Passive Sampling Methods Research Articles

Airborne microplastic monitoring: Developing a simplified outdoor sampling approach using pollen monitoring equipment

A novel, yet simple, airborne microplastic (MP) sampling approach using global pollen monitoring equipment was applied to identify, characterise and quantify outdoor airborne MPs for the first time. Modification of Burkard spore trap tape adhesive provided particle capture and facilitated downstream spectroscopy analysis. 36 polymer types were identified from a total of 21 days sampling using Burkard spore traps at two locations (United Kingdom and South Africa). MPs were detected in 95 % of daily samples. Mean MP particle levels were 2.0 ± 0.9 MP m-3 (11 polymer types) in Hull (U.K.), during March, 2.9 ± 2.0 MP m-3 (16 types) in Hull in July, and 11.0 ± 5.7 MP m-3 (29 types) in Gqeberha, (S.A.) in August 2023. The most abundant polymer type was nylon (Gqeberha). The approach was compared with two passive sampling methods whereby 27 polymer types were identified and of these, 6 types were above the limit of quantification (LOQ), with poly(methacrolein:styrene) (PMA/PS) the most abundant. Irregularly shaped MPs < 100 µm in length were predominant from all sampling approaches. For the first time, airborne MPs were chemically characterised and quantified using volumetric pollen sampling equipment, representing a viable approach for future airborne MP monitoring.

FRUGIVORY CAMTRAP: A dataset of plant-animal interactions recorded with camera traps.

Ecological interactions are a key component of biodiversity, essential for understanding ecosystem services and functioning. Recording and quantifying ecological interactions is challenging, frequently requiring complex logistics and substantial effort in the field. Camera traps are routinely used in ecology for various applications, and have proven to be an excellent method for passive and non-invasive sampling of plant-animal interactions. We implemented a standardized camera trap protocol to document vertebrate frugivores-fleshy fruitedplants interactions in Doñana National Park, SW Spain, with the central objective of inventorying the diversity of plant-animal ecological interactions providing seed dispersal services. From 2018 to 2023 we recorded pairwise interactions from which we obtained qualitative (presence-absence) and quantitative (frequency of visits) information. Each record in the dataset contains information of a visit by an individual animal to an individual plant, resulting in any form of fleshy-fruit use and provides information on visitation phenology, visit length, and feeding behavior. The dataset presented here includes 10,659 frugivory interaction events for 59 vertebrate species (46 birds, 13 mammals) recorded on 339 plant individuals from 13 different plant species which dominate the fleshy-fruited plant assemblage in the Doñana National Park. The most recorded animal species consuming fruits and playing a legitimate seed dispersal role was Curruca melanocephala (1678 records) among birds and Vulpes vulpes among mammals (751 records). Cervus elaphus, a fruit consumer with a marginal role as legitimate seed disperser, was the most recorded mammal species (1508 records). Avian frugivores, particularly those from the Sylviidae and Turdidae families, are widespread in the region and play a crucial role in maintaining the dispersal service for the fleshy-fruited plant populations in the area. The dataset offers highly versatile quantitative information that can be used to investigate frugivory from the highest resolution scale, the interaction event between pairs of individuals. In addition, other information that can be extracted includes the timing of interactions of animals and plants (their phenological couplings), activity periods of the animals, behavior during the events and preferences for individual plants within populations. There are no copyright restrictions on the data. When using the data from this data paper in publications, we kindly request that you cite the paper accordingly. Additionally, we encourage researchers and educators to inform us about how they are using this data, as we value feedback and would like to be aware of its various applications.

Taxonomic and functional diversity of foliage‐dwelling ants in conventional and organic agroecosystems in southern Brazil: A landscape perspective

Abstract In modern landscapes, understanding how land use and land cover, specifically agriculture, affect biodiversity and ecological functions is essential for conservation. According to Brazilian law, agroecosystems must include areas designated for biodiversity conservation called Legal Reserves. We evaluated the taxonomic and functional diversity of foliage‐dwelling ants in Legal Reserves of agroecosystems in the south of Rio Grande do Sul, Brazil. We aimed to understand how land use and land cover at different landscape scales affect the ant fauna. We sampled ant communities in organic and conventional agroecosystems using passive and active sampling methods (arboreal pitfall traps and active sample, respectively). For the analysis of functional diversity, we measured morphological attributes related to the ecological strategies of ants, such as perception of visual cues, foraging and resource acquisition. We characterized the landscape by visual interpretation of high‐resolution satellite imagery within a 100 m, 500 m and 1 km radius of the sampling areas. We did not identify any effects of cultivation systems on ant fauna. However, we found that landscape characteristics, such as the proportion of natural forest within 100 m, positively affected functional richness. Additionally, within 500 m, natural forest coverage, along with the proportion of cultivation, positively influenced ant incidence. We emphasize the function of Legal Reserves around farms, of serving as support to maintain the presence of ants and the diversity of ecological functions performed by these organisms. We also emphasize that new studies in the region should investigate how a higher homogenization of cultures and cultivation systems, including other phyto‐physiognomies, influence the myrmecofauna of these environments.

Improved passive sampling methods for wastewater to enable more sensitive detection of SARS-CoV-2 and its variants

Wastewater-based epidemiology (WBE) can be used as a part of a long-term strategy for detecting and responding rapidly to new outbreaks of infectious disease in the community. However, wastewater collected by grab samples may miss marker presence, and composite auto-sampling throughout a day is technically challenging and costly. Tampon swabs can be used as passive collectors of wastewater markers over hours, but recovery of the captured markers is a challenge. Our goal was to improve tampon elution methods for virus detection and variant analysis to increase the likelihood of detection near the Limit of Detection (LOD) and to potentially detect new or rare variants in a new outbreak. Counts of SARS-CoV-2 N1 and N2 markers in grab samples were compared to markers eluted from tampons that had been immersed in 3 sewersheds for 4–6 h during June to December 2023. We compared tampon elution methods that used different elution volumes, pressure, and amounts of Tween 20, evaluated after automated magnetic bead purification and RT-ddPCR of SARS-CoV-2 markers. Overall, method “SwabM2” in which tampons were eluted by high pressure squeeze in a 50 mL syringe after adding 2 mL of 0.5 X TE + 0.075 % Tween-20 yielded a median four-fold higher concentration of final purified SARS-CoV-2 markers than paired grab samples and significantly more than other tested tampon elution methods (p < 0.0001). Method SwabM2 was more likely to yield enough extracted nucleic acids for sequencing and also gave higher quality variant sequences than two other tampon elution methods. Variant analysis captured the Fall 2023 transition of variants from XBB to JN and “H” lineages. In summary, we demonstrated a tampon-based wastewater collecting and elution method that yielded higher counts, more detections near the LOD, and higher quality variant sequences compared to both grab samples and other tampon-based passive-collecting wastewater methods.

Spatially and temporally precise microbiome profiling in the small intestine using the SIMBA capsule with X-ray tracking

IntroductionFew minimally invasive options for sampling the small intestinal (SI) luminal fluid exist to study the SI microbiota in health and disease. To address the lack of tools and methods to study GI regions that are difficult to access, Nimble Science developed a fully autonomous and passive sampling method, the Small Intestine MicroBiome Aspiration (SIMBA™) capsule, for convenient, high-quality, and reliable sampling to study the diet-microbiota interactions in the SI. MethodsThe sealing efficacy and microbial DNA preservation capacity of the SIMBA capsules was first validated through in vitro simulation assays. Then, a clinical study was conducted with 20 healthy participants to validate the in vivo use of SIMBA capsules to reliably capture samples for SI microbiome analysis before and after an intervention (NCT04489329). Briefly, participants ingested the capsules at baseline and 7 days later, with a probiotic capsule containing a blend of L. rhamnosus R0011 and B. longum R0175. Following baseline SIMBA capsule ingestion, multiple low-dosage x-ray scans were performed to track the sampling location. Fecal samples corresponding with the baseline and intervention capsule were analyzed for comparison. ResultsThe SIMBA capsules’ performance in vitro demonstrated the potential for contamination-free sampling with preservation of the microbial communities. Within the clinical study, the capsules performed safely and reliably for collection of SI content. X-ray tracking confirmed that 97.2% of the capsules completed sample collection in the SI regions before reaching the colon. Importantly, our data showed that the capsules sampled in the right area of the intestines and that baseline SIMBA microbiome profile is significantly different from fecal microbiome profile. SIMBA successfully detected a concurrent probiotic intervention in the small intestine, which was not detectable using stool samples. DiscussionsThe high accuracy of sampling location and sealing efficacy of the SIMBA capsules makes them potentially useful research tools in clinical trials for studying diet-microbiota interactions in health and disease, and perhaps eventually for the clinical diagnosis of GI tract conditions affecting the SI such as SIBO.

A passive fish sampling method is representative for size but selective for parasite load

Fish capture in industrial aquaculture is both necessary (i.e., for transfer, monitoring and harvesting) and difficult. The most logistically feasible methods rely heavily on crowding, a process that is detrimental to fish welfare and production outcomes. Jump nets, which rely on passive capture via jumping behaviour, present a welfare-friendly alternative. But reliance on behaviour means capture is not guaranteed, and limited knowledge of their capture rate and sampling biases means they are not yet used to their full potential. Here, in sea-cages stocked with Atlantic salmon Salmo salar, we investigated how capture rate varied with net size, position, and time of day, and if salmon caught via jump net were representative of the sea-cage population. A comparison of jumping rates into surface rings (without nets) indicated that larger jump nets will catch more fish. Capture rate was highest in rings positioned in the centre of cages, and during the morning and evening. Jump nets sampled representatively for fish size but caught salmon with marginally lower condition (<2% difference) and with three times higher parasitic salmon louse (Lepeophtheirus salmonis) loads than fish caught using lift nets. Our results indicate that jump nets can be used as a size-representative sampling tool and to target lice infected salmon for treatment.

The Representativeness of Subslab Soil Gas Collection as Effected by Probe Construction and Sampling Methods

AbstractSubslab soil gas (SSSG) samples were collected as part of an investigation to evaluate vapor intrusion (VI) into a building. The June 2015 Office of Solid Waste and Emergency Response (OSWER) VI Guide (U.S. Environmental Protection Agency [U.S. EPA] 2015) does not provide specific, detailed recommendations regarding how to collect SSSG samples. The data collected in this study will be used to provide input into future OSWER VI Guidance documents on SSSG sample collection. To this end, three different types of subslab sampling ports were constructed with various sampling techniques within a hexagon‐shaped grid in near proximity to each other. Conventional‐, Vapor Pin‐, and California‐style ports were established in duplicate for continual analysis by onsite gas chromatography‐electron capture detection (GC‐ECD). Triplicate ports were established to evaluate active and passive long‐term sampling methods to determine short range temporal differences. Active sampling methods included evacuated stainless‐steel canisters fitted with capillary flow controllers (Modified U.S. EPA Method TO‐15 [U.S. EPA 1999a]) and sorbent tubes collected using a syringe (Modified EPA TO‐17 [U.S. EPA 1999b]). The Passive sampling method used was sorbent tube samples collected following the EPA TO‐17 sampling method (Modified). This study did not identify any systematic differences in sample results between conventional, Vapor Pin, and CA‐style probes for used in SSSG sampling. The decisions for site management would probably be the same for data from any subslab port style, active or passive sampling techniques over durations less than 2 weeks.

A scalable, passive sampling method for the quantification of airborne allergens

Traditionally, airborne concentrations of aeroallergens are sampled in a single location by an active sampler, which requires electricity and regular maintenance. However, aeroallergen concentrations may vary widely over urban and rural environments, requiring a method that is cost-effective and scalable so that many measurements can be made across an air shed. We developed such a method that uses passive sampling and light microscopy for analysis. Inexpensive and easy to operate, passive samplers rely on the gravitational settling of particles onto microscope slides. This determines airborne pollen concentration through: 1) sample collection using a modified Durham sampler, 2) preparation of samples for microscopy and strategic sample imaging, and 3) simplified particle measurements and calculation of pollen concentration following deposition velocity models proposed by Scheppegrell [1] and Wagner and Leith [2]. This method was verified with two sampling campaigns during the ragweed season of 2020 and the tree pollen season of 2021. The concentrations determined with the passive and Burkard sampling methods were found to be well-correlated (r > 0.99, r = 0.87) and precise (%CV = 20 %, 21 %). The validation of passive samplers will enable measurements of aeroallergens over wider spatial scales and help determine where aeroallergen exposure risks are greatest.•An inexpensive and low-cost method was developed to determine airborne pollen counts.•The method was evaluated for its accuracy and reproducibility.•The method can be applied to examine the concentrations and spatial variability of airborne pollen.

Estimation of nitrogen dioxide levels on streets from Fortaleza Brazil using passive sampling and multivariate analysis

The increase in the fleet of motor vehicles circulating in urban centers is one of the main generators of gaseous pollutants harmful to human health and the environment. Pollutants can be economically and effectively monitored through passive sampling. This study aims to estimate NO2 levels on roads of Fortaleza city /CE using the passive sampling method. 12 campaigns covered the rainy (March-June) and the dry (July-November) seasons in 2019. The seasonal averages of NO2 in the rainy season were higher than the dry one, and Almirante Rubim Street showed the greatest difference in the averages: 26.6 µg m-3 in the rainy and 19.3 µg m-3 in the dry season. The principal component analysis applied to the averages of NO2 concentration in the rainy and dry seasons, vehicle traffic and Height of the road/width ratio indicated that components 1, 2 and 3 explain 94.4% of the studied cases. Passive sampling proved to be efficient, contributing to the production of unpublished data about NO2 levels in streets of Fortaleza/Ceará/Brazil from mobile sources.

Enhancing Surgical Safety: Microbiological Air Control in Operating Theatres at University Medical Centre Maribor.

the aim of the study was to assess microbiological air quality in operating theatres by determining the level of microbiological contamination of the air and critical surfaces using the passive air sampling method and compliance of the operating theatre staff with infection control measures. The prospective study was conducted in the surgical block of the University Medical Centre Maribor. For two months continuously, ten operating theatres were assessed for microbial contamination of air and surfaces during quiet and active times of the day. A passive air sampling method with Petri dishes on an agar specially adapted for this purpose (plate count agar) was used. In addition, ten surgical procedures were observed to assess staff compliance with recommended practises. Air samples met microbiological standards in all operating theatres. In both sampling sessions of the day (quiet and active periods), microbial contamination of the air was always within the limit of 10 CFU/m3. The average number of bacterial colonies was zero to two during quiet phases and one to four during active phases. Approximately 60% of the isolates from the operating theatres belonged mainly to the genus Staphylococcus: S. epidermidis (36% of the isolates), S. hominis (17.5%) and S. haemolyticus (5.5%). The rest were identified as Streptococcus anginosus (23%) and Bacillus sp. (18%). Pathogenic bacteria and moulds were not present. In regard to staff compliance with good surgical practise, the former varied by behaviour and function, with non-compliance in pre-operative skin preparation and operating theatre congestion being notable. The cleanliness of the environment was satisfactory. Microbiological air control is extremely important for the safety and success of both surgical and postoperative practises. In spite of good results obtained in the study, further improvements in surgical staff compliance with good surgical practise are essential to reduce surgical site infections.

Utility of a modified o-DGT passive sampler for measurement of bisphenol analogues in freshwater and coastal waters

Bisphenol analogues (BPs) are commonly found in riverine and coastal waters. However, the lack of a reliable and robust passive sampling method has hindered our ability to monitor these compounds in aquatic systems. The study developed a novel organic-diffusive gradients in thin film (o-DGT) sampler based on stainless steel mesh membrane, polyacrylamide diffusive gel, and hydrophilic-lipophilic balance (HLB) binding gel. This innovative design tackled issues of filter membrane sorption in traditional o-DGT devices and potential gel damage in membrane-less o-DGT devices, showing promising application prospects. The mass accumulation of 15 target BPs was linear over 10 days in both freshwater (r2 ≥ 0.92) and seawater (r2 ≥ 0.94), with no saturation observed. The diffusion coefficients (D) through polyacrylamide diffusive gels ranged from 4.04 × 10−6 to 5.77 × 10−6 cm2 s−1 in freshwater and from 1.74 × 10−6 to 4.69 × 10−6 cm2 s−1 in seawater for the target BPs (except for bisphenol PH) at 22 °C. The D values of the target BPs in seawater were lower than those in freshwater due to the high salinity in seawater (35 ‰). The o-DGT samplers demonstrated good integrity in field applications. The total concentrations of the eight detected BPs ranged from 9.2 to 323 ng L−1, which was consistent with the measurements obtained by grab sampling. Among all BPs, bisphenol S, bisphenol F, and bisphenol A were consistently detected at all sites using both sampling methods. The concentrations of some novel BPs in coastal water measured by grab sampling were comparable to those measured in rivers, suggesting the need to strengthen pollution control of BPs in coastal areas. These results indicate that the o-DGT passive sampling method developed in the present study can be effectively used for monitoring BPs in freshwater and coastal environments.

Highly sensitive passive sampling of new pollutants in urban reclaimed water using hydrophilic-lipophilic balance sorbent-embedded cellulose acetate membrane

Urban reclaimed water is important water resource in China, while the residual new pollutants in the water largely challenge their safety for further use. China's action program for the management of new pollutants (also known as emerging contaminants) requires effective method for monitoring diverse new pollutants in water. This work proposed a highly sensitive passive sampling method for monitoring diverse new pollutants in urban reclaimed water. Hydrophilic–lipophilic balance sorbent-embedded cellulose acetate membranes (HECAMs) were dynamically deployed in self-developed continuous flow integrative sampling device (CFISD) for sampling four types of new pollutants with wide polarity ranges (1.11 < log Kow < 9.49) in a reclaimed water network for landscape irrigation in Beijing, China. The estimated equilibrium partition ratios of most chemicals between HECAM and water were over 104, which would provide low detection limits. In the 7-d high-efficiency deployment, thirty new pollutants were detected, which indicated incompletely removal of various new pollutants in wastewater treatment process. The dynamical accumulation data were successfully fitted by first-order kinetic model and different contaminants reached different accumulation phases in the HECAMs during 7 d. Acceptable and steady uptake rate constants and sampling rates were obtained with the use of CFISD in field sampling. The estimated time-weighted average concentrations for contaminants had wide concentration range and were from 0.03 ng L−1 (pendimethalin) to 3,394 ng L−1 (dibutyl phthalate) and this may lead to environmental risk for further use the reclaimed water. Dynamical deployment results also provided sensitive information of concentration fluctuations and twelve pollutants showed concentration fluctuations during the sampling period. In summary, HECAM showed high sensitivities and credible performance of monitoring diverse new pollutants in the urban reclaimed water.

Assessment of Portuguese fitness centers: Bridging the knowledge gap on harmful microbial contamination with focus on fungi

The lack of knowledge regarding the extent of microbial contamination in Portuguese fitness centers (FC) puts attendees and athletes at risk for bioaerosol exposure. This study intends to characterize microbial contamination in Portuguese FC by passive sampling methods: electrostatic dust collectors (EDC) (N = 39), settled dust (N = 8), vacuum filters (N = 8), and used cleaning mops (N = 12). The obtained extracts were plated in selective culture media for fungi and bacteria. Filters, EDC, and mop samples' extracts were also screened for antifungal resistance and used for the molecular detection of the selected Aspergillus sections. The detection of mycotoxins was conducted using a high-performance liquid chromatograph (HPLC) system and to determine the cytotoxicity of microbial contaminants recovered by passive sampling, HepG2 (human liver carcinoma) and A549 (human alveolar epithelial) cells were employed. The results reinforce the use of passive sampling methods to identify the most critical areas and identify environmental factors that influence microbial contamination, namely having a swimming pool. The cardio fitness area presented the highest median value of total bacteria (TSA: 9.69 × 102 CFU m−2.day−1) and Gram-negative bacteria (VRBA: 1.23 CFU m−2.day−1), while for fungi it was the open space area, with 1.86 × 101 CFU m−2.day−1. Aspergillus sp. was present in EDC and in filters used to collect settled dust. Reduced azole susceptibility was observed in filters and EDC (on ICZ and VCZ), and in mops (on ICZ). Fumonisin B2 was the only mycotoxin detected and it was present in all sampling matrixes except settled dust. High and moderate cytotoxicity was obtained, suggesting that A549 cells were more sensitive to samples’ contaminants. The observed widespread of critical toxigenic fungal species with clinical relevance, such as Aspergillus section Fumigati, as well as Fumonisin B2 emphasizes the importance of frequent and effective cleaning procedures while using shared mops appeared as a vehicle of cross-contamination.

Comparing the effectiveness of pitfall traps and active sampling methods for ants and spiders in a Chromolaena odorata invaded site

Background: Active and passive arthropod sampling techniques have their specific limitations. Pitfall trapping is a commonly used passive sampling method, and bush beating, aerial hand collection above the knee, aerial hand collection below the knee cryptic and non-cryptic are widely used active sampling techniques. Objective and method: Pitfall traps and four active sampling techniques were used in a Chromolaena odorata invaded site to compare the methods used in sampling arthropods in Buffelsdraai Conservancy outside the city of Durban, South Africa. Results: Pitfall traps were the most efficient and the most effective sampling technique with high species richness for both the ant (78%) and spider (76%) samples. One explanation for these differences could be the longer sampling time for passive sampling compared to active sampling. Conclusion: Compared to the subjective identification of species by collectors in active techniques, the non-selective capturing of species by pitfall traps improves its efficiency. The fewest taxa and individuals were collected by aerial hand collection techniques but these techniques are recommended to supplement pitfall traps. The combination of methods allows for the adequate sampling of the various strata found in vegetatively complex sites. An investigation into the possible use of canopy techniques in C. odorata sites would be beneficial, as it considers the various vegetation strata when sampling for biodiversity.

Determination of formaldehyde in indoor air by active and passive sampling methods

Formaldehyde (HCHO), the simplest molecule of the aldehyde group, is a toxic gas commonly found in indoor air. Many analysis methods have been developed to determine concentrations of formaldehyde in air, including sampling methods (active sampling and passive sampling), analytical methods (spectrophotometry, chromatography), and sensors. In general, the active sampling method is the standard and widely used method, and the passive sampling method is relatively simple, low-cost, and easy to implement. Gas sensing, meanwhile, is a quick detection method and has a lot of research potential. The purpose of this article is to compare analytical methods of formaldehyde in air and to summarize their advantages and disadvantages. This paper also focuses on HCHO passive samplers (the principle of operation, sampler geometries (tube, badge), validation experiments in the laboratory, and their applications in the determination of HCHO in personal/indoor air.

Calibration of a passive sampling device for the determination of nitrogen dioxide in ambient air

Nitrogen dioxide (NO2), a common air pollutant, has been widely admitted to be harmful to both the environment and human health, demanding its well-control procedure and corresponding quantification. In this study, NO2 in ambient air was collected by a passive sampling method using the Willems badge diffusive sampler, followed by a derivatization step with the Griess-Saltzman solution, and analyzed by ultraviolet-visible (UV–vis) spectroscopy at 543 nm. The device can be utilized for 168 h of continuous field sampling. The experimental sampling rate (Ke) of (4.02 ± 0.29) × 10−3 m3h−1 with a relative standard deviation (% RSD) of 9.6 % was determined by conducting parallel experiments between an active sampling method (ISO 6768:1998) and the Willems samplers. After exposure time, samplers could be stored for two weeks in a refrigerator at 4 °C before analyzing. The studied passive diffusive sampler was simple, low-cost, easy to reuse; permitted determining the average concentration of NO2 in ambient air. The average NO2 concentrations for 2-hour to 4-hour sampling periods at different studied sampling sites in Ho Chi Minh city (Vietnam) were ranged from 11.5 to 189 μg m−3.

A case study on the application of spore sampling for the monitoring of macrofungi.

Fungi play a vital role in ecosystem functioning, yet significant knowledge gaps persist in understanding their diversity and distribution leading to uncertainties about their threat status and extinction risk. This is partly owed to the difficulty of monitoring fungi using traditional fruiting body surveys. The present study evaluates airborne environmental DNA (eDNA) sampling as a monitoring tool with a focus on grassland macrofungi. We applied active and passive air sampling methods, complemented by extensive field surveys of waxcap and clavarioid fungi-species groups of high relevance for conservation. Twenty-nine species were recorded during the field surveys, 19 of which were also detectable by ITS2 metabarcoding of the collected samples. An additional 12 species from the studied genera were identified exclusively in air eDNA. We found that the patterns of species detection and read abundance in air samples reflected the abundance and occurrence of fruiting bodies on the field. Dispersal kernels fitted for the three dominant species predicted rapidly decreasing spore concentrations with increasing distance from fruitbodies. Airborne assemblages were dominated by a high diversity of common species, while rare and threatened red-listed species were under-represented, which underscores the difficulty in detecting rare species, not only in conventional surveys. Considering the benefits and drawbacks of air sampling and fruitbody surveys, we conclude that air sampling serves as a cost- and time-efficient tool to characterize local macrofungal communities, providing the potential to facilitate and improve future fungal monitoring efforts.

Wastewater-based epidemiology surveillance as an early warning system for SARS-CoV-2 in Indonesia.

Wastewater-based epidemiology (WBE) surveillance has been proposed as an early warning system (EWS) for community SARS-CoV-2 transmission. However, there is limited data from low-and middle-income countries (LMICs). This study aimed to assess the ability of WBE surveillance to detect SARS-CoV-2 in formal and informal environments in Indonesia using different methods of sample collection, to compare WBE data with patterns of clinical cases of COVID-19 within the relevant communities, and to assess the WBE potential to be used as an EWS for SARS-CoV-2 outbreaks within a community. We conducted WBE surveillance in three districts in Yogyakarta province, Indonesia, over eleven months (27 July 2021 to 7 January 2022 [Delta wave]; 18 January to 3 June 2022 [Omicron wave]). Water samples using grab, and/or passive sampling methods and soil samples were collected either weekly or fortnightly. RNA was extracted from membrane filters from processed water samples and directly from soil. Reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR) was performed to detect the SARS-CoV-2 N and ORF1ab genes. A total of 1,582 samples were collected. Detection rates of SARS-CoV-2 in wastewater reflected the incidence of community cases, with rates of 85% at the peak to 2% at the end of the Delta wave and from 94% to 11% during the Omicron wave. A 2-week lag time was observed between the detection of SARS-CoV-2 in wastewater and increasing cases in the corresponding community. WBE surveillance for SARS-CoV-2 in Indonesia was effective in monitoring patterns of cases of COVID-19 and served as an early warning system, predicting the increasing incidence of COVID-19 cases in the community.

Development and validation of diffusive gradients in thin-films for in situ monitoring of ionic liquids in waters.

Due to their wide applications, occurrence and "PFAS-like" environmental behaviors, ionic liquids (ILs) represent a new challenge for the environmental monitoring community, who require robust analytical methods that can determine accurately and efficiently their environmentally relevant concentrations. A new passive sampling method based on the diffusive gradients in thin films (DGT) technique was developed for the measurement of imidazole-based ILs in waters using a mixed-mode cation exchange (MCX) resin as the adsorbent. The selected binding gel had a high binding capacity (>170 μg per disc) for ILs. Diffusion coefficients measured using a diffusion cell correlated well with alkyl chain lengths (r2 = 0.95) and retention times (r2 = 0.88), providing a simple and rapid prediction approach for other ILs. The assembled MCX-DGT sampler exhibited a linear accumulation for at least 120 h. MCX-DGT also showed good performance under typical freshwater conditions (pH 5-8, ionic strength 0.001-0.01 M, and humic acid 0-5 mg L-1), while still being problematic for aquatic conditions with higher ionic strength (>0.1 M) or DOM (>10 mg L-1). Laboratory deployment (for up to 3 days) in spiked natural freshwater (SNW) resulted in linear mass uptakes for the short-chain ILs (C2-C8), and their DGT-measured concentrations agreed well with solution concentrations. However, MCX-DGT significantly overestimated the concentrations of the long-chain ILs (C10-C12) when deployed in SNW for one day or more, which is attributed to the strong competitive adsorption of the long-chain ILs by natural organic matter. In situ field evaluation along with grab sampling found no target ILs in a wastewater treatment plant and its receiving river, implying that these new chemicals might not be widely used in South China now. This is the first report on the DGT technique for ILs and might provide an effective tool for monitoring short chain length ILs in the aquatic environment in the near future.

Advancing the analytical toolkit in the investigation of vector mosquito host biting site selection.

High-resolution mass spectrometry and ion mobility spectrometry provide additional confidence in biological marker discovery and elucidation by adding additional peak capacity through physiochemical separation orthogonal to chromatography. Sophisticated analytical techniques have proved valuable in the identification of human skin surface chemicals used by vector mosquitoes to find their human host. Polydimethylsiloxane (PDMS) was used as a non-invasive passive wearable sampler to concentrate skin surface non-volatile and semi-volatile compounds prior to solvent desorption directly in an LC vial, thereby simplifying the link between extraction and analysis. Ultra-performance liquid chromatography with ion mobility spectrometry coupled with high-resolution mass spectrometry (UPLC-IMS-HRMS) was used for compound separation and detection. A comparison of the skin chemical profiles between the ankle and wrist skin surface region sampled over a 5-day period for a human volunteer was done. Twenty-three biomarkers were tentatively identified with the aid of a collision cross-section (CCS) prediction tool, seven associated with the ankle skin surface region and 16 closely associated with the wrist skin surface. Ten amino acids were detected and unequivocally identified on the human skin surface for the first time. Furthermore, 22 previously unreported skin surface compounds were tentatively identified on the human skin surface using accurate mass, CCS values and fragmentation patterns. Method limits of detection for the passive skin sampling method ranged from 8.7 (sulfadimethoxine) to 95 ng (taurine). This approach enabled the detection and identification of as-yet unknown human skin surface compounds and provided corresponding CCS values.