Search

A field study was conducted on 42 asphalt-roofing workers at 7 built-up roofing sites across the United States. Sixteen out of 42 samples show levels of exposure to asphalt fumes that exceed the current American Conference of Governmental In-dustrial Hygienists' (ACGIH R )-recommended threshold limit value of 0.5 mg/m 3 as benzene extractable inhalable particu-late. Statistically, the geometric mean of all 42 worker samples was 0.27 mg/m 3 (geometric standard deviation =3.40), the average was 0.70 mg/m 3 (standard deviation =1.69) and the median value was 0.24 mg/m 3 . The impact of work practices is discussed including the use of a novel product that uses a polymer skin to reduce fumes from built up roofing asphalt. Its use resulted in a reduction of benzene soluble matter (BSM) of >70%. Other testing measures utilized included total particu-late matter, total organic matter, simulated distillation, and fluorescence analysis. Additionally, a controlled pilot study using 16 kettle-area and 16 worker samples clearly showed that when the temperature of the kettle was reduced by 28C, there was a 38--59% reduction in fume exposure and a 54% reduction in fluorescence with standard asphalts. Reduction of BSM exposures using fuming-suppressed asphalt was also confirmed during this pilot plant study (81--92%), with fluo-rescence lowered by 88%. Confounding agents such as roof tear-off materials were also analyzed and their contribution to worker exposure is discussed. [ABSTRACT FROM AUTHOR]

Background: While smoking is the major cause of chronic obstructive pulmonary disease (COPD), occupational exposures to vapors, gases, dusts, and fumes (VGDF) increase COPD risk. This case-control study estimated the risk of COPD attributable to occupational exposures among construction workers., Methods: The study population included 834 cases and 1243 controls participating in a national medical screening program for older construction workers between 1997 and 2013. Qualitative exposure indices were developed based on lifetime work and exposure histories., Results: Approximately 18% (95% CI = 2-24%) of COPD risk can be attributed to construction-related exposures, which are additive to the risk contributed by smoking. A measure of all VGDF exposures combined was a strong predictor of COPD risk., Conclusions: Construction workers are at increased risk of COPD as a result of broad and complex effects of many exposures acting independently or interactively. Control methods should be implemented to prevent worker exposures, and smoking cessation should be promoted., (© 2015 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals, Inc.)

Unlabelled: Abstract Objective: The recent increase in asthma prevalence is thought to be partially due to environmental changes such as changes in air pollution and occupational exposures. Nationally representative information on workplace exposures among US adults with asthma is limited., Methods: We examined 2010 National Health Interview Survey data to determine the proportion of employed adults with asthma who had frequent workplace exposures., Results: Among adults with current asthma, 19.6% frequently worked outdoors, 17.5% were frequently exposed to workplace secondhand smoke and 28.1% were frequently exposed to workplace vapors, gas, dust or fumes. Adults ever told by a health professional that asthma is probably work-related, when compared to adults who were not, had increased odds of frequent work outdoors [prevalence odds ratio (POR)=2.76], frequent workplace exposure to secondhand smoke (POR=3.08) and frequent workplace exposure to vapors, gas, dust or fumes (POR=3.56)., Conclusions: To our knowledge, this is the first population-based study in USA that estimates the proportion of working adults with asthma that have frequent workplace exposures. Increasing the understanding of workplace exposures among adults with asthma will help enable prevention of asthma through workplace exposure reduction or avoidance. Future studies should further examine industries and occupations of individuals with asthma and frequent workplace exposures.

Limited information exists regarding the health risks associated with inhaling aerosols that are generated during resistance spot welding of metals treated with adhesives. Toxicology studies evaluating spot welding aerosols are non-existent. A resistance spot welding aerosol generator and inhalation exposure system was developed. The system was designed by directing strips of sheet metal that were treated with an adhesive to two electrodes of a spot welder. Spot welds were made at a specified distance from each other by a computer-controlled welding gun in a fume collection chamber. Different target aerosol concentrations were maintained within the exposure chamber during a 4-h exposure period. In addition, the exposure system was run in two modes, spark and no spark, which resulted in different chemical profiles and particle size distributions. Complex aerosols were produced that contained both metal particulates and volatile organic compounds (VOCs). Size distribution of the particles was multi-modal. The majority of particles were chain-like agglomerates of ultrafine primary particles. The submicron mode of agglomerated particles accounted for the largest portion of particles in terms of particle number. Metal expulsion during spot welding caused the formation of larger, more spherical particles (spatter). These spatter particles appeared in the micron size mode and accounted for the greatest amount of particles in terms of mass. With this system, it is possible to examine potential mechanisms by which spot welding aerosols can affect health, as well as assess which component of the aerosol may be responsible for adverse health outcomes.

Introduction: The contribution of occupational exposure to the risk of chronic obstructive pulmonary disease COPD in population-based studies is of interest. We compared the performance of self-reported exposure to a newly developed JEM in exposure-response evaluation., Methods: We used cross-sectional data from Multi-Ethnic Study of Atherosclerosis (MESA), a population-based sample of 45-84 year olds free of clinical cardiovascular disease at baseline. MESA ascertained the most recent job and employment, and the MESA Lung Study measured spirometry, and occupational exposures for 3686 participants. Associations between health outcomes (spirometry defined airflow limitation and Medical Research Council-defined chronic bronchitis) and occupational exposure [self-reported occupational exposure to vapor-gas, dust, or fumes (VGDF), severity of exposure, and a job-exposure matrix (JEM)-derived score] were evaluated using logistic regression models adjusted for non-occupational risk factors., Results: The prevalence of airflow limitation was associated with self-reported exposure to vapor-gas (OR 2.6, 95%CI 1.1-2.3), severity of VGDF exposure (P-trend < 0.01), and JEM dust exposure (OR 2.4, 95%CI 1.1-5.0), and with organic dust exposure in females; these associations were generally of greater magnitude among never smokers. The prevalence of chronic bronchitis and wheeze was associated with exposure to VGDF. The association between airflow limitation and the combined effect of smoking and VGDF exposure showed an increasing trend. Self-reported vapor-gas, dust, fumes, years and severity of exposure were associated with increased prevalence of chronic bronchitis and wheeze (P < 0.001)., Conclusions: Airflow limitation was associated with self-reported VGDF exposure, its severity, and JEM-ascertained dust exposure in smokers and never-smokers in this multiethnic study.