Urban Samples Research Articles

Inhalable antibiotic resistomes emitted from hospitals: metagenomic insights into bacterial hosts, clinical relevance, and environmental risks

BackgroundThreats of antimicrobial resistance (AMR) to human health are on the rise worldwide. Airborne fine particulate matter (PM2.5), especially those emitted from hospitals, could serve as a substantial yet lesser-known environmental medium of inhalable antibiotic resistomes. A genome-centric understanding of the hosting bacterial taxa, mobility potential, and consequent risks of the resistomes is needed to reveal the health relevance of PM2.5-associated AMR from clinical settings.ResultsCompared to urban ambient air PM2.5, the hospital samples harbored nearly twice the abundance of antibiotic resistantance genes (ARGs, ~ 0.2 log10(ARGs/16S rRNA gene)) in the summer and winter sampled. The profiled resistome was closely correlated with the human-source-influenced (~ 30% of the contribution) bacterial community (Procrustes test, P < 0.001), reflecting the potential antibiotic-resistant bacteria (PARB), such as the human commensals Staphylococcus spp. and Corynebacterium spp. Despite the reduced abundance and diversity of the assembled metagenomes from summer to winter, the high horizontal transfer potential of ARGs, such as the clinically relevant blaOXA and bacA, in the human virulent PARB remained unaffected in the hospital air PM samples. The occurring patterns of β-lactam resistance genes and their hosting genomes in the studied hospital-emitting PM2.5 were closely related to the in-ward β-lactam-resistant infections (SEM, std = 0.62, P < 0.01). Featured with more abundant potentially virulent PARB (2.89 genome copies/m3-air), the hospital samples had significantly higher resistome risk index scores than the urban ambient air samples, indicating that daily human exposure to virulent PARB via the inhalation of PM2.5 was ten times greater than from the ingestion of drinking water.ConclusionsThe significance of AMR in the studied hospital-emitting PM2.5 was highlighted by the greater abundance of ARGs, the prevalence of potentially virulent PARB, and the close association with hospital in-ward β-lactam infections. A larger-scale multi-source comparison of genome-resolved antibiotic resistomes is needed to provide a more holistic understanding to evaluate the importance of airborne AMR from the “One-Health” perspective.39Xa41gPReog5Lijw58oAnVideo

Comprehensive assessment of heavy elements and evaluation of potential human health risk in the urban environment: a case study from Novi Sad, Serbia.

This study aimed to determine seasonal (summer vs. winter) and spatial distribution of the selected heavy elements (HEs) (As, Cd, Co, Cr, Cu, Ni, and Pb) in soil samples collected from a typical Central European town, Novi Sad, Serbia. The highest Pb concentrations were observed in summer because of intensive ground-flushing, whereas Cu had its highest concentration in winter, which may be attributed to traffic emissions. Source characterization and spatial distribution were carried out using cluster analysis (CA), principal component analysis (PCA), variogram calculation and theoretical model fitting, GIS-based geostatistical methods, and positive matrix factorization (PMF) data processing tools. Environmental impact of HEs found in different functional areas demonstrated that the quantified concentrations of Pb, As, Co, and Cu ranked soil as unpolluted to moderately polluted, while the presence of Co, Ni, and Cr classified urban soil as moderately polluted. Pollution load index (PLI) suggested a significant HEs enrichment while the new modified approach to Nemerow integrated risk index (NIRI) indicated high risk, being extreme for some selected locations. Machine learning classifiers were used for the first time to identify the differences between urban soil and dust samples in situations when simultaneous analysis of both matrices was carried out, as well as for temporal distribution (summer versus winter), based on the obtained concentration of HEs. Variogram calculation suggested that the pattern in spatial variability within the system emerged from the combined action of key structural factors (e.g., the parent soil material, landforms and topography, and climate) and random factors related to human activities. The estimated human health risk for two segments of the population revealed that ingestion is the primary route of exposure to HEs for children and adults.

Как город приходит в село через кладбище: динамика погребальных практик Западной Сибири в XX - начале XXI в.

In modern science, the topic of the relationship between urban and rural in culture, the opposition of city and village, in-between phenomena and spheres, has been actualized. In this regard, it is interesting to study the infiltration of urban cultural samples, state initiatives to the areas that have long been within the framework of traditional culture, which were regulated by families and communities. On the one hand, during the 20th century. in Russia, the political system changes twice, on the other hand - in the middle of the century the economic order changes significantly, which leads to the emergence of new ritual specialists, the narrowing of the role of the family in the ritual and the appearance of new traditions. In Western Siberia, these big processes are superimposed on local specifics, forming local colorful solutions and ways of perceiving common practices. Field materials of ethnographic expeditions among the Russian population of Kurgan, Omsk, Novosibirsk and the south of the Tyumen oblasts make it clear: how urban practices are implemented and interpreted by people in these territories. Villagers are telling about the formation of the system of consumer services combines, which actually was forerunners of the commercial funeral offices of Post-Soviet era. Elements of “Red Funeral” traditions were implemented to the rural tradition culture. Some features were eliminated out of ritual practices, cause the new institutes take main part in the burial rites. In general terms, we can say that this is how the movement of cultural samples occurs. Over time, the elite samples becomes widespread, the urban comes to rural.

Precipitation of aqueous transition metals in particulate matter during the dithiothreitol (DTT) oxidative potential assay.

Transition metals in particulate matter (PM) are hypothesized to have enhanced toxicity based on their oxidative potential (OP). The acellular dithiothreitol (DTT) assay is widely used to measure the OP of PM and its chemical components. In our prior study, we showed that the DTT assay (pH 7.4, 0.1 M phosphate buffer, 37 °C) provides favorable thermodynamic conditions for precipitation of multiple metals present in PM. This study utilizes multiple techniques to characterize the precipitation of aqueous metals present at low concentrations in the DTT assay. Metal precipitation was identified using laser particle light scattering analysis, direct chemical measurement of aqueous metal removal, and microscopic imaging. Experiments were run with aqueous metals from individual metal salts and a well-characterized urban PM standard (NIST SRM-1648a, Urban Particulate Matter). Our results demonstrated rapid precipitation of metals in the DTT assay. Metal precipitation was independent of DTT but dependent on metal concentration. Metal removal in the chemically complex urban PM samples exceeded the thermodynamic predictions and removal seen in single metal salt experiments, suggesting co-precipitation and/or adsorption may have occurred. These results have broad implications for other acellular assays that study PM metals using phosphate buffer, and subsequently, the PM toxicity inferred from these assays.

Winter and Spring Variation in Sources, Chemical Components and Toxicological Responses of Urban Air Particulate Matter Samples in Guangzhou, China

Winter and Spring Variation in Sources, Chemical Components and Toxicological Responses of Urban Air Particulate Matter Samples in Guangzhou, China

Generating 2m fine-scale urban tree cover product over 34 metropolises in China based on deep context-aware sub-pixel mapping network

Contrast to the global forest, few trees live in cities but contribute significantly to urban environment and human health. However, the classical satellite-derived land cover/forest cover products with limited resolution are not fine enough for the identification of urban tree, which is usually appeared in small size and intersected with infrastructure. To relieve the dilemma, this study developed an urban tree specific sub-pixel mapping (SPM) architecture with deep learning approach, which aimed to generate 2m fine-scale urban tree cover product from 10 m Sentinel-2 images for large-scale area of 34 metropolises in China. The proposed approach has remarkable reconstruction ability for delineating the contextual characteristic of the urban tree patterns, and reliable generalization ability to large-scale area. In addition, this study creates a large-volume urban tree cover dataset (UTCD) with 0.13 billion urban tree samples at 2 m resolution, which fills the deficiency of standard dataset in urban tree cover research field. Quantitative analysis of our products was conducted on two typical study sites of Beijing and Wuhan. The results show that our products recover averagely more than 58.72% of urban tree covers that have been underestimated in the existing land cover/forest cover products, and outperforms the state-of-the-art approach both visually and quantitatively, by averagely 11.31% improvement in overall accuracy. From our annual products during 2016–2020, we found an evolution characteristic of urban tree cover: it is more stable in developed cities like Beijing, while more fluctuated in developing cities like Wuhan, and the alteration are usually concentrated at the outer-ring of downtown, which may be caused by the municipal planning and the land development of real estate industry.

Presence of SARS-CoV-2 RNA on Surfaces of Public Places and a Transportation System Located in a Densely Populated Urban Area in South America.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible RNA virus that causes COVID-19. Being aware of the presence of the virus on different types of surfaces and in different environments, and having a protocol for its detection, is important to understand the dynamics of the virus and its shedding patterns. In Ecuador, the detection of viral RNA in urban environmental samples has not been a priority. The present study analyzed samples from two densely populated neighborhoods and one public transportation system in Quito, Ecuador. Viral RNA presence was assessed using RT-LAMP. Twenty-eight out of 300 surfaces tested positive for SARS-CoV-2 RNA (9.33%). Frequently touched surfaces, especially in indoor spaces and on public transportation, were most likely to be positive for viral RNA. Positivity rate association for the two neighborhoods and for the surface type was not found. This study found viral RNA presence on urban surfaces; this information provides an insight into viral dissemination dynamics. Monitoring environmental SARS-CoV-2 could support the public health prevention strategies in Quito, Ecuador.

Occurrence and human exposure assessment of parabens in water sources in Osun State, Nigeria

Parabens are chemicals extensively used in pharmaceuticals, cosmetics, personal hygiene and food products as preservatives. They are classified as emerging contaminants with endocrine-disrupting capability. In this study, the concentrations of Methylparaben (MeP), Ethylparaben (EtP), Propylparaben (PrP) and Butylparaben (BuP) were obtained from groundwater, surface-water and packaged water samples collected from urban and rural areas of Osun State, Nigeria using HPLC-UV equipment. Data obtained were subjected to descriptive (Mean ± SD), inferential (Kruskal-Wallis test) and multivariate analyses. MeP had the highest average concentration of 163 and 68 μg L−1 in surface water and groundwater respectively while concentrations of MeP, EtP, PrP and BuP were higher than previously reported in other countries. Methylparaben had the highest detection frequencies (88.0 and 50.0%) followed by BuP (69.0 and 50.0%) in surface water and groundwater respectively. No significant difference was observed for concentrations of parabens in groundwater samples in urban and rural sampling sites, suggesting that people living around these sites are equally exposed to any health implications from the use of paraben-polluted potable water. Principal Component Analysis (PCA) data suggest that the pairs MeP & EtP, PrP & BuP (in surface water samples) and MeP, EtP, & PrP (in groundwater samples) are from similar pollution sources. Ecological risk assessment using Algae, Fish, and Daphnia suggests Daphnia as the most sensitive organism while BuP and PrP show the highest health risk. Human exposure assessment showed that higher overall median estimated daily intake (EDI) values for groundwater were observed in infants (1.71 μg kg−1 bw day−1, ∑PBs) compared to toddlers (1.03 μg kg−1 bw day−1, ∑PBs), children (0.64 μg kg−1 bw day−1, ∑PBs), teenagers (0.51 μg kg−1 bw day−1, ∑PBs) and adults (0.62 μg kg−1 bw day−1, ∑PBs). Although these values are below limits set in a few countries, potential bioaccumulation could lead to severe health consequences.

The Effect of Urban Spatial Form on Energy Efficiency: A Cross-Sectional Study in China

Rational planning and optimization of urban spatial form to achieve the goal of energy efficient utilization and carbon emission reduction is one of the important ways to improve energy efficiency. We deconstruct urban spatial form into centrality, aggregation and complexity, and analyze net effect and its heterogeneity of urban spatial form on energy efficiency with OLS, quantile regression model as well as grouped regression model. The results show that the effects of urban spatial centrality and complexity on energy efficiency are nonlinear. For the vast majority of cities, strengthening urban spatial centrality will significantly improve energy efficiency, but the growth rate will gradually decrease. The impact effect of urban complexity on energy efficiency has the characteristics of U-shaped trend with an inflection point value of 0.429. And for the three-quarters of urban samples, enhancing urban spatial complexity will reduce energy efficiency. The positive effect of urban spatial aggregation on energy efficiency is only significant in cities with high quantile for energy efficiency. In terms of urban heterogeneity, the positive effects of spatial centrality and aggregation on energy efficiency are more obvious in megacities with a permanent population of more than 5 million, and the negative effect of spatial complexity on energy efficiency is more obvious in small and medium-sized cities. Whether it is promotion or inhibition, the urban samples with high energy efficiency are more affected by the change of urban spatial form. Optimizing the urban spatial form is one of the important ways to improve the energy efficiency, and the policy setting should give full consideration to the urban heterogeneity and classified policies.

Human health risks associated with urban soils in mining areas

We studied the chemical composition of As and Pb in total (<2 mm) and fine fractions (<50 μm) of 52 urban soil samples from Minas de Riotinto (mining area) and Aracena (non-exposed area) in SW Spain. In addition to a soil phytotoxicity bioassay using Lactuca Sativa L., we modelled and performed carcinogenic and non-carcinogenic human health risk assessment, later comparing our data with relative cancer mortality rates reported at the municipal level.This study demonstrates that mineralized bedrock and natural soil-forming processes affect the geochemistry of natural (in-situ) urban soils, which in many cases surpass the regulatory levels for As (36 mg/kg) and Pb (275 mg/kg). Fine fractions of in-situ and mixed urban soils —susceptible of inhalation— are significantly enriched in As and Pb with respect to fine fractions of aggregate materials (ex-situ soils of chalky sands and gravel) in Minas de Riotinto. The soils in Minas de Riotinto are significantly enriched in As (total and fine fractions) and Pb (total fraction) with respect to Aracena. Despite elevated bulk concentrations of As and Pb, only one in-situ sample exhibits phytotoxic effects of the soil-water extracts on Lactuca Sativa L. seeds. Health risk assessment of these towns as exposure areas indicates that the soils of Minas de Riotinto are indeed a health risk to the residents, whereas there is no potential risk in Aracena. The reported relative mortality rates in Minas de Riotinto show a greater mortality of carcinogenic tumors potentially related to As and Pb exposure, including lung cancer.Both soil type and use must be considered when administrators or policy-makers evaluate health risks involved in urbanistic decision-making. To minimize exposure risk and adverse health outcomes, we recommend that in-situ soils surpassing regulatory levels for As and Pb in public playgrounds and passing areas should be covered with aggregate materials.

Report of Antibiotic Resistance in Urban and Rural Wastewaters from West Bengal, India

Aims: This study aims at comparative identification of antibiotic resistance patterns in bacteria isolated from samples collected from rural environment (LS) and urban environments (SS). Metagenomic profiling gave us insights into the microbial abundance of the two samples. This study focused on culture-based methods for complete identification of antibiotic resistant isolates and estimation of comparative antibiotic resistance among the two samples.&#x0D; Study Design: Untreated medical waste and anthropogenic waste disposal can lead to the propagation of different antibiotic resistant strains in wastewater environments both in urban and rural set ups which provide an insight towards this study approach mentioned in the methodology segment.&#x0D; Place and Duration of Study: Sewer system of a medical facility located in Purulia, India was the collection site for liquid sludge. Solid sludge and associated wastewater were collected in vicinity of a large urban medical facility from central Kolkata, India.&#x0D; Methodology: Physico-chemical properties were analyzed followed by microbiological and biochemical characterization. The antibiotic resistance patterns were determined by Kirby-Bauer disc diffusion assay. Potent multidrug resistant isolates were identified using 16srRNA gene amplification followed by Phylogenetic profiling, using CLC Genomics workbench.&#x0D; Results: We observed maximum resistance in an E. coli isolate which was resistant up to 22 antibiotics. Combined data for resistance from urban and rural samples were found to exhibit 83.9% resistance to beta lactams, 85.7% to macrolides, 44.2% to fluoroquinolones, 50% to glycopeptides and cephalosporins, 35.7 % to carbapenems and sulfonamides, 28.5 % to tetracycline, and 23.8 % to aminoglycosides.&#x0D; Conclusion: The high prevalence of antibiotic-resistant bacteria harbouring diverse resistance traits across samples indicated towards probable horizontal gene transfer across environmental niches. This study can prove to be useful to understand and map the patterns of resistance and stringently apply the counter measures related to public health practices.

Temporal Evolution of Organochlorine Pesticides Residues in Kola Nuts (Cola nitida Vent Nuts. Schott &amp; Endl.) Processing in Eastern of Côte d’Ivoire

Aims: The objective of this study is to monitor the evolution of organochlorine residues levels in kola nuts collected from various actors in the eastern producing region of Côte d'Ivoire.&#x0D; Study Design: Kola nuts samples were collected from farmers, collectors and urban stores in the Eastern of Côte d’Ivoire.&#x0D; Place and Duration of Study: Health Department of Hydrology Health and Toxicology, Training and Research Unit of Pharmaceutical and Biological Sciences, Abidjan, Côte d’Ivoire, running 2016-2019.&#x0D; Methodology: A total of 225 samples were analyzed using Gas chromatography–tandem mass spectrometry (Agilent 7010B Triple Quadrupole GC/MS System).&#x0D; Results: Data showed that all 21 pesticides analyzed were detected in kola nuts samples. Statistical analysis indicated no significant difference in OCPs sub-group used by actors during the three-crop studied. The mean levels of HCHs, DDTs and cyclodienes were ranged from 5±1– 136.67±77.3 µg/kg FW, 5±1 – 116.67±63.2 µg/kg FW and 5±1 - 145±63.2 µg/kg FW, respectively. Otherwise, farmer’s levels of OCPs were lower than those detected in kola nuts from collectors and urban stores samples. Thus, compared to the MRL set by the World Health Organization/Food and Agricultural Organization, the farmer’s samples are lower than limits fixed, unlike the contents registered with collectors and urban stores. In the latter, nearly 80% to 100% of kola nuts collected are contaminated with hexachlorinated residues (HCHs) and heptachlor.&#x0D; Conclusion: There is the need to keep monitoring ecotoxicological chemical substances in kola nuts produced in Côte d’Ivoire and take steps that ensure health safety of end users. Care should be taken since residues could pose chronic health risk for adults and children.

Does Teacher Training Narrow the Educational Gap between Urban and Rural Students? Empirical Evidence from CEPS Baseline Data

Based on the baseline data of the China Education Panel Survey, this paper explored the relationship between teacher training and academic performance in urban and rural samples respectively and the impact of teacher training on the urban-rural gap of students' academic performance. The results showed that: firstly, there was a significant urban-rural gap in academic performance, and the gap in high quantiles and language subjects were even larger. Secondly, the results of unconditional quantile regression showed that teacher training could improve the performance of urban students with different academic levels and rural students with intermediate or above academic levels, but it cannot improve the performance of rural students with lower academic levels. In addition, the overall effect of teacher training in urban areas is significantly higher than that in rural areas. Thirdly, different quantiles of Oaxaca-Blinder decomposition found that the endowment effect and the coefficient effect of teacher training were the important causes of the urban-rural performance gap, but the relative sizes of the two were different according to the different grades and different quantiles of performance distribution. Therefore, to increase the training opportunities and improve the training quality of rural teachers as well as enhance the resource conversion rate of rural students are of great practical significance for narrowing the urban-rural performance gap.

Does Social Capital Promote Health?

The determinants of health are influenced by genetics, lifestyle, social environment, medical conditions, etc. As an informal system, social capital plays an increasingly recognized role in individual health. The purpose of this paper is to discuss the direct and indirect effects of social capital on individual health in China. Using cross-sectional data from the China Family Panel Studies 2016, this paper explores the effects of cognitive and structural social capital on individual health from a micro perspective. The results show that both types of social capital have significant positive effects on individual health, and this effect remains after endogeneity is considered. The two types of social capital show obvious heterogeneity in age samples, urban and rural samples and north–south samples. In addition, the mechanism analysis shows that the health promotion effects of the two types of social capital are mainly derived from the effects of informal finance and access to medical resources. Based on the above findings, this paper puts forward policy recommendations.

Efficiency of South African water utilities: a double bootstrap DEA analysis

ABSTRACT Although the efficiency of the water sector has been studied extensively utilizing data envelopment analysis (DEA), most of the literature tends to use the conventional DEA model to compute efficiency scores. In addition, there are many studies that undertake a second stage regression of the efficiency scores against a set of covariates. However, such second-stage analyses are problematic due to potential serial correlation inherent in the estimated efficiency scores. To determine the bias-corrected efficiency scores of rural and urban water utilities in South Africa, this study uses a robust, non-parametric DEA bootstrapping model to generate them. Moreover, little is known about relative performance of the conventional DEA versus bias-corrected DEA. In addition, the truncated double-bootstrap regression results provide insights into the drivers of efficiency, including how water policies and the political and institutional contexts of water utilities can impact relative efficiencies. We found that there are significant differences between the rankings and efficiency scores generated by the conventional DEA model compared to the double-bootstrap DEA model, for both urban and rural samples. The regression model found the location and the ratio of metered to unmetered connections to be significant determinants of efficiency for both urban and rural water utilities.

A comparison of precipitation and filtration-based SARS-CoV-2 recovery methods and the influence of temperature, turbidity, and surfactant load in urban wastewater

Wastewater-based epidemiology (WBE) has become a complimentary surveillance tool during the SARS-CoV-2 pandemic. Viral concentration methods from wastewater are still being optimised and compared, whilst viral recovery under different wastewater characteristics and storage temperatures remains poorly understood. Using urban wastewater samples, we tested three viral concentration methods; polyethylene glycol precipitation (PEG), ammonium sulphate precipitation (AS), and CP select™ InnovaPrep® (IP) ultrafiltration. We found no major difference in SARS-CoV-2 and faecal indicator virus (crAssphage) recovery from wastewater samples (n = 46) using these methods, PEG slightly (albeit non-significantly), outperformed AS and IP for SARS-CoV-2 detection, as a higher genome copies per litre (gc/l) was recorded for a larger proportion of samples. Next generation sequencing of 8 paired samples revealed non-significant differences in the quality of data between AS and IP, though IP data quality was slightly better and less variable. A controlled experiment assessed the impact of wastewater suspended solids (turbidity; 0–400 NTU), surfactant load (0–200 mg/l), and storage temperature (5–20 °C) on viral recovery using the AS and IP methods. SARS-CoV-2 recoveries were >20% with AS and <10% with IP in turbid samples, whilst viral recoveries for samples with additional surfactant were between 0–18% for AS and 0–5% for IP. Turbidity and sample storage temperature combined had no significant effect on SARS-CoV-2 recovery (p > 0.05), whilst surfactant and storage temperature combined were significant negative correlates (p < 0.001 and p < 0.05, respectively). In conclusion, our results show that choice of methodology had small effect on viral recovery of SARS-CoV-2 and crAssphage in wastewater samples within this study. In contrast, sample turbidity, storage temperature, and surfactant load did affect viral recovery, highlighting the need for careful consideration of the viral concentration methodology used when working with wastewater samples.

Public health significance of dental fluorosis among 12-15 years old school children in Zeway, Oromia Region, Ethiopia

IntroductionWhile fluoride is accepted as being effective in the prevention of dental caries, the excessive consumption of fluoride can put bones and teeth at risk of developing fluorosis. Dental fluorosis is a condition affecting teeth and is caused by an increased intake of fluoride over an extended period during tooth development. Fluoride ingested through drinking water during dental development, until the age of six, may promote the development of fluorosis.PurposeThe purpose of this study was to assess the public health significance of dental fluorosis among 12-15 years old school children in Zeway, Oromia Region, EthiopiaMaterial and MethodsA descriptive cross-sectional study was conducted between June 5, 2018, and July 9, 2018. A total of 1290 school children, aged 12 – 15 years participated in the study. The public health significance of dental fluorosis among the study participants was measured by using the community fluorosis index catalog. ResultThe community fluorosis index of the total population studied was 2.02, which denotes the ‘Marked’ public health significance of the condition. The public health significance of dental fluorosis increased with increasing distance away from the city center. The community fluorosis index score of the rural population studied was the highest (2.76 ) compared to the scores of semi-urban (2.26) and urban (1.76) samples, respectively.ConclusionDental fluorosis is a major public health problem in the study population. Beside the general intervention, more attention needs to be given to the semi-urban and rural communities to identify the risk factors of dental fluorosis in the areas and eliminate or modify them to mitigate the prevalence of this oral health problem in the study population.

Detection of antimicrobial resistance genes in urban air.

To understand antibiotic resistance in pathogenic bacteria, we need to monitor environmental microbes as reservoirs of antimicrobial resistance genes (ARGs). These bacteria are present in the air and can be investigated with the whole metagenome shotgun sequencing approach. This study aimed to investigate the feasibility of a method for metagenomic analysis of microbial composition and ARGs in the outdoor air. Air samples were collected with a Harvard impactor in the PM10 range at 50 m from a hospital in Budapest. From the DNA yielded from samples of PM10 fraction single‐end reads were generated with an Ion Torrent sequencer. During the metagenomic analysis, reads were classified taxonomically. The core bacteriome was defined. Reads were assembled to contigs and the ARG content was analyzed. The dominant genera in the core bacteriome were Bacillus, Acinetobacter, Leclercia and Paenibacillus. Among the identified ARGs best hits were vanRA, Bla1, mphL, Escherichia coli EF‐Tu mutants conferring resistance to pulvomycin; BcI, FosB, and mphM. Despite the low DNA content of the samples of PM10 fraction, the number of detected airborne ARGs was surprisingly high.

Incorporating bioaccessibility and source apportionment into human health risk assessment of heavy metals in urban dust of Xiamen, China

Heavy metals in urban dust could pose noticeable human health risks, but there are few studies focusing on comprehensive human health risk assessment with the incorporation of both bioaccessibility and source apportionment in urban dust. Thus, fifty-eight urban dust samples were collected from kindergartens in Xiamen to analyze the bioaccessibility-based, source-specific health risk of heavy metals (V, Co, Ni, As, Mo, Cr, Mn, Cu, Zn, and Pb). Most heavy metals, except for V and Mn, were significantly enriched in urban dust based on their values of geoaccumulation index (Igeo) and may be influenced by human activities. The oral bioaccessibility values of heavy metals, which were estimated by the Solubility/Bioaccessibility Research Consortium (SBRC) in vitro model, ranged from 1.563% to 76.51%. The source apportionment determined by applying the absolute principal component analysis-multiple linear regression (APCS-MLR) model indicated five main potential sources, coal combustion, traffic and industrial, natural, construction and furniture sources, and unidentified sources, with contributions of 34.09%, 20.72%, 18.72%, 7.597% and 18.87%, respectively, to the accumulation of heavy metals in urban dust. After incorporating bioaccessibility adjustments, lower non-carcinogenic and carcinogenic risks of heavy metals were observed than those based on total metal content, with the mean hazard index (HI) values being less than the threshold value (1) and the mean total carcinogenic risk (TCR) values exceeding the precautionary criterion (10-6) for both adults and children. By combining bioaccessibility-based health risk assessment and source apportionment, traffic and industrial emissions and coal combustion dominated the noncarcinogenic and carcinogenic risks induced by heavy metals in urban dust, respectively. This study is expected to promote the systematic integration of source apportionment and bioaccessibility into health risk estimation for heavy metal contamination in urban dust, thus providing useful implications for better human health protection.

What Are the Differences between Two Environmental Films Sampled 1 km Apart?

Environmental films are atmospheric materials that passively deposit and form coatings on most outdoor surfaces. Film heterogeneity in the chemical makeup and physical form often makes understanding their contributions to the environment difficult. It is well known that cities or rural areas produce unique films. To study how this trend changes with a known distance, we characterize two films, collected at the same time, separated by ∼1 km: representing city (CB) and suburban (CP) areas. The chemical analysis shows that the urban (CB) film, in comparison to its suburban (CP) counterpart, has higher surface coverage (+4.8%) and higher elemental diversity in metals. The physical form and roughness show that the urban (CB) sample collects more particulate than the suburban (CP) sample. This accumulation increases the surface area suggesting that the urban (CB) sample forms faster and maintains higher adsorption capacity than the suburban sample. The urban (CB) sample has metals often associated with fireworks meaning that surfaces could act as a sink and source for metallic species impacting local ecosystems through rainwater wash-off. The urban samples discharge more of the accumulated material (inorganic and organic water-soluble species) when extracted with water (+2 μg/cm2). This means that urban sites, like buildings, contribute more to waste water pollution than the suburban sites, like houses. There is also potential for this contribution to be more harmful in urban areas. These findings have important applications in understanding air and water quality in urban and suburban areas.