Air pollution exposure is harmful to human health and reducing it at the level of an individual requires measurements and assessments that capture the spatiotemporal variability of different ...microenvironments and the influence of specific activities. In this paper, activity-specific and general indoor and outdoor exposure during and after a period of high concentrations of particulate matter (PM), e.g., an atmospheric thermal inversion (ATI) in the Ljubljana subalpine basin, Slovenia, was assessed. To this end, personal particulate matter monitors (PPM) were used, worn by participants of the H2020 ICARUS sampling campaigns in spring 2019 who also recorded their hourly activities. ATI period(s) were determined based on data collected from two meteorological stations managed by the Slovenian Environmental Agency (SEA). Results showed that indoor and outdoor exposure to PM was significantly higher during the ATI period, and that the difference between mean indoor and outdoor exposure to PM was much higher during the ATI period (23.0 µg/m3) than after (6.5 µg/m3). Indoor activities generally were associated with smaller differences, with cooking and cleaning even having higher values in the post-ATI period. On the other hand, all outdoor activities had higher PM values during the ATI than after, with larger differences, mostly >30.0 µg/m3. Overall, this work demonstrated that an individual-level approach can provide better spatiotemporal resolution and evaluate the relative importance of specific high-exposure events, and in this way provide an ancillary tool for exposure assessments.
•Riverbed biofilms were examined in situ during colonization and over four seasons.•The impact of pollution with PET fibres was investigated.•PET inhibited biofilm activity and affected ...community-level metabolic profiles.•Utilization of synthetic polymers was higher in sediments with more PET fibres.
Worldwide, the production of plastics is increasing, and plastic pollution in aquatic environments is a major global concern. Under natural conditions, plastic weathers to smaller pieces called microplastics (MP), which come in various shapes, with fibers often being the most common in freshwater sediments. The hyporheic zone, an ecotone between surface and groundwater, is important for the transport and fate of all MP particles. The main metabolic pathways in rivers take place in the hyporheic zone and are driven by a diverse microbial community. The objective of this study was to investigate in situ whether the presence of PET fibers in riverbed sediments affects patterns of colonization and the seasonal dynamics of microbial metabolic activities in the hyporheic zone. The effects of the presence of PET on microbial metabolism were evaluated in situ over a month (colonization study) and over a year (seasonal study) by measuring total protein content (TPC), and microbial respiration as respiratory electron transport system activity (ETSA) and by community-level physiological profiling (CLPP). Additionally, PET fibers were examined under a scanning electron microscope (SEM), and isotopic analysis (δ13C) of PET was performed after one year of exposure to field conditions. The findings demonstrated that during colonization and biofilm formation, and also over the seasons, the date had a large and significant impact on biofilm growth and activity, while PET presence slightly suppressed microbial biomass (TPC) and respiratory activity (ETSA). Overall microbial activity was repressed in the presence of PET fibers but there was a higher capacity for the utilization of complex synthetic polymer substrates (i.e., Tween 40) which have previously been linked to polluted environments. SEM micrographs showed diverse microbial communities adhering to PET fibers but little surface deterioration. Similarly, isotopic analysis suggested little deterioration of PET fibers after one year of in situ conditions. The study indicated that PET fibers present in riverbed sediments could have impacts on the metabolic functioning in rivers and thus affect their self-cleaning ability.
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Epidemiological and exposure studies concerning particulate matter (PM) often rely on data from sparse governmental stations. While low-cost personal monitors have some drawbacks, recent developments ...have shown that they can provide fairly accurate and fit-for-purpose data. Comparing a stochastic, i.e., agent-based model (ABM), with environmental, biometric and activity data, collected with personal monitors, could provide insight into how the two approaches assess PM exposure and dose. An ABM was constructed, simulating a PM exposure/dose assessment of 100 agents. Their actions were governed by inherent probabilities of performing an activity, based on population data. Each activity was associated with an intensity level, and a PM pollution level. The ABM results were compared with real-world results. Both approaches had comparable results, showing similar trends and a mean dose. Discrepancies were seen in the activities with the highest mean dose values. A stochastic model, based on population data, does not capture well some specifics of a local population. Combined, personal sensors could provide input for calibration, and an ABM approach can help offset a low number of participants. Implementing a function of agents influencing others transport choice, increased the importance of cycling/walking in the overall dose estimate. Activists, agents with an increased transport influence, did not play an important role at low PM levels. As concentrations rose, higher shares of activists (and their influence) caused the dose to increase. Simulating a person's PM exposure/dose in different scenarios and activities in a virtual environment provides researchers and policymakers with a valuable tool.
•Results from ABM model and personal monitors show similar trends and mean PM doses•Largest discrepancies in activities with the highest mean dose•Activists influencing other agents' mode of transport not relevant at low PM levels•Higher PM concentrations and higher share of activists increases dose
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•Representativity of precipitation stable isotope monitoring network is evaluated.•Unrepresented and redundantly covered areas in Slovenia and Hungary revealed.•The national networks ...were evaluated separately and combined with neighboring ones.•Mutual information exchange among the networks increases δ18O estimation precision.•The current research is the first example on such a geostatistical assessment.
A detailed knowledge of the stable isotope signature of precipitation is the basis of investigations in a variety of scientific fields and applications. To obtain robust and reliable results, the representativity of the currently operating (at least, as of 2018) precipitation stable isotope monitoring stations across Slovenia (n = 8) and Hungary (n = 9) was evaluated on the basis of amount-weighted annual averages with the aim of revealing any redundantly (i.e. over-) represented or un(der)represented areas. In the case of the latter, optimal locations for additional sites were suggested in Slovenia and Hungary. The networks of both countries are design-based systems that need to be fine-tuned for long-term optimized operation. The evaluation of the monitoring network was performed taking into consideration the stations operating in Slovenia and Hungary, as well as closely situated ones operating in neighboring countries. The evaluation was carried out in nine different combinations, using spatial simulated annealing, with regression kriging variance as a quality measure. The results showed that (i) there are over- and un(der)represented areas in the network, an issue requiring remedial action, (ii) the mutual information exchange of the precipitation stable isotope monitoring networks of Slovenia and Hungary increases the precision of precipitation δ18O estimation by ~0.3‰ in a 15–30 km wide zone near the borders, and (iii) by an even greater degree in the neighboring countries’ stations. The current research may be termed pioneering in the matter of the detailed geostatistical assessment of spatial representativity of a precipitation stable isotope monitoring network, and as such, can serve as an example for future studies aiming for the spatial optimization of other regional precipitation stable isotope monitoring networks.
Multi-elemental (Ca, Mg, Na, K, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Tl, V, and Zn) and stable isotope (i.e., δ2H, δ18O, and δ13CDIC) analyses were performed on 13 (8 ...Slovenian and 5 imported) bottled mineral and spring waters from the Slovenian market. In addition, 87Sr/86Sr isotope ratios were determined for the first time. In all analyzed bottled waters, the majority of elements were present although in low concentrations, and according to EU legislation, all were suitable for human consumption. Also, concentrations of major elements (Ca, Mg, Na, and K) were in general agreement with the values reported on the bottle labels, and any differences were the consequence of the natural variability of the water source used for bottling. The exception was one spring water, for which the source location changed, which was confirmed by the δ2H, δ18O, and δ13CDIC data. Two mineral waters had distinctive elemental compositions due to the particular geology of their recharge areas. The δ13CDIC was also investigated to decipher the carbonate contribution in the bottled waters. The results suggest that dissolution of carbonates and non-equilibrium carbonate dissolution by carbonic acid produced from soil zone CO2 are the predominant geochemical processes influencing the δ13CDIC values of bottled water.
Integrity of freshwater surface- and groundwater ecosystems and their ecological and qualitative status greatly depends on ecological processes taking place in streambed sediments overgrown by ...biofilm, in the hyporheic zone (HZ). Little is known about the interactions and effects of multiple stressors on biologically driven processes in the HZ. In this study, machine learning (ML) tools were used to provide evidence-based information on how stressors and ecologically important environmental factors interact and drive ecological processes and microbial biomass. The ML technique of decision trees using the J48 algorithm was applied to build models from a data set of 342 samples collected over three seasons at 24 sites within the catchments of five gravel-bed rivers in north-central Slovenia. Catchment-scale land use data and reach-scale environmental features indicating the HZ morphology and physical and chemical characteristics of water were used as predictive variables, while respiration (R) and microbial respiratory electron transport system activity (ETSA) were used as response variables indicating ecological processes and total protein content (TPC) indicating microbial biomass. Separate models were built for two HZ depths: 5–15 cm and 20–40 cm. The models with R as a response variable have the highest predictive performance (67–89%) showing that R is a good indicator of complex environmental gradients. The ETSA and TPC models were less accurate (42–67%) but still provide valuable ecological information. The best model show that temperature when combined with selected water quality elements is an important predictor of R at depth of 5–15 cm. The ETSA and TPC models show the combined effects of temperature, catchment land use and selected water quality elements on both response variables. Overall, this study provides new knowledge on how ecological processes occurring in the HZ respond to catchment and reach-scale variables, and provides evidence-based information about complex interactions between temperature, catchment land use and water quality. These interactions are highly dependent on the selection of the response variable, i.e., each response variable is influenced by a specific combination of predictive environmental variables.
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•Multiple stressors effects on hyporheic zone were studied using machine learning.•Biological response in hyporheic zone was well predicted by decision tree models.•Models with respiration as response variable had the highest predictive performance.•Temperature, land use and water quality jointly defined hyporheic zone response.•Models provided new knowledge on interactions among stressors.
To gain a comprehensive understanding of the effects of air pollution on human health, it is imperative to assess exposure at an individual level. This necessitates the use of personal monitoring ...equipment that can record exposure in real-time while simultaneously capturing relevant biometric data and the activities being undertaken by the individual. The dataset presented herein encompasses data from five distinct sources, collected in Ljubljana, Slovenia:
(a) Questionnaire filled out by all participants for general information, i.e., age, height, weight.
(b) Time Activity Diaries maintained by participants.
(a) A personal particulate matter sensing unit that recorded data on PM1, PM2.5, PM10, ambient temperature, relative humidity, and geographical location coordinates.
(b) A wrist-worn Smart Activity Tracker that captures heart rate and movement data.
(c) An Indoor Air Quality sensing unit, specifically the uHoo device, which measures parameters such as Temperature, Relative Humidity, CO2, TVOC, PM2.5, CO, O3, NO2, and Air Pressure.
Participants were equipped with these sensors for two separate 1-week durations in 2019, specifically during a heating season and a non-heating season, as part of the ICARUS H2020 project. Throughout these periods, data was recorded at a 1-minute resolution. Additionally, based on the collected data, an inhalation rate was determined, and an inhalation adjusted exposure (or intake dose) was computed. The richness and granularity of this dataset not only offer insights into the direct health implications of air pollution exposure but also provide a valuable resource for urban planners, environmental scientists, and policymakers aiming to design healthier living environments and implement effective air quality regulations.
Groundwater is a valuable source of water for human consumption, and its quality is a current issue worldwide. Understanding carbon and water cycling presents the basis of biogeochemical reactions ...occurring in the aquifer; therefore, understanding their interaction is imperative for sustainable water management. In the paper, this interaction was investigated within the complex surface water (SW)–groundwater (GW) system in the Varaždin region (Croatia) by using a multi-parameter approach: δ13CDIC values, carbon species (DIC, DOC), δ18O and δ2H values, geochemical indicators (T, pH, DO, EC), and δ13C measurements in solids. Both δ18O/δ2H and δ13CDIC were recognized as good indicators to differentiate shallow and deep GW. Transit time of water (TT) was evaluated as an important parameter in controlling carbon cycling within the SW–GW system. Shallow GW is characterized by shorter TT, seasonal changes in carbon species and δ13CDIC, and lower possibility of carbon capture in the system. Deep GW has longer TT without pronounced seasonal changes in carbon species and δ13CDIC. The conceptual model of the carbon cycle revealed major sources and sinks of CO2 in the study area. Our results suggest that GW acts as both source and sink for CO2, depending on the prevailing geochemical process. Surface waters are primarily a source of CO2, excluding the gravel pit, which acts primarily as a sink for CO2. Our study shows that the current SW–GW dynamics regulate carbon balance without having negative impacts on groundwater quality but also demonstrates that implementing carbon cycle in water management studies is of vital importance for sustainable use of groundwater.
It is generally observed that precipitation is gradually depleted in 18O and 2H isotopes as elevation increases (‘altitude’ effect) or when moving inland from seacoasts (‘continental’ effect); the ...regionally accurate estimation of these large-scale effects is important in isotope hydrological or paleoclimatological applications. Nevertheless, seasonal and spatial differences should be considered. Stable isotope composition of monthly precipitation fallen between January 2016 and December 2018 was studied for selected stations situated along an elevation transect and a continental transect in order to assess the isotopic ‘altitude’ and ‘continental’ effects in modern precipitation across the Adriatic–Pannonian region. Isotopic characteristics argue that the main driver of the apparent vertical depletion of precipitation in heavy stable isotopes is different in summer (raindrop evaporation) and winter (condensation), although, there is no significant difference in the resulting ‘altitude’ effect. Specifically, an ‘altitude’ effect of −1.2‰/km for δ18O and −7.9‰/km for δ2H can be used in modern precipitation across the Adriatic–Pannonian region. Isotopic characteristics of monthly precipitation showed seasonally different patterns and suggest different isotope hydrometeorological regimes along the continental transect. While no significant decrease was found in δ18O data moving inland from the Adriatic from May to August of the year, a clear decreasing trend was found in precipitation fallen during the colder season of the year (October to March) up to a break at ~400 km inland from the Adriatic coast. The estimated mean isotopic ‘continental’ effect for the colder season precipitation is −2.4‰/100 km in δ18O and −20‰/100 km in δ2H. A prevailing influence of the Mediterranean moisture in the colder season is detected up to this breakpoint, while the break in the δ18O data probably reflects the mixture of moisture sources with different isotopic characteristics. A sharp drop in the d-excess (>3‰) at the break in precipitation δ18O trend likely indicates a sudden switch from the Mediterranean moisture domain to additional (mainly Atlantic) influence, while a gradual change in the d-excess values might suggest a gradual increase of the non-Mediterranean moisture contribution along the transect.
The Varaždin aquifer is the only source of drinking water for inhabitants of the Varaždin County. In the last decades, groundwater contamination with nitrate has become an increasing problem. ...Therefore, there is a need to define the origin of nitrate as the first step in groundwater remediation. The data in this article consist of δ18O and δ15N values in nitrate in groundwater, and δ15N in solid matter. Groundwater was sampled in the period from April 2018 to December 2019 at 10 different sites by pumping the wells, and directly in the gravel pit in Šijanec. Representative solid samples of plants, soil, manure, and synthetic fertilizers were collected from arable land in two field campaigns (July and October 2019). The presented dataset can be used as a baseline for identification of nitrate sources in groundwater and possible nitrate attenuation processes. The data is related to the research article “Tracking the nitrogen cycle in a vulnerable alluvial system using a multi proxy approach: case study Varaždin alluvial aquifer, Croatia.” 1.
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