A limited number of published studies have evaluated concentrations of airborne fibers in outdoor air, with even fewer assessing typical air concentrations in the ambient air near fiberglass wool manufacturing facilities. Building upon the assessment by Switala et al. (1994), area samples for airborne fiber concentrations (diameters of less than 3 µm, lengths greater than 5 µm, and aspect ratios equal to or greater than 5 to 1) were collected at fixed locations along the fence lines of three fiberglass wool manufacturing facilities in the United States. Samples were analyzed by the National Institute for Occupational Safety and Health (NIOSH) Method 7400, via phase contrast microscopy (PCM) using "B" counting rules. A total of 134 samples were collected across the three plants. Overall, 73% of the samples collected were below the limit of quantification (LOQ). Using the Kaplan-Meier (KM) method for estimation of values below the LOQ, the geometric mean fiber concentration for all plants combined was 0.0028 fibers per cubic centimeter (f/cc), with the 95 percentile upper confidence level at 0.0049 f/cc. Of those samples with detectable concentrations of airborne fibers ( = 36), when further analyzed using energy dispersive X-ray (EDX) analysis, only one sample had a detectable glass fiber concentration at 0.0045 f/cc, which was noted as the detection limit for the method. This glass fiber concentration is within the range anticipated for ambient fibrous glass near production facilities, suggesting consistency with measurements made by Switala et al. (1994), despite changes in production methods (i.e., use of different binders) since 1994 and the use of updated methods for treatment of values below the LOQ in the current assessment.

This paper aims to investigate the effectiveness of personal protective equipment (PPE) in reducing firefighter exposure to various hazardous chemicals from the smoke emitted during fires. A systematic review of peer-reviewed articles was undertaken utilizing five databases: Medline, Embase, Web of Science, Scopus, and CINHAL. Studies published between 2013 and 2023 that investigated the effectiveness of PPE in reducing firsthand exposure to at least one chemical were included. Extracted data were grouped into two overarching themes related to PPE: (a) Respiratory Protection and (b) Personal Protective Clothing (PPC). Overall, 21 studies met the inclusion criteria and were considered for further analysis. Respiratory protection, particularly self-contained breathing apparatus (SCBA), offered the most protection in preventing inhalation exposure to chemical hazards. There was limited evidence on the effectiveness of firefighter turnout gear in reducing skin contamination. Combustion contaminants, especially highly volatile compounds like benzene, were found to permeate and penetrate through and around the protective clothing. In conclusion, certain respirators, particularly SCBA, provided the best protection against inhalation exposure to chemicals; however, PPC did not appear to provide complete protection, particularly against the more volatile chemicals like benzene.

Greenhouses are space-efficient structures used in the production of produce. However, occupational health issues like exposure to chemicals, and physiological and postural stresses are experienced by operators while performing farm activities due to the enclosed environment of the greenhouse. This study assesses chemical exposure and physiological and postural parameters of operators during spraying with two different types of sprayers (Battery-powered knapsack sprayer [Battery sprayer] and AC-powered stationary sprayer [Stationary sprayer]) with two different application techniques (continuous and alternate row). The mean Potential Dermal Exposure (PDE) for a continuous row of spraying was 54 and 70 mL h with battery and stationary sprayers, respectively. However, PDE in alternate row spraying was approximately 16 and 25% less in battery and stationary sprayers than in a continuous row. The upper and left portions of the body had higher exposure compared to the lower and right half portions in all treatments. The ergonomic parameters (physiological and postural assessment) in continuous and alternate row spraying techniques did not differ but varied with the type of sprayer used. Mean values of energy expenditure rate, body part discomfort score, overall discomfort score, and risk index were 210 ± 35 W, 27 ± 2.0, 6.1 ± 0.4, and 1.0, respectively, in the battery sprayer compared to 290 ± 80 W, 35 ± 4.1, 8.3 ± 1.0, and 2.0 in the stationary sprayer. This study concluded that the use of a battery sprayer with an alternate row spraying technique resulted in lower dermal exposure (45 mL h) and was ergonomically less demanding.

Trichloramine is a disinfection by-product in chlorinated swimming pools. It can evaporate into the air and irritate eyes and airways among swimmers and pool workers. This study aimed to evaluate airborne concentrations of trichloramine in different types of indoor swimming pools. Altogether, 72 swimming pools across Sweden were included; 36 exercise pools, 16 instruction pools, seven adventure pools, and 13 rehabilitation pools. In total, 167 sampling sessions were performed with the majority ( = 91) conducted in public exercise pools. Repeated sampling sessions on different days were performed within all pool categories. Airborne trichloramine was measured stationary by the poolside using active sampling on quartz filters. In total, 434 air samples were collected. The geometric mean (GM) concentration of trichloramine for the exercise pools was 0.12 mg/m (range GM: 0.02-0.29 mg/m) and for about 30% the GM exceeded the Swedish public health guideline value (0.2 mg/m). The geometric mean for instruction pools was 0.18 mg/m and for adventure pools 0.20 mg/m. Trichloramine concentrations were statistically significantly lower in rehabilitation pools (GM: 0.03 mg/m) compared with the other pool categories. A statistically significant effect of time of the day for sampling was found for the exercise and instruction pools, with higher trichloramine levels during evenings compared with mornings and afternoons. For the rehabilitation pools, trichloramine was significantly higher during the cold season compared with the warm season. Variability in trichloramine concentrations was attributed to between-pool as well as within-pool variances. The within-pool variability encourages a repeated sampling strategy to capture the variation between different days. These findings have implications for exposure assessment in epidemiological studies as well as for indoor air quality monitoring. Trichloramine can cause acute irritative effects at elevated levels, and since trichloramine concentrations may differ depending on the time of the day it is recommended that full-day stationary measurements are supplemented with short-term samplings to capture these variations.

While monitoring physiological strain is recommended to safeguard workers during heat exposure, it is logistically challenging. The perceptual strain index (PeSI) is a subjective estimate thought to reflect the physiological strain index (PSI) that requires no direct monitoring. However, advanced age and chronic diseases (hypertension/type 2 diabetes [T2D]) influence the perception of heat stress, potentially limiting the utility of the PeSI. We therefore assessed whether the relation and agreement between the PeSI and PSI during simulated work in various environmental conditions is modified by age and T2D/hypertension. Thirteen young adults and 37 older adults without ( = 14) and with T2D ( = 10) or hypertension ( = 13) walked on a treadmill (∼200 W/m) for 180 min or until termination (volitional fatigue, rectal temperature ≥39.5 °C) in 16, 24, 28, and 32 °C wet-bulb globe temperatures. Rectal temperature and heart rate were recorded to calculate PSI (0-10 scale). Rating of perceived exertion and thermal sensation were recorded to calculate PeSI (0-10 scale). The relation between hourly PSI and PeSI was assessed via linear mixed models. Mean bias (95% limits of agreement [LoA]) between PSI and PeSI was assessed via Bland-Altman analysis. PSI increased with PeSI ( < 0.001), but the slope of this relation was not different between young and older adults ( = 0.189) or as a function of chronic disease (within older adults;  = 0.183). The mean bias between PSI and PeSI was small (0.02), but the 95% LoA was wide (-3.3-3.4). Together, a linear relation between PeSI and PSI was observed but agreement between these measures varied considerably across individuals and thus PeSI should not be used as a surrogate marker of PSI. Caution should be taken when utilizing the PeSI to estimate physiological strain on workers.

Filtering face piece (FFP) masks according to EN 149 are essential components of personal protective equipment against biological agents from an occupational health and hospital hygiene perspective. Therefore, shortages due to increased demand or supply bottlenecks can lead to staff threats due to the risk of infection. To determine whether FFP masks could be made reusable in a hospital setting, a thermal reprocessing concept (steam at 105 °C with a holding phase of 10 min) was evaluated in a bed reprocessing chamber. The results indicate that it is logistically possible to establish a reprocessing concept. Of 267 reprocessed masks, 48 were rejected by inspection because of defect strapping, trapped hair, misfolding, and missing lot number or deformation, and 22 masks were rejected by bacteriological examination because of contamination > 10 CFU of total bacteria per 25 cm or the presence of . Two selected mask models maintained the expected mask performance equivalent to the FFP2 standard after reprocessing. Thermal reprocessing resulted in a virucidal effect. The results show that reprocessing of FFP masks in hospitals is possible. However, the success of reprocessing depends on the type of mask used. This study identified a suitable mask type for which the reported method is bactericidal and virucidal without impairing mask performance. The reported method required the use of a stationary hospital bed reprocessing chamber (sanitizing washer), so it cannot be used everywhere. Other methods and procedures should be tested to be independent of a bed reprocessing chamber and therefore may be more mobile and flexible.

Awareness about laying hen welfare has led to the phase-out of conventional battery cages in favor of the adoption of alternative housing systems for egg production in many countries. However, the greater freedom of movement for animals and the presence of manure and litter (sawdust, straw, feathers, etc.) on the floor in some alternative housing systems may be suitable conditions for dusts, bacteria, and fungi to be aerosolized, raising concerns about indoor air quality and respiratory health of workers. The present project aimed at assessing and comparing indoor air quality and bioaerosols in conventional and alternative houses for laying hens. Six were conventional houses (with battery cages), six were enriched colonies, and six were aviary (multi-level cage-free houses) visited in Eastern Canada from 2020-2022. Higher airborne concentrations of particulate matter (PM) from all size fractions (PM1, PM2.5, PM4, PM10, and total dust), culturable bacteria, total endotoxins, and were found in aviaries compared to houses for laying hens in conventional and enriched colonies. Total endotoxin and concentrations were higher in enriched colonies than in conventional laying-hen housing systems. and sp. were detected in few hen houses. This study highlights possible markers for indoor air quality evaluation inside laying hen houses. These airborne contaminants could be targeted by mitigation strategies to improve indoor air quality in alternative housing systems for laying hens.

A very small proportion of all chemicals in commerce have (OELs) based on quantitative risk assessments which require estimates of exposure-response relationships (XRs). For only 18 of the 94 chemicals declared by NIOSH to be carcinogens were human XRs reported in or calculable from published reports. For the 18 carcinogens, 96 such XRs could be derived (corresponding to chemicals with multiple associated cancer end-points and/or multiple source studies). Twenty-four of 96 XR estimates came directly from reported statistical models (on continuous cumulative exposure), 45 were derived from summary study-population attributes, and 27 came from categorical analyses. Using the 96 XRs, OEL conferring one-per-thousand excess lifetime risk were calculated. OSHA's OEL, (PEL) were then compared to OEL derived from the 96 XRs. For 88 of the 96 calculated OELs (for which a corresponding PEL exists) all but 10 fell below the current PEL. Thirty-four OEL estimates were 10- to 100-fold below the PEL and 21 were greater than 100-fold below the PEL. This same pattern was observed using the different methods for deriving XRs. These findings can guide priorities in setting standards and the method is not limited to carcinogens.

Flushing uncovered toilets in hospitals has been shown to produce toilet plume aerosols (TPA) in a wide size ranging from nanometers to micrometers. Studies have shown that TPA can carry infectious pathogens and hazardous drugs used in cancer treatment. To mitigate the risk of exposure, some researchers have recommended covering the toilet during flushing, and guidelines from the Oncology Nursing Society have specifically recommended covering the toilet when flushing excreta from patients receiving chemotherapy. Because existing literature primarily focused on controlled laboratory settings or small case studies, there has been a need for a real-world, multi-center study in clinical settings to measure TPA by flushing both covered and un-covered toilets. To address this gap, the authors initiated a multicenter study to measure TPA in clinical settings and to assess the effectiveness of a commercially available, portable, and reusable toilet cover. The study enrolled 15 hospital centers (145 toilets) in nine U.S. states which included seven National Cancer Institute (NCI)-designated comprehensive cancer centers. The particle number concentrations were measured using a TSI optical particle counter (TSI 9306) with six size bins (0.3 to 25.0 µm) positioned 22 inches above the floor. The results showed that the ambient particle number concentrations in the HEPA-filtered floor bathrooms (376 ± 857#/L) are significantly lower than the non-HEPA-filtered ones (7,432 ± 9,207#/L). The mean particle number concentrations generated by flushing are 3,951 ± 8,606#/L with a median of 1,916#/L, ranging from 136#/L to 71,959#/L. Results with cover demonstrated a reduction in the total number of particles of 101 ± 11% regardless of the HEPA filter usage ( = 0.0002 in the Mann-Whitney U test). Mixed-effects modeling revealed that the overall level of particle reduction is substantial regardless of state (nine total), floor levels, flush volumes, and inpatient versus outpatient. This study provides evidence supporting the use of the tested portable toilet cover as an intervention to reduce healthcare workers', patients', and visitors' exposure to toilet plume aerosols in clinical settings.

Firefighters can be occupationally exposed to a wide range of airborne pollutants during fire-extinguishing operations. The overall study aim was to characterize occupational exposure to smoke for several groups of workers responding to fires, with specific aims to determine the correlations between exposure markers and to biologically assess their systemic exposure to polycyclic aromatic hydrocarbons (PAHs) in urine. Personal exposure measurements of equivalent black carbon (eBC), elemental carbon (EC), organic carbon (OC), nitrogen dioxide (NO), PAHs, lung deposited surface area (LDSA), and particle number concentration (PNC) of ultrafine particles were performed on firefighters, observers, and post-fire workers during firefighting exercises. Urine samples were collected before and after exposure and analyzed for PAH metabolites. Additional routes for PAH skin exposure were investigated by wipe sampling on defined surfaces: equipment, personal protective equipment (PPE), and vehicles. Among workers without PPE, observers generally had higher exposures than post-fire workers. The observers and post-fire workers had an occupational exposure to smoke measured e.g. as EC of 7.3 µg m and 1.9 µg m, respectively. There was a good agreement between measurements of carbonaceous particles measured as EC from filters and as eBC with high time resolution, especially for the observers and post-fire workers. Ultrafine particle exposure measured as LDSA was two times higher for observers compared to the post-fire workers. The urinary levels of PAH metabolites were generally higher in firefighters and observers compared to post-fire workers. Investigation of PAH contamination on firefighters' PPE revealed high PAH contamination on surfaces with frequent skin contact both before and after cleaning. Exposure to smoke can be assessed with several different exposure markers. For workers residing unprotected around fire scenes, there can be high peak exposures depending on their behavior concerning the smoke plume. Several workers had high urinary PAH metabolite concentrations even though they were exposed to low air concentrations of PAHs, indicating skin absorption of PAH as a plausible exposure route.

Non-medical masks such as disposable non-medical, commercially produced cloth, and homemade masks are not regulated like surgical masks. Their performance, in terms of filtration efficiency and breathability, is variable and unreliable. This research provides a quantitative evaluation of various non-medical masks, assesses their fabrics' potential for the reduction of transmission of bioaerosols such as the SARS-CoV-2 virus, and compares them to surgical masks and N95 filtering facepiece respirators. Using a testing line with a NaCl challenge aerosol, four types of commercial reusable cloth masks, two types of disposable non-medical masks, three types of surgical or N95 masks, and seven types of commonly available materials were tested individually and in combinations. The testing line and procedure were adapted from the ASTM F2299-03: Standard Test Method for Determining the Initial Efficiency of Materials Used in Medical Face Masks to Penetration by Particulates Using Latex Spheres testing method used for testing surgical masks. Filtration efficiencies at 0.15 µm particle diameter at a face velocity of 25 cm/sec for commercial cloth masks, disposable non-medical masks, surgical masks, commercial mask combinations, and homemade combinations ranged from 16-29%, 39-76%, 91-97%, 51-95%, and 45-94%, respectively. The pressure drop results for the different masks and material combinations were all under 3 mm HO/cm except for one material configuration. This study builds on other research that looks at individual materials and masks by testing combinations alongside the individual masks and materials. With proper layering, household materials can achieve the filtration efficiency and low pressure drop requirements of surgical masks. The filtration capabilities of disposable and cloth mask fabrics vary considerably meaning that they are not a reliable or consistent facemask option, regardless of fit.

A job-exposure matrix (JEM) is a tool that can estimate diesel engine exhaust (DEE) exposures. JEMs based on expert judgment or measurement data are limited by the information available at the time of development. Over time, more information about hazardous exposures is understood through additional measurements and peer-reviewed publications. This study presents a systematic approach to updating an existing DEE JEM using published data to better reflect current scientific knowledge. The literature was searched for occupational exposure studies that measured DEE as elemental carbon (EC) between January 2010 and May 2022. Four-digit North American Industry Classification System (NAICS) 2002 and National Occupational Classification-Statistics (NOC-S) 2006 codes were assigned to each identified subgroup within the studies. EC exposures were categorized as low (0-10 µg/m), moderate (10-20 µg/m), or high (>20 µg/m). Weighted arithmetic means were calculated for each industry-occupation intersection (IOI) identified in the literature. These means were used to adjust, or retain, the existing exposure level within the JEM cells using a decision tree based on the number of studies, workplace locations, and pooled sample size of the weighted mean. Concordance was measured between the updated JEM (Diesel Exhaust in Canada JEM (DEC-JEM)), the previous (existing) JEM, and the Canadian Job-Exposure Matrix (CANJEM). Thirty-seven studies were identified from the published literature reporting on 53 unique IOIs (20 NAICS and 34 NOC-S codes), including occupations in the mining, construction, and transportation industries. Exposure levels for 66% of identified IOIs increased, most in construction and mining. After the decision tree's results were expanded to the full DEC-JEM, the exposure level of 486 IOIs (12.5% of DEC-JEM) and 286,710 workers (15.8% of DEE-exposed workers) increased. There was a significant correlation between qualitative exposure levels in the updated DEC-JEM and CANJEM (Kendall's τ = 0.364,  < 0.001). This study describes a systematic approach to updating an existing JEM to incorporate new scientific knowledge. The updated DEC-JEM better reflects existing exposure knowledge in several industries, particularly construction. Future analyses include investigating its use as an exposure assessment tool in disease surveillance.

Exposure to silica dust presents a risk for the development of lung disease for stone carvers in Nakhon Ratchasima province, Thailand. This study aimed to develop a rapid prediction model for the assessment of silicosis risk among 243 stone carvers who were exposed to silica at work from August and October 2023 in Nakhon Ratchasima, Thailand. Demographic characteristics collected in questionnaires were work information; basic health information; health behavior data, including prevention and control of silicosis; knowledge; attitude; and practices for surveillance, prevention, and control of silicosis. Respirable crystalline silica (RCS) exposures were measured by conducting personal air sampling. Risk scores of silicosis were calculated and a rapid prediction model for assessment of silicosis risk among stone carvers was determined. It was found that 11 variables were significantly associated with silicosis risk scores ( < 0.05). However, it was demonstrated that only four significant influential variables, including the concentration of silica dust exposure (mg/m), working hours per day, underlying diseases, and separation of residence from a workplace were acceptable for conducting a silicosis risk assessment using multiple regression analysis (R = 0.675). This study indicated that a prediction model can be used for the assessment of silicosis risk among stone carvers. Therefore, the use of this prediction model is recommended to evaluate the risk associated with exposure to RCS of stone carvers in Nakhon Ratchasima province, Thailand due to its simplicity, accuracy, and time-saving attributes.

An occupational health study was conducted inside reinforced-concrete earth-covered munitions storage magazines (ECMs) at Fort Wingate Depot Activity (FWDA), a former military facility near Gallup, New Mexico. A two-phased approach was used: (1) HEPA vacuuming of bulk dust and (2) wipe sample verification post-vacuuming. Site-specific occupational health criteria were derived to evaluate potential risk from inhalation of bulk dust (Phase 1) and dermal contact of residual dust (Phase 2). In Phase 1, no explosives detections exceeded site-specific screening criteria. Any explosives detected, with or without criteria were carried forward into Phase 2. In Phase 2, no exceedances were noted for detected explosives with criterion. Using structure/reactivity characteristics within the explosives category, surrogates were assigned to the six (6) explosives without occupational health screening criteria. Based upon structural similarities within the analysis category, assignments of surrogates to explosives without criteria did not adversely impact the study conclusions. In Phase 1, lead was detected in bulk dust in all 35 igloos and all detections exceeded the applicable criterion for commercial/industrial workers. In Phase 2, all lead detections in wipe samples were below the wipe screening criteria. Study results indicated the ECM interiors posed no unacceptable dermal occupational risk for explosives or lead residues following bulk dust removal. High-efficiency particulate air (HEPA) filter vacuuming of interior bulk dust in ECMs at FWDA reduced occupational risk/hazard for exposure via inhalation and dermal contact for commercial/industrial worker activities under worst-case exposure conditions. Both phases of this sampling design are widely applicable, provided the site-specific assumptions made for this study are evaluated for suitability to another specific application and adjusted if needed.

Given the global burden of COVID-19 among healthcare workers (HCWs), it is expected that they face an elevated risk of developing post-COVID-19 syndrome. The objectives of this study were to evaluate the prevalence of post-COVID-19 syndrome and associated risk factors in HCWs followed for a median time of 18 months by conducting a retrospective cohort study. All HCWs with confirmed COVID-19 during the period from January 2021 to December 2022 were included in the study. HCWs were regularly assessed after COVID-19 diagnosis, so post-COVID-19 syndrome data could be collected. During the study period, 463 HCWs were included in the study, 227 (49.0%) of which experienced post-COVID-19 syndrome. The most common persistent symptoms were fatigue ( = 147 [32.5%]), memory disorders ( = 98 [21.5%]), dyspnea ( = 73 [16.0%]), anxiety/depression ( = 69 [15.0%]), and cough ( = 43 [9.4%]). Female sex and obesity were statistically associated with the development of post-COVID-19 syndrome. A high prevalence of post-COVID-19 syndrome in HCWs was found. Female sex and obesity appear to be risk factors associated with a higher prevalence of post-COVID-19 syndrome. Special attention should be given to these patients with risk factors during follow-up in the COVID-19 recovery period.

Exposure to biosolids in human waste handling occupations is associated with a risk for illness due to microbial infections. Although several years of exposure to biosolids might be hypothesized to be a prophylaxis against infection, the risks associated with infections from antibiotic-resistant organisms can also be a potential concern. Therefore, this study aimed to conduct a screening level risk assessment by deriving occupational exposure limits (OELs) characterizing the risks of adverse health effects among workers in human waste handling occupations with a focus on exposure to two pharmaceuticals commonly found in biosolids: ciprofloxacin (CIP) and azithromycin (AZ). Epidemiological and exposure studies of workers exposed to biosolids were identified through searches of major scientific databases. Screening OELs (sOELs) for these antibiotics were derived using a standardized methodology. The airborne concentrations of CIP and AZ antibiotics were determined using an exposure factors approach. The health-based exposure limits (i.e., sOELs) and the acceptable daily exposure (ADE) values for both of these antibiotics were derived as 80 μg/m and 12 μg/kg-day, respectively. An exposure factor approach suggested that inhalation route exposures to CIP and AZ are well below the sOELs and ADE daily doses, and likely too low to cause direct adverse health effects through antibiotic inhalation. A critical review of epidemiological studies on different occupations handling biosolids showed that the workers in industries with potential biosolids exposure have experienced an increased incidence of microbial-exposure-related illness. The health effects seen in the workers have been attributed to bacterial, viral, and protozoan infections. To the extent that bacteria are the pathogen of concern, it is not clear whether these bacteria are resistant to antibiotics commonly found in biosolids. It is also unclear whether the presence of antibiotics or antibiotic-resistant bacteria increases the susceptibility of these workers. Additional studies will provide more definitive estimates of inhalation and dermal exposures to CIP and AZ and could verify the exposure estimates in this study based on the literature and common exposure factors.

Airborne particulates in iron ore mining are a risk factor for adverse human lung effects. In this study, fine particulates deposited on surfaces of about 1.5 m above the ground and 6 meters from a milling unit of the Gol-e-Gohar iron ore mine were collected through wipe sampling. Dust particles less than 5 µm in diameter were separated with an electronic sieve. Aliquots were prepared from the sieved iron ore dust estimated to be equivalent to respiratory exposure in the iron ore mill in the concentrations of 1, 5, 10, 50, 100, and 250 µg/mL, which were intended to represent equivalent inhaled doses from working one month to a working life (25 years) in the mine. The airborne concentration of respirable particles was about five times the threshold limit value given (TLV) for iron oxide published by the American Conference of Governmental Industrial Hygienists. The toxicity range was estimated to be equivalent to an accumulated dose associated with working from one month to a working life in the mine. Treatment of the A549 cells resulted in decreased dehydrogenase activity and cell glutathione content and increased reactive oxygen species (ROS) generation, mitochondrial membrane permeability, and cell apoptosis-necrosis rates. The results of this study revealed the possibility of lung damage at cell doses for respirable airborne iron oxide particles estimated to be equivalent to accumulated lifetime exposures among Gol-e-Gohar miners. Further studies are recommended to investigate the effect of actual contaminants in the workplace on the occurrence of health effects on workers.