Search

Gas-phase concentrations of semi-volatile organic compounds (SVOCs) were calculated from gas/particle (G/P) partitioning theory using their measured particle-phase concentrations. The particle-phase data were obtained from an existing filter measurement campaign (27 January 2003- 2 October 2005) as a part of the Denver Aerosol Sources and Health (DASH) study, including 970 observations of 71 SVOCs (Xie et al., 2013). In each compound class of SVOCs, the lighter species (e.g. docosane in n alkanes, fluoranthene in PAHs) had higher total concentrations (gas+particle phase) and lower particle-phase fractions. The total SVOC concentrations were analyzed using positive matrix factorization (PMF). Then the results were compared with source apportionment results where only particle-phase SVOC concentrations were used (particle only-based study; Xie et al., 2013). For the particle only-based PMF analysis, the factors primarily associated with primary or secondary sources (n alkane, EC/sterane and inorganic ion factors) exhibit similar contribution time series (r = 0.92-0.98) with their corresponding factors (n alkane, sterane and nitrate+sulfate factors) in the current work. Three other factors (light n alkane/PAH, PAH and summer/odd n alkane factors) are linked with pollution sources influenced by atmospheric processes (e.g. G/P partitioning, photochemical reaction), and were less correlated (r = 0.69-0.84) with their corresponding factors (light SVOC, PAH and bulk carbon factors) in the current work, suggesting that the source apportionment results derived from particle-only SVOC data could be affected by atmospheric processes. PMF analysis was also performed on three temperature-stratified subsets of the total SVOC data, representing ambient sampling during cold (daily average temperature <10 °C), warm (≥10 °C and ≤20 °C) and hot (>20 °C) periods. Unlike the particle only-based study, in this work the factor characterized by the low molecular weight (MW) compounds (light SVOC factor) exhibited strong correlations (r = 0.82-0.98) between the full data set and each sub-data set solution, indicating that the impacts of G/P partitioning on receptor-based source apportionment could be eliminated by using total SVOC concentrations. [ABSTRACT FROM AUTHOR]

Gas-phase concentrations of semi-volatile organic compounds (SVOCs) were calculated from gas/particle (G/P) partitioning theory using their measured particle-phase concentrations. The particle-phase data were obtained from an existing filter measurement campaign (27 January 2003-2 October 2005) as a part of the Denver Aerosol Sources and Health (DASH) study, including 970 observations of 71 SVOCs (Xie et al., 2013). In each compound class of SVOCs, the lighter species (e.g. docosane in nalkanes, fluoranthene in PAHs) had higher total concentrations (gas+particle phase) and lower particle-phase fractions. The total SVOC concentrations were analyzed using positive matrix factorization (PMF). Then the results were compared with source apportionment results where only particle-phase SVOC concentrations were used (filterbased study; Xie et al., 2013). For the filter-based PMF analysis, the factors primarily associated with primary or secondary sources (n-alkane, EC/sterane and inorganic ion factors) exhibit similar contribution time series (r = 0.92-0.98) with their corresponding factors (n-alkane, sterane and nitrate+sulfate factors) in the current work. Three other factors (light n-alkane/PAH, PAH and summer/odd n-alkane factors) are linked with pollution sources influenced by atmospheric processes (e.g. G/P partitioning, photochemical reaction), and were less correlated (r = 0.69-0.84) with their corresponding factors light SVOC, PAH and bulk carbon factors) in the current work, suggesting that the source apportionment results derived from filter-based SVOC data could be affected by atmospheric processes. PMF analysis was also performed on three temperaturestratified subsets of the total SVOC data, representing ambient sampling during cold daily average temperature < 10°C), warm (≥ 10°C and ≤ 20°C) and hot (> 20°C) periods. Unlike the filter-based study, in this work the factor characterized by the low molecular weight (MW) compounds (light SVOC factor) exhibited strong correlations r = 0.82-0.98) between the full data set and each sub-data set solution, indicating that the impacts of G/P partitioning on receptor-based source apportionment could be eliminated by using total SVOC concentrations. [ABSTRACT FROM AUTHOR]

With larger numbers of adult patients with cystic fibrosis (CF) in the workplace, the issue of disability has arisen increasingly. We examined relationships between measures of pulmonary impairment and work/school capability and then determined whether quantification of aerobic fitness improved predictability of disease-related disability. We studied 73 patients with CF who performed lung function and exercise capacity tests, completed a work/education questionnaire, and were scored for clinical and chest radiographic status. Patients who were characterized as unemployed and in poor health had more severe pulmonary disease according to American Thoracic Society impairment/disability criteria. Subjects were further classified into three groups based on employment or education status over the preceding 12 months. FEV1, maximal oxygen consumption, Schwachman-Kulczycki clinical and Brasfield radiographic scores, and frequency of pulmonary exacerbations over 2 years were associated with disability, but change in FEV1 over 2 years and oxygen saturation at rest or exertion were not. FEV1 and Schwachman-Kulczycki scores were the best independent predictors of impairment/disability; specific thresholds used in other pulmonary diseases were of limited utility. We conclude that after accounting for either current level of FEV1 or Schwachman-Kulczycki scores, no other physiological or clinical measures contribute to predicting limitation in a work or school environment. [ABSTRACT FROM AUTHOR]

A pilot study tested the feasibility of conducting occupational health research in Bangladesh while examining prevalence of asbestos-related diseases including asbestosis, work-related respiratory symptoms, and attitudes to occupational health and safety among a group of internal migrant ship breakers. Data was collected on clinical and work history, respiratory symptoms, and occupational health and safety practices in Bengali. A B-reader read all postero-anterior chest x-rays. In the 104 male ship breakers studied, prevalence of asbestos-related disease was 12%, of which asbestosis accounted for 6%. Knowledge of asbestos and occupational health and safety measures were almost nonexistent. The prevalence of asbestos-related diseases is low compared to studies in shipbuilders and repairers, but a risk underestimate could have resulted from challenges identified during study design and implementation including: industry noncooperation and a culture of corruption; technological and language barriers; and a regional lack of physician knowledge and research on occupational diseases. [ABSTRACT FROM AUTHOR]

Background: The use of biomass as a cooking fuel is commonplace in developing countries and has been associated with chronic bronchitis and obstructive airway disease. Methods: A cross-sectional survey was done in the village of Solis, close to Mexico City. Lifelong nonsmoking women 38 yr of age or older (n = 841) completed a questionnaire on respiratory symptoms and illnesses and on cooking fuel use, and performed spirometry in their homes. Particulate matter concentration was measured with a nephelometer in the kitchen for 1 h, while the subject was cooking. Results: The peak indoor concentration of particulate matter (PM(10), particles with a diameter of 10 mum or less) often exceeded 2 mg/m(3). Compared with those cooking with gas, current use of a stove burning biomass fuel was associated with increased reporting of phlegm (27 vs. 9%) and reduced FEV(1)/FVC (79.9 vs. 82.8%). Levels of FEV(1) were 81 ml lower and cough was more common (odds ratio, 1.7; 95% confidence interval, 1.0-2.8) in women from homes with higher PM(10) concentrations. All women found with moderate airflow obstruction (Global Initiative for Chronic Obstructive Lung Disease stage II and above) were cooking with biomass stoves. Conclusion: Women cooking with biomass fuels have increased respiratory symptoms and a slight average reduction in lung function compared with those cooking with gas. [ABSTRACT FROM AUTHOR]

A six year follow up study of 750 aluminium smelter workers was undertaken to evaluate the relationship between the leucocyte count at the start of the study and the rate of decline in lung function. An inverse relationship between the leucocyte count and the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) was present cross sectionally irrespective of cigarette smoking habit. The initial leucocyte count was also significantly related to the mean annual decline in FEV1 in smokers (p = 0.04) but not in former smokers or those who had never smoked. These observations suggest that the leucocyte count is a factor influencing the annual decline in FEV1 in smokers. [ABSTRACT FROM AUTHOR]