodified biochar were 0.99 g and 4.95, respectively. When the optimized ORBm was placed at the single-SMFC cathode, the voltage output and copper removal increased by 4.6 and 2.1 times, respectively, compared with the system without ORBm. This shows that the ORBm can improve the migration of Cu2+ in the sediment, providing a promising remediation method for Cu-contaminated sediments.

The practical meaning of the classical optimizing method and Angular Detection Photometer (ADP) in coagulation tests of surface water

Because of the growing deficit of clean water, rational use of its supplies through adaptation of purification techniques to the needs is becoming vital. The commonly used coagulation process requires optimization tools and techniques. The following were used in this paper to optimize coagulation of natural water pollutants: the standard jar test method with direct filtration and the angular detection photometry (ADP) method. We tested two aluminium coagulants – PAC with different basicity – and an iron coagulant: PFS. A modified jar test method allowed to obtain results similar to those of the sedimentation method. At the optimum doses 1.3 mg Al/mg C org. and 2 mg Fe/mg Corg – colour (PtCo), A254, A436 – achieved reduction in the 84–96% range and DOC 60–67% after filtration. The titration method using an ADP successfully allows determine optimum coagulant doses. The SD and FI values were determined based on the recorded fluctuations of the signals measured by detectors placed at three angles relative to the IR beam. A variation in SD was observed, depending on the angle of detection and the coagulant and correlates well (R2 =0.6–0.86) with sedimentation time ST, which was twice as long in the case of fine suspension in the PFS.

Complete photodegradation of tetracycline induced by surface microenvironment of graphitic carbon nitride/silver phosphate

Silver phosphate (Ag3PO4) is a promising photocatalyst, but the photo-corrosion issue limits an effective and comprehensive photocatalysis degradation of tetracycline (TC). In this work, a unique graphitic carbon nitride-Ag3PO4 (KCN-AP(40 %)) core-shell structure was prepared via a simple chemical sedimentation method. The unique graphitic carbon nitride sheet encloses Ag3PO4 to trap excited electrons from the conduction band position of Ag3PO4, suppressing the reduction of Ag+ and Ag metal deposition on the surface of Ag3PO4. Under visible light irradiation, the optimized KCN-AP(40 %) can photodegrade nearby 100 % of TC within 20 min with a first-order kinetic constant of 0.127 min−1, which is 3.34 and 3.97-folds higher than those of Ag3PO4 and graphitic carbon nitride, respectively. A series of factors that may affect photoactivity of KCN-AP (40 %) including pH, inorganic ions, and organic matter are investigated. In final, the photodegradation mechanisms and intermediates were proposed based on ex-situ HPLC-MS. This work explains the deep decomposition of TC and presents a facile approach for designing and manufacturing Ag3PO4 based nanohybrids.

Summary of Experiments and Influencing Factors of Sediment Settling Velocity in Still Water

Sediment deposition significantly impacts soil erosion processes, consequently influencing the geographical morphology and surrounding environments of reservoirs and estuaries. Given the intricate nature of sediment deposition, it is imperative to consolidate and analyze existing research findings. Presently, studies on sediment settling velocity primarily employ theoretical, laboratory, and field experimentation methods. Theoretical approaches, rooted in mechanics, examine the various forces acting on sediment particles in water to derive settling velocity equations. However, they often overlook external factors like temperature, salinity, organic matter, and pH. Although laboratory experiments scrutinize the influence of these external factors on sedimentation velocity, sediment settling is not solely influenced by individual factors but rather by their collective interplay. Field observations offer the most accurate depiction of sediment deposition rates. However, the equipment used in such experiments may disrupt the natural sedimentation process and damage flocs. Moreover, measurements of sediment particle size from different instruments yield varied results. Additionally, this paper synthesizes the impact of suspended sediment concentration, particle size, shape, temperature, salinity, and organic matter on sediment settling velocity. Future research should focus on innovating new laboratory observation methods for sediment settling velocity and utilizing advanced scientific and technological tools for on-site measurements to provide valuable insights for further investigation into sediment settling velocity.

MICROBIAL AIR POLLUTION IN POLTAVA

Regular monitoring of air quality indicators, including microbial composition, is crucial for public health and should be a cornerstone of national healthcare policy. However, existing scientific literature lacks comprehensive data on microbial air pollution in Ukraine, particularly in Poltava and its surrounding areas. This study aims to assess the level of microbial air pollution across various districts within Poltava city.&#x0D; Materials and methods. The Koch sedimentation method was used to assess the level of microbial air pollution in the districts of Poltava. For this purpose, atmospheric air sampling was taken in park zones of various districts in the city of Poltava during October 2023. For comparison, air samples were taken in deciduous and coniferous forests of villages adjacent to the city. According to the results of cultivation, the total microbial count (TCM) of the air in 1 m3 of each sample was calculated separately.&#x0D; Statistical analysis of the obtained results was carried out using the standard Microsoft Excel 2019 and GraphPad Prism Software 10.1.0 software packages. (US, 2023).&#x0D; Results. The study has revealed the greatest microbial pollution of atmospheric air was found in Pavlenkivskyi Park (Kyiv District, Poltava City). The air quality index of atmospheric air in Corpusnyi Park turned out to be 4 times lower, compared to the air index of the Kyiv district. During the cultivation of atmospheric air samples taken in the Voiniv-Afghantsiv park (Shevchenkivskyi district of the city), the TCM was determined to be 8.2 times lower than that of the Pavlenkivskyi park. Interestingly, the "Peremoha" park (Shevchenkivskyi district) exhibited the lowest levels of microbial contamination. Overall, the Podilskyi district demonstrated favorable air quality indicators, surpassed only by the "Peremoha" park. However, it's important to note the presence of hemolytic streptococci in this district, which poses a potential health risk.&#x0D; Conclusion. The highest level of microbial air pollution has been found in the Kyiv district of Poltava, the lowest level is within the boundaries of the Shevchenkivskyi district on the territory of the "Peremoha" park. Microbiological air quality in Poltava's park areas exhibits an inverse relationship with proximity to the city's central roads.

Air quality assessment in (semi) liquid food packaging environments

This study aimed to assess the prevalence of airborne microorganisms within the packaging areas of (semi) liquid food product facilities, considering the impact of outdoor microbiological air, seasonal fluctuations, rural-urban differences and environmental parameters such as temperature and relative humidity. Additionally, the effectiveness of both natural ventilation and air handling units were evaluated against total viable and non-viable particulate matter.Air samples were collected from the packaging areas of fourteen diverse (semi) liquid food producers and the outdoor environment in Flanders, Belgium, over the course of four separate days from January to September 2022. Airborne microorganisms, including total mesophilic plate count (TMPC) and yeast and mould (Y&M) count, were sampled using impaction and settle plate methods on Plate Count Agar and Rose Bengal Chloramphenicol agar, respectively. Simultaneously, a laser particle counter was used to collect and categorise particles into six size-based channels, while environmental parameters were monitored using a hygrometer.The study revealed a wide range of concentrations of airborne microorganisms across various companies (indoor TMPC ranging from 1.35 ± 0.65 log cfu/m3 to 3.42 ± 0.16 log cfu/m3 and Y&M count ranging from 1.22 ± 0.65 log cfu/m3 to 3.10 ± 0.08 log cfu/m3), irrespective of outdoor air quality. Neither relative humidity nor temperature exhibited any influence on TMPC and Y&M count. Companies equipped with high-efficiency filter air handling unit showed decreased concentrations of airborne microorganisms, although this trend did not align with their total particle counts. Moreover, no correlation was observed between total particle count and either TMPC or Y&M count. Additionally, impaction and sedimentation methods demonstrated a strong correlation.In conclusion, the diversity in airborne microorganism concentrations within food packaging areas is influenced by multiple factors, with air handling unit filters playing a pivotal role. High-efficiency filters were found to reduce microorganism levels, but their impact on total particle counts was less pronounced.