Air Sampling Device Research Articles

Influenza A(H5N1) shedding in air corresponds to transmissibility in mammals.

An increase in spillover events of highly pathogenic avian influenza A(H5N1) viruses to mammals suggests selection of viruses that transmit well in mammals. Here we use air-sampling devices to continuously sample infectious influenza viruses expelled by experimentally infected ferrets. The resulting quantitative virus shedding kinetics data resembled ferret-to-ferret transmission studies and indicated that the absence of transmission observed for earlier A(H5N1) viruses was due to a lack of infectious virus shedding in the air, rather than the absence of necessary mammalian adaptation mutations. Whereas infectious human A(H1N1pdm) virus was efficiently shed in the air, infectious 2005 zoonotic and 2024 bovine A(H5N1) viruses were not detected in the air. By contrast, shedding of infectious virus was observed for 1 out of 4 ferrets infected with a 2022 European polecat A(H5N1) virus and a 2024 A(H5N1) virus isolated from a dairy farm worker.

Surgical Face Mask as an Air Sampling Device for Assessing Personal Exposure to Airborne Antimicrobial Resistance Gene-Bearing Bacteria.

In this study, we assessed the feasibility of using a surgical face mask as a sampling device to collect airborne antimicrobial resistance genes (ARGs). The method entails collection of ARG-bearing microbes on face masks, followed by their DNA extraction and quantification by qPCR analysis. Analysis of masks worn by volunteers showed an apparent mask wearing time-dependent accumulation of 16S rRNA gene and select ARGs trapped on masks, highlighting the applicability of the method in monitoring personal ARG exposure through inhalation. The sampling method was then validated for reproducibility and compared with a filter-based sampling method before application in different environmental settings to further assess personal exposure to ARGs. In comparison with the filter-based method, our new sampling method does not require a sampling pump and is more user-friendly. More importantly, it records ARG exposure down to the personalized level; thus, it may be used in routine monitoring of occupational exposure and surveillance of ARG concentrations in indoor environments.

Bacterial contamination of air and surfaces during dental procedures-An experimental pilot study using Staphylococcus aureus.

The oral cavity contains numerous microorganisms, including antimicrobial-resistant bacteria. These microorganisms can be transmitted via respiratory particles from patients to healthcare providers and vice versa during dental care. We evaluated the spread of Staphylococcus aureus during standardized dental procedures using different scaling devices and rinsing solutions. During systematic therapy for dental biofilm removal (guided biofilm therapy), using an airflow or ultrasound device to a model simulation head. Staphylococcus aureus suspension was injected into the mouth of the model to mimic saliva. Different suction devices (conventional saliva ejector or a prototype) and rising solutions (water or chlorhexidine) were used. To assess contamination with S. aureus, an air-sampling device was placed near the oral cavity and samples of surface areas were collected. S. aureus was only detected by air sampling when the conventional saliva ejector with airflow was used. No growth was observed during treatments with the ultrasonic piezo instrument or the prototype suction device. Notably, a rinsing solution of chlorhexidine digluconate decreased the bacterial load compared to water. Surface contamination was rarely detected (1 of 120 samples). Although our findings indicate potential airborne bacterial transmission during routine prophylactic procedures, specific treatment options during biofilm removal appear to reduce air contamination. These options include ultrasonic piezo devices or the prototype suction device. The use of chlorhexidine reduced the CFU counts of S. aureus detected by air sampling. Surface contamination during dental procedures was a rare occurrence.

AirDNA sampler: An efficient and simple device enabling high-yield, high-quality airborne environment DNA for metagenomic applications.

Analyzing temporal and spatial distributions of airborne particles of biological origins is vital for the assessment and monitoring of air quality, especially with regard to public health, environmental ecology, and atmospheric chemistry. However, the analysis is frequently impeded by the low levels of biomass in the air, especially with metagenomic DNA analysis to explore diversity and composition of living organisms and their components in the air. To obtain sufficient amounts of metagenomic DNA from bioaerosols, researchers usually need a long sampling time with an expensive high-volume air sampler. This work shows the utilization of an air sampling device containing an economical, high-volume portable ventilation fan in combination with customized multi-sheet filter holders to effectively obtain high yields of genomic DNA in a relatively short time. The device, named 'AirDNA' sampler, performed better than other commercial air samplers, including MD8 Airport and Coriolis compact air samplers. Using the AirDNA sampler, an average DNA yield of 40.49 ng (12.47-23.24 ng at 95% CI) was obtained in only 1 hour of air sampling with a 0.85 probability of obtaining ≥10 ng of genomic DNA. The genomic DNA obtained by the AirDNA system is of suitable quantity and quality to be further used for amplicon metabarcoding sequencing of 16S, 18S, and cytochrome c oxidase I (COI) regions, indicating that it can be used to detect various prokaryotes and eukaryotes. Our results showed the effectiveness of our AirDNA sampling apparatus with a simple setup and affordable devices to obtain metagenomic DNA for short-term or long-term spatiotemporal analysis. The technique is well suited for monitoring air in built environments, especially monitoring bioaerosols for health purposes and for fine-scale spatiotemporal environmental studies.

Occurrence and backtracking of microplastic mass loads including tire wear particles in northern Atlantic air

Few studies report the occurrence of microplastics (MP), including tire wear particles (TWP) in the marine atmosphere, and little data is available regarding their size or sources. Here we present active air sampling devices (low- and high-volume samplers) for the evaluation of composition and MP mass loads in the marine atmosphere. Air was sampled during a research cruise along the Norwegian coast up to Bear Island. Samples were analyzed with pyrolysis-gas chromatography-mass spectrometry, generating a mass-based data set for MP in the marine atmosphere. Here we show the ubiquity of MP, even in remote Arctic areas with concentrations up to 37.5 ng m−3. Cluster of polyethylene terephthalate (max. 1.5 ng m−3) were universally present. TWP (max. 35 ng m−3) and cluster of polystyrene, polypropylene, and polyurethane (max. 1.1 ng m−3) were also detected. Atmospheric transport and dispersion models, suggested the introduction of MP into the marine atmosphere equally from sea- and land-based emissions, transforming the ocean from a sink into a source for MP.

Detection of hospital environmental contamination during SARS-CoV-2 Omicron predominance using a highly sensitive air sampling device.

The high transmissibility of SARS-CoV-2 has exposed weaknesses in our infection control and detection measures, particularly in healthcare settings. Aerial sampling has evolved from passive impact filters to active sampling using negative pressure to expose culture substrate for virus detection. We evaluated the effectiveness of an active air sampling device as a potential surveillance system in detecting hospital pathogens, for augmenting containment measures to prevent nosocomial transmission, using SARS-CoV-2 as a surrogate. We conducted air sampling in a hospital environment using the AerosolSenseTM air sampling device and compared it with surface swabs for their capacity to detect SARS-CoV-2. When combined with RT-qPCR detection, we found the device provided consistent SARS-CoV-2 detection, compared to surface sampling, in as little as 2 h of sampling time. The device also showed that it can identify minute quantities of SARS-CoV-2 in designated "clean areas" and through a N95 mask, indicating good surveillance capacity and sensitivity of the device in hospital settings. Active air sampling was shown to be a sensitive surveillance system in healthcare settings. Findings from this study can also be applied in an organism agnostic manner for surveillance in the hospital, improving our ability to contain and prevent nosocomial outbreaks.

Molecular Typing of Bacterial Pathogens Isolated from Air, Non-Living Surfaces and Clinical Sources in Diyala Governorate Using MLST Technique

The study aimed to isolate and diagnose bacterial species from clean room air samples for caesarean sections, natural childbirth, sterile preterm infants halls and the sub-corridors leading to these halls and main corridors of the hospital and from the air outside hospital building with isolation and diagnosis of bacterial species from non- living surface and clinical samples that were withdrawn from inside Al-Zahra Hospital for Women and Children in AL-Muqdadiya district in Diyala Governorate – Iraq that extends at latitudes (-3.33 and -36.6) north and longitudes (-44.22 and 45.56) east, during the period from 25 December 2021 to 19 February 2022 in light of the lack of studies that are concerned with this aspect, as 192 air samples were taken distributed to the hospital halls, such as the surgery hall and its sub-corridor leading to it, the delivery hall and its sub-corridor leading to it, the sterile preterm infant unit and its sub-corridor leading to it, the main corridor of these halls, and the air outside the hospital environment, where the air samples distributed into two groups, the first included 96 samples collected in the morning before the start of work at 8 am and the second also included 96 samples collected during Work (noon) at 12 noon ; also, 208 different swabs were collected from patients included 85 swabs after surgeries (caesarean section after suture lift after 7-10 days after delivery), 60 vaginal swabs from patients inside the delivery hall and 63 swabs from newborns lying inside the sterile preterm hall. Also, swabs were collected from non-living surfaces amounting to 100 swabs withdrawn from the natural delivery bed, caesarean section, floors, ventilation outlets, anesthesia device, fluid withdrawal device, incubators for preterm infants, ventilator and dressing cart. The total number of samples withdrawn by the effective method using the SAS air sampling device was 192, with 24 samples for each site, of which 172 samples were given a positive growth rate of 89.5%, the gram-positive bacteria constituted 69%, while the gram-negative bacteria formed an isolation rate of 31%. Sixty vaginal swabs were collected from women in the delivery hall during the examination before the birth began, 33 swabs gave a positive growth rate of 55%, of which 33 were bacterial isolated, the gram negative bacteria formed the isolates by 69.7%. 63 swabs were taken from newborns in the neonatal unit (either normal or caesarean section), those who were admitted to the preterm care hall as a result of complications during childbirth (suffering from shortness, rapid breathing and high bile in the first place, and from inflammation of the respiratory tract and urinary tract infection in the second degree), 38 swabs gave a positive growth rate of 63.3%, of which 38 bacterial isolates were mostly gram-negative bacteria. 85 swabs were taken from caesarean section wounds (7-10 days after caesarean section when the suture is lifted), 29 swabs gave a positive growth rate of 34%, the majority of which were 75.7% gram-negative bacteria. Twenty-six surface swabs gave a positive growth with a rate of 26%, of which 26 different bacterial isolates. The data of the bacterial typing analysis of the three strains of E. coli (multi-resistant bacteria) used in the molecular study by using MLST technique by using housekeeping genes showed that they are globally registered strains on the site of the Institute Pasteur in France, as the results showed that two bacterial isolates, which bear numbers (17,119) of air samples and clinical samples respectively, belong to the same strain (sequence type (ST)=741), while isolates No. (72) of surface samples belong to a different strain (ST=390). Molecular typing (MLST) was performed on three isolates of K. pneumonia (multi-resistant bacteria) where housekeeping genes were used for the purpose of testing. The strains obtained are new strains that have not been isolated before in Iraq, which means that our isolates are not registered in the MLST database at the Institute Pasteur in France.

The impact of ventilation rate on reducing the microorganisms load in the air and on surfaces in a room-sized chamber.

Hospital-acquired infections (HAIs) are a global challenge incurring mortalities and high treatment costs. The environment plays an important role in transmission due to contaminated air and surfaces. This includes microorganisms' deposition from the air onto surfaces. Quantifying the deposition rate of microorganisms enables understanding surface contamination and can inform strategies to mitigate the infection risk. We developed and validated a novel Automated Multiplate Passive Air Sampling (AMPAS) device. This enables sequences of passive deposition samples to be collected over a controlled time period without human intervention. AMPAS was used with air sampling to measure the effect of ventilation rate and spatial location on the deposition rate of aerosolized Staphylococcus aureus in a 32 m3 chamber. Increasing the ventilation rate from 3 to 6 ACH results in a reduction of microbial load in the air and on surfaces by 45% ± 10% and 44% ± 32%, respectively. The deposition rate onto internal surfaces λd was calculated as 1.38 ± 0.48 h-1 . Samples of airborne and surface microorganisms taken closer to the ventilation supply showed a lower concentration than close to the extract. The findings support the importance of controlling the ventilation and the environmental parameters to mitigate both air and surface infection risks in the hospital environment.

Are aerosol control devices effective in preventing the spread of dental aerosol?

BackgroundIn dental clinics, aerosols produced from dental instruments have become a matter of concern following breakout of coronavirus disease 19 (COVID-19) evolving into a pandemic. This study compared aerosol reduction systems and in terms of their ability to reduce Enterococcus faecalis (E. faecalis) contaminated aerosol in a simulated dental office set-up.MethodsClosed clinic model with manikin and mandibular molar typodont was simulated. For 10 min, the air and water dispersed by the rotating bur mounted on an aerator was contaminated by pouring the suspension containing 1–3 × 108 CFU/mL E. faecalis directly on the bur. During and after the procedures, the air within the cabin was also sampled. CFU count was recorded and scored. The mean CFU scores obtained from agar plate count and air sampling device was compared using Kruskal–Wallis H test among groups with 5% significance threshold.ResultsThe use of WS Aerosol Defender device led to greater CFU scores on the agars levelled to patient’s chest compared to other directions (p = 0.001). Combined use of VacStation and WS Aerosol Defender resulted in significantly decreased CFU score in the air samples compared to experimental and positive control groups (p = 0 < 0.05).ConclusionsAlthough the devices prevented the spread of aerosol around the patient to some extent, they could not completely eliminate the contaminated aerosol load in the cabin environment.

A study of the vertical homogeneity of trace gases in East Asian continental outflow

East Asian continental outflows containing with pollutants may deteriorate air quality in the downwind region via long-range transport (LRT). In particular, cold fronts with high wind speeds generally promote the LRT of air pollutants to further downwind areas, including Taiwan. To gain an insightful understanding of the characteristics and vertical homogeneity of trace gases in East Asian continental outflows, as well as their relation with atmospheric meteorological conditions, whole air samples were collected above a cape at the northern tip of the island of Taiwan during frontal passages. Aerial samples were collected at multiple altitudes from the surface to a maximum height of 700 m with a multicopter sounding platform carrying a robotic whole air sampling device. Simultaneously, aerial meteorological variables of temperature and wind vector from near the surface to a maximum height of 1000 m were also measured during the whole air sampling periods. An array of 106 volatile organic compounds (VOCs) as well as CO, CO2, and CH4 were analyzed to characterize the air composition and vertical homogeneity of trace gases. The results revealed rather homogeneous vertical distributions of most VOCs, CO, CO2, and CH4 in the frontal passages, indicating well-mixed conditions of trace gases in the East Asian continental outflows. The strong wind shear and minimal temperature inversion associated with the frontal passage likely induced turbulence and increased vertical mixing. Furthermore, higher levels of species characteristic of the East Asian continent were observed from the surface up to hundreds of meters above the cape, revealing a strong inflow of polluted air masses from the East Asian continent brought by cold frontal passages.

Airborne environmental DNA for terrestrial vertebrate community monitoring

SummaryBiodiversity monitoring at the community scale is a critical element of assessing and studying species distributions, ecology, diversity, and movements, and it is key to understanding and tracking environmental and anthropogenic effects on natural ecosystems.1, 2, 3, 4 Vertebrates in terrestrial ecosystems are experiencing extinctions and declines in both population numbers and sizes due to increasing threats from human activities and environmental change.5, 6, 7, 8 Terrestrial vertebrate monitoring using existing methods is generally costly and laborious, and although environmental DNA (eDNA) is becoming the tool of choice to assess biodiversity, few sample types effectively capture terrestrial vertebrate diversity. We hypothesized that eDNA captured from air could allow straightforward collection and characterization of terrestrial vertebrate communities. We filtered air at three localities in the Copenhagen Zoo: a stable, outside between the outdoor enclosures, and in the Rainforest House. Through metabarcoding of airborne eDNA, we detected 49 vertebrate species spanning 26 orders and 37 families: 30 mammal, 13 bird, 4 fish, 1 amphibian, and 1 reptile species. These spanned animals kept at the zoo, species occurring in the zoo surroundings, and species used as feed in the zoo. The detected species comprise a range of taxonomic orders and families, sizes, behaviors, and abundances. We found shorter distance to the air sampling device and higher animal biomass to increase the probability of detection. We hereby show that airborne eDNA can offer a fundamentally new way of studying and monitoring terrestrial communities.

Evidence of Air and Surface Contamination with SARS-CoV-2 in a Major Hospital in Portugal.

As the third wave of the COVID-19 pandemic hit Portugal, it forced the country to reintroduce lockdown measures due to hospitals reaching their full capacities. Under these circumstances, environmental contamination by SARS-CoV-2 in different areas of one of Portugal’s major Hospitals was assessed between 21 January and 11 February 2021. Air samples (n = 44) were collected from eleven different areas of the Hospital (four COVID-19 and seven non-COVID-19 areas) using Coriolis® μ and Coriolis® Compact cyclone air sampling devices. Surface sampling was also performed (n = 17) on four areas (one COVID-19 and three non-COVID-19 areas). RNA extraction followed by a one-step RT-qPCR adapted for quantitative purposes were performed. Of the 44 air samples, two were positive for SARS-CoV-2 RNA (6575 copies/m3 and 6662.5 copies/m3, respectively). Of the 17 surface samples, three were positive for SARS-CoV-2 RNA (200.6 copies/cm2, 179.2 copies/cm2, and 201.7 copies/cm2, respectively). SARS-CoV-2 environmental contamination was found both in air and on surfaces in both COVID-19 and non-COVID-19 areas. Moreover, our results suggest that longer collection sessions are needed to detect point contaminations. This reinforces the need to remain cautious at all times, not only when in close contact with infected individuals. Hand hygiene and other standard transmission-prevention guidelines should be continuously followed to avoid nosocomial COVID-19.

Detection of Hospital Environmental Contamination During SARS-CoV-2 Omicron Predominance Using a Highly Sensitive Air Sampling Device

Detection of Hospital Environmental Contamination During SARS-CoV-2 Omicron Predominance Using a Highly Sensitive Air Sampling Device

Modeling polyurethane foam (PUF)-air partition coefficients for persistent organic pollutants using linear and non-linear chemometric methods

As an indispensable basic parameter in measuring the concentration of compounds by passive air sampling (PAS) devices, the partition coefficient could be further employed in quantitative analysis of environmental quality. Thus, it is an essential factor that should be fully considered in measuring and researching passive air sampling with respect to emerging compounds. In view of the polyurethane foam (PUF) has been used extensively for PAS, attempts to establish several traditional linear (pp-LFERs and QSPRs-MLR) and popular non-linear methods (QSPRs-ANN) were made in this work, to predict PUF-air partition coefficients (KPA) values at various ambient temperatures. It is noted that this work covers the partition characteristics of compounds at most cases of ambient temperatures by in silico models. These models were developed on large datasets, including 362 compounds from 14 different categories (e.g. Benzenes, PAHs, PCBs and Pesticides). The obtained 12 models have satisfactory prediction performance, goodness-of-fit and robustness as indicated by a series of mathematical statistics and multi-verification. In order to better explore the concentration level of organic pollutants in the atmosphere, internal comparison of the developed silico models were made in this work. Additionally, the essential nature and action mechanism of molecular descriptor indicated that ionization potential, polarizability, hydrophilicity, molecular bond and molecular branching had key action to partition process of chemicals. The proposed prediction models can act as a promising and effective tool for developing environmental assessment prediction methods.

Detection of Environmental Spread of SARS-CoV-2 and Associated Patient Characteristics.

Understanding transmission of severe acute respiratory syndrome coronavirus 2 informs infection prevention practices. Air sampling devices were placed in patient hospital rooms for consecutive collections with and without masks. With patient mask use, no virus was detected in the room. High viral load and fewer days from symptom onset were associated with viral particulate dispersion.

Development of A Low-cost Simultaneous Low Volume Air Sampler Controlled with Sonic Venturi

This study presents the results of designing a low-cost air sampler for multi-component analysis of PM2.5. We developed a multi-channel air sampling device using sonic venturi (critical nozzle) that supplies a constant airflow rate of 16.7 L/min. The constant flow rate is achieved with a backpressure ratio of 0.8 or less with a nozzle diameter of 1.375 mm. The sampler halves the cost of comparable devices and simplifies the hardware by replacing the flow meters with critical nozzles. For quantitative evaluation, we measured the coefficient of variation (CV) of each component simultaneously collected five samples at various particulate matter concentrations. This sampler can use different types of filters such as polytetrafluoroethylene and quartz fiber filter at the same time. Meteorological conditions such as ambient temperature, relative humidity and atmospheric pressure did not seem to affect much the flow rate of the sampler. The CV of multi sample analysis for TSP and PM2.5 concentrations in all sampling periods were less than 10%. CV of multi sample analysis for most of the major inorganic elements being within the range of 15% or less shows that the precision is sufficient for reliable measurement. We believe that the low-cost multiple air sampler will be used world-widely, and it can contribute to many researchers in both developed and developing countries.

A low-volume air sampling method for legacy and novel brominated flame retardants in indoor environment using a newly developed sorbent mixture

Brominated flame retardants (BFRs) are a series of stable and outstanding flame retardants bringing human exposure risks in indoor environment. However, sampling methods now available for BFRs are solvent-consuming and relatively complicated. This study provides a new option of low-volume air sampling device using cartridges with a sorbent mixture for different types of legacy and novel BFRs. In this study, we found that HC-C18 sorbent is most suitable for polybrominated diphenyl ethers (PBDEs) and novel BFRs (NBFRs) enrichment, and that NH2 for hexabromocyclododecanes (HBCDs). The sorbent mixture was optimized using a complex of HC-C18 and NH2 sorbents with elution recovery of 69.4% ± 7.9–117% ± 10%, pumping-through recovery of 84.5% ± 7.9–127% ± 36%, and breakthrough recovery of 70.8% ± 3.4–118% ± 6% for PBDEs, NBFRs, and HBCDs in indoor air. A sequential elution was also achieved using hexane for PBDEs and NBFRs and ethyl acetate for HBCDs. The method was validated with field sampling at nine student dormitory rooms. For legacy BFRs, all the isomers of HBCDs were detected in the air of nine rooms with the median concentrations of 91, 33, and 25 pg/m3 for (±)α-HBCD, (±)β-HBCD, (±)γ-HBCD, respectively, while PBDEs were hardly detected. In contrast, NBFRs were detected at total concentrations of 15–811 pg/m3. Pentabromotoluene (PBT) was the most frequently detected NBFRs with a median concentration of 4 pg/m3, followed by EHTBB at 56 pg/m3 and HBBZ at 21 pg/m3. For the risk assessment, the total hazard index value for air inhalation of BFRs was estimated at 6.1⎓10−4–0.35, which are consistently lower than 1, indicating no immediate health risk, while their long-term effects remain worth concerns.

Concurrent measurement of microbiome and allergens in the air of bedrooms of allergy disease patients in the Chicago area

The particulate and biological components of indoor air have a substantial impact on human health, especially immune respiratory conditions such as asthma. To better explore the relationship between allergens, the microbial community, and the indoor living environment, we sampled the bedrooms of 65 homes in the Chicago area using 23the patient-friendly Inspirotec electrokinetic air sampling device, which collects airborne particles for characterization of both allergens and microbial DNA. The sampling device captured sufficient microbial material to enable 16S rRNA amplicon sequencing data to be generated for every sample in the study. Neither the presence of HEPA filters nor the height at which the air sampling device was placed had any influence on the microbial community profile. A core microbiota of 31 OTUs was present in more than three quarters of the samples, comprising around 45% of the relative sequence counts in each bedroom. The most abundant single organisms were Staphylococcus, with other core taxa both human and outdoor-associated. Bacterial alpha diversity was significantly increased in bedrooms that reported having open windows, those with flowering plants in the vicinity, and those in homes occupied by dogs. Porphyromonas, Moraxella, Sutterella, and Clostridium, along with family Neisseraceae, were significantly enriched in homes with dogs; interestingly, cats did not show a significant impact on microbial diversity or relative abundance. While dog allergen load was significantly correlated with bacterial alpha diversity, the taxa that significantly correlated with allergen burden did not exclusively overlap with those enriched in homes with dogs. Alternaria allergen load was positively correlated with bacterial alpha diversity, while Aspergillus allergen load was negatively correlated. The Alternaria allergen load was also significantly correlated with open windows. Microbial communities were significantly differentiated between rural, suburban, and urban homes and houses that were physically closer to each other maintained significantly more similar microbiota. We have demonstrated that it is possible to determine significant associations between allergen burden and the microbiota in air from the same sample and that these associations relate to the characteristics of the home and neighborhoods.

Air Sampling: A Mini-denuder Sampling Device for Direct Desorption in an Inlet of a Gas Chromatograph for the Analyses of Airborne Gaseous Phase Pollutants and Airborne Particulate Phase Pollutants

We introduce a compact mini-denuder air sampling device consisting of a regular gas chromatograph (GC) inlet liner for the simultaneous concentration of separate airborne gaseous and particulate phases in a single-step. Denuder materials are thermally desorbed in a regular inlet of a GC using routine equipment available in any chromatography laboratory. The simplicity of the technique makes it ideal for resource-poor laboratories. Keywords: Air sampling, gas chromatography, denuder, polydimethylsiloxane (PDMS), thermal desorption

Bedroom exposure to airborne allergens in the Chicago area using a patient-operated sampling device

BackgroundIn current practice, allergens in vacuum-collected dust are used as surrogates for inhalable allergens. We developed an air-sampling device that can be used by patients for direct measurement of airborne allergen concentrations in their own homes. ObjectiveTo demonstrate the use of this device to establish allergen concentration reference ranges in a target population and to evaluate associations between patient-reported information and measured allergen concentrations. MethodsPatients from 5 allergist's practices in the Chicagoland region were provided with instructions, questionnaires, informed consent forms, and samplers to run for 5 days in their bedrooms. Samples were collected from cartridges and assayed by multiplex immunoassays for 12 common household allergens and enzyme-linked immunosorbent assay for ragweed. ResultsUnique allergen profiles were obtained for 102 patient homes. Samples with allergen concentrations above the limit of detection were as follows: total dust mite, 28%; cat, 61%; dog, 64%; mouse, 12%; rat, 0%; cockroach, 4%; Alternaria, 6%; Aspergillus, 21%; birch pollen 1%; grass, 8%; and ragweed, 5%. Of those, 75 completed questionnaires, providing meta-data for further analysis. Pet allergens correlated significantly with number of pets owned. Humidity correlated with dust mite allergens, open windows with Alternaria and mouse allergens, and high-efficiency particulate air filter use with reduced levels of several allergens. Many other variables showed no significant correlations. ConclusionThe combination of ease of use, high air-sampling rate, and sensitive immunoassays permitted the measurement of airborne allergen concentrations in homes and establishment of reference ranges. Patient-reported information permitted identification of factors that could relate to allergen concentrations and suggested remedial measures.