Passive Air Samplers Research Articles

Mycological analysis in three schools over four seasons using passive air sedimentation

The aim of the study is the isolation and identification of fungi using passive air sedimentation. This study analyzed 540 mycological samples from three primary schools in Zenica, collected in September, December, February, and May. Each season, 135 samples were taken from five rooms (two classrooms, a gym, a locker room, and a library) in each school. Samples were collected three times daily at three different heights with 15-minute exposure times. Samples were refrigerated and transported in sterile bags, incubated for 24 hours, and inoculated on specific agars with and without additives. Plates were incubated at 37°C and 25°C for up to 7 days, followed by examinations. Petri dishes were used for passive air sampling, and colonies were counted after incubation. The average number of microorganisms (CFU/m³) was calculated using Omeliansky’s method. Statistical methods included the Chi-squared test and p-value. Colony appearance was assessed visually and microscopically using a light microscope. Growth rate, size, structure, and color changes were monitored. In September, the highest mold concentrations were at H. Kikić Primary School (796 CFU/m³, not significant), M. Dizdar Primary School (1260 CFU/m³, not significant), and A. Šantić Primary School (3980 CFU/m³, significant). Penicillium spp. and Alternaria spp. were most prevalent, with Alternaria spp. significant at H. Kikić Primary School. In December, the highest mold/yeast concentrations were at H. Kikić Primary School (4578 CFU/m³, not significant), M. Dizdar Primary School (1924 CFU/m³, significant), and A. Šantić Primary School (2587 CFU/m³, not significant). Penicillium spp. was most prevalent. In February, the highest mold concentrations were at H. Kikić Primary School (4578 CFU/m³, not significant), M. Dizdar Primary School (2786 CFU/m³, not significant), and A. Šantić Primary School (5838 CFU/m³, significant). Aspergillus spp. and Penicillium spp. were equally prevalent. In May, the highest mold/yeast concentrations were at H. Kikić Primary School (6568 CFU/m³, significant), M. Dizdar Primary School (3516 CFU/m³, significant), and A. Šantić Primary School (7431 CFU/m³, significant). Aspergillus spp. was most prevalent. These findings highlight the importance of regular monitoring and implementing appropriate ventilation measures to manage air quality and health concerns in schools.

Archetypes of Spatial Concentration Variability of Organic Contaminants in the Atmosphere: Implications for Identifying Sources and Mapping the Gaseous Outdoor Inhalation Exposome.

Whereas inhalation exposure to organic contaminants can negatively impact human health, knowledge of their spatial variability in the ambient atmosphere remains limited. We analyzed the extracts of passive air samplers deployed at 119 unique sites in Southern Canada between 2019 and 2022 for 353 organic vapors. Hierarchical clustering of the obtained data set revealed four archetypes of spatial concentration variability in the outdoor atmosphere, which are indicative of common sources and similar atmospheric dispersion behavior. "Point Source" signatures are characterized by elevated concentration in the vicinity of major release locations. A "Population" signature applies to compounds whose air concentrations are highly correlated with population density, and is associated with emissions from consumer products. The "Water Source" signature applies to substances with elevated levels in the vicinity of water bodies from which they evaporate. Another group of compounds displays a "Uniform" signature, indicative of a lack of major sources within the study area. We illustrate how such a data set, and the derived spatial patterns, can be applied to support the identification of sources, the quantification of atmospheric emissions, the modeling of air quality, and the investigation of potential inequities in inhalation exposure.

Assessment of VOCs emission inventory in Seoul through spatiotemporal observations using passive and online PAMS measurements

We have conducted a quantitative analysis of volatile organic compounds (VOCs) in Seoul from September 2022 to June 2023, employing passive air samplers (PAS) at 25 sites and continuous monitoring at five photochemical assessment monitoring stations (PAMS). Comparing VOCs concentrations and compositions from PAS and PAMS during the same time periods, we found that most VOCs showed no significant difference (p-value >0.05) between the methods, except for olefins, which were overestimated by 24 % in passive sampling, confirming PAS as an effective tool for assessing the spatial distribution of VOCs species over large areas. Throughout Seoul, median values of total volatile organic compounds (TVOCs) concentrations collected with passive samplers remained stable with a standard deviation of 1.22 ppbv, typically ranging from 11 to 13 ppbv, except for an increase during winter in the southwestern regions of the city, where intense industrial and vehicular emissions are reported in the current Clean Air Policy Support System (CAPSS) emissions inventory. Positive matrix factorization (PMF) analysis using the passive data revealed general consistency in the spatial distribution of area and road emissions when compared with CAPSS emission inventory, although localized discrepancies were observed. In quantitative assessments of TVOCs comparing PAS observations with emission-based models, modeled values were within 1.5 times the interquartile range of observed PAS concentrations over Seoul. However, the lack of detection of emission hotspots in southeastern Seoul in the PAS data, coupled with the omission of photochemical loss in our dispersion-only models, indicates that the current CAPSS emission inventory may significantly underestimate actual ambient VOCs levels, especially in summer.

Atmospheric concentrations of per- and polyfluoroalkyl substances and their emissions at a waste recycling facility producing refuse-derived paper and plastics densified fuel

To better understand the types and concentrations of per- and polyfluoroalkyl substances (PFAS) emitted into the air from waste recycling facilities that produce refuse-derived paper and plastics densified fuel (RPF) from industrial waste, we conducted an air sampling campaign at a waste recycling facility in Japan. Both passive and active air sampling were conducted, and the samples collected were used to quantify the PFAS emitted into the air during the production of RPF. Overall, few ionic PFAS were detected in the air at the facility; however, high levels of neutral PFAS (8.21–53.4 ng/m3; 20.7–130 pmol/m3) were measured in the air near the heat molding machines. The two neutral PFAS detected at the highest concentrations were 6:2 fluorotelomer alcohol and 6:2 fluorotelomer methacrylate, which are currently unregulated under the Stockholm Convention, suggesting that product manufacturers have shifted away from using regulated PFAS. Small amounts of regulated PFAS such as 8:2 fluorotelomer methacrylate and 8:2 fluorotelomer acrylate were measured in some parts of the facility. Analysis of the concentrations of PFAS in the exhaust gas from the heat molding machines revealed neutral PFAS concentrations (537–2160 ng/m3; 1350–5040 pmol/m3) that were 1–2 orders of magnitude higher than those in the surrounding indoor air. The total emission of neutral PFAS from the facility to the environment was estimated to be 0.066–0.260 g/day (0.168–0.607 mmol/day), depending on whether air volume discharged as exhaust gas or as indoor ventilation was considered. A contribution analysis of the emissions revealed that treating the exhaust gas from the heat molding machines, which constitutes over 94 % of the total emissions, is very effective at reducing PFAS emissions from the facility.

Height-Resolved Analysis of Indoor Airborne Microbiome: Comparison with Floor Dust-Borne Microbiome and the Significance of Shoe Sole Dust.

Exposure to the indoor airborne microbiome is closely related to the air that individuals breathe. However, the floor dust-borne microbiome is commonly used as a proxy for indoor airborne microbiome, and the spatial distribution of indoor airborne microbiome is less well understood. This study aimed to characterize indoor airborne microorganisms at varying heights and compare them with those in floor dust. An assembly of three horizontally and three vertically positioned Petri dishes coated with mineral oil was applied for passive air sampling continuously at three heights without interruption. The airborne microbiomes at the three different heights showed slight stratification and differed significantly from those found in the floor dust. Based on the apportionment results from the fast expectation-maximization algorithm (FEAST), shoe sole dust contributed approximately 4% to indoor airborne bacteria and 14% to airborne fungi, a contribution that is comparable to that from the floor dust-borne microbiome. The results indicated that floor dust may not be a reliable proxy for indoor airborne microbiome. Moreover, the study highlights the need for height-resolved studies of indoor airborne microbiomes among humans in different activity modes and life states. Additionally, shoe sole-dust-associated microorganisms could potentially be a source to "re-wild" the indoor microbiota.

Residential proximity to conventional and unconventional wells and exposure to indoor air volatile organic compounds in the Exposures in the Peace River Valley (EXPERIVA) study

BackgroundIn a previous study located in Northeastern British Columbia (Canada), we observed associations between density and proximity of oil and gas wells and indoor air concentrations of certain volatile organic compounds (VOCs). Whether conventional or unconventional well types and phases of unconventional development contribute to these associations remains unknown. ObjectiveTo investigate the associations between proximity-based metrics for conventional and unconventional wells and measured indoor air VOC concentrations in the Exposures in the Peace River Valley (EXPERIVA) study samples. MethodsEighty-four pregnant individuals participated in EXPERIVA. Passive indoor air samplers were analyzed for 47 VOCs. Oil and gas well legacy data were sourced from the British Columbia Energy Regulator. For each participant's home, 5 km, 10 km and no buffer distances were delineated, then density and Inverse Distance Square Weighted (ID2W) metrics were calculated to estimate exposure to conventional and unconventional wells during pregnancy and the VOC measurement period. Multiple linear regression models were used to test for associations between the well exposure metrics and indoor air VOCs. For exposure metrics with >30% participants having a value of 0, we dichotomized exposure (0 vs. >0) and performed ANOVAs to assess differences in mean VOCs concentrations. ResultsAnalyses indicated that: 1) conventional well density and ID2W metrics were positively associated with indoor air acetone and decanal; 2) unconventional well density and ID2W metrics were positively associated with indoor air chloroform and decamethylcyclopentasiloxane, and negatively associated with decanal; 3) drilling specific ID2W metrics for unconventional wells were positively associated with indoor air chloroform. ConclusionOur analysis revealed that the association between the exposure metrics and indoor air acetone could be attributed to conventional wells and the association between exposure metrics and indoor air chloroform and decamethylcyclopentasiloxane could be attributed to unconventional wells.

Impact of anthropogenic activities on atmospheric chlorinated paraffins in Ghana using polyurethane foam disk - passive air sampler

Chlorinated paraffins (CPs) are a global concern due to their high production, ubiquity in the environment and potential toxicity. In Ghana, there is a significant research gap on the concentration and sources of CPs in the air, as well as insufficient regular monitoring programs to track CP levels over time. This study utilized polyurethane foam-based passive air samplers (PUF-PAS) to examine the concentrations, sources and potential human health risks of CPs in the atmosphere surrounding e-waste sites, urban areas, commercial areas and control/background areas in Ghana. The medium-chain CPs (MCCPs) dominated with an average concentration of 26.0 ± 40.1 ng/m3 and ranged from 1.78 to 240 ng/m3. Short-chain CPs (SCCPs) ranged from 0.05 to 15.2 ng/m3 and had an average concentration of 3.48 ± 3.99 ng/m3. The very short-chain CPs (C9-CPs), had an average concentration of 0.544 ± 0.524 ng/m3 and ranged from 0.091 to 2.14 ng/m3. MCCPs exceeded SCCPs by a factor of 7.5 and C9-CPs by a factor of 48. C14Cl8 was the dominant congener in MCCPs and C10Cl7 was also the dominant congener in SCCPs. E-waste was the main contributor to SCCPs and MCCPs (>30 %) in Ghana. The assessed non-cancer risks associated with CP exposure were within acceptable ranges. For cancer risk, MCCPs indicated high potential health risk but C9-CPs and SCCPs showed low risk. To the best of our knowledge, this is the first study on CPs in Ghana's atmosphere, and e-waste was identified as the country's main source of CPs. This study will help regulatory bodies create policies and procedures to control the use and disposal of chlorinated paraffins.

Temporal variations in airborne PCDD/F and dl-PCB concentrations surrounding the dioxin-remediated areas in Da Nang, Vietnam, and health risk assessments.

The air pollution levels from polychlorodibenzo-p-dioxins/polychlorodibenzofurans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) in three residential areas located north, west, and south of the Da Nang airport were determined by using passive air samplers containing polyurethane foam (PUF) discs with 3-month sampling intervals from 2017 to 2020. The total toxic equivalents (∑TEQs) of the PCDD/Fs and dl-PCBs, using WHO2005-TEFs, were highest north of the airport (134 to 10610fg WHO-TEQ/PUF day, with an average of 1108fg WHO-TEQ/PUF day). The ∑TEQs were lower west of the airport, between 159 and 381fg WHO-TEQ/PUF day and averaged 230fg WHO-TEQ/PUF day. The lowest ∑TEQs occurred south of the airport, with ranges of 76 and 331fg WHO-TEQ/PUF day and an average of 152fg WHO-TEQ/PUF day. Construction activities, including excavation and transportation of dioxin-contaminated soil north of the airport, have increased airborne PCDD/F and dl-PCB contamination and health risks. The average daily doses of PCDD/Fs and dl-PCBs through inhalation (ADDA) for residents located north of the airport were the highest (10.9 to 3434fg WHO-TEQ/kg BW/day and average: 597fg WHO-TEQ/kg BW/day). Residents located west of the airport faced lower health risks (13-123fg WHO-TEQ/kg BW/day and average: 39fg WHO-TEQ/kg BW/day). Residents south of the airport were exposed to a minimum of 6.2-107fg WHO-TEQ/kg BW/day, with an average of 28fg WHO-TEQ/kg BW/day. The maximum and average ADDA values for residents north of the airport exceeded 10% of the tolerable daily intake (TDI) recommended by the WHO (100-400fg WHO-TEQ/kg BW/day). In comparison, all the ADDA values for residents located west and south of the airport were less than and within 10% of the TDI.

Environmental bacterial load during surgical and ultrasound procedures in a Swedish small animal hospital

BackgroundEnvironmental bacteria in animal healthcare facilities may constitute a risk for healthcare-associated infections (HAI). Knowledge of the bacterial microflora composition and factors influencing the environmental bacterial load can support tailored interventions to lower the risk for HAI. The aims of this study were to: (1) quantify and identify environmental bacteria in one operating room (OR) and one ultrasound room (UR) in a small animal hospital, (2) compare the bacterial load to threshold values suggested for use in human healthcare facilities, (3) characterise the genetic relationship between selected bacterial species to assess clonal dissemination, and (4) investigate factors associated with bacterial load during surgery.Settle plates were used for passive air sampling and dip slides for surface sampling. Bacteria were identified by Matrix Assisted Laser Desorption—Time Of Flight. Antimicrobial susceptibility was determined by broth microdilution. Single nucleotide polymorphism-analysis was performed to identify genetically related isolates. Linear regression was performed to analyse associations between observed explanatory factors and bacterial load.ResultsThe bacterial load on settle plates and dip slides were low both in the OR and the UR, most of the samples were below threshold values suggested for use in human healthcare facilities. All settle plates sampled during surgery were below the threshold values suggested for use in human clean surgical procedures.Staphylococcus spp. and Micrococcus spp. were the dominating species. There was no indication of clonal relationship among the sequenced isolates. Bacteria carrying genes conveying resistance to disinfectants were revealed.Air change and compliance with hygiene routines were sufficient in the OR. No other factors possibly associated with the bacterial load were identified.ConclusionsThis study presents a generally low bacterial load in the studied OR and UR, indicating a low risk of transmission of infectious agents from the clinical environment. The results show that it is possible to achieve bacterial loads below threshold values suggested for use in human healthcare facilities in ORs in small animal hospitals and thus posing a reduced risk of HAI. Bacteria carrying genes conveying resistance to disinfectants indicates that resistant bacteria can persist in the clinical environment, with increased risk for HAI.

Temporal, spatial, and seasonal variations in airborne PCDD/F and dl-PCB concentrations around Bien Hoa hot spot, Vietnam, and health risk assessments

Passive air samplers were used to monitor polychlorodibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) between 2020 and 2022 in four residential areas around Bien Hoa hot spot (BHS) including Trung Dung (TD), Tan Phong (TP), Quang Vinh (QV), and Buu Long (BL). The total toxic equivalents of PCDD/Fs and dl-PCBs (∑TEQs) were highest in the TD area, from 284 to 642 fg TEQ/PUF day. Next was the QV area, where ∑TEQs ranged from 229 to 569 fg TEQ/PUF day. Then, ∑TEQs varied from 205 to 503 fg TEQ/PUF day in the TP area. The lowest ∑TEQs were between 179 and 385 fg TEQ/PUF day in the BL area. The temporal, spatial, and seasonal variations in concentrations of PCDD/Fs and dl-PCBs were related to the prevailing wind direction and the distance from each area to the dioxin hot spot. The average ∑TEQs for all four areas surrounding BHS in the dry season (423 fg TEQ/PUF day) were 1.4 times higher than in the rainy season (303 fg TEQ/PUF day). Health risk assessments from airborne dioxin exposure were estimated using the average daily doses through inhalation (ADDI). The ADDI for residents surrounding BHS ranged from 14.6 to 208 fg TEQ/kg BW/day. The ADDI values by areas were as follows: 23.2–208 fg TEQ/kg BW/day in the TD, 18.7–184 fg TEQ/kg BW/day in the QV, 16.7–163 fg TEQ/kg BW/day in the TP, and 14.6–125 fg TEQ/kg BW/day in the BL. These ADDI values remained within and below the 10% threshold of the WHO-recommended tolerable daily intake (100–400 fg TEQ/kg BW/day). It is necessary to control the excavation activities inside the BHS and cover the temporary storage sites of dioxin-contaminated materials to minimize the emissions of PCDD/Fs and dl-PCB into the ambient air.

Evaluation of the performance of a passive air sampling technique to measure current-use pesticides in a tropical environment

Evaluation of the performance of a passive air sampling technique to measure current-use pesticides in a tropical environment

Former landfills as environmental liabilities in central Chile: Evidence from a pilot study in Lepanto

AbstractThe former Lepanto landfill in the Santiago Metropolitan Region in Central Chile ceased operations in 2002 after 24 years. Currently, a biogas recovery center operates on this site. The objective of this pilot study was to evaluate the atmospheric concentrations of two polycyclic aromatic hydrocarbons (PAHs, i.e., phenanthrene and fluoranthene) at three points downwind from the former Lepanto landfill using passive air samplers and polyurethane foam disks to provide 3‐month average concentrations of contaminants during winter months. The results showed concentrations ranging between 2 and 65 ng m−3 and decreasing with distance from the former landfill. Given that the distance to other potential sources was similar in all sampling sites, the evidence found suggested that the former Lepanto landfill may contribute to the local PAH inventory. Thus, we suggest that former landfills are potential candidates for long‐term monitoring as they can represent a less‐known environmental liability for residents. Additionally, we provide insights on how the Chilean environmental protection system can establish reclamation steps for their management after closure.

“Hg distribution and accumulation in soil and vegetation in areas impacted by artisanal gold mining in the Southern Amazonian region of Madre de Dios, Peru.”

Artisanal and small-scale gold mining (ASGM) is the primary global source of anthropogenic mercury (Hg) emissions. It has impacted the Amazon rainforest in the Peruvian region of Madre de Dios. However, few studies have investigated Hg's distribution in terrestrial ecosystems in this region. We studied Hg's distribution and its predictors in soil and native plant species from artisanal mining sites. Total Hg concentrations were determined in soil samples collected at different depths (0–5 cm and 5–30 cm) and plant samples (roots, shoots, leaves) from 19 native plant species collected in different land cover categories: naked soil (L1), gravel piles (L2), natural regeneration (L3), reforestation (L4), and primary forest (L5) in the mining sites. Hg levels in air were also studied using passive air samplers. The highest Hg concentrations in soil (average 0.276 and 0.210 mg kg−1 dw.) were found in the intact primary forest (L5) at 0–5 cm depth and in the plant rooting zones at 5–30 cm depth, respectively.Moreover, the highest Hg levels in plants (average 0.64 mg kg−1 dw) were found in foliage of intact primary forest (L5). The results suggest that the forest in these sites receives Hg from the atmosphere through leaf deposition and that Hg accumulates in the soil surrounding the roots. The Hg levels found in the plant leaves of the primary forest are the highest ever recorded in this region, exceeding values found in forests impacted by Hg pollution worldwide and raising concerns about the extent of the ASGM impact in this ecosystem. Correlations between Hg concentrations in soil, bioaccumulation in plant roots, and soil physical-chemical characteristics were determined. Linear regression models showed that the soil organic matter content (SOM), pH, and electrical conductivity (EC) predict the Hg distribution and accumulation in soil and bioaccumulation in root plants.

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.

Indoor and outdoor NO2 and SO2 levels in 13 randomly selected preschools from 7 districts in Mpumalanga Province, South Africa

AbstractBackgroundAir pollution is a serious worldwide issue, where both outdoor and indoor air quality have a substantial impact on the health of children. Children are more vulnerable to the effects of air pollution due to their developing respiratory systems and higher respiration rates than adults. These children dedicate a substantial amount of time to the preschool setting. The study sought to evaluate the concentration of NO2 and SO2 in both outdoor and indoor environments of preschool facilities.MethodsConcurrently, the levels of NO2 and SO2 were measured indoors and outdoors at 13 randomly selected preschools in 7 districts in Mpumalanga Province, South Africa. Radiello passive air samplers were employed to collect gaseous samples.ResultsThe mean levels of NO2 indoors and outdoors were within the recommended criteria outlined by the World Health Organization (WHO), specifically target levels 1–3. Additionally, these values were also below the air quality guides outlined by South Africa, both for yearly and 1‐h mean measurements. Nevertheless, both levels remained above the suitable threshold of 10 µg m−3 outlined by the WHO air quality guidelines.ConclusionsIt is important to implement proactive measures such as enhancing airflow systems, employing air filters and reducing potential sources of air pollution in preschools, to aid in reducing exposure to indoor and outdoor NO2 and SO2.

Comparison of active measurements, lichen biomonitoring, and passive sampling for atmospheric mercury monitoring

The number of atmospheric mercury (Hg) monitoring stations is growing globally. However, there are still many regions and locations where Hg monitoring is limited or non-existent. Expansion of the atmospheric Hg monitoring network could be facilitated by the use of cost-effective monitoring methods. As such, biomonitoring and passive monitoring offer a unique alternative to well-established monitoring by active measurements, since they do not require a power supply and require minimal workload to operate. The use of biomonitoring (lichens and mosses) and passive air samplers (PASs) (various designs with synthetic materials) has been reported in the literature, and comparisons with active measurement methods have also been made. However, these studies compared either biomonitoring or PASs (not both) to only one type of active measurement. In our work, we used transplanted (7 sampling sites) and in situ lichens (8 sampling sites) for biomonitoring, two PASs from different producers (3 sampling sites), and two different active measurement types (continuous and discontinuous active measurements, 1 and 8 sampling sites, respectively) to evaluate their effectiveness as monitoring methods. In the 9-month sampling campaign, 3 sampling locations with different characteristics (unpolluted, vicinity of a cement plant, and vicinity of a former Hg mine) were used. The results obtained with lichens and PASs clearly distinguished between sampling locations with different Hg concentrations; using both PASs and lichens together increased the confidence of our observations. The present work shows that biomonitoring and passive sampling can be effectively used to identify areas with elevated atmospheric Hg concentrations. The same can be said for discontinuous active measurements; however, the discrepancy between atmospheric Hg concentrations derived from PASs and discontinuous active measurements should be further investigated in the future.Graphical

Assessment of some air pollutants in the Sanctuary of the Beata Vergine dei Miracoli (Saronno, Italy) and first evaluation of a new axial passive sampler for nitrogen dioxide

In the present study the concentration of some air pollutants (nitrogen dioxide, sulphur dioxide, hydrogen sulphide, ammonia and BTEX, i.e. benzene, toluene, ethylbenzene and xylene) was monitored inside and outside the Sanctuary of the Beata Vergine dei Miracoli (Saronno, Italy) by passive air sampling (using radial samplers), during two sampling periods in 2022 (April 27-May 11 and May 11-May 25). Concurrently, particulate matter (PM10 and PM2.5) concentration was determined by using sensors based on laser scattering technology. Moreover, we took advantage of the location of this sanctuary (proximity to an air monitoring central unit) to evaluate the performance of a new axial-type sampler for nitrogen dioxide. Sulphur dioxide concentration was in the range 0.8–3.1 µg/m3, with outdoor values higher than indoor ones, whereas no detectable concentrations of hydrogen sulphide were found (<0.1 µg/m3). A different trend was observed for ammonia, where indoor concentrations were higher than outdoor ones (3.6–5.5 vs 2.7–3.1 µg/m3). Among BTEX, only for benzene statistical differences (p-value < 0.05) between the indoor and outdoor concentrations were found, suggesting additional indoor sources for this hydrocarbon. Toluene results as the most abundant among these hydrocarbons (1.7–2.3 µg/m3) in outdoor environments, whereas, in indoor environments, benzene has the higher concentration (6–9 µg/m3). The indoor concentrations of NO2 (15.4–22.2 µg/m3 for radial samplers and 48–60 µg/m3 for axial samplers) are not only much higher than the recommended limit values to guarantee proper conservation of artefacts (5 µg/m3), but also close to the values for human health preservation (40 µg/m3), suggesting the need of proper strategy to improve indoor air quality inside the Sanctuary. The preliminary results obtained for the new axial-type sampler for nitrogen dioxide are very encouraging, given the closeness of the obtained concentration data to those measured by monitoring central unit, even though further experiments will have to be carried out to validate this sampler.

Passive Air Sampling Networks Combined with Multivariate Statistics Reveal Widespread Non-Aroclor Polychlorinated Biphenyl Sources to the Canadian Atmosphere

Passive Air Sampling Networks Combined with Multivariate Statistics Reveal Widespread Non-Aroclor Polychlorinated Biphenyl Sources to the Canadian Atmosphere

Modeling PAH Mixture Interactions in a Human In Vitro Organotypic Respiratory Model.

One of the most significant challenges in human health risk assessment is to evaluate hazards from exposure to environmental chemical mixtures. Polycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous contaminants typically found as mixtures in gaseous and particulate phases in ambient air pollution associated with petrochemicals from Superfund sites and the burning of fossil fuels. However, little is understood about how PAHs in mixtures contribute to toxicity in lung cells. To investigate mixture interactions and component additivity from environmentally relevant PAHs, two synthetic mixtures were created from PAHs identified in passive air samplers at a legacy creosote site impacted by wildfires. The primary human bronchial epithelial cells differentiated at the air-liquid interface were treated with PAH mixtures at environmentally relevant proportions and evaluated for the differential expression of transcriptional biomarkers related to xenobiotic metabolism, oxidative stress response, barrier integrity, and DNA damage response. Component additivity was evaluated across all endpoints using two independent action (IA) models with and without the scaling of components by toxic equivalence factors. Both IA models exhibited trends that were unlike the observed mixture response and generally underestimated the toxicity across dose suggesting the potential for non-additive interactions of components. Overall, this study provides an example of the usefulness of mixture toxicity assessment with the currently available methods while demonstrating the need for more complex yet interpretable mixture response evaluation methods for environmental samples.

Effect of Dhupana (medicated fumigation) on the microbial concentration in the indoor air in Kumaragara (pediatric OPD and IPD): an experimental study

Abstract Introduction: Bioaerosols causing infectious diseases are a major concern for the environmental safety in hospital indoors. Chemical fumigation used for controlling infectious bioaerosols leads to several health hazards such as allergic reactions, hyperbilirubinemia, carcinogenicity, and toxicity. Corrosion of metal surfaces, bleaching of fabrics, risk of accidental consumption, high cost, unpleasant odor, flammability, and formation of toxic gases are other concerns. In Ayurveda, Dhupana (medicated fumigation) is advocated for controlling invisible agents capable of disease transmission. It can be a safer alternative to chemical fumigation. However, many ingredients of classical Dhupana preparations are rare or impractical to use; hence, a novel “Shodashanga Dhupa” (16-ingredient fumigation preparation) was formulated using easily accessible ingredients of classical Dhupana formulations. Materials and Methods: The antimicrobial and antifungal activities of Shodashanga Dhupa were ascertained by enumerating colony-forming units (CFUs) in the passive air samples obtained from hospital rooms before and after 1 h of Dhupana. These samples were collected on suitable agar media, and the settle plate method was carried out. Results: There was improvement in the Index of Microbial Air Contamination and a statistically significant reduction in bacterial CFUs in the pediatric outpatient department (P = 0.000218) and in the Panchakarma therapy room (P = 0.000218). There was a statistically significant reduction in fungal CFUs (P = 0.0137) in the pediatric outpatient department and in the Panchakarma therapy room (P = 0.00109) after 1 h of Dhupana. Conclusion: The study suggests that fumigation with common herbs and spices is effective in decreasing bacterial and fungal bioaerosol concentration in the indoor air of hospital rooms, and it can be used as an economical, hassle-free, and safe method of disinfection.