Personal Air Research Articles

How Does Personal Hygiene Influence Indoor Air Quality?

Humans are known to be a continuous and potent indoor source of volatile organic compounds (VOCs). However, little is known about how personal hygiene, in terms of showering frequency, can influence these emissions and their impact on indoor air chemistry involving ozone. In this study, we characterized the VOC composition of the air in a controlled climate chamber (22.5 m3 with an air change rate at 3.2 h-1) occupied by four male volunteers on successive days under ozone-free (∼0 ppb) and ozone-present (37-40 ppb) conditions. The volunteers either showered the evening prior to the experiments or skipped showering for 24 and 48 h. Reduced shower frequency increased human emissions of gas-phase carboxylic acids, possibly originating from skin bacteria. With ozone present, increasing the number of no-shower days enhanced ozone-skin surface reactions, yielding higher levels of oxidation products. Wearing the same clothing over several days reduced the level of compounds generated from clothing-ozone reactions. When skin lotion was applied, the yield of the skin ozonolysis products decreased, while other compounds increased due to ozone reactions with lotion ingredients. These findings help determine the degree to which personal hygiene choices affect the indoor air composition and indoor air exposures.

Assessing exposure to airborne fungi and bacteria in the horse-riders environment: A pilot study

Among airborne biological contaminants, several pathogenic and/or allergenic fungi and bacteria can affect the health of horses and humans. Exposure to primary biological aerosol particles (PBAP) in the equine environment remains poorly understood, although environmental factors play a major role in the development of respiratory diseases and impaired performance in horses. This pilot study was conducted during a training course for young racers. Ambient and personal air samples provided original data on the microbial composition of PBAP in the riders’ immediate environment (stable, outdoor, riding arena), using culture-based and metagenomic approaches. The culture-based approach showed average levels of fungi and bacteria of 2.3 × 104 and 8.3 × 105 CFU/m3 respectively during training. Seventy-one and 50 fungal and bacterial species were respectively identified, while the metagenomic approach identified 211 and 285, respectively. It should be noted, however, that two-thirds of the bacterial and fungal genera were found by both approaches. Among these species, various pathogenic and/or allergenic fungi (Alternaria spp., Aspergillus spp., Cladosporium spp. and Lichtheimia ramosa) and bacteria (Aeromonas spp., Bacillus spp., Pseudomonas spp. and Staphylococcus spp.) were highlighted. This study underlines the value of the combined use of culture-based and metagenomic approaches to provide an overview of the distribution of different fungal and bacterial phyla, genera and species in the equine environment. Statistical analysis also suggests interactions between microbiological contaminants (bacteria and mold) and climatic parameters (rain, wind, temperature).

Assessment of Occupational Exposure to Inhalable Aerosols in an Instant Powdered Food Manufacturing Plant in Norway

BackgroundIn the food manufacturing industry, exposure to inhalable aerosols contributes to respiratory illnesses such as occupational asthma and rhinitis. However, there is a lack of comprehensive exposure assessment studies. This study evaluated occupational exposure to inhalable aerosols in an instant powdered food manufacturing plant during work operations involving dried food and powders. MethodsIn total, 50 workers from an instant powdered food manufacturing plant were recruited. Personal inhalable aerosol exposure measurements were taken for both full-shift and task-based activities. The concentrations of inhalable aerosols were analyzed to identify any variation within and across departments, as well as between seasons, handedness, and sex. ResultsIn total, 134 personal air samples were collected, and the particulate mass was determined gravimetrically. The concentrations of inhalable aerosols ranged from 0.1 to 27 mg/m3 for full-shift exposure measurements and 3.1 to 73 mg/m3 for task-based measurements. Statistically significant differences in mean aerosol concentrations were found across departments (A:B p < 0.001, A:C p < 0.05, B:C p < 0.001) and between seasons (p < 0.001). ConclusionThis study revealed high exposure to inhalable aerosols among workers, particularly those involved in manual weighing, mixing, and adding powders. The significant differences between departments highlight the specific activities contributing to increased inhalable aerosol concentrations. Seasonal variations were also evident, with autumn showing higher concentrations of inhalable aerosols in all departments compared with summer. These findings emphasize the importance of understanding the distribution of aerosol concentrations across different work tasks and departments, particularly during different seasons.

Asbestos exposures associated with the use and handling of drilling mud additives.

This paper summarizes historical asbestos exposure data collected during the handling of short-fiber chrysotile asbestos that was used as an additive to drilling fluid in oil and gas exploration. A total of 1171 industrial hygiene (IH) personal and area air samples were collected and analyzed from more than 20 drilling rigs between 1972 and 1985. The dataset consists of 1097 short-term samples (<240min) with more than 80% having sample durations less than 30min. Average airborne fiber concentrations measured during asbestos handling activities ranged from 0.62 f/cc to 3.39 f/cc using phase-contrast microscopy (PCM). An additional 14 samples were considered long-term samples (>240min) and there were 60 samples with no reported sample duration. Eight-hour time-weighted average (8-h TWA) results, calculated using short-term samples, along with long-term samples greater than 240min, did not exceed contemporaneous Occupational Safety and Health Administration (OSHA) permissible exposure limits (PELs). This analysis fills a data gap in the evaluation of asbestos exposures from the use of drilling mud additives (DMAs) that contained chrysotile asbestos.

345 Fostering academic-community research teams to conduct community-engaged research in environmental justice communities: The RISE Communities R25 program

OBJECTIVES/GOALS: Residents of environmental justice (EJ) communities experience significantly higher rates of negative health outcomes associated with poor air quality. Low-cost air sensors may supplement regulatory monitoring to better measure air pollution at local scales, but widespread application of this technology remains limited due to many challenges. METHODS/STUDY POPULATION: To address these obstacles, we designed a training program to equip community and academic research partners with the skills and knowledge to successfully apply low-cost sensors in community-engaged environmental health research. The R esearch Innovations using Sensor Technology in Environmental Justice Communities (RISE Communities) program was established through an NIEHS R25 award in 2022 and has three specific aims: 1) Foster community-academic partnerships through research education, training, and team development activities, 2) Provide technical training in the application of low-cost sensors for indoor, outdoor, and personal air monitoring in EJ communities, and 3) Establish a community of practice to address air quality in communities nationwide. RESULTS/ANTICIPATED RESULTS: We hosted our first cohort in August 2023, training five community-academic research teams in team collaboration, community-engaged research, and technical skills for collecting and analyzing data from PurpleAir sensors. Each team received 12 sensors to take to their home EJ communities to begin their projects. Community of practice development continues through interactive webinars and development of a web-based repository of training videos and discussion board posts. Evaluation data show high participant learning and satisfaction, with mean confidence scores improving on 6/8 metrics. Evaluation data also suggest several areas for improvement such as more time spent in teams for planning and additional opportunities for interaction within the cohort and with program instructors for problem-solving. DISCUSSION/SIGNIFICANCE: Effective training for team-based community-engaged research requires careful planning for team development and study implementation. Longitudinal training and support for the technical aspects of utilizing air sensors is also critical to team success. The RISE Communities program is actively recruiting for future training cohorts.

Abstract 3438: Associations between estimated endotoxin exposure and circulating immunological markers among male farmers

Abstract Occupational exposure to endotoxin has been associated with reduced lung cancer risk. Farmers who perform certain tasks (e.g., raising hogs) can be highly exposed to endotoxin. The mechanisms through which endotoxin could confer a lower risk of lung cancer, while likely to be immune mediated, are not clear. To address this gap, we evaluated associations between estimated endotoxin exposure and circulating immunologic markers among male farmers in the Biomarkers of Exposure and Effect in Agriculture (BEEA) study. Our investigation included 122 non-smoking farmers from Iowa, oversampling those raising hogs (n=61). We evaluated 58 serologic markers, including some linked to lung cancer, that were measured using multiplex bead-based assays. Based on an algorithm linking personal air measurements in BEEA and published data to reported farming tasks, we estimated cumulative endotoxin exposure in the last 30 days and 12 months before sample collection. We used multivariable linear regression to estimate geometric mean ratios of immune markers across exposure quartiles, overall and by season of sample collection. Higher endotoxin exposure in the last 30 days was associated with increased levels of FGF-2, MIP-3A/CCL20, and sIL-4R (Ptrend ≤ 0.02), and with decreased levels of MDC/CCL22 (Ptrend = 0.02). In analyses stratified by season, the positive associations with FGF-2 and MIP-3A/CCL20 were most apparent in the winter (Ptrend = 0.002 and 0.03, respectively); we also observed an inverse association with sCD27 levels in the summer (Ptrend = 0.03). Similar patterns were observed for endotoxin exposure in the last 12 months. This study is the first to use novel algorithm-based endotoxin exposure estimates to evaluate associations with intermediate lung cancer-related markers. Several markers were associated with endotoxin levels in an exposure-response manner. Our findings suggest possible biological mechanisms through which endotoxin may reduce risk of lung cancer. Table 1. Associations between estimated endotoxin exposure in the last 30 days and selected serum im Citation Format: Somayina C. Ezennia, Laura E. Beane-Freeman, Vicky C. Chang, Shuai Xie, Gabriella Andreotti, Melissa C. Friesen, Jonathan N. Hofmann. Associations between estimated endotoxin exposure and circulating immunological markers among male farmers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3438.

Longitudinal assessment of oxidative stress markers and their relationship with exposure to PM2.5 and its bound metals in healthy participants

ObjectiveExposure to ambient PM2.5 and its bound metals poses a risk to health and disease, via, in part, oxidative stress response. A variety of oxidative stress markers have been used as markers of response, but their relevance to environmental exposure remains to be established. We evaluated, longitudinally, a battery of oxidative stress markers and their relationship with the exposure of PM2.5 and its bound metals in a panel of healthy participants. Material and methodsLevels of residence- and personal-based ambient air PM2.5 and its bound metals, as well as of lung function parameters, were assessed in a total of 58 questionnaire-administered healthy never smoker participants (male, 39.7%). Levels of urinary oxidative stress markers, including Nε-(hexanoyl)-lysine (HEL; an early lipid peroxidation product), 4-hydroxynonenal (4-HNE), N7-methylguanine (N7-meG), and 8-hydroxy-2-deoxyguanosine (8-OHdG), plasma antioxidants [superoxide dismutase (SOD) and glutathione peroxidase (GPx), and urinary metals were measured by ELISA, LC-MS, and ICP-MS, respectively. The results of three repeated measurements at two-month intervals were analyzed using the Generalized Estimating Equation (GEE). ResultsAfter adjusting for confounders, residence- and personal-based PM2.5 levels were positively associated with HEL (β = 0.22 and 0.18) and N7-meG (β = 0.39 and 0.13). Significant correlations were observed between personal air PM2.5-Pb and urinary Pb with HEL (β = 0.08 and 0.26). While FVC, FEV1, FEV1/FVC, MMF, and PEFR predicted% were normal, a negative interaction (pollutant*time, P < 0.05) was noted for PM2.5-V, Mn, Co, Ni, Zn, As, and Pb. Additionally, a negative interaction was found for N7-meG (β = −21.35, −18.77, −23.86) and SOD (β = −26.56, −26.18, −16.48) with FEV1, FVC, and PEFR predicted%, respectively. ConclusionThese findings emphasize potential links between environmental exposure, internal dose, and health effects, thereby offering valuable markers for future research on metal exposure, oxidative stress, and health outcomes.

A temporal evaluation of respirable crystalline silica exposure for construction tasks.

Personal air monitoring using a TSI SidePak AM520 personal aerosol monitor was performed on a northern Colorado construction site during five tasks from the OSHA Table 1: Specified Exposure Control Methods When Working With Materials Containing Crystalline Silica to estimate silica dust concentrations in real time. Photometric measurements were modified using a gravimetric correction factor and a % respirable crystalline silica adjustment. Each task was sampled once; sample time ranged from 14 min to 40 min, with a mean sample time of 27 min. The mean silica dust concentration estimates (μg/m3) (standard deviation [SD]) for the five tasks computed from the TSI SidePak AM520 respirable dust measurements were core drilling 12 μg/m3 [2.46], grinding 918 μg/m3 [1134.08], cutting with a walk-behind saw 36 μg/m3 [79.67], jackhammering 27 μg/m3 [23.24], and dowel drilling 66 μg/m3 [77.65]. Silica exposure estimates from real-time monitoring can be used to identify exposures that may be related to inadequate controls or worker behaviors that contribute to peak exposures. Respirable crystalline silica exposure estimates presented here are likely not generalizable to other construction sites or tasks.

The Association Between Personal Air Pollution Exposures and Fractional Exhaled Nitric Oxide (FeNO): A Systematic Review.

Airway inflammation is a common biological response to many types of environmental exposures and can lead to increased nitric oxide (NO) concentrations in exhaled breath. In recent years, several studies have evaluated airway inflammation using fractional exhaled nitric oxide (FeNO) as a biomarker of exposures to a range of air pollutants. This systematic review aims to summarize the studies that collected personal-level air pollution data to assess the air pollution-induced FeNO responses and to determine if utilizing personal-level data resulted in an improved characterization of the relationship between air pollution exposures and FeNO compared to using only ambient air pollution exposure data. Thirty-six eligible studies were identified. Overall, the studies included in this review establish that an increase in personal exposure to particulate and gaseous air pollutants can significantly increase FeNO. Nine out of the 12 studies reported statistically significant FeNO increases with increasing personal PM2.5 exposures, and up to 11.5% increase in FeNO per IQR increase in exposure has also been reported between FeNO and exposure to gas-phase pollutants, such as ozone, NO2, and benzene. Furthermore, factors such as chronic respiratory diseases, allergies, and medication use were found to be effect modifiers for air pollution-induced FeNO responses. About half of the studies that compared the effect estimates using both personal and ambient air pollution exposure methods reported that only personal exposure yielded significant associations with FeNO response. The evidence from the reviewed studies confirms that FeNO is a sensitive biomarker for air pollutant-induced airway inflammation. Personal air pollution exposure assessment is recommended to accurately assess the air pollution-induced FeNO responses. Furthermore, comprehensive adjustments for the potential confounding factors including the personal exposures of the co-pollutants, respiratory disease status, allergy status, and usage of medications for asthma and allergies are recommended while assessing the air pollution-induced FeNO responses.

Evaluating one engine inoperative conditions in subscale electric vertical take-off and landing aircraft: An in-depth tethered hover test analysis

The direction of propeller rotation in a distributed electric-powered vertical take-off and landing (eVTOL) aircraft significantly influences control forces and induced drag during both helicopter and fixed-wing modes. This study proposes a strategy to determine the most effective rotational direction for each propeller. This approach effectively mitigates one-engine-inoperative (OEI) conditions during helicopter mode for a subscale eVTOL referred to as the optionally piloted personal air vehicle (OPPAV). Moreover, the study developed an optimal control law using the linear programming method, which minimizes the maximum power required for individual motors under OEI conditions. The lowest maximum power was achieved under OEI conditions when both the front and rear propellers in each pod rotated in the same direction. Furthermore, to validate this proposed control law, a tethered hover test was performed using the subscale OPPAV under OEI conditions. Our findings demonstrate that determining the rotational direction of propellers using the newly proposed reconfiguration control method significantly enhances the safety of eVTOL aircraft operating under OEI conditions.

Occupational inhalation exposure during surface disinfection—exposure assessment based on exposure models compared with measurement data

BackgroundFor healthcare workers, surface disinfections are daily routine tasks. An assessment of the inhalation exposure to hazardous substances, in this case the disinfectant´s active ingredients, is necessary to ensure workers safety. However, deciding which exposure model is best for exposure assessment remains difficult.ObjectiveThe aim of the study was to evaluate the applicability of different exposure models for disinfection of small surfaces in healthcare settings.MethodsMeasurements of the air concentration of active ingredients in disinfectants (ethanol, formaldehyde, glutaraldehyde, hydrogen peroxide, peroxyacetic acid) together with other exposure parameters were recorded in a test chamber. The measurements were performed using personal and stationary air sampling. In addition, exposure modelling was performed using three deterministic models (unsteady 1-zone, ConsExpo and 2-component) and one modifying-factor model (Stoffenmanager®). Their estimates were compared with the measured values using various methods to assess model quality (like accuracy and level of conservatism).ResultsThe deterministic models showed overestimation predominantly in the range of two- to fivefold relative to the measured data and high conservatism for all active ingredients of disinfectants with the exception of ethanol. With Stoffenmanager® an exposure distribution was estimated for ethanol, which was in good accordance with the measured data.Impact statementTo date, workplace exposure assessments often involve expensive and time consuming air measurements. Reliable exposure models can be used to assess occupational inhalation exposure to hazardous substances, in this case surface disinfectants. This study describes the applicability of three deterministic and one modifying-factor model for disinfection of small surfaces in healthcare settings, in direct comparison to measurements performed and will facilitate future exposure assessments at these workplaces.

Empowering community health professionals for effective air pollution information communication

BackgroundAir pollution remains a significant public health risk, particularly in urban areas. Effective communication strategies remain integral to overall protection by encouraging the adoption of personal air pollution exposure reduction behaviours. This study aims to explore how community health professionals can be empowered to communicate air pollution information and advice to the wider community, to encourage the uptake of desired behaviours in the population.MethodsThe study adopted a qualitative methodology, where four homogenous Focus Group Discussions (FGDs) were held with a range of community health professionals, including Health Care Professionals, Community Health and Wellbeing Workers (CHWWs) and Social Prescribing Link Workers (SPLW). A classical content analysis was conducted with the Structural Empowerment Theory (SET) and Psychological Empowerment Theory (PET) as guiding concepts.ResultsFive key themes were identified: from a structural empowerment perspective: [1] resources and support, [2] knowledge. From a psychological empowerment perspective: [3] confidence as advisor, [4] responsibility as advisor, and [5] residents’ receptiveness to advice. It was concluded that advice should be risk stratified, clear, easy to follow and provide alternatives.ConclusionThis study identified ways for community health professionals to be empowered by local councils or other organisations in providing advice on air pollution, through the provision of essential structural support and opportunities to enhance their knowledge and confidence in the subject. Implementing recommendations from this study would not only empower community health professionals to advise on air pollution to the wider community but also increase adherence to health advice.

Exploring Personal Exposure to Airborne Microplastics across Various Work Environments in Pathum Thani Province, Thailand.

This study used personal air samplers to assess the concentration of airborne microplastics exposed by different occupational groups during their working hours. The personal air sampler was placed in the "breathing zone" of the worker during working hours to collect microplastic exposure data. Occupations examined included housekeepers, laundromat staff, office workers, van drivers, street vendors, maintenance technicians in wastewater treatment plants, and waste segregation officers in the university and market. The level of airborne microplastic exposure was found to be influenced by the daily activities and environmental conditions of the workplace. Waste segregation officers in the university and market exhibited the highest levels of exposure to airborne microplastics, at 3964 ± 2575 microplastics per cubic meter (n/m3) and 3474 ± 678 n/m3, respectively. Further analysis focused on airborne microplastics less than 10 µm in size which can be taken in through inhalation. During the 8 h working period, the waste segregation officer in the university recorded the highest 10 µm airborne microplastic intake, at 5460 pieces, followed by the waste segregation officer in the market at 3301 pieces, housekeepers at 899 pieces, van drivers at 721 pieces, maintenance technicians in WWTPs at 668 pieces, laundromat staff at 454 pieces, street vendors at 249 pieces, and office workers at 131 pieces.

Hexavalent chromium still a concern in Sweden – Evidence from a cross-sectional study within the SafeChrom project

ObjectivesHexavalent chromium (Cr(VI)) is classified as a human carcinogen. Occupational Cr(VI) exposure can occur during different work processes, but the current exposure to Cr(VI) at Swedish workplaces is unknown. MethodsThis cross-sectional study (SafeChrom) recruited non-smoking men and women from 14 companies with potential Cr(VI) exposure (n = 113) and controls from 6 companies without Cr(VI) exposure (n = 72). Inhalable Cr(VI) was measured by personal air sampling (outside of respiratory protection) in exposed workers. Total Cr was measured in urine (pre- and post-shift, density-adjusted) and red blood cells (RBC) (reflecting Cr(VI)) in exposed workers and controls. The Bayesian tool Expostats was used to assess risk and evaluate occupational exposure limit (OEL) compliance. ResultsThe exposed workers performed processing of metal products, steel production, welding, plating, and various chemical processes. The geometric mean concentration of inhalable Cr(VI) in exposed workers was 0.15 μg/m3 (95% confidence interval: 0.11–0.21). Eight of the 113 exposed workers (7%) exceeded the Swedish OEL of 5 μg/m3, and the Bayesian analysis estimated the share of OEL exceedances up to 19.6% for stainless steel welders. Median post-shift urinary (0.60 μg/L, 5th-95th percentile 0.10–3.20) and RBC concentrations (0.73 μg/L, 0.51–2.33) of Cr were significantly higher in the exposed group compared with the controls (urinary 0.10 μg/L, 0.06–0.56 and RBC 0.53 μg/L, 0.42–0.72). Inhalable Cr(VI) correlated with urinary Cr (rS = 0.64) and RBC-Cr (rS = 0.53). Workers within steel production showed the highest concentrations of inhalable, urinary and RBC Cr. Workers with inferred non-acceptable local exhaustion ventilation showed significantly higher inhalable Cr(VI), urinary and RBC Cr concentrations compared with those with inferred acceptable ventilation. Furthermore, workers with inferred correct use of respiratory protection were exposed to significantly higher concentrations of Cr(VI) in air and had higher levels of Cr in urine and RBC than those assessed with incorrect or no use. Based on the Swedish job-exposure-matrix, approximately 17 900 workers were estimated to be occupationally exposed to Cr(VI) today. ConclusionsOur study demonstrates that some workers in Sweden are exposed to high levels of the non-threshold carcinogen Cr(VI). Employers and workers seem aware of Cr(VI) exposure, but more efficient exposure control strategies are required. National strategies aligned with the European strategies are needed in order to eliminate this cause of occupational cancer.

Firefighters' personal exposure to gaseous PAHs during controlled forest fires: A case study with estimation of respiratory health risks and in vitro toxicity

Firefighters are daily exposed to adverse health-hazardous pollutants. Polycyclic aromatic hydrocarbons (PAHs), well known endocrine disruptors with carcinogenic, mutagenic, and teratogenic properties, are among the most relevant pollutants. The characterization of firefighters' occupational exposure to airborne PAHs remains limited; information is scarce for European firefighters. Also, the in vitro assessment of firefighters' respiratory health risks is inexistent. To reply to these scientific gaps, this work characterizes the levels of gaseous PAH in firefighters' personal air during regular working activities at controlled forest fires and at fire stations (control group). Breathable levels were 2.2–26.7 times higher during fire events than in the control group (2.63–32.63 μg/m3versus 1.22 μg/m3, p < 0.001); the available occupational guidelines (100 and 200 μg/m3 defined by the US National Institute for Occupational Safety and Health and the North American Occupational Safety and Health Administration, respectively) were not exceeded. Concentrations of (possible/probable) carcinogenic PAHs were 1.9–15.3 times superior during firefighting (p < 0.001). Increased values of total benzo(a)pyrene equivalents (p = 0.101), dose rates (p < 0.001), and carcinogenic risks (p = 0.063) were estimated in firefighters during controlled fires comparatively with the control group. Firefighters' breathable gaseous phase collected during fire events contributed to induce a significant viability decrease (<70 %; p < 0.05) in A549 and Calu-3 cell lines. The principal component analysis (PCA) allowed the differentiation between firefighters participating in controlled fire events from the control group. PCA analysis demonstrated the potential of PAHs to distinguish different sources of firefighters´ occupational exposure and of combining estimated health risk parameters with in vitro toxicities determined with human-breathable air collected during real-life scenarios. Overall, the participation in controlled fire events contributes to the respiratory health burden of firefighting forces. However, more studies are needed to corroborate these preliminary findings, explore the respiratory toxicological mechanisms, and support the implementation of preventive actions and mitigation strategies to pursue firefighters' health.

Occupational risk assessment of glutaraldehyde through personal air monitoring in a hospital setting.

Glutaraldehyde is a high-efficiency disinfectant that has been included in the protocols of some hospitals for controlling the spread of SARS-CoV-2, together with sodium hypochlorite and quaternary ammonium disinfectants. However, exposure has been poorly studied in workplace settings, despite the association between glutaraldehyde and respiratory diseases and skin conditions in exposed workers. This study evaluated the magnitude of exposure associated with the use of glutaraldehyde in healthcare workers across various work areas of a first level of Hospital-Based Care in Colombia. Workers were classified into similar exposure groups (SEGs) based on work areas and tasks performed, and airborne concentrations of glutaraldehyde were measured in different work areas of each SEG through direct monitoring. The 95th percentile of glutaraldehyde concentrations in all SEGs studied exceeded the TLV-C immediately after use. Cleaning workers and nurses had the highest exposures to glutaraldehyde. Results indicate that workers were overexposed and highlight the need to implement controls to reduce exposure. The high-exposure levels also raise the need to consider glutaraldehyde substitution and adequate use of personal protective equipment (PPE).

Ensemble of ensembles for fine particulate matter pollution prediction using big data analytics and IoT emission sensors

Purpose The study aims to develop a multilayer high-effective ensemble of ensembles predictive model (stacking ensemble) using several hyperparameter optimized ensemble machine learning (ML) methods (bagging and boosting ensembles) trained with high-volume data points retrieved from Internet of Things (IoT) emission sensors, time-corresponding meteorology and traffic data. Design/methodology/approach For a start, the study experimented big data hypothesis theory by developing sample ensemble predictive models on different data sample sizes and compared their results. Second, it developed a standalone model and several bagging and boosting ensemble models and compared their results. Finally, it used the best performing bagging and boosting predictive models as input estimators to develop a novel multilayer high-effective stacking ensemble predictive model. Findings Results proved data size to be one of the main determinants to ensemble ML predictive power. Second, it proved that, as compared to using a single algorithm, the cumulative result from ensemble ML algorithms is usually always better in terms of predicted accuracy. Finally, it proved stacking ensemble to be a better model for predicting PM2.5 concentration level than bagging and boosting ensemble models. Research limitations/implications A limitation of this study is the trade-off between performance of this novel model and the computational time required to train it. Whether this gap can be closed remains an open research question. As a result, future research should attempt to close this gap. Also, future studies can integrate this novel model to a personal air quality messaging system to inform public of pollution levels and improve public access to air quality forecast. Practical implications The outcome of this study will aid the public to proactively identify highly polluted areas thus potentially reducing pollution-associated/ triggered COVID-19 (and other lung diseases) deaths/ complications/ transmission by encouraging avoidance behavior and support informed decision to lock down by government bodies when integrated into an air pollution monitoring system Originality/value This study fills a gap in literature by providing a justification for selecting appropriate ensemble ML algorithms for PM2.5 concentration level predictive modeling. Second, it contributes to the big data hypothesis theory, which suggests that data size is one of the most important factors of ML predictive capability. Third, it supports the premise that when using ensemble ML algorithms, the cumulative output is usually always better in terms of predicted accuracy than using a single algorithm. Finally developing a novel multilayer high-performant hyperparameter optimized ensemble of ensembles predictive model that can accurately predict PM2.5 concentration levels with improved model interpretability and enhanced generalizability, as well as the provision of a novel databank of historic pollution data from IoT emission sensors that can be purchased for research, consultancy and policymaking.

Effects of short-term air pollution exposure on symptoms development in the course of idiopathic pulmonary fibrosis

ABSTRACT Background Lately a potential detrimental effect of air pollution to idiopathic pulmonary fibrosis emerged. We aimed to assess the effects of short-term air pollution exposure to the clinical course of IPF. Research design and methods IPF patients were followed intensively for four nonconsecutive study periods between 13 July 2020 and 5 September 2021. Short-term exposure to O3, NO2 and PM10 concentrations was estimated using spatio-temporal land use regression models. Associations among symptoms, lung function, oxygen saturation, and short-term personal air pollutant exposure were assessed through multiple mixed effects logistic regression models. Results Data for up to 24 IPF patients (mean age: 72.2 ± 7.6 years) were analyzed. We detected positive significant associations between cough and a 10 μg/m3 increase in same day mean level of NO2 (OR = 1.59, 95%CI: 1.00–2.53), PM10 (OR = 2.42, 95%CI: 1.54–3.79), and O3 (OR = 1.63, 95%CI: 1.14–2.32). A 10 μg/m3 increase in same day mean level of NO2 was also associated with the risk of appearance of wheezing (OR = 3.01, 95%CI: 1.00–9.04), while exposure to O3 was associated with common cold (OR = 6.30, 95%CI: 3.59–11.07). No significant associations were detected between short-term exposure to air pollutants and forced vital capacity or saturation of oxygen. Conclusions Short-term exposure to increased concentrations of air pollutants is an independent risk factor for IPF symptoms' aggravation.

Investigation of personal air pollution exposures and occupants’ fresh air demands in two office buildings in Switzerland

This study assessed personal exposures to indoor air pollutants in office environments with dynamic occupancy profiles. A two-week field campaign was conducted in two Swiss office buildings, examining three target areas in each building. We measured air temperature (T), relative humidity (RH), CO2, PM2.5, and PM10 levels at three stationary locations of each target area. Four office workers carried a customized vest to monitor personal CO2 and PM levels near their breathing zone. Using smartwatches, the workers completed hourly surveys about their activity profiles and preferences for outdoor air. We found that CO2 and PM10 concentrations were 1.2–1.3x and 1.8–2.5x higher, respectively, in the personal monitor compared to stationary sensors. Occupants had higher personal CO2 levels during sitting activity and higher personal PM levels during standing activity. Lunch/coffee/call activities were associated with discernible peaks of personal exposure to CO2, PM2.5, and PM10. The higher T coupled with lower RH measured at the personal level was associated with higher occupant demands for outdoor air.

Report-Back of Personal Air Sampling Results and Study Participants' Perceived Knowledge, Attitudes, and Awareness of Air Pollution.

Report-Back of Personal Air Sampling Results and Study Participants' Perceived Knowledge, Attitudes, and Awareness of Air Pollution.