Establishment of Repeated In Vitro Exposure System for Evaluating Pulmonary Toxicity of Representative Criteria Air Pollutants Using Advanced Bronchial Mucosa Models.

There is mounting evidence that shows the association between chronic exposure to air pollutants (particulate matter and gaseous) and onset of various respiratory impairments. However, the corresponding toxicological mechanisms of mixed exposure are poorly understood. Therefore, in this study, we aimed to establish a repeated exposure setting for evaluating the pulmonary toxicological effects of diesel exhaust particles (DEP), nitrogen dioxide (NO2), and sulfur dioxide (SO2) as representative criterial air pollutants.

Addressing the challenges of E-cigarette safety profiling by assessment of pulmonary toxicological response in bronchial and alveolar mucosa models.

Limited toxicity data on electronic cigarette (ECIG) impede evidence-based policy recommendations. We compared two popular mixed fruit flavored ECIG-liquids with and without nicotine aerosolized at 40 W (E-smoke) with respect to particle number concentrations, chemical composition, and response on physiologically relevant human bronchial and alveolar lung mucosa models cultured at air-liquid interface. E-smoke was characterized by significantly increased particle number concentrations with increased wattage (25, 40, and 55 W) and nicotine presence.

Analysis of Acrolein Exposure Induced Pulmonary Response in Seven Inbred Mouse Strains and Human Primary Bronchial Epithelial Cells Cultured at Air-Liquid Interface.

Background: Acrolein is a major component of environmental pollutants, cigarette smoke, and is also formed by heating cooking oil. We evaluated the interstrain variability of response to subchronic inhalation exposure to acrolein among inbred mouse strains for inflammation, oxidative stress, and tissue injury responses. Furthermore, we studied the response to acrolein vapor in the lung mucosa model using human primary bronchial epithelial cells (PBEC) cultured at an air-liquid interface (ALI) to evaluate the findings of mouse studies.

Clinical, Epidemiological and Experimental Approaches to Assess Adverse Health Outcomes of Indoor Biomass Smoke Exposure: Conclusions from An Indo-Swedish Workshop in Mysuru, January 2020.

This report summarizes the outcome of a workshop held in Mysuru, India in January 2020 addressing the adverse health effects of exposure to biomass smoke (BMS). The aim of the workshop was to identify uncertainties and gaps in knowledge and possible methods to address them in the Mysuru study on Determinants of Health in Rural Adults (MUDHRA) cohort. Specific aims were to discuss the possibility to improve and introduce new screening methods for exposure and effect, logistic limitations and other potential obstacles, and plausible strategies to overcome these in future studies.

Chloroanisoles and Chlorophenols Explain Mold Odor but Their Impact on the Swedish Population Is Attributed to Dampness and Mold.

We recently reported that mold odor may be explained by chloroanisoles (CAs) formed by microbial biotransformation of chlorophenols (CPs) in legacy wood preservatives. Here we examine psychophysical aspects of CAs and trace their historic origins in buildings. Our exposure of healthy volunteers shows that 2,4,6-triCA is often perceived as unpleasant, characterized as musty or moldy and is detected at 13 ng/m or lower.

Evaluation of diacetyl mediated pulmonary effects in physiologically relevant air-liquid interface models of human primary bronchial epithelial cells.

Diacetyl is an artificial flavouring agent, known to cause bronchiolitis obliterans. Diacetyl-induced pulmonary effects were assessed in human primary bronchial epithelial cells (PBEC) cultured at air-liquid interface (ALI). The PBEC-ALI models were exposed to clean air (sham) and diacetyl vapour (1, 3, 10 and 30 ppm) for 30 min.

Washout kinetics of ethanol from the airways following inhalation of ethanol vapors and use of mouthwash.

Breath analyzers are commonly used to test for alcohol intoxication, i.e., elevated systemic levels of ethanol, at workplaces and among vehicle drivers.

Down-regulation of the inflammatory response after short-term exposure to low levels of chemical vapours.

Objective: To investigate the relation between signs and symptoms of irritation and biomarkers of inflammatory markers in blood in healthy volunteers exposed to different chemical vapours for 2 or 4 hours in an exposure chamber.

Methods: The investigated chemicals were: acetic acid (5 and 10 ppm), acrolein (0.05 and 0.

Measures of odor and lateralization thresholds of acrolein, crotonaldehyde, and hexanal using a novel vapor delivery technique.

Introduction: Humans are exposed to aldehydes in a variety of environmental situations. Aldehydes generally have a strong odor and are highly irritating to the mucous membranes. Knowledge about odor perception and especially irritation potency in humans is thus essential in risk assessment and regulation, e.

Inflammatory effects of acrolein, crotonaldehyde and hexanal vapors on human primary bronchial epithelial cells cultured at air-liquid interface.

The cytotoxicity of aldehydes was studied using human primary bronchial epithelial cells (PBEC) cultured at the air-liquid interface (ALI) or under submerged conditions. PBEC were exposed for 30min via the air phase to acrolein (0.1-1mg/m), crotonaldehyde (1.

Acute effects of acrolein in human volunteers during controlled exposure.

Context: Acrolein is a reactive aldehyde mainly formed by combustion. The critical effect is considered to be irritation of the eyes and airways; however, the scarce data available make it difficult to assess effect levels.

Objective: The aim of the study was to determine thresholds for acute irritation for acrolein.

Blood and exhaled air can be used for biomonitoring of hydrofluorocarbon exposure.

Various hydrofluorocarbons (HFCs) have replaced the ozone-depleting chlorofluorocarbons and hydrochlorofluorocarbons during the last decades. The objective of this study was to examine the usefulness of blood and breath for exposure biomonitoring of HFCs. We compared data on blood and exhaled air from a series of experiments where healthy volunteers were exposed to vapors of four commonly used HFCs; 1,1-difluoroethane, 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, and 1,1,1,3,3-pentafluoropropane.

Acute effects of exposure to vapors of hydrogen peroxide in humans.

Hydrogen peroxide is a reactive chemical mainly used for bleaching, as a disinfectant, and as a general oxidizing agent. The aim of this study was to investigate subtle acute effects of inhaled hydrogen peroxide vapors. Eleven healthy volunteers were exposed to 0 (clean air), 0.

Swedish forensic data 1992-2009 suggest hydrogen cyanide as an important cause of death in fire victims.

Between 60 and 80% of all deaths related to fire are attributed to toxic fumes. Carbon monoxide (CO) is commonly thought to be the major cause. However, hydrogen cyanide (HCN) is also formed.

Uptake and disposition of 1,1-difluoroethane (HFC-152a) in humans.

The aim of this study was to determine the toxicokinetics of inhaled 1,1-difluoroethane (HFC-152a) in humans. Healthy volunteers were exposed to 0, 200 or 1000 ppm 1,1-difluoroethane for 2h at light exercise in an exposure chamber. Capillary blood, urine and exhaled air were sampled up to 22 h post-exposure and analyzed for 1,1-difluoroethane.

Visual analogue scales: How can we interpret them in experimental studies of irritation in the eyes, nose, throat and airways?

The aim of this study was to investigate if visual analogue scales (VAS) of objective symptoms could be validated against objective measurements in exposure studies of chemical vapours in humans. This validation comprises the results of symptom ratings of irritation and objective measurements of effects of the eye, nose and throat from studies of nine different chemicals. The objective measurements included blinking frequency as a measure of eye irritation, acoustic rhinometry of nose irritation and the lung function parameter FEV₁ of irritation in the throat and airways.

Experimental exposure to 1,1,1,3,3-pentafluoropropane (HFC-245fa): uptake and disposition in humans.

The aim of this study was to determine the toxicokinetics of inhaled 1,1,1,3,3-pentafluoropropane (HFC-245fa) in humans. Five healthy volunteers of each sex were exposed in random order to 0, 100, or 300 ppm HFC-245fa for 2 h at light exercise (50 W) in an exposure chamber. Capillary blood, urine, and exhaled air were sampled up to 22 h postexposure and analyzed for HFC-245fa.

Liquid-air partition coefficients of 1,1-difluoroethane (HFC152a), 1,1,1-trifluoroethane (HFC143a), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1,1,2,2-pentafluoroethane (HFC125) and 1,1,1,3,3-pentafluoropropane (HFC245fa).

Blood-air and tissue-blood coefficients (lambda) are essential to characterize the uptake and disposition of volatile substances, e.g. by physiologically based pharmacokinetic (PBPK) modelling.

Influence of gender on the metabolism of alcohols in human saliva in vitro.

Objective: The aim of this study was to investigate possible gender differences in salivary metabolism of two alcohols, ethanol and 2-propanol. Ethanol and its metabolite acetaldehyde may play important roles in tumour development, especially in the upper digestive tract. 2-Propanol is tested to elucidate our previous findings, where gender-specific differences in salivary acetone levels were seen after exposure to this alcohol.

Acute effects of exposure to vapours of standard and dearomatized white spirits in humans. 1. Dose-finding study.

A move from 'standard' white spirit (stdWS, 15-20% aromatics) to low-aromatic or dearomatized white spirit (deWS) has been seen, as the latter are considered to carry a smaller risk of health effects. However, data on health risks of deWS on humans are sparse. The aim of this dose-finding study was to identify thresholds of irritation and central nervous system (CNS) effects of the two types of white spirit, as a basis for more detailed studies.

Acute effects of exposure to vapours of standard and dearomatized white spirits in humans. 2. Irritation and inflammation.

Low aromatic and dearomatized white spirits (deWS) are often considered less hazardous to health than 'standard' or aromatic white sprit (stdWS, 15-20% aromatics). However, data on health effects of deWS in humans are sparse and controlled exposure studies are lacking. The aim of this study was to compare deWS and stdWS with respect to irritation and inflammation.

Acute effects of 1-octen-3-ol, a microbial volatile organic compound (MVOC)--an experimental study.

Acute effects were assessed from exposure to a common volatile compound of microbial origin, the aliphatic alcohol 1-octen 3-ol (octenol). Twenty-nine volunteers performed symptom reports, measurement of blink frequency by electromyography, measurement of the eye break-up time, vital staining of the eye, nasal lavage, acoustic rhinometry, transfer tests and dynamic spirometry. Subjects were during 2h in random order exposed to either 10mg/m(3) of octenol or clean air as control.

Acute effects of some volatile organic compounds emitted from water-based paints.

Objective: Acute effects during controlled exposure to some of the volatile organic compounds emitted from water-based paints were evaluated.

Methods: Healthy volunteers (10 atopics, 10 nonatopics, and 10 painters) were exposed to a mixture of propyleneglycol, texanol, diethyleneglycol monoethylether, diethyleneglycol monobutyl ether, and dipropyleneglycol monomethyl ether at a total concentration of 35 mg/m3 (G), a mixture of G and ammonia (15 mg/m3) (GA), and clean air (C).

Results: Subjective ratings of irritation in eyes, nose, throat, and dyspnea were significantly higher during the G and GA conditions, when compared with during the C condition.

Experimental exposure to 1,1,1-trifluoroethane (HFC-143a): uptake, disposition and acute effects in male volunteers.

The aim of this study was to determine the toxicokinetics and some effects of 1,1,1-trifluoroethane (HFC-143a) in humans. Nine male volunteers were experimentally exposed to 500ppm HFC-143a for 2h during light physical exercise (50W) in an exposure chamber. Blood, urine and exhaled air were sampled before, during and up to 19h after exposure and analysed for HFC-143a by gas chromatography.

Phenotyping of cytochrome P450 2E1 in vitro and in vivo.

The aim of the present study was to develop and improve methods for phenotyping of CYP2E1, an important enzyme in the biotransformation of many industrial chemicals, therapeutic drugs and endogenous substances. The possibility to measure CYP2E1 activity in lymphocytes by using p-nitrophenol as a substrate and CYP2E1 protein levels by flow cytometry were studied in vitro. Further, the conventional chlorzoxazone method for in vivo phenotyping was studied by adjusting the dose to body weight in 10 healthy volunteers.