Occupational exposure and health surveys at metal additive manufacturing facilities.

Introduction: Additive manufacturing is a novel state-of-the art technology with significant economic and practical advantages, including the ability to produce complex structures on demand while reducing the need of stocking materials and products. Additive manufacturing is a technology that is here to stay; however, new technologies bring new challenges, not only technical but also from an occupational health and safety perspective. Herein, leading Swedish companies using metal additive manufacturing were studied with the aim of investigating occupational exposure and the utility of chosen exposure- and clinical markers as predictors of potential exposure-related health risks.

Exploring Methods for Surveillance of Occupational Exposure from Additive Manufacturing in Four Different Industrial Facilities.

3D printing, a type of additive manufacturing (AM), is a rapidly expanding field. Some adverse health effects have been associated with exposure to printing emissions, which makes occupational exposure studies important. There is a lack of exposure studies, particularly from printing methods other than material extrusion (ME).

[Exhaled droplets and Covid-19].

Exhaled droplets are composed of water, salts and organic material and the physical designation is particles. These particles vary in size from 0.01 µm to very large, e g produced during coughing.

Two techniques to sample non-volatiles in breath-exemplified by methadone.

The particles in exhaled breath provide a promising matrix for the monitoring of pathological processes in the airways, and also allow exposure to exogenous compounds to be to assessed. The collection is easy to perform and is non-invasive. The aim of the present study is to assess if an exogenous compound-methadone-is distributed in the lining fluid of small airways, and to compare two methods for collecting methadone in particles in exhaled breath.

The effect of exhalation flow on endogenous particle emission and phospholipid composition.

Exhaled particles constitute a micro-sample of respiratory tract lining fluid. Inhalations from low lung volumes generate particles in small airways by the airway re-opening mechanism. Forced exhalations are assumed to generate particles in central airways by mechanisms associated with high air velocities.

Low Levels of Exhaled Surfactant Protein A Associated With BOS After Lung Transplantation.

Background: There is no clinically available marker for early detection or monitoring of chronic rejection in the form of bronchiolitis obliterans syndrome (BOS), the main long-term complication after lung transplantation. Sampling and analysis of particles in exhaled air is a valid, noninvasive method for monitoring surfactant protein A (SP-A) and albumin in the distal airways.

Methods: We asked whether differences in composition of exhaled particles can be detected when comparing stable lung transplant recipients (LTRs) (n = 26) with LTRs who develop BOS (n = 7).

Surfactant Protein A in Exhaled Endogenous Particles Is Decreased in Chronic Obstructive Pulmonary Disease (COPD) Patients: A Pilot Study.

Background: Exhaled, endogenous particles are formed from the epithelial lining fluid in small airways, where surfactant protein A (SP-A) plays an important role in pulmonary host defense. Based on the knowledge that chronic obstructive pulmonary disease (COPD) starts in the small airway epithelium, we hypothesized that chronic inflammation modulates peripheral exhaled particle SP-A and albumin levels. The main objective of this explorative study was to compare the SP-A and albumin contents in exhaled particles from patients with COPD and healthy subjects and to determine exhaled particle number concentrations.

Exhaled particles as markers of small airway inflammation in subjects with asthma.

Exhaled breath contains suspended particles of respiratory tract lining fluid from the small airways. The particles are formed when closed airways open during inhalation. We have developed a method called Particles in Exhaled air (PExA ) to measure and sample these particles in the exhaled aerosol.

Evidence for an N-methyl transfer reaction in phosphatidylcholines with a terminal aldehyde during negative electrospray ionization tandem mass spectrometry.

Lipidomic analysis of the complex mixture of lipids isolated from biological systems can be a challenging process that often involves tandem mass spectrometry and interpretation of both precursor ions and product ions relative to the molecular structure of the lipids. Therefore, detailed understanding of the gas-phase ion chemistry occurring for each class of phospholipids is critically important for an accurate assignment of lipid structure. Some oxidized phosphatidylcholines are known to be biologically active and responsible for pathological events, and are therefore important targets for detection in lipidomic studies.

Identification of oxidized phospholipids in bronchoalveolar lavage exposed to low ozone levels using multivariate analysis.

Chemical reactions with unsaturated phospholipids in the respiratory tract lining fluid have been identified as one of the first important steps in the mechanisms mediating environmental ozone toxicity. As a consequence of these reactions, complex mixtures of oxidized lipids are generated in the presence of mixtures of non-oxidized naturally occurring phospholipid molecular species, which challenge methods of analysis. Untargeted mass spectrometry and statistical methods were employed to approach these complex spectra.

Comparison of exhaled endogenous particles from smokers and non-smokers using multivariate analysis.

Background: Smoking, along with many respiratory diseases, has been shown to induce airway inflammation and alter the composition of the respiratory tract lining fluid (RTLF). We have previously shown that the phospholipid and protein composition of particles in exhaled air (PEx) reflects that of RTLF. In this study, we hypothesized that the composition of PEx differs between smokers and non-smokers, reflecting inflammation in the airways.

Effects of breath holding at low and high lung volumes on amount of exhaled particles.

Exhaled breath contains particles originating from the respiratory tract lining fluid. The particles are thought to be generated during inhalation, by reopening of airways closed in the preceding expiration. The aim here was to explore processes that control exhaled particle concentrations.

Effects on airways of short-term exposure to two kinds of wood smoke in a chamber study of healthy humans.

Introduction: Air pollution causes respiratory symptoms and pulmonary disease. Airway inflammation may be involved in the mechanism also for cardiovascular disease. Wood smoke is a significant contributor to air pollution, with complex and varying composition.

Exhaled endogenous particles contain lung proteins.

Background: We recently developed a novel, noninvasive method for sampling nonvolatile material from the distal airways. The method is based on the collection of endogenous particles in exhaled air (PEx). The aim of this study was to characterize the protein composition of PEx and to verify that the origin of PEx is respiratory tract lining fluid (RTLF).

Surfactant protein A and albumin in particles in exhaled air.

In this study we test the hypothesis that endogenous particles in exhaled air (PEx), non-invasively sampled from lower airways, are well suited for the analysis of respiratory tract lining fluid (RTLF) proteins, i.e., surfactant protein A (SP-A) and albumin.

Effect of airway opening on production of exhaled particles.

The technique of sampling exhaled air is attractive because it is noninvasive and so allows repeated sampling with ease and no risk for the patient. Knowledge of the biomarkers' origin is important to correctly understand and interpret the data. Endogenous particles, formed in the airways, are exhaled and reflect chemical composition of the respiratory tract lining fluid.

Airway monitoring by collection and mass spectrometric analysis of exhaled particles.

We describe a new method for simultaneously collecting particles in exhaled air for subsequent chemical analysis and measuring their size distribution. After forced exhalation, particles were counted and collected in spots on silicon wafers with a cascade impactor. Several phospholipids were identified by time-of-flight secondary ion mass spectrometric analysis of the collected spots, suggesting that the particles originated from the lower airways.

Exhaled breath malondialdehyde as a marker of effect of exposure to air pollution in children with asthma.

Background: Assessment of the adverse effects of oxidative stress related to air pollution is limited by the lack of biological markers of dose to the lungs.

Objective: We evaluated the use of exhaled breath condensate (EBC) malondialdehyde as a biomarker of exposure to traffic-related pollution in children with asthma as part of a panel study in Mexico City.

Methods: Standard spirometry and collection of EBC and nasal lavage were performed.