Occupational Inhalation Research Articles

Air Pollution and Rheumatoid Arthritis Risk and Progression: Implications for the Mucosal Origins Hypothesis and Climate Change for RA Pathogenesis.

The goal of this review paper is to summarize the main research and findings regarding air pollution and its association with the risk and progression of rheumatoid arthritis (RA). The most studied components of air pollution included particulate matter of ≤ 2.5 microns in diameter (PM2.5), PM10, carbon monoxide (CO), nitrogen dioxide (NO2), nitric oxide (NOx), sulfur dioxide (SO2), and ozone (O3). In addition, specific occupations and occupational inhalants have been investigated for RA risk. Several studies showed that increased exposure to air pollutants increased the risk of developing RA, particularly seropositive RA. There was evidence of gene-inhalant interactions for seropositive RA risk. Fewer studies have been conducted on RA disease activity and bone erosions. Some studies suggest that patients with RA-associated interstitial lung disease may have worse outcomes if exposed to air pollution. We summarized associations between air pollution and increased RA risk, including RA-associated interstitial lung disease. Relatively few studies investigated air pollution and RA disease activity or other outcomes. These results suggest an important role of air pollution for seropositive RA development and suggest that climate change could be a driver in increasing RA incidence as air pollution increases.

Assessing lifetime occupational chrysotile inhalation exposure, respiratory symptoms, and lung cancer risk among brake maintenance workers in Malaysia.

This study aimed to estimate workers' occupational lifetime exposure to chrysotile and examine the respiratory symptoms and lung cancer risk. A total of 112 workers were interviewed about their occupational histories. Exposure modeling using information on the determinants of exposure was used to estimate chrysotile emissions. The cumulative lifetime exposure was then assessed for each worker. Respiratory symptoms were obtained using a validated questionnaire. Lung cancer mortality rate was also predicted using a model. Almost all the workers were male and young (mean age = 30 years, SD = 7). The estimated lifetime occupational chrysotile inhalation exposure ranged from 0.0001 to 0.0486 f/mL.years (median = 0.0018 f/mL.years, IQR = 0.486). A high prevalence of cough symptom (11.7%), and low estimated cancer risk (<1%) were reported. In conclusion, the lung cancer risk among our cohort of workers was at a low level because of lower cumulative lifetime occupational chrysotile exposure.

Characterization of occupational inhalation exposures to particulate and gaseous straight and water-based metalworking fluids

Exposure assessments to metalworking fluids (MWF) is difficult considering the complex nature of MWF. This study describes a comprehensive exposure assessment to straight and water-based MWFs among workers from 20 workshops. Metal and organic carbon (OC) content in new and used MWF were determined. Full-shift air samples of inhalable particulate and gaseous fraction were collected and analysed gravimetrically and for metals, OC, and aldehydes. Exposure determinants were ascertained through observations and interviews with workers. Determinants associated with personal inhalable particulate and gaseous fractions were systematically identified using mixed models. Similar inhalable particle exposure was observed for straight and water-based MWFs (64–386 µg/m3). The gaseous fraction was the most important contributor to the total mass fraction for both straight (322–2362 µg/m3) and water-based MWFs (101–699 µg/m3). The aerosolized particles exhibited low metal content irrespective of the MWF type; however, notable concentrations were observed in the sumps potentially reaching hazardous concentrations. Job activity clusters were important determinants for both exposure to particulate and gaseous fractions from straight MWF. Current machine enclosures remain an efficient determinant to reduce particulate MWF but were inefficient for the gaseous fraction. Properly managed water-based MWF meaning no recycling and no contamination from hydraulic fluids minimizes gaseous exposure. Workshop temperature also influenced the mass fractions. These findings suggest that exposures may be improved with control measures that reduce the gaseous fraction and proper management of MWF.

Risk assessment for perfluorooctanoic acid (PFOA) in air, blood serum and water: mortality from liver and kidney disease

BackgroundCancer and non-cancer associations have been observed with PFAS (perfluoroalkyl and polyfluoroalkyl) substances in the general population, in populations from locally contaminated environments and in exposed workers.MethodsA quantitative risk assessment...

Occupational Inhalation Health Risk Assessment of TCE Exposure in the Korean Manufacturing Industry

This study aimed to assess the health risks to workers in the Korean manufacturing industries using trichloroethylene (TCE). In Republic of Korea, TCE has permissible exposure limits. In 2014, the permissible exposure limits were exceeded in two cases, necessitating a health risk assessment. The exposure value of TCE in the workplace was determined using Korea’s Workplace Environmental Monitoring Program (WEMP), and risk assessment was performed by applying a probabilistic distribution using a Monte Carlo simulation. When evaluating non-carcinogenic risks at the 50th percentile, all 20 industries had acceptable risk, and at the 95th percentile, 12 of the 20 industries had unacceptable risk. Following the cancer risk assessment, 17 out of 20 industries had unacceptable risks, and the 95th percentile of all industries had unacceptable risks. The non-carcinogenic and carcinogenic risks of TCE were highest during metal fabrication. Based on these results, metal fabrication was chosen as an industry that should receive management priority in Korea. The findings of this study serve as a foundation for managing TCE among manufacturing workers.

Pulmonary Alveolar Proteinosis Secondary to Chronic Ethylene Oxide Occupational Inhalation

In this case report, a 40-year-old male patient with a persistent and productive cough lasting over 2 weeks, accompanied by dyspnea, who received an anti-tuberculosis drug regimen for 12 months without any clinical improvement at a different hospital before being referred to Persahabatan Central General Hospital was presented. In-depth clinical, and radiological investigations, the periodic acid-Schiff (PAS)-positive related to pulmonary alveolar proteinosis (PAP) confirmed through transbronchial biopsy (TBB). PAP is a rare lung disease with exceptionally low prevalence and incidence, Notably, the patient’s occupational environment played a crucial role in the diagnosis, as we identified occupational PAP secondary to chronic inhalation of ethylene oxide in a poorly ventilated work setting and inadequate respiratory protection. The patient was administered inhaled filgrastim (1 vial) at four intervals over 30 days, yielding favorable and satisfactory clinical as well as radiological outcomes.

Evaluation of Oxidative Stress Induced by Occupational Inhalation Exposure to N2O, an Anesthetic Gas

Introduction: Nitrous oxide (N2O) is the most common anesthetic gas used in operating rooms. The major objective of this investigation is to measure N2O values in two modes: first, when the ventilation system is on, and second, when it is off; and to determine the biomarkers of oxidative stress associated with this exposure among operating room personnel.&#x0D; Materials and Methods: A cross-sectional study was conducted on 60 operating room personnel as the N2O exposed group, and on 60 nurses as the referent group. N2O concentrations were determined according to NIOSH method 6600. Total antioxidant capacity (TAC) levels, malondialdehyde (MDA), and superoxide dismutase (SOD) activities were also measured.&#x0D; Results: The concentrations of N2O in the presence and absence of ventilation systems were significantly higher than the recommended exposure limit (REL) of 25 ppm recommended by NIOSH. The levels of TAC and SOD were significantly lower in participants exposed to N2O in comparison with the referent group. Adjusted for age, work experience, and sex, exposure to N2O was found to be an occupational risk factor for low levels of TAC and SOD, so that exposure to N2O reduced TAC and SOD levels by 0.16 mM and 0.75 U/ml, respectively.&#x0D; Conclusion: The present study shows that the operating room personnel are exposed to levels of N2O several times more than the REL of this gas and this heavy exposure is associated with a significant increase in oxidative stress.

Spatiotemporal variations, sources, and atmospheric transformation potential of volatile organic compounds in an industrial zone based on high-resolution measurements in three plants

Industrial emissions are significant sources of volatile organic compounds (VOCs). This study conducted a field campaign at high temporal and spatial resolution to monitor VOCs within three plants in an industrial park in southern China. VOC concentrations showed significant spatial variability in this industrial zone, with median concentrations of 75.22, 40.53, and 29.41 μg/m3 for the total VOCs in the three plants, respectively, with oxygenated VOCs (OVOCs) or aromatics being the major VOCs. Spatial variability within each plant was also significant but VOC-dependent. Seasonal variations in the VOC levels were governed by their industrial emissions, meteorological conditions, and photochemical losses, and they were different for the four groups of VOCs. The temporal and spatial variations in the VOC compositions suggest similar sources of each class of VOCs during different periods of the year in each plant. The diurnal patterns of VOCs (unimodal or bimodal) clearly differed from those at most industrial/urban locations previously, reflecting a dependence on industrial activities. The secondary transformation potential of VOCs also varied temporally and spatially, and aromatics generally made the predominant contributions in this industrial park. The loss rate of OH radicals and ozone formation potential were highly correlated, but the linear relationship substantially changed in summer and autumn due to the intensive emissions of an OVOC species. The lifetime cancer and non-cancer risks via occupational inhalation of the VOCs in the plants were acceptable but merit attention. Taking the secondary transformation potential and health risks into consideration, styrene, xylene, toluene, trichloroethylene, and benzene were proposed to be the priority VOCs regulated in the plants.

Acute occupational inhalation injuries-United States, 2011-2022.

Inhalation injuries due to acute occupational exposures to chemicals are preventable. National surveillance of acute inhalation exposures is limited. This study identified the most common acute inhalation exposure-related incidents by industry sector among US workers. To characterize inhalation-related injuries and their exposures during April 2011-March 2022, state and federal records from the Occupational Safety and Health Administration (OSHA) Occupational Safety and Health Information System (OIS) accident database were analyzed. Industry-specific injury, hospitalization, and fatality rates were calculated. The most frequent acute inhalation incidents investigated by OSHA were caused by inorganic gases (52.9%) such as carbon monoxide (CO) or acids, bases, and oxidizing chemical agents (12.9%) such as anhydrous ammonia. The largest number of fatal and nonfatal injuries were reported in the manufacturing (28.6%) and construction (17.2%) sectors. Workers were affected by acute inhalation exposures in most industries. Using this surveillance, employers can recognize frequently-occurring preventable acute inhalation exposures by industry, such as inorganic gases in the manufacturing sector, and implement prevention measures. Training of workers on exposure characteristics and limits, adverse health effects, and use of protective equipment by exposure agent can prevent inhalation injuries.

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.

Occupational non-communicable respiratory diseases in industrial and agricultural workers

Introduction. Harmful inhalation effects in the workplace, most of which are preventable, determine more than 10% of chronic non-infectious bronchopulmonary pathology over the world at the population level. In this regard, updated information on inhalation risk factors in various sectors of the economy and the prevalence of diseases associated with them is important for the scientific justification of targeted programs for the prevention of occupational respiratory diseases. &#x0D; Materials and methods. On the basis of the competent statistical materials of the Rospotrebnadzor Department for the Saratov region, a retrospective analysis of the prevalence of occupational non-communicable respiratory diseases (ONRD) and factor inhalation effects in various industries and agriculture of the region was carried out using generally accepted methods.&#x0D; Results. For the period from 2009 to 2019 in the territory of the Saratov region one hundred sixty seven industrial workers (58 people), and agriculture &#x0D; (109 people) were established to be diagnosed with 189 ONRD. Despite a fivefold reduction in cases of detection of ONRD over the past decade, &#x0D; non-communicable respiratory diseases occupied the second rank in the structure of accumulated occupational morbidity (25.1%). The range of the contribution of ONRD to the total pool of occupational diseases for different years of observation was from 13.9 to 37.5% in the industrial sector, from &#x0D; 13.3 to 33.3% in agriculture. The largest number of ONRD cases were registered in plant-growing workers (51.9%), manufacturing industries (23.3%), and livestock (10.1%); the smallest number in those engaged in mining (2.6%). The first ranks in the structure of the accumulated ONRD were occupied by chronic obstructive pulmonary disease (33.9%), chronic dust-free non-obstructive bronchitis (31.2%), and occupational bronchial asthma (23.3%), associated with air pollution of the working environment with silicon-containing, organic dust and sensitizing agents, the genesis of which was determined by the specifics &#x0D; of working conditions.&#x0D; Limitation. The gender factor was not taken into account when analyzing the prevalence of ONRD and its nosological structure.&#x0D; Conclusion. The data obtained can be used in the development of comprehensive medical and hygienic programs to improve occupational conditions and preserve the longevity of industrial and agricultural workers.

Impact of climate change on allergic diseases in Germany.

Allergic diseases, especially inhalation allergies, have reached epidemic levels and environmental factors play an important role in their development. Climate change influences the occurrence, frequency, and severity of allergic diseases. The contents of this article were selected by the authors and developed section by section according to their expertise and the current state of knowledge. The sections were then discussed and agreed upon amongst all authors. The article highlights direct and indirect effects of climate change on allergies. It goes into detail about the connections between climate change and (new) pollen allergens as well as (new) occupational inhalation allergens, explains the effects of climate change on the clinical picture of atopic dermatitis, discusses the connections between air pollutants and allergies, and provides information about the phenomenon of thunderstorm asthma. There is a need for action in the field of pollen and fungal spore monitoring, allergy and sensitisation monitoring, urban planning from an allergological perspective, and changes in the working environment, among others.

Immunotoxicity induced by occupational inhalation exposure to waste anesthetic gases: a historical cohort study.

This was a historical cohort study in which 30 male participants with at least one year of work experience in the operating room at the time of the study and 30 unexposed referent subjects were investigated. Exposure levels were quantified by measuring the urinary concentrations of nitrous oxide (N2O), isoflurane, and sevoflurane gases by headspace gas chromatography-mass spectrometry. Serum concentrations of interleukin-4 (IL-4), Th2-type cytokines, and interferon-gamma (IFN-γ) were measured by the ELISA method. Additionally, an automated hematology analyzer was used for the white blood cell count and white blood cell differential test. The data were analyzed using SPSS software for Windows version 21. Mean urinary concentrations of N2O, isoflurane, and sevoflurane were found to be 211.57±75.15, 4.06±0.96, and 19.51±12.96 ppb, respectively. In simplistic statistical data analysis, significant differences were noted between exposed and control groups as far as the mean serum cytokines levels (IFN-γ, IL-4) were concerned. Furthermore, after adjusting for important confounders, statistical analysis showed that the IFN-γ, IL-4, and the ratio of IFN-γ/IL-4 were significantly higher in the exposed group than in the referent subjects. These findings provide corroborative evidence to further substantiate the contention that exposure to anesthetics agents (N2O, isoflurane, and sevoflurane) is associated with subtle, subclinical, prepathological changes in the parameters of immune function. The long-term ramification of these changes requires further investigation.

70 Inhalation Exposure of Copper Particles - Quantitative Differentiation Between Copper Oxides and Metallic Copper

Abstract Inhalation exposure to copper and its inorganic compounds can occur in various industrial sectors such as ore mining, production of electrical equipment etc. Toxic effects of copper and its oxides have been shown to be attributed to i. particle size and ii. dissolution/release of copper ions. The latter being dependend on the chemical composition of the copper particle and its size. Hence, in the context of occupational inhalation exposure to those compounds emphasis should not only be directed towards particle size but also to the copper species. We have developed an ICP-MS based method that allows quantitative distinction between copper oxides (CuxO) and metallic copper (mCu) upon sampling on mixed-cellulose ester (MCE) membrane filters. This approach is based on the different dissolution properties of CuxO and mCu in dilute acid. Systematic assessment of the approach in regard to filter load and extraction time have been conducted and successfully applied to field samples.

Levels of Clara cell secretory protein and surfactant protein A in municipal solid waste management workers in Ibadan, Southwest Nigeria

Toxic pneumonitis and related respiratory symptoms are common among waste management workers (WMWs). Products of different cellular responses following exposure to toxic components of wastes can lead to the production of a variety of biomolecules. There is a growing recognition of the importance of biomarkers in risk assessment and a strong advocacy for their determination and use as indicators of health and safety. This study assessed the prevalence of respiratory symptoms and the relevance of pulmonary surfactant protein A (SP-A) and Clara cell 16 protein (CC16) as indicators of occupational inhalation exposure to toxic substances and irritants in WMW. A total of 172 subjects consisting of 112 WMWs and 60 Non-WMWs were recruited by purposive sampling. Data on socio-economic and work-related symptoms were collected using structured questionnaire. CC16 and SP-A were determined by ELISA in serum samples. Clinical history reveals a slightly higher prevalence of respiratory symptoms in WMWs relative to control subjects. Increased permeability of the lung-blood barrier, characterized by significant elevation of serum SP-A and serum CC16, was associated with respiratory symptoms in WMWs. Steady increases in SP-A and CC16, respectively, in relation to occupational duration were observed in WMWs relative to control. Receiver operating characteristic curve and multivariate analyses revealed SP-A and CC16 as important lung biomarkers for assessing sub-clinical effects of occupational exposure. Our data suggest SP-A and CC16 may be relevant indicators for assessing occupational inhalation exposure to toxic substances and irritants among WMWs.

Needlelike, short and thin multi-walled carbon nanotubes: comparison of effects on wild type and p53+/− rat lungs

Carbon nanotubes (CNTs) are nanomaterials presenting an occupational inhalation risk during production or handling. The International Agency for Research on Cancer classified one CNT, Mitsui-7 (MWNT-7), as ‘possibly carcinogenic to humans’. In recognition of their similarities, a proposal has been submitted to the risk assessment committee of ECHA to classify all fibers with ‘Fibre Paradigm’ (FP)-compatible dimensions as carcinogenic. However, there is a lack of clarity surrounding the toxicity of fibers that do not fit the FP criteria. In this study, we compared the effects of the FP-compatible Mitsui-7, to those of NM-403, a CNT that is too short and thin to fit the paradigm. Female Sprague Dawley rats deficient for p53 (GMO) and wild type (WT) rats were exposed to the two CNTs (0.25 mg/rat/week) by intratracheal instillation. Animals (GMO and WT) were exposed weekly for four consecutive weeks and were sacrificed 3 days or 8 months after the last instillation. Exposure to both CNTs induced acute lung inflammation. However, persistent inflammation at 8 months was only observed in the lungs of rats exposed to NM-403. In addition to the persistent inflammation, NM-403 stimulated hyperplasic changes in rat lungs, and no adenomas or carcinomas were detected. The degree and extent of hyperplasia was significantly more pronounced in GMO rats. These results suggest that CNT not meeting the FP criteria can cause persistent inflammation and hyperplasia. Consequently, their health effects should be carefully assessed.

Invited Perspective: Air Pollutants, Genetics, and the Mucosal Paradigm for Rheumatoid Arthritis Risk.

Invited Perspective: Air Pollutants, Genetics, and the Mucosal Paradigm for Rheumatoid Arthritis Risk.

ECETOC TRAv3: An In-depth Comparison of Publicly Available Measurement Data Sets With Modelled Estimates of Occupational Inhalation Exposure to Chemicals.

In this study, 129 exposure situations (ESs) with six or more measured inhalation exposures to dust from solids or vapour from liquids in occupational settings were compared with modelled European Centre of Ecotoxicology and Toxicology of Chemicals (ECETOC) targeted risk assessment tool, version 3 (TRAv3) estimates. The measurement data were extracted from previously published studies examining TRAv3 performance and pooled into a curated database. The comparison exercise focussed on the vapour exposure scenarios, as there were too few dust scenarios for a meaningful analysis of any required model corrections. A group of experts in the exposure modelling field retrieved and reviewed the input parameters used in these ESs. Where considered appropriate, modifications were applied to better match the input parameter definitions and the scope of applicability of the TRAv3. Differences and mean absolute error (MAE) were calculated between the log-transformed modelled exposure value and the 75th percentile of each measured data set and regression analysis was performed. The results indicated that the TRAv3 overestimated 80% of the measured data sets. Both over- and underestimations were mostly by factors 1-5. The calculated MAE for liquids was 0.7, indicating that on average the difference between the 75th percentile and the TRAv3 estimate was less than one order of magnitude. A multiple linear regression showed that some input parameters such as medium volatility, certain process categories (PROC), industrial setting, and the presence of local exhaust ventilation are associated with underestimations. The results of the regression analysis can be used by TRAv3 users to review the degree of over- or underestimation in their current exposure assessments, compared to the curated database. Although multiple linear regression is an appropriate methodology to characterize the TRAv3's performance, more data sets are still needed in view of some remaining data gaps. Nevertheless, the results of the current analysis are being used by ECETOC to further develop the tool as a suitably conservative screening tool for use in REACH chemical safety assessment of occupational exposure to chemicals.

RA risk from occupational inhalation.

RA risk from occupational inhalation.

Strategies for refinement of occupational inhalation exposure evaluation in the EPA TSCA risk evaluation process.

The focus on occupational exposures in the first published risk evaluations of existing chemicals by the Environmental Protection Agency (EPA) under the amended Toxic Substances Control Act (TSCA) puts a welcome spotlight on protecting the health of workers in the United States. Because new, fit-for-purpose occupational exposure assessment methodologies were developed by EPA, the objective of this analysis was to evaluate these methodologies in light of other existing occupational risk assessment frameworks. We focused our analysis on three chlorinated chemicals (methylene chloride, carbon tetrachloride, perchloroethylene). The EPA's methods were evaluated relative to peer-reviewed and professional organizations' guidelines for conducting site- and facility-based exposure assessment. Analyses of several key phases in the EPA approach were conducted to evaluate the effect of alternative approaches on exposure estimates. The revised exposure estimates using these alternative approaches yielded substantially different exposure estimates from those in the TSCA risk evaluations for these chemicals. The results also demonstrated the importance of utilizing a tiered approach to exposure estimation that includes collecting qualitative data, defining similar exposure groups, and integrating well-parameterized models with empirical data. These approaches aid in preventing mischaracterization of exposures and generating exposure estimates representative of current industrial practices. Collaboration among industry, EPA, and other government agencies to develop a harmonized approach to exposure assessment would improve the methodological rigor of, and increase stakeholder confidence in, the results of TSCA risk evaluations.