Infection with SARS-CoV-2, the etiologic agent of the ongoing COVID-19 pandemic, is accompanied by the shedding of the virus in stool. Therefore, the quantification of SARS-CoV-2 in wastewater ...affords the ability to monitor the prevalence of infections among the population via wastewater-based epidemiology (WBE). In the current work, SARS-CoV-2 RNA was concentrated from wastewater in a catchment in Australia and viral RNA copies were enumerated using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) resulting in two positive detections within a six day period from the same wastewater treatment plant (WWTP). The estimated viral RNA copy numbers observed in the wastewater were then used to estimate the number of infected individuals in the catchment via Monte Carlo simulation. Given the uncertainty and variation in the input parameters, the model estimated a median range of 171 to 1,090 infected persons in the catchment, which is in reasonable agreement with clinical observations. This work highlights the viability of WBE for monitoring infectious diseases, such as COVID-19, in communities. The work also draws attention to the need for further methodological and molecular assay validation for enveloped viruses in wastewater.
Display omitted
•First study that reports the detection of SARS-CoV-2 in wastewater in Australia.•The presence of SARS-CoV-2 was confirmed by sequencing.•A median range of 171 to 1090 infected persons was identified in the catchment.•Further methodological and molecular assay validation will be required.
We analyze star formation in the nuclei of nine Seyfert galaxies at spatial resolutions down to 0.085", corresponding to length scales of order 10 pc in most objects. Our data were taken mostly with ...the near-infrared adaptive optics integral field spectrograph SINFONI. The stellar light profiles typically have size scales of a few tens of parsecs. In two cases there is unambiguous kinematic evidence for stellar disks on these scales. In the nuclear regions there appear to have been recent, but no longer active, starbursts in the last 10-300 Myr. The stellar luminosity is less than a few percent of the AGN in the central 10 pc, whereas on kiloparsec scales the luminosities are comparable. The surface stellar luminosity density follows a similar trend in all the objects, increasing steadily at smaller radii up to similar to 10 super(13) L unk kpc super(-2) in the central few parsecs, where the mass surface density exceeds 10 super(4) M unk pc super(-2). The intense starbursts were probably Eddington limited and hence inevitably short lived, implying that the starbursts occur in multiple short bursts. The data hint at a delay of 50-100 Myr between the onset of star formation and subsequent fueling of the black hole. We discuss whether this may be a consequence of the role that stellar ejecta could play in fueling the black hole. While a significant mass is ejected by OB winds and supernovae, their high velocity means that very little of it can be accreted. On the other hand, winds from AGB stars ultimately dominate the total mass loss, and they can also be accreted very efficiently because of their slow speeds.
Single-cell atlases often include samples that span locations, laboratories and conditions, leading to complex, nested batch effects in data. Thus, joint analysis of atlas datasets requires reliable ...data integration. To guide integration method choice, we benchmarked 68 method and preprocessing combinations on 85 batches of gene expression, chromatin accessibility and simulation data from 23 publications, altogether representing >1.2 million cells distributed in 13 atlas-level integration tasks. We evaluated methods according to scalability, usability and their ability to remove batch effects while retaining biological variation using 14 evaluation metrics. We show that highly variable gene selection improves the performance of data integration methods, whereas scaling pushes methods to prioritize batch removal over conservation of biological variation. Overall, scANVI, Scanorama, scVI and scGen perform well, particularly on complex integration tasks, while single-cell ATAC-sequencing integration performance is strongly affected by choice of feature space. Our freely available Python module and benchmarking pipeline can identify optimal data integration methods for new data, benchmark new methods and improve method development.
There is currently a clear benefit for many countries to utilize wastewater-based epidemiology (WBE) as part of ongoing measures to manage the coronavirus disease 2019 (COVID-19) global pandemic. ...Since most wastewater virus concentration methods were developed and validated for nonenveloped viruses, it is imperative to determine the efficiency of the most commonly used methods for the enveloped severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Municipal wastewater seeded with a human coronavirus (CoV) surrogate, murine hepatitis virus (MHV), was used to test the efficiency of seven wastewater virus concentration methods: (A–C) adsorption-extraction with three different pre-treatment options, (D–E) centrifugal filter device methods with two different devices, (F) polyethylene glycol (PEG 8000) precipitation, and (G) ultracentrifugation. MHV was quantified by reverse-transcription quantitative polymerase chain reaction and the recovery efficiency was calculated for each method. The mean MHV recoveries ranged from 26.7 to 65.7%. The most efficient methods were adsorption-extraction methods with MgCl2 pre-treatment (Method C), and without pre-treatment (Method B). The third most efficient method used the Amicon® Ultra-15 centrifugal filter device (Method D) and its recovery efficiency was not statistically different from the most efficient methods. The methods with the worst recovery efficiency included the adsorption-extraction method with acidification (A), followed by PEG precipitation (F). Our results suggest that absorption-extraction methods with minimal or without pre-treatment can provide suitably rapid, cost-effective and relatively straightforward recovery of enveloped viruses in wastewater. The MHV is a promising process control for SARS-CoV-2 surveillance and can be used as a quality control measure to support community-level epidemic mitigation and risk assessment.
Display omitted
•Seven virus concentration methods were evaluated to recover CoV from wastewater.•The mean MHV recoveries ranged from 26.7 to 65.7%.•Adsorption-extraction with MgCl2 pre-treatment most efficiently concentrated MHV.•MHV seems to be an appropriate process control.
Concentrations of nine organophosphate flame retardants (OPFRs) and eight polybrominated diphenyl ethers (PBDEs) were measured in samples of indoor dust (n = 85) and air (n = 45) from Australian ...houses, offices, hotels, and transportation (buses, trains, and aircraft). All target compounds were detected in indoor dust and air samples. Median ∑9OPFRs concentrations were 40 μg/g in dust and 44 ng/m3 in indoor air, while median ∑8PBDEs concentrations were 2.1 μg/g and 0.049 ng/m3. Concentrations of FRs were higher in rooms that contained carpet, air conditioners, and various electronic items. Estimated daily intakes in adults are 14000 pg/kg body weight/day and 330 pg/kg body weight/day for ∑9OPFRs and ∑8PBDEs, respectively. Our results suggest that for the volatile FRs such as tris(2-chloroethyl) phosphate (TCEP) and TCIPP, inhalation is expected to be the more important intake pathway compared to dust ingestion and dermal contact.
Display omitted
•TBOEP was the predominant FR in dust, and TCIPP had the highest concentrations in air.•Highest concentrations of FRs were found in dust samples from transport vehicles.•Concentrations of FRs were higher in houses contained carpet, air-conditioners.•EDIs for adults are 9.0 and 0.074 ng/kg/day for ∑9OPFRs and ∑8PBDE, respectively.
Human biomonitoring studies have shown that concentrations of perfluorooctane sulfonic acid (PFOS) in men are higher than in women. We investigate sex differences in elimination of PFOS by fitting a ...population-based pharmacokinetic model to six cross-sectional data sets from 1999 to 2012 from the US National Health and Nutrition Examination Survey (NHANES) and derive human first-order elimination rate constants (k E) and corresponding elimination half-lives (t 1/2) for PFOS, where t 1/2 = ln 2/k E. We use a modified version of the Ritter population-based pharmacokinetic model and derive elimination rate constants separately for men and women. The model accounts for population-average lifetime changes in PFOS intake, body weight, and menstruation rate. We compare the model-derived elimination rate constant for hypothetical nonmenstruating women to the elimination rate constant for men and women when menstruation is included as a loss process to evaluate the hypothesis that loss of PFOS by menstruation is an important process for women. The modeled elimination half-life for men is 4.7 years, and the modeled elimination half-life for women when excluding losses from menstruation is 3.7 years. The elimination half-life for women when menstruation is included in the model is 4.0 years. Thus, menstruation accounts for 30% of the discrepancy in elimination of PFOS between men and women. The remaining discrepancy is likely due to other sex-specific elimination routes that are not considered in our modeling.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus which causes coronavirus disease (COVID-19), has spread rapidly across the globe infecting millions of people and causing ...significant health and economic impacts. Authorities are exploring complimentary approaches to monitor this infectious disease at the community level. Wastewater-based epidemiology (WBE) approaches to detect SARS-CoV-2 RNA in municipal wastewater are being implemented worldwide as an environmental surveillance approach to inform health authority decision-making. Owing to the extended excretion of SARS-CoV-2 RNA in stool, WBE can surveil large populated areas with a longer detection window providing unique information on the presence of pre-symptomatic and asymptomatic cases that are unlikely to be screened by clinical testing. Herein, we analysed SARS-CoV-2 RNA in 24-h composite wastewater samples (n = 63) from three wastewater treatment plants (WWTPs) in Brisbane, Queensland, Australia from 24th of February to 1st of May 2020. A total of 21 samples were positive for SARS-CoV-2, ranging from 135 to 11,992 gene copies (GC)/100 mL of wastewater. Detections were made in a Southern Brisbane WWTP in late February 2020, up to three weeks before the first clininal case was reported there. Wastewater samples were generally positive during the period with highest caseload data. The positive SARS-CoV-2 RNA detection in wastewater while there were limited clinical reported cases demonstrates the potential of WBE as an early warning system to identify hotspots and target localised public health responses, such as increased individual testing and the provision of health warnings.
Display omitted
•SARS-CoV-2 RNA was detected in wastewater when clinical cases were low.•The decline of the RNA occurrence in wastewater aligned with the tapering of the epidemic.•SARS-CoV-2 RNA in wastewater showed no correlation with daily cases.•Early detection of SARS-CoV-2 in wastewater is useful for COVID-19 management.
Microplastic contamination of the marine environment is widespread, but the extent to which the marine food web is contaminated is not yet known. The aims of this study were to go beyond visual ...identification techniques and develop and apply a simple seafood sample cleanup, extraction, and quantitative analysis method using pyrolysis gas chromatography mass spectrometry to improve the detection of plastic contamination. This method allows the identification and quantification of polystyrene, polyethylene, polyvinyl chloride, polypropylene, and poly(methyl methacrylate) in the edible portion of five different seafood organisms: oysters, prawns, squid, crabs, and sardines. Polyvinyl chloride was detected in all samples and polyethylene at the highest total concentration of between 0.04 and 2.4 mg g–1 of tissue. Sardines contained the highest total plastic mass concentration (0.3 mg g–1 tissue) and squid the lowest (0.04 mg g–1 tissue). Our findings show that the total concentration of plastics is highly variable among species and that microplastic concentration differs between organisms of the same species. The sources of microplastic exposure, such as packaging and handling with consequent transference and adherence to the tissues, are discussed. This method is a major development in the standardization of plastic quantification techniques used in seafood.
Leaching of perfluoroalkyl acids (PFAAs) from a local point source, a fire-fighting training area, has led to extensive contamination of a groundwater aquifer which has spread underneath part of a ...nearby town, Oakey, situated in the State of Queensland, Australia. Groundwater is extracted by residents from privately owned wells for daily activities such as watering livestock and garden beds. The concentration of 10 PFAAs in environmental and biological samples (water, soil, grass, chicken egg yolk, serum of horses, cattle and sheep), as well as human serum was investigated to determine the extent of contamination in the town and discuss fate and redistribution of PFAAs. Perfluorooctane sulfonate (PFOS) was the dominant PFAA in all matrices investigated, followed by perfluorohexane sulfonate (PFHxS). PFOS concentrations measured in water ranged between <0.17–14μg/L, concentrations of PFHxS measured between <0.07–6μg/L. PFAAs were detected in backyards (soil, grass), livestock and chicken egg yolk. Significant differences (p<0.01) in PFOS and PFHxS concentrations in two groups of cattle were found, one held within the contamination plume, the other in the vicinity but outside of the contamination plume. In human serum PFOS concentrations ranged from 38 to 381μg/L, while PFHxS ranged from 39 to 214μg/L. Highest PFOS concentrations measured in human serum were >30-fold higher compared to the general Australian population. Through use of contaminated groundwater secondary sources of PFAA contamination are created on private property, leading to further redistribution of contamination and creation of additional human exposure pathways.
Display omitted
•Widespread PFAA groundwater contamination originating from a point source•PFAAs detected in eight biotic and abiotic matrices.•Redistribution of PFAAs occurring from the point source through water usage•Creation of secondary sources and human relevant exposure pathways
•PFASs concentrations have been quantified at a FTG (up to 230μgg−1 for PFOS).•PFAS have been found within the concrete up to 12cm depth.•The total mass load of 15 PFASs is estimated at 1.7kg for the ...whole FTG.•A transport model for PFOS, PFOA and 6:2FTS is created under field condition.•FTG will keep emitting these chemicals in rainfall runoff for several years/decades.
The present study investigates the occurrence and fate of 15 perfluoroalkyl substances (PFASs) and one fluorotelomer sulfonate from a firefighting training ground (FTG) that was contaminated by intensive use of aqueous film forming foams (AFFF). The contamination levels and their spatial and vertical distribution are assessed in the structure. At the surface of the pad, perfluorooctane sulphonate (PFOS) is the dominant PFASs measured, with concentration varying from 10 to 200μgg−1. PFASs were also detected in a concrete core at up to 12cm depth, suggesting the vertical movement and higher transport potential of shorter chain compounds. The estimated mass load of linear PFOS in this specific pad was >300g with a total of 1.7kg for the sum of all PFASs analyzed. The kinetics of desorption of PFOS, PFOA and 6:2FTS from the concrete into an overlaying static water volume has been measured under field conditions at two constant temperatures. Fitting the desorption data and estimated rainfall/runoff to a kinetic model suggests that this and similar firefighting training pads will likely remain a source of PFASs for many decades (t0.5=25 years for PFOS).
PDF
