Plastic particles in urban compost and their grain size distribution.

Gathering information on plastic particles in composts and the processes they undergo is important in terms of potentially limiting their further entry into the environment, for example, in improving the fertilising properties of soils. Microplastics (MPs) were determined in composts produced from urban greenery. They are present in decreasing order: polyethylene terephthalate, polystyrene, polyethylene, and polypropylene. The determination of polymers and additives used to improve their properties was performed by pyrolysis and gas chromatography with mass spectrometric detection (Py-GC/MS). Additives and microplastics are most concentrated in composts in the 0.315-0.63 and 0.63-1.25 mm grain size class, together with the carbon contained in the compost dry matter. Additives form 0.11-0.13% of MPs in dry matter of compost. The average concentration of microplastics in the particle size class from 0.63 to 1.25 mm is 2434 ± 224 mg/kg; in the total sample of composts, it is 1368 ± 286 mg/kg of P-MPs. For composts with particle size <2.5 mm, a relationship between the C/N ratio and the plastic particle concentration was statistically significant. It documents a similar behaviour of lignocellulose and plastic particles during the degradation processes. A relationship between the concentration of polymer markers and additives in the compost dry matter and their concentrations in the leachate has been demonstrated. The leachability from compost is higher for additives than for chemical compounds originating from the decomposition of the main components of MPs. The suitability of the use of the compost for agricultural purposes was monitored by the germination index (GI) for watercress. The lowest value of the GI was determined in the particle size class from 0.63 to 1.25 mm. The leachability of polymer markers and additives alone cannot explain the low GI value in this grain size class. The GI value is also influenced by the leachability of chemical compounds characterised by the value of dissolved organic carbon (DOC) and water-leachable nitrogen (Nw). A statistically significant dependence between DOC/Nw and the germination index value was found.

Environmental impact assessment of the coal yard and ambient pollution.

This study investigates the vertical distribution of pollutants emitted from coal yards using unmanned aerial vehicles (UAVs). Vertical concentration measurements of black carbon (BC) and particulate matter (PM) in a range of 1 m to 100 m above ground level (AGL) in the central coal yard showed clear spatial patterns and gradients of these pollutants. In addition, measurements were taken at specific heights (1 m, 30 m AGL, and 60 m AGL) at seven locations approximately 3 km from the yard. Thirteen measurements were carried out during the non-heating period under similar weather conditions. The measured BC concentrations decreased significantly with increasing altitude, with ground-level concentrations reaching 1.88 ± 0.61 µg/m3 and decreasing by over 46% at 80 m AGL. Similarly, PM10 concentrations at 60 m AGL decreased by 21.7%, with values of 25.99 ± 9.24 µg/m3 measured near the ground level and 16.52 ± 8.31 µg/m3 at 60 m AGL. The maximum coal particle pollution from the coal depot ranges from 500 to 1,000 m. The study showed a significant decrease in BC concentrations with height above the coal yard surface. Concentrations of PM10 and PM10-TSP showed a complex distribution influenced by local emissions and long-range particle transport. Meteorological factors, especially wind speed and direction, significantly influenced the pollutant dispersion. In addition, higher pollutant concentrations were measured during dry periods than after rainfall. The findings of this study contribute to a better understanding of the dispersion patterns and potential impacts of coal dust, enabling the implementation of targeted mitigation strategies and improved pollution control measures.

Small-Sided Games versus Continuous Endurance Training in Female Handball Players.

The main aim of the study was to compare the training methods of continuous endurance training versus handball small-sided games (SSGs) in female handball players during the preseason. Eighteen female handball players from a first league in the Czech Republic voluntarily participated in the study. They were divided into two groups (the SSG group [n = 9; age: 21.22 ± 3.03 years] and a running group (RG) [n = 9; age: 23.78 ± 3.77 years]). Both groups continued regular preseason training for six weeks. The SSG group played two small-sided games per week (a total of 12 games during the monitoring period) in their training sessions during the monitored six-week period. The RG ran twice per week, participating in continuous endurance training in the 12 training sessions during the monitored six-week period. Fitness tests (pretest/posttest) were performed prior to the six weeks of intervention and one week afterwards. The order of the fitness tests in sequence was as follows: 20-m and 30-m sprints, a Modified Agility T test (MAT), a Standing Long-Jump Test, ball-throwing velocity, and a Yo-Yo Intermittent Test level 1. In the SSG group, there was a significant improvement in the T test (p = 0.034), ball-throwing velocity (p = 0.019), and the Yo-Yo IR1 (p = 0.003) performance. The RG showed a significant improvement in the Standing Long-Jump Test (p = 0.049), ball-throwing velocity (p = 0.003), and the Yo-Yo IR1 (p = 0.003) performance. In conclusion, the SSGT method had a positive effect on female players' MAT, ball-throwing velocity and YoYo IR1 results, and the CERT method had a significant effect only on the YoYo IR1 results. Handball SSGs are a more suitable training method due to exercise specificity.

The use of polymer compounds in the deposits from the combustion of briquettes in domestic heating as an identifier of fuel quality.

The utilisation of waste wood from furniture production brings new problems connected with an incomplete thermochemical decomposition of additives (chemicals for improving properties of plastics) in small heating with the addition of sources. Unique organic compounds produced by the combustion of waste wood allow the identification of the type of fuel. The organic compounds contained in the char deposits were analysed by pyrolysis gas chromatography with mass spectrometry. The deposits from the combustion of briquettes from furniture production contain organic compounds originating by decomposition of phenolic resins, aminoplasts (urea-formaldehyde, resorcinol-formaldehyde and melamine), polyurethanes and wood glue. Additives contained in the deposits include plasticisers such as phthalates (DEHP, dibutyl phthalate and diisobutyl phthalate), flame retardants (2-propanol, 1-chlorophosphate (3:1) and p-terphenyl). Deposits from the combustion of briquettes from virgin wood do not contain these compounds. The total amount of compounds identified in the deposits from the boiler, which do not come from virgin wood combustion, varies in the range between 4.25 and 6.25 g/kg. Phthalates (55.5%) and PVAc adhesives (18.6%) are the main anthropogenic compounds in the deposits from domestic boilers.

The Impact of Distance Education during the COVID-19 Pandemic on Physical Activity and Well-Being of Czech and Polish Adolescents.

BACKGROUND: The aim of this study was to identify the changes in the structure of weekly physical activity (PA) and well-being among adolescent boys and girls between habitual education (HE) and distance education (DE) during the pandemic in secondary schools. METHODS: The research was carried out in 12 Czech and 18 Polish schools during 2019 to 2020 academic session for HE and 2020 to 2021 academic session for DE. The research involved 723 girls and 626 boys aged 15 to 18 years. The structure of the weekly PA was assessed using the International Physical Activity Questionnaire-Long Form, while well-being was assessed using the World Health Organization-5 Well-Being Index. RESULTS: There was a statistically significant decrease of PA among boys in school PA, transportation PA, recreation PA, vigorous PA, moderate PA, walking, and overall weekly PA during the DE resulting from the pandemic. In girls, during DE, a decrease was observed in school PA, vigorous PA, and overall PA. During DE, a high level of well-being was reported by only 34.9% of girls (43.8% during HE) and 50% of boys (65.6% during HE). CONCLUSIONS: The observed low PA and high incidence of depressive symptoms in adolescents in distance education during pandemic constraints are a challenge for schools to change in supporting physical activity, eliminating similar negative impacts on school life in the future.

Differences and Associations between Physical Activity Motives and Types of Physical Activity among Adolescent Boys and Girls.

Interventions aimed at motivation for physical activity (PA) are mostly beneficial, but the effects on preventing the decrease in PA are not entirely clear, especially in girls. The main aim of this study was to identify the differences and associations between PA motives and types of PA in boys and girls and between low and high motivated boys and girls. Another aim is to identify the types of motivation and PA that increase the likelihood of achieving PA recommendations and to propose ways of increasing PA among low motivated adolescents. The research carried out before the COVID-19 pandemic (2010-2019) and involved 2,149 Czech and 1,927 Polish adolescents aged 15-19 years. The International Physical Activity Questionnaire-Long Form was used to identify the level of PA types, while PA motivation was examined through the Motives for Physical Activities Measure-Revised. During the ten years, a decline was observed in enjoyment, fitness, and social motives. An increase in appearance motives was observed in girls, while no significant changes were seen in boys. Boys showed a higher motivation for PA than girls in enjoyment, competence, fitness, and social motives, while girls were high motivated in appearance motives. The greatest statistically significant differences between low and high motivated individuals were found in the associations between recreation/vigorous PA and between all types of motivation in boys and girls in both countries. The strongest associations in both genders were observed between enjoyment/competence motives and recreation/vigorous PA. Respecting and using the associations between the types of PA motives and types of PA in low and high motivated boys and girls can support feelings of PA enjoyment, increase PA, support the achievement of PA recommendations, and positively affect adolescents' healthy lifestyles.

The quality of composts prepared in automatic composters from fruit waste generated by the production of beverages.

Ensuring the processing of food waste from the production of food and beverages intheautomatic composters can be difficult because of the physicochemical properties of input raw materials. Very often, the final product does not meet the requirements forcomposts according to the European Compost Network. Optimisation of input food waste from theproduction ofbeverages was performed by the addition of the bulk materials such assawdust and clay minerals (bentonite). Toxicity of the compost is caused by organic compounds with polar and non-polar properties. These compounds belong to the groups ofalcohols, aldehydes and ketones, carboxylic acids, tannin, and phenols, coumarins and terpenes. Phytotoxicity is mostly influenced by the group of terpenes. The addition ofsawdust used as bulking agent decreases the concentrations of almost all chemical compounds. Thegroup of tannin and compounds containing phenols represents an exception because these compounds are released from sawdust.

Environmental risks related to organic compounds from the combustion of paper briquettes in domestic boilers.

Environmental risks connected with the combustion of paper/cardboard briquettes are still not sufficiently known. This paper aims to bring attention to the risks related to the utilisation of paper briquettes in local boilers and to characterise these risks by means of the identification of organic compounds in deposits from exhaust flues. The identification of the chemical compounds was performed by pyrolysis gas chromatography with mass spectrometric detection. Paper/cardboard briquettes contain 119 compounds of biogenic origin derived from major biomass components and 53 additives. Additives are used both for improving the properties of paper and in printing inks. By burning the paper briquettes, the same 53 compounds from the additive group were caught in the deposits from the flue gas pathway, occurring in the range of 1-10% of the concentration of individual compounds (additives) contained in the input fuel. Compounds that are very stable during the combustion process have an enrichment factor (EF) >30, which corresponded to approximately 3% of the additive capture in deposits. The highest values were found for plasticisers (phthalates). Many of the primary organic compounds contained in the input raw material do not decompose during combustion and can have adverse effects on human health.

A comprehensive interdisciplinary view at the Return to Sport after COVID-19 infection.

The COVID-19 pandemic has affected the whole world. It applies to all age and social groups. It is no different with athletes. So far, we cannot say for sure what the long-term consequences of SARS-CoV-2 infection are. Recent evidence, however, suggests that we should be very careful when returning to sports. After self-isolation, the athlete should undergo a Preparticipation Physical Examination and then pay attention to the gradual dosing of the load to prevent complications. Lifestyle changes and care for the mental health of athletes are also necessary during the illness. In this work, we present a comprehensive methodology for returning to sports after COVID-19 for medical and coaching teams caring for athletes divided according to the course of the disease. In scientific literature, similar algorithms are called "Return to Play" or "Return to Sport". Creating an exact algorithm can make the Return to Play process more efficient and safer. However, increased attention still needs to be paid to certain organ systems and specific symptoms that could indicate long-term consequences to the new type of coronavirus.

Does Vigorous Physical Activity Contribute to Adolescent Life Satisfaction?

BACKGROUND: Physical and mental health are the basis of life satisfaction (LS), even during adolescence. The aim of this study was to identify the associations between LS and types of physical activity (PA) in Czech and Polish boys and girls. METHODS: The research involved 933 girls and 663 boys aged 15-19 years. LS was diagnosed using the Bern Subjective Well-Being Questionnaire and the WHO-5 Well-Being Index. The International Physical Activity Questionnaire-long form (IPAQ-LF) questionnaire was used to identify the types of weekly PA. RESULTS: Adolescents with the highest LS had more recreational, moderate, vigorous, and total weekly PA. The strongest associations between LS and PA were in the Czech and Polish boys and girls who participated in vigorous PA (VPA). The recommendations for VPA were fulfilled by 45% of Czech and 46% of Polish boys and 40% of Czech and 50% of Polish girls, with the highest LS. The most significant positive moderator between LS and PA was participation in organized PA. Boys with the highest LS were 1.94 times more likely to meet the weekly recommendation of VPA than boys with the lowest LS. Similarly, girls with the highest LS were 1.77 times more likely to meet these recommendations. CONCLUSIONS: Promoting both current subjective well-being and organized PA, with an emphasis on achieving the VPA recommendations, may support general LS and a healthy lifestyle in adolescents.

The potential environmental risks of the utilization of composts from household food waste.

Modern technologies (especially with the help of autonomous measurement and control systems) introduced automatic composters for the disposal of household food waste production. Environmental risks connected with the utilization of these composts can be characterized by the high electrical conductivity caused by a presence of sodium chloride in food. Electrical conductivity influences the ecotoxicity of the composts. The presence of pesticides in composted food also represents an important environmental problem. The following pesticides were found in compost samples from household food waste: 1,3,5-triazine, methyl trithion, bifenthrin, bifenox, carbophenothion, pirimicarb, dioxacarb, desmetryn. Pesticide content in composts varied from 0.3 to 16.3 µg/kg, the average value being 30.4 ± 10.1 µg/kg dry matter. The higher decomposition was found of "modern" pesticides in the composters. The removal of salts can ensure that inhibition will be < 30% while washing with the ratio of 1:3 will result in the inhibition < 5%. However, this way of processing is not effective for other organisms-Poecilia reticulata (mortality 100%) and Daphnia magna (immobilisation 100%) using this procedure as well as washing of the compost in the ratio 3:1.

Spent coffee ground as renewable energy source: Evaluation of the drying processes.

Spent coffee ground (SCG) is an environmental nuisance material, but, if appropriately processed it can be converted into pellets, and thus, used as an energy source. The moisture content of the final product should be below 10%, to ensure safe storage, and elimination of microorganism growth (particularly moulds). The present study aims to identify the optimal drying process for removing moisture from SCG and to investigate changes to the composition of SCG due to drying, at temperatures around 75 °C, so that the dried SCG to qualify as renewable energy source. Three drying processes were employed for SCG drying (with initial moisture content of about 65%): oven drying, solar drying and open air sun drying, while SCG samples were placed in aluminium trays with thicknesses of 1.25, 2.5 and 4 cm. Based on the experimental results for SCG samples with thickness 2.5 cm, the open air sun drying process required 10 h to reach final moisture content of 37%, while solar drying achieved 10% moisture content in 10 h and oven drying achieved 7% moisture content in 6 h. The solar drying process proved as the most advantageous, due to low energy requirements and adequate quality of dried SCG. Also, experiments indicated that SCG storage at "normal room conditions" resulted to equilibrium moisture content in SCG of 8%, regardless of the initial moisture content. Furthermore, instrumental analyses of the SCG, revealed changes to its composition for a number of chemical groups, such as aldehydes, ketones, phytosterols, alkaloids, lactones, alcohols, phenols, pyrans and furans, among others. It was also identified that the SCG colour was affected due to the drying process.

Physical Activity of Secondary School Adolescents at Risk of Depressive Symptoms.

BACKGROUND: The aim of the study is to analyze the associations between depressive symptoms (DS), well-being and different types of physical activity (PA) in adolescents. METHODS: Overall, 368 girls and 228 boys aged 15-19 years were involved in the research. To explore the composition of weekly PA, we used the IPAQ-Long questionnaire, and a pedometer was used to monitor weekly PA. The prevalence of DS was diagnosed by the Bern Subjective Well-Being Questionnaire and the WHO-5 Well-Being Index. RESULTS: The girls and boys who reported the most DS and the lowest level of well-being had significantly less weekly recreational PA. The girls who reported the fewest DS had a 2.12 times greater odds of meeting the 11,000 steps/day recommendation than did the girls with the most DS, whereas we did not detect statistically significant differences in rates of meeting the recommendation in the boys with distinct levels of DS. CONCLUSIONS: The study confirms the stronger negative associations between DS and PA, especially among girls. The greatest opportunities for behavioral change in adolescents at the highest risk of DS are in the promotion of recreational PA.

Variation of the chemical composition of street dust in a highly industrialized city in the interval of ten years.

Street dust can be re-suspended into the atmosphere by wind and vehicle passage in an urban area. Street dust is affecting the environmental quality of the atmosphere and human health. A detailed study was conducted to determine the changes in concentrations of heavy metals and magnetic susceptibility by comparison of samples of street dust obtained in the years 2008 and 2018 at the same localities. An amount of dust per m2 of road area was highly variable for individual localities (47 g/m2 - 1.37 kg/m2), with arithmetic mean (229.7 ± 85.97 g/m2) in the year 2018. Silt particles in street dust (<0.063 mm) represented approx. 15-20%, sand particles approx. 63-70% and gravel 10-20%. Iron (5-6%) has significant concentrations in street dust. The highest concentrations are represented by the series Mn ˃ Zn ˃ Cr ˃ Cu ˃ Pb ˃ Ni. Comparison of metal concentrations in the years 2008 and 2018 showed a comparable level of iron and a lower level of lead. The significant enrichment was found for Cu, Cr and Zn expressed by enrichment factor in the range from 5 to 20. High values of magnetic susceptibility of street dust are caused by metallurgy. Metals except Cu are bound in magnetic particles and have a high correlation coefficient with magnetic susceptibility.

Academic Stress and Physical Activity in Adolescents.

The issue of work-related mental health needs to be addressed at the school level. The aim of this study was to explore the associations between academic stress (AS) of adolescent boys and girls and their physical activity (PA) during recesses and after school and to propose measures to promote the adoption of lifelong healthy working habits. Adolescents from 16 schools in the Czech Republic and 6 schools in Poland participated in the study (187 boys and 339 girls). Monitoring of PA and cognitive stress was conducted during one school day. We used ActiTrainer accelerometers to monitor PA and physical inactivity. Data on time of PA and self-reported AS in school lessons were collected using recording sheets. We split the participants into two groups: those without a self-reported stressor and those who indicated one or more stressors. Differences in overall PA during recesses, as well as after-school PA, between boys with and without AS were not statistically significant for any PA characteristics. We observed similar results for girls. Repeated measures ANOVA confirmed that differences in PA (steps/hour) during recesses following particular lessons between participants with and without AS were not statistically significant in boys or girls (F (4,1612) = 1.83, p=0.121 , η p 2=0.005). It is noteworthy that girls with AS were statistically significantly more likely to meet the 6000 steps after school time recommendation (39%) than girls without AS (18%; p < 0.001). The study did not confirm the assumption that adolescents reporting AS have less PA during recesses or even after school than adolescents without AS. However, the overall low PA of adolescents during recesses and after school highlights the need to compensate for AS by adequate PA. This is especially true for adolescents with recurrent AS in several consecutive lessons.

Active Travel of Czech and Polish Adolescents in Relation to Their Well-Being: Support for Physical Activity and Health.

The adoption of active travel (AT) habits in adolescence, supported by positive emotions, increases the chances of a lifelong positive attitude towards AT. The aim of this study was to assess the associations between active travel and well-being (WB), and to estimate the share of AT in weekly physical activity (PA) and its contribution to meeting the weekly PA recommendations in adolescents. The International Physical Activity Questionnaire-long form and the WHO-5 questionnaire were used to assess the level of AT, weekly PA and well-being of 2805 adolescents from 36 Czech and 39 Polish schools. A higher rate of AT is only significantly associated with higher well-being in girls. However, meeting AT recommendations in combination with higher WB increased the likelihood of meeting the weekly PA recommendations in both girls and boys. AT accounts for 22.5% of weekly PA of Czech (Polish 24.2%) boys. Concerning girls, it accounts for 24.9% of weekly PA in the Czech Republic and 24.5% in Poland. Meeting AT recommendations should be part of comprehensive school-based PA programs. State, school and municipal policies in the Central European region should pay more attention to the improvement of WB and the built environment for AT in secondary school adolescents.

The possibilities to identify combusted fuel based on an analysis of ash from local heating.

Combustion of undesirable components with a high calorific value (waste: plastics, rubber, chipboard, plywood etc.) contribute to an increased emissions of PM particles. The possibility of identification of non-desirable fuels was verified by analysis of unburned carbon from bottom ash by means of pyrolysis-GC/MS. Compounds derived from thermal conversion of main wood components in the unburned carbon are formed by aldehydes, ketones, alkanes, alkenes, alkanoates, polycyclic aromatic hydrocarbons, compounds containing benzene, compounds containing phenol and nitrogen. Unburned carbon from plywood/chipboard contains compounds with nitrogen (heterocyclic and aliphatic) in increased concentrations (33-51 ng/mg) compared with unburned carbon from pure wood (7-12 ng/mg). The concentrations increased almost two times were proved for compounds containing phenols in unburned carbon from wood composite. Total amount of determined organic compounds is also almost two times higher than that contained in unburned carbon from wood. The indication of waste wood combustion from unburned carbon is possible using the ratio: phenol/(2-methylphenol+4-methylphenol).

Effects of Environmental Context on Physiological Response During Team Handball Small Sided Games.

This study examined the distance covered and physiological effects of altering the number of players during small-sided games (SSG) in team handball. Twelve professional female handball players [24.6±3.7 years, 172±6.2 cm, 68.2 ± 9.9kg, 22.7 ± 2 kg/m2] participated in this study. The SSG were played, first with five on each side (SSG 5), then four (SSG 4), then three (SSG 3). Each game was four minutes long, followed by three minutes of rest. The distance covered and time spent in four speed zones (based on player movement speed) were selected for analysis: Zone 1 (0-1.4 m/s), Zone 2 (1.5-3.4 m/s), Zone 3 (3.5-5.2 m/s), and Zone 4 (>5.2 m/s). Statistically significant differences were found in Zone 2, between conditions SSG 3 and SSG 4 (p=.049,ω2= .32). The highest average heart rate (HR) occurred during SSG 3. Average HR between SSG 3 (89.7 % HRmax) and SSG 5 (87.8 % HRmax) (p= .04, ω2= .26) were also significantly different. Participant HR response between the speed zones was not statistically significant. HR response was negatively correlated with the number of players within the SSG condition. Statistically significant results were found for RPE between SSG 3 and the other two SSG conditions (SSG 4, p = .01, and SSG 5, p = .00). These results indicate that changing the number of SSG players can be used to manipulate the physiological response during handball training.

Mental Load and Its Compensation by Physical Activity in Adolescents at Secondary Schools.

AIM: Sedentary behaviour and increasing mental load in adolescents is one of the major health problems of the contemporary youth. The aim of the study is to analyze the associations between mental load and physical activity (PA) in adolescents in school-day segments. METHODS: 381 adolescents (120 boys, 261 girls) took part in the research which was conducted in 19 secondary schools in the Czech Republic. Participants throughout the whole day (1-3 days) wore an ActiTrainer accelerometer that monitors PA and heart rate (HR). The reports covered 727 school days. The participants were divided into two groups with lower and higher mental load. RESULTS: Boys and girls with higher mental load in lessons do not compensate this load in neither volume nor intensity of PA during recess in greater amount than those who had lower mental load. In the individual school-day segments (apart from the time before school) no significant differences between the groups were found. CONCLUSION: When creating a habit of immediate compensation for mental load in lessons by PA, it is necessary to pay attention to boys and girls with higher mental load in lessons. The adoption of the habit should be supported by adequate physical literacy of both students and teachers and by changes in the school programme.