Jan-Olof Levin

Different airway inflammatory responses in asthmatic and healthy humans exposed to diesel

Particulate matter (PM) pollution adversely affects the airways, with asthmatic subjects thought to be especially sensitive. The authors hypothesised that exposure to diesel exhaust (DE), a major source of PM, would induce airway neutrophilia in healthy subjects, and that either these responses would be exaggerated in subjects with mild allergic asthma, or DE would exacerbate pre-existent allergic airways. Healthy and mild asthmatic subjects were exposed for 2 h to ambient levels of DE (particles with a 50% cut-off aerodynamic diameter of 10 µm (PM10) 108 µg·m−3) and lung function and airway inflammation were assessed. Both groups showed an increase in airway resistance of similar magnitude after DE exposure. Healthy subjects developed airway inflammation 6 h after DE exposure, with airways neutrophilia and lymphocytosis together with an increase in interleukin‐8 (IL‐8) protein in lavage fluid, increased IL‐8 messenger ribonucleic acid expression in the bronchial mucosa and upregulation of the endothelial adhesion molecules. In asthmatic subjects, DE exposure did not induce a neutrophilic response or exacerbate their pre-existing eosinophilic airway inflammation. Epithelial staining for the cytokine IL‐10 was increased after DE in the asthmatic group. Differential effects on the airways of healthy subjects and asthmatics of particles with a 50% cut-off aerodynamic diameter of 10 µm at concentrations below current World Health Organisation air quality standards have been observed in this study. Further work is required to elucidate the significance of these differential responses.

Diesel exhaust enhances airway responsiveness in asthmatic subjects.

Particulate matter (PM) pollution has been associated with negative health effects, including exacerbations of asthma following exposure to PM peaks. The aim of the present study was to investigate the effects of short-term exposure to diesel exhaust (DE) in asthmatics, by specifically addressing the effects on airway hyperresponsiveness, lung function and airway inflammation. Fourteen nonsmoking, atopic asthmatics with stable disease, on continuous treatment with inhaled corticosteroids, were included. All were hyperresponsive to methacholine. Each subject was exposed to DE (particles with a 50% cut-off aerodynamic diameter of 10 microm (PM10) 300 microg x m(-3)) and air during 1 h on two separate occasions. Lung function was measured before and immediately after the exposures. Sputum induction was performed 6 h, and methacholine inhalation test 24 h, after each exposure. Exposure to DE was associated with a significant increase in the degree of hyperresponsiveness, as compared to after air, of 0.97 doubling concentrations at 24 h after exposure (p < 0.001). DE also induced a significant increase in airway resistance (p=0.004) and in sputum levels of interleukin (IL)-6 (p=0.048). No changes were detected in sputum levels of methyl-histamine, eosinophil cationic protein, myeloperoxidase and IL-8. This study indicated that short-term exposure to diesel exhaust, equal to high ambient levels of particulate matter, is associated with adverse effects in asthmatic airways, even in the presence of inhaled corticosteroid therapy. The increase in airway responsiveness may provide an important link to epidemiological findings of exacerbations of asthma following exposure to particulate matter.

Volatile metabolites from microorganisms grown on humid building materials and synthetic media

Growth of different microorganisms is often related to dampness in buildings. Both fungi and bacteria produce complicated mixtures of volatile organic compounds that include hydrocarbons, alcohols, ketones, sulfur- and nitrogen-containing compounds etc. Microbially produced substances are one possible explanation of odour problems and negative health effects in buildings affected by microbial growth. A mixture of five fungi, Aspergillus versicolor, Fusarium culmorum, Penicillium chrysogenum, Ulocladium botrytis and Wallemia sebi were grown on three different humid building materials (pinewood, particle board and gypsum board) and on one synthetic medium. Six different sampling methods were used, to be able to collect both non-reactive volatile organic compounds and reactive compounds such as volatile amines, aldehydes and carboxylic acids. Analysis was performed using gas chromatography, high-performance liquid chromatography and ion chromatography, mass spectrometry was used for identification of compounds. The main microbially produced metabolites found on pinewood were ketones (e.g. 2-heptanone) and alcohols (e.g. 2-methyl-1-propanol). Some of these compounds were also found on particle board, gypsum board and the synthetic medium, but there were more differences than similarities between the materials. For example, dimethoxymethane and 1,3,5-trioxepane and some nitrogen containing compounds were found only on particle board. The metabolite production on gypsum board was very low, although some terpenes (e.g. 3-carene) could be identified as fungal metabolites. On all materials, except gypsum board, the emission of aldehydes decreased during microbial growth. No low molecular weight carboxylic acids were identified.

Identification of cis- and trans-verbenol in human urine after occupational exposure to terpenes

SummaryUrine from sawmill workers exposed to α-pinene, β-pinene and Δ-3-carene was collected and hydrolyzed with β-glucuronidase at pH 5.0 for 24h at 37°C. After hydrolysis the urine was cleaned on a SEP-PAK C18 cartridge. The cartridge was eluted with n-heptane. The eluate was injected onto a gas chromatograph equipped with a 25-m (0.32-mm ID) SP-1000 capillary column. The major peak in the chromatogram was identified by GC-MS as trans-verbenol by electron impact at 70 eV. cis-Verbenol was also identified. These metabolites could not be detected in non-hydrolyzed urine from the exposed workers or in hydrolyzed urine from an unexposed individual. The recoveries of the verbenols from hydrolyzed urine were in the range of 85 to 94% and the metabolites were stable both in urine and in n-heptane after sample cleaning at −20°C for at least 12 weeks. We suggest that these metabolites are formed from α-pinene by hydroxylation.

Quantification of melatonin in human saliva by liquid chromatography-tandem mass spectrometry using stable isotope dilution.

A method for the determination of melatonin in human saliva has been developed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS). Saliva was collected in plastic tubes. 7-D-Melatonin was added as internal standard and the samples were cleaned and concentrated by solid-phase extraction. The limit of detection was 1.05 pg x ml(-1) and the limit of quantification was 3.0 pg x ml(-1). The accuracy of the method was +/-14% at 5.60 pg x ml(-1) and +/-9% at 19.6 pg x ml(-1). The precision was +/-13% at 6.18 pg x ml(-1) and +/-11% at 31.2 pg x ml(-1), respectively. Our HPLC-MS-MS method shows a high sensitivity and specificity for melatonin and more reliable results compared with a radioimmunoassay. The chromatographic method has been used to determine the circadian rhythm of melatonin among three nurses working the night shift and a patient suffering from an inability to fall asleep at night.

Sampling and analysis of particulate and gaseous polycyclic aromatic hydrocarbons from coal tar sources in the working environment

Abstract A sampling method for polycyclic aromatic hydrocarbons (PAH) in workplace atmospheres using a standard glass fiber filter with a back-up section of Amberlite XAD-2 is described. Filters and XAD are solvent-desorbed and, without further clean-up, the solutions are submitted to high performance liquid chromatographic analysis using fluorimetric detection. Recovery of PAH from XAD-2 was studied, and was found to be in the range 80–100%. The sampling method was evaluated in a coke plant, an aluminium plant and in a creosote impregnating plant. The method described is rapid and sensitive for the determination of the most important workplace PAH, and accounts for both particulate and gaseous PAH.

Airway inflammation in iron ore miners exposed to dust and diesel exhaust

The aim of the present study was to investigate if underground miners exposed to dust and diesel exhaust in an iron ore mine would show signs of airway inflammation as reflected in induced sputum. In total, 22 miners were studied, once after a holiday of at least 2 weeks and the second time after 3 months of regular work. Control subjects were 21 “white-collar” workers. All subjects completed a questionnaire regarding medical and occupational history, and underwent lung function testing and induced sputum collection. Total and differential cell counts and analyses of the fluid phase of the induced sputum were performed. Sampling of personal exposure to elemental carbon, nitrogen dioxide and inhalable dust was recorded. The average concentrations of inhalable dust, nitrogen dioxide and elemental carbon were 3.2 mg·m−3, 0.28 mg·m−3 and 27 µg·m−3, respectively. Miners had increased numbers of inflammatory cells, mainly alveolar macrophages and neutrophils, and increased concentrations of fibronectin, metalloproteinase-9 and interleukin-10 in induced sputum compared with controls. In conclusion, miners in an underground iron ore mine demonstrated persistent airway inflammation that was as pronounced after a 4-week holiday as after a 3-month period of work underground in the mine.

High‐performance liquid‐chromatographic determination of fgrivialdehyde in air in the ppb to ppm range using diffusive sampling and hydrazone formation

Abstract A diffusive sampler has been developed and validated for determination of formaldehyde with a sensitivity of 5 ppb in an 8‐h sample. The sampler consists of a 20×45 mm filter impregnated with 2,4‐dinitrophenyl‐hydrazine and phosphoric acid and mounted in a polypropylene housing. The uptake rate was determined to be 25.2 ml‐min‐1, with a relative standard deviation of 6.7%. The uptake rate was independent of formaldehyde concentration (0.07–3.7 mg‐m‐3), sampling time (15–480 min), relative humidity (10–80%). The effect of wind velocity (0.05–1.0 m.s‐1) was also studied. The sampler was also validated in the field.

Diffusive air sampling of reactive compounds. A review

Methods for diffusive sampling of reactive compounds in air are reviewed. Sampler types include sorbent, liquid and filter samplers. The most versatile sampler for reactive compounds is the filter sampler, where reactive compounds are trapped on a reagent-coated filter. Applications are described for the sampling of reactive organics and inorganics. Aldehydes can be sampled using a 2, 4-dinitrophenylhydrazine-coated filter, and amines with a filter coated with 1-naphthyl isothiocyanate. The derivatives formed are determined by high-performance liquid chromatography with ultraviolet detection. Inorganics such as ozone and nitrogen oxides can also be determined with the filter sampler technique.

Determination of volatile amines in air by diffusive sampling, thiourea formation and high-performance liquid chromatography

Abstract A diffusive sampling method for the determination of primary and secondary amines in air was evaluated. The sampler consists of a filter, impregnated with naphthyl isothiocyanate, in a polypropylene housing. A substituted thiourea is formed in situ during sampling, which is desorbed and determined by high-performance liquid chromatography. The sampler was validated for the sampling of methylamine, allylamine, isopropylamine, n -butylamine and dimethylamine using standard amine atmospheres, and the uptake rates for the five amines were determined. The effect on uptake rate of amine concentration, sampling time and relative humidity was investigated and found to be small. The detection limits for the amines studied are below 50 μg/m 3 for an 8-h sample.