The atmosphere is the major contributor of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Baltic Sea environment. In this study, we investigated the potential of using metals along with PCDD/Fs as markers of important emission sources of PCDD/Fs in air. The air concentrations of PCDD/F congeners (n = 17), other persistent organic pollutants (n = 8) and metals (n = 16) were determined in summer and winter air using high volume samplers at a rural field station (Aspvreten, Sweden) located close to the Baltic Sea coast. During winter, PCDD/F levels were on average 20 times higher than in summer (5.1 ± 5.8 fg toxicity equivalents (TEQ) m-3 and 0.26 ± 0.18 fg TEQ m-3, respectively) mostly due to a higher fraction of PCDFs. The increased levels of PCDD/Fs were pronounced mainly in air masses that had travelled from southern (S) and eastern (E) compass sectors. A principal component analysis (PCA) of metal levels in Scots pine (Pinus sylvestris) needles sampled to reflect various air emission source types helped to identify potential marker metals for selected known atmospheric emission sources of PCDD/Fs and to rank among the candidate source types. Brown coal burning, domestic burning and heavy oil burning appeared to be the source types that contribute most of the PCDD/Fs in Baltic Sea air. The current study demonstrates a successful approach for source tracing of PCDD/Fs in air, where integrated indices from seasonal and spatial patterns of PCDD/Fs as well as metal source markers were used to trace and rank sources.
- MeSH
- Principal Component Analysis MeSH
- Atmosphere chemistry MeSH
- Pinus sylvestris chemistry MeSH
- Metals analysis MeSH
- Air Pollutants analysis MeSH
- Plant Leaves chemistry MeSH
- Environmental Monitoring methods MeSH
- Oceans and Seas MeSH
- Polychlorinated Dibenzodioxins analysis MeSH
- Dibenzofurans, Polychlorinated analysis MeSH
- Seasons MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Oceans and Seas MeSH
- Sweden MeSH
- Names of Substances
- Metals MeSH
- Air Pollutants MeSH
- Polychlorinated Dibenzodioxins MeSH
- Dibenzofurans, Polychlorinated MeSH
BACKGROUND: Contact tracing is one of the most effective non-pharmaceutical interventions in the COVID-19 pandemic. This study uses a multi-agent model to investigate the impact of four types of contact tracing strategies to prevent the spread of COVID-19. METHODS: In order to analyse individual contact tracing in a reasonably realistic setup, we construct an agent-based model of a small municipality with about 60.000 inhabitants (nodes) and about 2.8 million social contacts (edges) in 30 different layers. Those layers reflect demographic, geographic, sociological and other patterns of the TTWA (Travel-to-work-area) Hodonín in Czechia. Various data sources such as census, land register, transport data or data reflecting the shopping behaviour, were employed to meet this purpose. On this multi-graph structure we run a modified SEIR model of the COVID-19 dynamics. The parameters of the model are calibrated on data from the outbreak in the Czech Republic in the period March to June 2020. The simplest type of contact tracing follows just the family, the second tracing version tracks the family and all the work contacts, the third type finds all contacts with the family, work contacts and friends (leisure activities). The last one is a complete (digital) tracing capable of recalling any and all contacts. We evaluate the performance of these contact tracing strategies in four different environments. First, we consider an environment without any contact restrictions (benchmark); second with strict contact restriction (replicating the stringent non-pharmaceutical interventions employed in Czechia in the spring 2020); third environment, where the measures were substantially relaxed, and, finally an environment with weak contact restrictions and superspreader events (replicating the situation in Czechia in the summer 2020). FINDINGS: There are four main findings in our paper. 1. In general, local closures are more effective than any type of tracing. 2. In an environment with strict contact restrictions there are only small differences among the four contact tracing strategies. 3. In an environment with relaxed contact restrictions the effectiveness of the tracing strategies differs substantially. 4. In the presence of superspreader events only complete contact tracing can stop the epidemic. INTERPRETATION: In situations, where many other non-pharmaceutical interventions are in place, the specific extent of contact tracing may not have a large influence on their effectiveness. In a more relaxed setting with few contact restrictions and larger events the effectiveness of contact tracing depends heavily on their extent.
- Keywords
- Agent-based model, Epidemiological model, Network model, Non-pharmaceutical interventions,
- MeSH
- COVID-19 * epidemiology MeSH
- Disease Outbreaks prevention & control MeSH
- Humans MeSH
- Pandemics prevention & control MeSH
- SARS-CoV-2 MeSH
- Contact Tracing MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
A Turbo Pascal program for eye-hand coordination testing using standard PC XT/AT mouse is presented. The contour segments of three simple figures (square, circle and triangle) are chosen as tracing trajectories. Tracing performance expressed in root mean squared (RMS) and modulus mean error (MME) measures are calculated and used, together with tracing time for evaluation of eye hand coordination ability.
- MeSH
- Diagnosis, Computer-Assisted standards MeSH
- Humans MeSH
- Nervous System Diseases diagnosis physiopathology MeSH
- Psychophysiology MeSH
- Psychomotor Performance * MeSH
- Software MeSH
- Art * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
This study examines the metal(loid) contents (As, Cd, Cr, Cu, Mn, Ni, Pb, Sb, Tl and Zn) and Pb isotopes in different environmental compartments (soil, road dust, house dust) from the industrial vicinity of Volos, central Greece. The area surrounding two steel factories, a cement plant, an industrial area and the city core were considered as potential hot spots of metal(loid) contamination. Significant anthropogenic enrichments of Cd, Pb and Zn in relation to local baseline were identified for the soil (median Enrichment Factors of 7, 15 and 8, respectively) and road dusts around the steel factory located at Velestino area. The high contents of As, Sb and Tl in the soil and road dust around the cement plant are attributed to natural sources of contamination associated with adjacent mineralization. The soil samples in the city core exhibited moderate enrichments with respect to typical tracers (Pb, Zn) of anthropogenic contamination in urban areas. Anthropogenic influences in terms of metal(loid) concentrations were more pronounced for the road and house dust material. The Pb isotopic ratios of soil (206Pb/207Pb = 1.154 to 1.194), road dust (206Pb/207Pb = 1.144 to 1.174) and house dust (206Pb/207Pb = 1.129 to 1.171) were between those of the local bedrock and anthropogenic Pb sources. Industrial Pb from the steel plant was the predominant anthropogenic Pb source with relative contributions of ~49% for the soil, ~42% for the road dust and ~44% for the house dust samples. For the road and house dust material, the geochemical signature obtained from Pb isotopic compositions and elemental ratios suggests additional contributors from vehicular emissions. The results of this study demonstrate the suitability of soil to trace natural and anthropogenic impacts in industrial areas and the sensitivity of the road and house dust material to record anthropogenic (industrial and vehicular-derived) contamination in such environments.
- Keywords
- Cement factory, Lead isotopes, Potentially toxic elements, Source identification, Steel plants,
- Publication type
- Journal Article MeSH
There is growing concern about the rising levels of dissolved organic matter (DOM) in surface waters across the Northern hemisphere. However, only limited research has been conducted to unveil its precise origin. Compositional changes along terrestrial-aquatic pathways can help determine the terrestrial sources of DOM in streams. Stream water, soil water and soil horizons were sampled at four sites representing typical settings within a forested catchment in the Ore Mountains (Erzgebirge, Germany) from winter 2020 to spring 2022. The samples were analyzed using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The resulting data were successfully subjected to semi-automatic processing of the molecular composition of DOM, reaching a percentage of identified peaks up to 98 %. Principal component analysis (PCA) and cluster analyses were carried out to identify distinct differences between DOM from the potential sources and in the streams. According to the PCA, organic soil horizons, soil water, and stream water samples could be clearly distinguished. Cluster analysis revealed that soil water DOM at all depths of Peats and deeper horizons of the Peaty Gleysols contributed the most to DOM in the stream section dominated by organic soils. In areas dominated by mineral soils, stream DOM resembled the DOM from the deeper mineral horizons of Cambisols and Podzols. Overall, our results suggested that most of the DOM exported from the catchment was derived from deeper mineral soil horizons, with little contribution of DOM derived from organic soils. Therefore, DOM fingerprint analysis of in-situ soil water proved to be a promising approach for tracing back the main sources of stream water DOM.
- Keywords
- DOM characterization, DOM sources, PCA, Py-GC/MS, Soil water, Stream water,
- Publication type
- Journal Article MeSH
Microplastic pollution poses a significant threat to coastal ecosystems worldwide. Despite its widespread occurrence, knowledge on the prevalence and fate of microplastics across food webs is limited. To bridge this gap, we conducted an extensive study on microplastic contamination in mudflats, mangroves, and sand beaches being key habitats for wintering shorebirds on the west coast of India. Using a comprehensive multi-matrix approach covering water, sediment, biofilm, plankton, benthic macroinvertebrates, and migratory shorebird droppings, we analysed microplastic contamination across ten coastal sites from 2020 to 2022. Our findings show spatial and temporal variations in microplastics widespread in water and sediments, influenced by human activities. Notably, an increase in microplastics within prey and shorebird droppings coincide with a decline in prey abundance and shorebird populations. The prevalence of fibre-shaped microplastics indicates that common sources include discarded fishing gear and domestic sewage. The types of microplastics ingested by shorebirds varied depending on their feeding strategies, with biofilms serving as significant reservoirs of microplastics, facilitating their transfer to shorebirds. Epibenthic feeders, with a more limited foraging range, displayed the lowest levels of microplastics, while species foraging through multiple sediment layers exhibited higher concentrations. These findings underscore the urgent need for stricter conservation measures to tackle plastic pollution at its source. The study raises concerns about the potential harmful effects of microplastic contamination on the population of migratory shorebirds along the west coast of India. Continued research is crucial to understand the ecological impacts of microplastics on wintering shorebirds and to develop effective conservation strategies.
- Keywords
- Biomagnification, Coastal ecosystems, Foraging strategy, Microplastics, Shorebird abundance, Waterbirds,
- MeSH
- Water Pollutants, Chemical * analysis MeSH
- Ecosystem MeSH
- Animal Migration MeSH
- Microplastics * analysis MeSH
- Environmental Monitoring * MeSH
- Plastics * analysis MeSH
- Food Chain MeSH
- Birds * MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- India MeSH
- Names of Substances
- Water Pollutants, Chemical * MeSH
- Microplastics * MeSH
- Plastics * MeSH
Samples of lichens, snow and particulate matter (PM10, 24 h) are used for the source identification of air pollution in the heavily industrialized region of Ostrava, Upper Silesia, Czech Republic. An integrated approach that uses different environmental samples for metal concentration and Pb isotope analyses was applied. The broad range of isotope ratios in the samples indicates a combination of different pollution sources, the strongest among them being the metallurgical industry, bituminous coal combustion and traffic. Snow samples are proven as the most relevant indicator for tracing metal(loid)s and recent local contamination in the atmosphere. Lichens can be successfully used as tracers of the long-term activity of local and remote sources of contamination. The combination of PM10 with snow can provide very useful information for evaluation of current pollution sources.
- Keywords
- Atmospheric contamination, Lichens, Metals, Pb isotopes, Snow,
- MeSH
- Atmosphere chemistry MeSH
- Isotopes analysis MeSH
- Metals analysis MeSH
- Air Pollutants analysis MeSH
- Lichens metabolism MeSH
- Environmental Monitoring methods MeSH
- Particulate Matter analysis MeSH
- Industry MeSH
- Snow chemistry MeSH
- Coal analysis MeSH
- Air Pollution analysis MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
- Names of Substances
- Isotopes MeSH
- Metals MeSH
- Air Pollutants MeSH
- Particulate Matter MeSH
- Coal MeSH
The low frequency of nontuberculous mycobacterial infections, nonspecific symptoms for individual mycobacteria, and the lack of specific identification methods could alter correct diagnosis. This study presents a combined microbiology and molecular-based approach for Mycobacterium marinum detection in four aquarists with cutaneous mycobacterial infection. Simultaneously, ecology screening for M. marinum presence in the aquarists' fish tanks was performed. A total of 38 mycobacterial isolates originated from four human patients (n = 20), aquarium animals (n = 8), and an aquarium environment (n = 10). Isolate identification was carried out using 16S rRNA sequence analysis. A microbiology-based approach, followed by 16S rRNA sequence analysis, was successfully used for detection of M. marinum in all four patients. Animal and environmental samples were simultaneously examined, and a total of seven mycobacterial species were isolated: Mycobacterium chelonae , Mycobacterium fortuitum , Mycobacterium gordonae , Mycobacterium kansasii , Mycobacterium mantenii , Mycobacterium marinum , and Mycobacterium peregrinum . The presence of M. marinum was proven in the aquarium environments of two patients. Although M. marinum is described as being present in water, it was detected only in fish.
- MeSH
- Anti-Bacterial Agents pharmacology therapeutic use MeSH
- Mycobacterium Infections, Nontuberculous diagnosis drug therapy microbiology pathology MeSH
- Clarithromycin pharmacology therapeutic use MeSH
- Middle Aged MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Environmental Microbiology MeSH
- Mycobacterium marinum classification drug effects genetics isolation & purification MeSH
- Mycobacterium classification genetics isolation & purification MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Fishes microbiology MeSH
- Treatment Outcome MeSH
- Animals MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- Clarithromycin MeSH
- RNA, Ribosomal, 16S MeSH
Understanding the links between sources of magnetic particles and bioaccessibility of metal(loids) in environmental sampling media is crucial for better evaluating human health risks, although relevant information in the scientific literature is scarce. Here, soil, road and house dust samples from a heavy industrial area in Greece were characterized in a multidisciplinary study combining magnetic measurements, SEM/EDS analyses, bioaccessibility measurements and Pb isotopic analyses of bioaccessible Pb. The oral and inhalable bioaccessible fractions of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were assessed by applying simulated gastric and lung solutions. SEM/EDS analysis revealed the abundant presence of anthropogenic Fe-containing spherules of industrial origin in all sampling media, often containing minor contents of Cr, Cu, Mn, Pb and Zn. The inhalation bioaccessibility (%) in all environmental compartments was higher than the oral one for most elements analyzed in the present study. Clear associations between magnetic susceptibility and bioaccessible amounts of most of analyzed elements were encountered for the soil and road dust. The isotopic analyses of bioaccessible Pb showed that there are significant differences in the isotopic ratios between total and bioaccessible Pb. We conclude that Pb solubilized by the simulated gastric and lung extractions is principally anthropogenic, representing a mixture of industrial Pb and Pb related to the past usage of leaded petrol. Low values of 206Pb/207Pb were accompanied by high bioaccessible contents of Cd, Pb and Zn indicating that anthropogenic (mostly industrial) sources exert influence on the bioaccessible forms of these metals. Coupling magnetic and bioaccessibility measurements with stable isotopic technique of bioaccessible Pb is more reliable for determining Pb and other metal sources with high oral and inhalation bioaccessibility.
- Keywords
- House dust, Lead isotopes, Metal bioaccessibility, Road dust, Soil, Urban geochemistry,
- MeSH
- Risk Assessment MeSH
- Soil Pollutants * analysis MeSH
- Humans MeSH
- Environmental Monitoring MeSH
- Dust analysis MeSH
- Soil MeSH
- Metals, Heavy * analysis MeSH
- Cities MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Greece MeSH
- Cities MeSH
- Names of Substances
- Soil Pollutants * MeSH
- Dust MeSH
- Soil MeSH
- Metals, Heavy * MeSH
Thallium (Tl) concentration and isotope data have been recorded for contaminated soils and a set of industrial wastes that were produced within different stages of Zn ore mining and metallurgical processing of Zn-rich materials. Despite large differences in Tl levels of the waste materials (1-500mgkg-1), generally small changes in ε205Tl values have been observed. However, isotopically lighter Tl was recorded in fly ash (ε205Tl∼-4.1) than in slag (ε205Tl∼-3.3), implying partial isotope fractionation during material processing. Thallium isotope compositions in the studied soils reflected the Tl contamination (ε205Tl∼-3.8), despite the fact that the major pollution period ended more than 30 years ago. Therefore, we assume that former industrial Tl inputs into soils, if significant, can potentially be traced using the isotope tracing method. We also suggest that the isotope redistributions occurred in some soil (subsurface) horizons, with Tl being isotopically heavier than the pollution source, due to specific sorption and/or precipitation processes, which complicates the discrimination of primary Tl. Thallium isotope analysis proved to be a promising tool to aid our understanding of Tl behavior within the smelting process, as well as its post-depositional dynamics in the environmental systems (soils).
- Keywords
- Fractionation, Isotopes, Soil, Thallium, Waste,
- Publication type
- Journal Article MeSH