A urinary biomarker for monitoring exposures to 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate in rats.

2,2,4-Trimethyl-1,3-pentanediol monoisobutyrate (TMPD-MB) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TMPD-DB) are widely used primarily as surface stabilizers for water-based paints and plasticizers, respectively. Exposure to these compounds has been suspected as being associated with sick building syndrome and allergic diseases such as asthma in general populations. Therefore, it is very important to be able to know the amounts of these compounds absorbed into the body in order to evaluate its adverse effects on humans in living environments. In the present study, the urinary excretion kinetics of TMPD-MB and TMPD-DB were studied in animals to establish for urinary metabolites suitable as biomarkers for monitoring exposure. A single dose (48-750 mg/kg body weight) of TMPD-MB or TMPD-DB was administered intraperitoneally to male Sprague-Dawley rats, and their urine was collected periodically for a week. Two major metabolites, 2,2,4-trimethyl-1,3-pentanediol (TMPD) and 3-hydroxy-2,2,4-trimethylvaleric acid (HTMV), were measured in the urine samples. Their kinetics were evaluated by moment analysis of the urinary excretion rates of the metabolites versus time curves. The urinary excretion amounts of HTMV were suggested to be proportional to the absorption amounts over a wide exposure range of both TMPD-MB and TMPD-DB. The amounts of HTMV accounted for almost the same level, i.e., 4-5% of the dose at the lowest dosage, in rats tested for both TMPD-MB and TMPD-DB. Urinary HTMV was considered to be an optimal biomarker for monitoring exposure to mixtures of these compounds.

Enamel and Dentin Etching with Glycolic, Ferulic, and Phosphoric Acids: Demineralization Pattern, Surface Microhardness, and Bond Strength Stability.

This study evaluated the etching pattern, surface microhardness, and bond strength for enamel and dentin submitted to treatment with phosphoric, glycolic, and ferulic acids. Enamel and dentin blocks were treated with phosphoric, glycolic, and ferulic acid to evaluate the surface and adhesive interface by scanning electron microscopy (2000×). Surface microhardness (Knoop) was evaluated before and after etching, and microtensile bond strength was evaluated after application of a two-step adhesive system (Adper Single Bond 2, 3M ESPE) at 24 hours and 12 months storage time points. Analysis of variance (ANOVA) and Tukey's test showed a decrease in the microhardness values for both substrates after application of each acid (p<0.0001). The reduction percentage was significantly higher for enamel treated with phosphoric acid (59.9%) and glycolic acid (65.1%) than for ferulic acid (16.5%) (p<0.0001), and higher for dentin that received phosphoric acid (38.3%) versus glycolic acid (27.8%) and ferulic acid (21.9%) (p<0.0001). Phosphoric and glycolic acids led to homogeneous enamel demineralization, and promoted the opening of dentinal tubules, whereas ferulic acid led to enamel surface demineralization and partially removed the smear layer. The adhesive-enamel interface showed micromechanical embedding of the adhesive in the interprismatic spaces when phosphoric and glycolic acids were applied. Ferulic acid showed no tag formation. Microtensile bond strength at both time points, and for both substrates, was lower with ferulic acid (p=0.0003/E; p=0.0011/D; Kruskal Wallis and Dunn). The bond strength for enamel and dentin decreased when using phosphoric and glycolic acids at the 12-month time evaluation (p<0.05). Glycolic acid showed an etching pattern and microhardness similar to that of phosphoric acid. Ferulic acid was not effective in etching the enamel or dentin, and it did not provide satisfactory bond strength to dental substrates.

Comparison of ConsExpo estimated exposure levels to glycol ethers during professional cleaning work to existing regulatory occupational exposure limit values.

Objectives. Researchers have shown that cleaning workers have an increased risk of asthma and rhinitis, mainly due to exposure to chemical substances present in the cleaning products they use. Among the important substances are glycol ethers, increasingly used as components in cleaning products. This study aimed to assess exposure levels of glycol ether in professional cleaning products and compare them to existing regulatory exposure limit values. Methods. Information from safety data sheets of the products is used to identify the glycol ethers present in the cleaning products and their respective concentrations. Other sources were used to obtain the relevant data required for use in the tool to generate exposure assessments. Exposure levels for various cleaning work exposure scenarios were estimated using the ConsExpo Web tool. Results. The estimated exposure values are significantly lower than the existing regulatory occupational exposure limit (OEL) values for the different glycol ethers. Conclusions. The study showed that the risk of exposure to glycol ethers by inhalation from professional cleaning products is minimal as exposure estimates were much below the regulatory OEL values.

Optimizing Concentration of Polyethelene Glycol for Exosome Isolation from Plasma for Downstream Application.

BACKGROUND: Exosomes are ubiquitous extracellular nanovesicles secreted from almost all living cells that are thought to be involved in several important cellular processes, including cell-cell communication and signaling. Exosomes serve as a liquid biopsy tool for clinical and translational research. Although many techniques have been used to isolate exosomes, including ultracentrigation, size-exclusion chromatography, and immunocapturing-based techniques, these techniques are not convenient, they require expensive instrumentation, and they are unhandy for clinical samples. Precipitation techniques from available commercial kits that contain polyethelene glycol (PEG) are now widely used, but these kits are expensive, especially if a large number of biological samples are to be processed. OBJECTIVE: the purpose of this study is to compare and optimize the efficacy of different concentrations of PEG with two commercial kits ExoQuick (SBI) and Total Exosome Isolation (TEI) from Invitrogen in human plasma. METHODS AND MATERIALS: we determined exosome quantity, size distribution, marker expression, and downstream application. RESULTS: among the precipitation methods, we found the size of particles and concentrations with 10-20% PEG are similar to ExoQuick and better than TEI. Interestingly, we detected cfDNA with ExoQuick and 10-20% PEG but not TEI and 5% PEG. Moreover, 10% PEG detection of miR-122 and miR-16 expression was superior to ExoQuick and TEI. Furthermore, in proteomics results it also found the identified proteins better than commercial kits but there was a high level of contamination of other proteins in serum. CONCLUSIONS: together, these findings show that an optimal concentration of 10% PEG serves as a guide for use with clinical samples in exosome isolation for downstream applications.

Impact of glycol-based solvents on indoor air quality-Artificial fog and exposure pathways of formaldehyde and various carbonyls.

Artificial fog is commonly employed in the entertainment industry and indoor household celebrations. The fog is generated from glycol-based solvents, which can also be found in e-cigarettes and personal care products. Although potential health impacts of glycol inhalation are frequently cited by studies of e-cigarette smoking, the dynamics and the chemical composition of glycol-based aerosols have never been studied systematically. The objective of this work is to investigate the impact of glycol-based aerosol on indoor air quality. Specifically, we targeted artificial fogs generated with common glycols, including propylene glycol (PG) and triethylene glycol (TEG). With the aid of a novel aerosol collecting and monitoring instrument setup, we obtained time-resolved aerosol profiles and their chemical compositions in an experimental room. Artificial fog has given rise to a significant amount of ultra-fine particulate matter, demonstrating its negative impact on indoor air quality. Additionally, we found a high concentration (9.75 mM) of formaldehyde and other carbonyls in fog machine fluids stored for months. These compounds are introduced to the indoor air upon artificial fog application. We propose that carbonyls have accumulated from the oxidative decomposition of glycols, initiated by OH radicals and singlet oxygens (1 O2 ) and likely sustained by autooxidation. Oxidation of glycols by indoor oxidants has never been reported previously. Such chemical processes can represent an unrecognized source of toxic carbonyl compounds which is also applicable to other glycol-based solvents.

On-tissue boronic acid derivatization for the analysis of vicinal diol metabolites in maize with MALDI-MS imaging.

Derivatization reactions are commonly used in mass spectrometry to improve analyte signals, specifically by enhancing the ionization efficiency of those compounds. Vicinal diols are one group of biologically important compounds that have been commonly derivatized using boronic acid. In this study, a boronic acid with a tertiary amine was adapted for the derivatization of vicinal diol metabolites in B73 maize tissue cross-sections for mass spectrometry imaging analysis. Using this method, dozens of vicinal diol metabolites were derivatized, effectively improving the signal of those metabolites. Many of these metabolites were tentatively assigned using high-resolution accurate mass measurements. In addition, reaction interference and cross-reactivity with various other functional groups were systematically studied to verify data interpretation.

A Single-Column Gas Chromatography Method for Quantifying Toxic Alcohols.

BACKGROUND: Rapid identification and quantification of toxic alcohols and ethylene glycol is imperative for appropriate treatment. Clinical laboratories frequently rely on direct injection gas chromatography (GC) methods, but these methods require inlet maintenance and multiple GC systems. To overcome these challenges, we developed a single-column headspace GC method for both toxic alcohols and glycols that streamlines patient sample analysis for toxic alcohol ingestion. METHODS: Optimal parameters for nonderivatized (volatile) and derivatized (glycol) plasma samples were determined using a 7890 A headspace sampler, an Agilent 7697 A GC system, a DB-200 column, and a flame ionization detector. Limit of Quantification (LoQ), linearity, imprecision, carry-over, method comparison, and interference studies were performed using quality control materials and prepared plasma samples. RESULTS: Our volatile method is linear to 3000 mg/L (ethanol) with LoQ concentrations below 20 mg/L (ethanol). The glycol method is linear to 2000 mg/L (ethylene glycol) with LoQ concentrations below 40 mg/L (ethylene glycol). Total assay impression ranged from 1.7% for ethanol to 13.3% for propylene glycol. Both methods were free of sample carryover and compared favorably with a similar clinical method at an outside laboratory. Propionic acid, an accumulating metabolite in methylmalonic acidemia that interferes with ethylene glycol identification by a different method, did not interfere with the ethylene glycol method reported here. CONCLUSIONS: Our single-column headspace GC method provides reliable, robust, and rapid identification and quantification of commonly encountered toxic alcohols. Clinical laboratories relying on direct injection Gas Chromatography (GC) for toxic alcohol analysis face challenges including frequent inlet maintenance, sample carryover, or the need for separate GC systems for volatile and glycol analysis. We summarize our development and optimization of two headspace GC methods for nonderivatized (volatile) and derivatized (glycol) plasma samples that use a single DB-200 analytical column. These methods are comparable to other GC methods, not prone to sample carryover, eliminate the need for multiple GC systems or columns, and are readily applicable to other laboratories that provide toxic alcohol analysis.

Identification of adjuvants in plant protection products applying a suspect screening workflow based on orthogonal techniques.

In this study, the identification of adjuvants (surfactants and solvents) in quizalofop-p-ethyl plant protection products (PPPs) was carried out by applying nuclear magnetic resonance (NMR), ultra-high-performance liquid chromatography (UHPLC) and gas chromatography (GC), both coupled to high-resolution mass spectrometry (HRMS), and using a suspect analysis approach. NMR provided a rapid and global overview of the composition of the studied samples and supported the tentative identification of the glycol ether family, commonly employed as surfactants, and 2-ethyl-1-butanol. UHPLC-HRMS was used for characterization of the glycol polymer surfactants, while GC-HRMS was used to obtain information about volatile organic compounds (benzene or naphthalene derivates) present in the PPPs. A total of nine adjuvants were characterized in the tested PPPs, belonging to naphthalene, benzene, sulphate and fatty acid esters of glycerol families. In addition, the estimation of compound concentrations was carried out using GC(LC)-HRMS, and finally, these concentration levels were related to their toxicity values.

Cleaning workers' exposure to volatile organic compounds and particulate matter during floor polish removal and reapplication.

The floor polish removal (FPR) and reapplication (FPA) are important cleaning tasks in public buildings that have hard floor surfaces. Usually, the FPR and FPA are conducted once or twice a year, during the periodic cleaning of these buildings. The FPR can be performed either chemically (CFPR) or by using dry scrubber (DFPR), when the polish is ground from the floor. In this study, cleaning workers' exposure to volatile organic compounds (VOCs) and particulate matter (PM) during the FPR and FPA, and the differences in the exposures between the two FPR methods were investigated. In total, three buildings located in Central Finland were included, and total of six cleaning workers (two per building) participated in the study. In Buildings 1 and 2, the CFPR and FPA were performed and in Building 3, the DFPR was conducted. TVOC (total volatile organic compounds) concentrations in the breathing zone of the workers during the CFPR were 8,740 and 390 µg/m3 (SD 3,290 and 180 µg/m3) for Buildings 1 and 2, respectively. During the DFPR in Building 3, the average TVOC concentration was 400 µg/m3 (SD 180 µg/m3, stationary sampling). The TVOC concentrations during the FPA were high, 1,640 and 2,170 µg/m3 on average (SD 1,570 and 930 µg/m3) for Buildings 1 and 2, respectively. Glycol ethers were the most prominent VOCs during the CFPR and FPA, whereas carboxylic acids were the most common during the DFPR. The inhalable dust concentrations in the workers' breathing zone were noticeably higher during the DFPR (1.55 mg/m3 on average, SD 0.01 mg/m3) than the CFPR (0.24 mg/m3 on average, SD 0.05 mg/m3). Finnish occupational exposure limit value for organic inhalable dust is 5 mg/m3. As the products used during the CFPR and FPA contain glycol ethers and ethanolamines that are absorbed via the skin as well, the use of skin protection is recommended. Whereas the use of FFP3 respirators and skin protection are recommended during the DFPR to prevent the PM exposure.

Simultaneous determination of glycol ethers and their acetates in cosmetics by gas chromatography with mass spectrometry.

A gas chromatography with mass spectrometry method was developed for the simultaneous determination of ten kinds of glycol ethers and their acetates in cosmetics. The samples were extracted with methanol/ethyl acetate (80:20, v/v), further treated with vortex and ultrasound, and analyzed by gas chromatography with mass spectrometry. The concentration of each analyte was calibrated by the external standard method. Under the optimal conditions, the analytes showed linear relationship in the range of 0.05-25 mg/L with determination coefficients larger than 0.9987. The limits of detection and quantification were in the range of 0.09-0.59 and 0.31-1.95 mg/kg, respectively. The average recoveries of three spiked levels were 80.2-105.4% with intra- and interday precisions of 1.1-6.3 and 1.9-6.5%, respectively. Method validation from different labs confirmed the satisfactory recoveries and precisions. This method shows advantages of simple, high sensitivity, and high recovery, which can be applied to the detection of glycol ethers and acetates in cosmetics.

Assessing electronic cigarette emissions: linking physico-chemical properties to product brand, e-liquid flavoring additives, operational voltage and user puffing patterns.

Users of electronic cigarettes (e-cigs) are exposed to particles and other gaseous pollutants. However, major knowledge gaps on the physico-chemical properties of such exposures and contradictory data in published literature prohibit health risk assessment. Here, the effects of product brand, type, e-liquid flavoring additives, operational voltage, and user puffing patterns on emissions were systematically assessed using a recently developed, versatile, e-cig exposure generation platform and state-of-the-art analytical methods. Parameters of interest in this systematic evaluation included two brands (A and B), three flavors (tobacco, menthol, and fruit), three types of e-cigs (disposable, pre-filled, and refillable tanks), two puffing protocols (4 and 2 s/puff), and four operational voltages (2.2-5.7 V). Particles were generated at a high number concentration (106-107 particles/cm3). The particle size distribution was bi-modal (∼200 nm and 1 µm). Furthermore, organic species (humectants propylene glycol and glycerin, nicotine) that were present in e-liquid and trace metals (potassium and sodium) that were present on e-cig heating coil were also released into the emission. In addition, combustion-related byproducts, such as benzene and toluene, were also detected in the range of 100-38,000 ppbv/puff. Parametric analyzes performed in this study show the importance of e-cig brand, type, flavor additives, user puffing pattern (duration and frequency), and voltage on physico-chemical properties of emissions. This observed influence is indicative of the complexity associated with the toxicological screening of emissions from e-cigs and needs to be taken into consideration.

Analysis of glycols, glycol ethers, and other volatile organic compounds present in household water-based hand pump sprays.

The aim of this investigation is to clarify the types and concentrations of VOCs present in various commercial household water-based hand pump spray products used in Japan, and to estimate their average concentrations in indoor air when the spray product is used. We selected glycol and glycol ethers as the main target compounds, as these chemicals were detected at high frequencies and concentrations in a national survey of Japanese indoor air pollution. The extraction of these chemicals using graphite carbon cartridges was examined, with good recoveries and reproducibilities being obtained. Eighteen chemicals were analyzed in 54 commercial products and 8 chemicals were detected. More specifically, dipropylene glycol (DPG) was present in 44 samples (1.1 × 101-1.8 × 104 µg/mL); propylene glycol (PG) was present in 22 samples (1.5 × 101-2.9 × 104 µg/mL); diethylene glycol monoethyl ether (DGMEE) was found in 15 samples (trace amount-1.9 × 103 µg/mL); diethylene glycol (DEG) was present in 9 samples (1.0 × 101-2.4 × 103 µg/mL); 1,3-butandiol (13BG) was found in 5 samples (trace amount-7.4 × 103 µg/mL); 2-ethyl-1-hexanol (2E1H) was detected in 5 samples (3.2 × 10-1-4.4 × 101 µg/mL); diethylene glycol monobutyl ether (DGMBE) was present in 4 samples (2.1 × 101-7.1 × 101 µg/mL); and 3-methoxy-3-methylbutanol (MMB) was found in 2 samples (2.4 × 101-4.7 × 102 µg/mL). In addition, the average concentrations of these chemicals in indoor air were estimated using their maximum concentrations observed in the spray product. The estimated average concentrations of the chemicals in indoor air were determined to range between 1.0 × 10-2 and 1.0 mg/m3, with the exception of 2E1H and DGMBE. Furthermore, the estimated average concentrations of PG, 13BG, and DGMEE in indoor air were comparable to or higher than those reported in a national survey of Japanese indoor air pollution. It therefore appeared that household water-based hand pump sprays may contribute to the presence of these chemicals in indoor air. In contrast, estimated average concentrations of 2E1H in indoor air were low, its concentrations observed in a national survey of Japanese indoor air pollution are likely due to the use of plasticizers and paints.

Concentration of Nicotine and Glycols in 27 Electronic Cigarette Formulations.

Personal battery-powered vaporizers or electronic cigarettes were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. Electronic cigarettes and their e-cigarette liquid formulations are virtually unregulated. These formulations are typically composed of propylene glycol and/or glycerin, flavoring components and an active drug, such as nicotine. Twenty-seven e-cigarette liquid formulations that contain nicotine between 6 and 22 mg/L were acquired within the USA and analyzed by various methods to determine their contents. They were screened by Direct Analysis in Real Time™ Mass Spectrometry (DART-MS). Nicotine was confirmed and quantitated by high-performance liquid chromatography-tandem mass spectrometry, and the glycol composition was confirmed and quantitated by gas chromatography-mass spectrometry. The DART-MS screening method was able to consistently identify the exact mass peaks resulting from the protonated molecular ion of nicotine, glycol and a number of flavor additives within 5 mmu. Nicotine concentrations were determined to range from 45 to 131% of the stated label concentration, with 18 of the 27 have >10% variance. Glycol composition was generally accurate to the product description, with only one exception where the propylene glycol to glycerin percentage ratio was stated as 50:50 and the determined concentration of propylene glycol to glycerin was 81:19 (% v/v). No unlabeled glycols were detected in these formulations.

Boronate Affinity Fluorescent Nanoparticles for Förster Resonance Energy Transfer Inhibition Assay of cis-Diol Biomolecules.

Förster resonance energy transfer (FRET) has been essential for many applications, in which an appropriate donor-acceptor pair is the key. Traditional dye-to-dye combinations remain the working horses but are rather nonspecifically susceptive to environmental factors (such as ionic strength, pH, oxygen, etc.). Besides, to obtain desired selectivity, functionalization of the donor or acceptor is essential but usually tedious. Herein, we present fluorescent poly(m-aminophenylboronic acid) nanoparticles (poly(mAPBA) NPs) synthesized via a simple procedure and demonstrate a FRET scheme with suppressed environmental effects for the selective sensing of cis-diol biomolecules. The NPs exhibited stable fluorescence properties, resistance to environmental factors, and a Förster distance comparable size, making them ideal donor for FRET applications. By using poly(mAPBA) NPs and adenosine 5'-monophosphate modified graphene oxide (AMP-GO) as a donor and an acceptor, respectively, an environmental effects-suppressed boronate affinity-mediated FRET system was established. The fluorescence of poly(mAPBA) NPs was quenched by AMP-GO while it was restored when a competing cis-diol compounds was present. The FRET system exhibited excellent selectivity and improved sensitivity toward cis-diol compounds. Quantitative inhibition assay of glucose in human serum was demonstrated. As many cis-diol compounds such as sugars and glycoproteins are biologically and clinically significant, the FRET scheme presented herein could find more promising applications.

Influence of relative humidity on VOC concentrations in indoor air.

Volatile organic compounds (VOCs) may be emitted from surfaces indoors leading to compromised air quality. This study scrutinized the influence of relative humidity (RH) on VOC concentrations in a building that had been subjected to water damage. While air samplings in a damp room at low RH (21-22%) only revealed minor amounts of 2-ethylhexanol (3 µg/m(3)) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB, 8 µg/m(3)), measurements performed after a rapid increase of RH (to 58-75%) revealed an increase in VOC concentrations which was 3-fold for 2-ethylhexanol and 2-fold for TXIB. Similar VOC emission patterns were found in laboratory analyses of moisture-affected and laboratory-contaminated building materials. This study demonstrates the importance of monitoring RH when sampling indoor air for VOCs in order to avoid misleading conclusions from the analytical results.

A systematic review of health effects of electronic cigarettes.

OBJECTIVE: To provide a systematic review of the existing literature on health consequences of vaporing of electronic cigarettes (ECs). METHODS: Search in: PubMed, EMBASE and CINAHL. INCLUSION CRITERIA: Original publications describing a health-related topic, published before 14 August 2014. PRISMA recommendations were followed. We identified 1101 studies; 271 relevant after screening; 94 eligible. RESULTS: We included 76 studies investigating content of fluid/vapor of ECs, reports on adverse events and human and animal experimental studies. Serious methodological problems were identified. In 34% of the articles the authors had a conflict of interest. Studies found fine/ultrafine particles, harmful metals, carcinogenic tobacco-specific nitrosamines, volatile organic compounds, carcinogenic carbonyls (some in high but most in low/trace concentrations), cytotoxicity and changed gene expression. Of special concern are compounds not found in conventional cigarettes, e.g. propylene glycol. Experimental studies found increased airway resistance after short-term exposure. Reports on short-term adverse events were often flawed by selection bias. CONCLUSIONS: Due to many methodological problems, severe conflicts of interest, the relatively few and often small studies, the inconsistencies and contradictions in results, and the lack of long-term follow-up no firm conclusions can be drawn on the safety of ECs. However, they can hardly be considered harmless.

Analytical procedures for the determination of fuel combustion products, anti-corrosive compounds, and de-icing compounds in airport runoff water samples.

The purpose of this study is to propose and evaluate new procedures for determination of fuel combustion products, anti-corrosive and de-icing compounds in runoff water samples collected from the airports located in different regions and characterized by different levels of the activity expressed by the number of flights and the number of passengers (per year). The most difficult step in the analytical procedure used for the determination of PAHs, benzotriazoles and glycols is sample preparation stage, due to diverse matrix composition, the possibility of interference associated with the presence of components with similar physicochemical properties. In this study, five different versions of sample preparation using extraction techniques, such as: LLE and SPE, were tested. In all examined runoff water samples collected from the airports, the presence of PAH compounds and glycols was observed. In majority of the samples, BT compounds were determined. Runoff water samples collected from the areas of Polish and British international airports as well as local airports had similar qualitative composition, but quantitative composition of the analytes was very diverse. New and validated analytical methodologies ensure that the necessary information for assessing the negative impact of airport activities on the environment can be obtained.

[Indoor air guide values for glycol ethers and glycol esters. Announcement of the Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and of the Supreme State Health Authorities]. / Richtwerte für Glykolether und Glykolester in der Innenraumluft. Mitteilung der Ad-hoc-Arbeitsgruppe Innenraumrichtwerte der Kommission Innenraumlufthygiene und der Obersten Landesgesundheitsbehörden.

The German Ad-hoc Working Group on Indoor Guidelines of the Indoor Air Hygiene Committee and of the Supreme State Health Authorities is issuing indoor air guide values to protect public health. For health evaluation of glycol ethers and glycol esters in air, the entire group of substances with data for 47 compounds was analysed in order to gain a unique assessment. For some glycol ethers reproductive and haematological effects are of central interest, whereas for others effects on liver and kidneys are crucial. Moreover, some glycol ethers were also shown to cause irritation of the respiratory tract. Fourteen compounds could be characterized either by relevant inhalation studies or by analogies drawn to strongly related substances. For these compounds individual guide values were derived, the respective guide value I ranging from 0.02-2 mg/m(3) (Tab. 2). The derivation of guide values considered the time exposure of the population as compared to working people or animal studies. The duration of the respective study, the interindividual variability--by a factor of 10--and the enhanced respiratory rate in children as compared to adults--by a factor of 2--were further taken into account. To allow for extrapolation from animal to human exposure differences in toxicodynamics were considered by a factor of usually 2.5. For compounds with insufficient data a default guide value II and I of 0.05 and 0.005 ppm, respectively, was recommended based on the statistical analysis of the available data of all glycol ethers. In order to achieve a total evaluation of all glycol ethers and glycol esters found in indoor air the proportional concentrations of each compound divided by the respective guide value were aggregated to give a total guide value. The total guide values are regarded to be complied with if their respective value falls below 1.

Airborne molds and bacteria, microbial volatile organic compounds (MVOC), plasticizers and formaldehyde in dwellings in three North European cities in relation to sick building syndrome (SBS).

There are few studies on associations between airborne microbial exposure, formaldehyde, plasticizers in dwellings and the symptoms compatible with the sick building syndrome (SBS). As a follow-up of the European Community Respiratory Health Survey (ECRHS II), indoor measurements were performed in homes in three North European cities. The aim was to examine whether volatile organic compounds of possible microbial origin (MVOCs), and airborne levels of bacteria, molds, formaldehyde, and two plasticizers in dwellings were associated with the prevalence of SBS, and to study associations between MVOCs and reports on dampness and mold. The study included homes from three centers included in ECRHS II. A total of 159 adults (57% females) participated (19% from Reykjavik, 40% from Uppsala, and 41% from Tartu). A random sample and additional homes with a history of dampness were included. Exposure measurements were performed in the 159 homes of the participants. MVOCs were analyzed by GCMS with selective ion monitoring (SIM). Symptoms were reported in a standardized questionnaire. Associations were analyzed by multiple logistic regression. In total 30.8% reported any SBS (20% mucosal, 10% general, and 8% dermal symptoms) and 41% of the homes had a history of dampness and molds There were positive associations between any SBS and levels of 2-pentanol (P=0.002), 2-hexanone (P=0.0002), 2-pentylfuran (P=0.009), 1-octen-3-ol (P=0.002), formaldehyde (P=0.05), and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (Texanol) (P=0.05). 1-octen-3-ol (P=0.009) and 3-methylfuran (P=0.002) were associated with mucosal symptoms. In dwellings with dampness and molds, the levels of total bacteria (P=0.02), total mold (P=0.04), viable mold (P=0.02), 3-methylfuran (P=0.008) and ethyl-isobutyrate (P=0.02) were higher. In conclusion, some MVOCs like 1-octen-3-ol, formaldehyde and the plasticizer Texanol, may be a risk factor for sick building syndrome. Moreover, concentrations of airborne molds, bacteria and some other MVOCs were slightly higher in homes with reported dampness and mold.

Comparison of the effects of e-cigarette vapor and cigarette smoke on indoor air quality.

CONTEXT: Electronic cigarettes (e-cigarettes) have earned considerable attention recently as an alternative to smoking tobacco, but uncertainties about their impact on health and indoor air quality have resulted in proposals for bans on indoor e-cigarette use. OBJECTIVE: To assess potential health impacts relating to the use of e-cigarettes, a series of studies were conducted using e-cigarettes and standard tobacco cigarettes. METHODS AND MATERIALS: Four different high nicotine e-liquids were vaporized in two sets of experiments by generic 2-piece e-cigarettes to collect emissions and assess indoor air concentrations of common tobacco smoke by products. Tobacco cigarette smoke tests were conducted for comparison. RESULTS: Comparisons of pollutant concentrations were made between e-cigarette vapor and tobacco smoke samples. Pollutants included VOCs, carbonyls, PAHs, nicotine, TSNAs, and glycols. From these results, risk analyses were conducted based on dilution into a 40 m³ room and standard toxicological data. Non-cancer risk analysis revealed "No Significant Risk" of harm to human health for vapor samples from e-liquids (A-D). In contrast, for tobacco smoke most findings markedly exceeded risk limits indicating a condition of "Significant Risk" of harm to human health. With regard to cancer risk analysis, no vapor sample from e-liquids A-D exceeded the risk limit for either children or adults. The tobacco smoke sample approached the risk limits for adult exposure. CONCLUSIONS: For all byproducts measured, electronic cigarettes produce very small exposures relative to tobacco cigarettes. The study indicates no apparent risk to human health from e-cigarette emissions based on the compounds analyzed.