ObjectivesLittle is known about health outcomes related to electronic cigarette (EC) use, despite its growing popularity. The aim of this study is to investigate the association between EC use and asthma.MethodsThe study design is a cross-sectional study. A total of 35,904 high school students were included as the final study population. The presence of asthma was based on a student’s self-reported doctor diagnosis of asthma in the past 12 months.ResultsPrevalence rates of asthmatics in ‘current EC users’ (n = 2,513), ‘former EC users’ (n = 2,078), and ‘never EC users’ (n = 31,313), were 3.9% (n = 98), 2.2% (n = 46) and 1.7% (n = 530), respectively. Comparing ‘current EC’ users with ‘never EC’ users, the unadjusted OR for asthma was 2.36 (95% CI: 1.89–2.94). In order to control for the effect of conventional cigarette (CC) smoking, after stratifying the subjects by the three CC smoking categories (never CC, former CC, and current CC), within the ‘never CC’ category, the unadjusted OR for asthma for ‘current EC’ users was 3.41 (95% CI: 1.79–6.49), and the adjusted OR was 2.74 (95% CI: 1.30–5.78). Severe asthma was reflected by the number of days absent from school due to asthma symptoms; current EC users had the highest adjusted OR for severe asthma compared to ‘never EC’ users.ConclusionsWhen compared to a reference population of high school students in South Korea, EC users have an increased association with asthma and are more likely to have had days absent from school due to severe asthma symptoms. In conclusion, the results indicate that EC use may be a risk factor for asthma. The results may be useful in developing a scientific basis for the evaluation of a potential health hazard by EC.

Control banding (CB) strategies offer simplified processes for controlling worker exposures in the absence of firm toxicological and exposure information. The nanotechnology industry is an excellent candidate for applying such strategies with overwhelming uncertainties of work-related health risks posed by nanomaterials. A recent survey shows that a majority of nanomaterial producers are not performing a basic risk assessment of their product in use. The CB Nanotool, used internationally, was developed to conduct qualitative risk assessments to control nanoparticle exposures. Nanotoxicology experts have requested standardization of toxicological parameters to ensure better utility and consistency of research. Such standardization would fit well in the CB Nanotool's severity and probability risk matrix, therefore enhancing the protection of nanotechnology industry workers. This article further evaluates the CB Nanotool for structure, weighting of risk factors, and utility for exposure mitigation, and suggests improvements for the CB Nanotool and the research needed to bolster its effectiveness.

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Lawrence Livermore National Laboratory (LLNL) is a Department and Energy (DOE) and National Nuclear Security Administration (NNSA) research and development (R&D) facility that is operated by the Lawrence Livermore National Security (LLNS) LLC. What makes LLNL unique from a majority of organizations with over 6,000 employees is its primary R&D focus, rather than a traditional production or manufacturing working environment. Most large-scale enterprises worldwide with ORM models within occupational health and safety management systems (OHSMS) are focused on a finite number of uniform activities.LLNL's R&D focus breaks away from traditional systems by consistently performing unique work. Therefore, the creation of new and potentially hazardous operations and related occupational exposures is standard. Perhaps an expected outcome of this large-scale R&D work is a pervasive regulatory oversight.Though based in California, the California Occupational Safety and Health Administration (OSHA) does not oversee LLNL's activities. Instead, Federal OSHA (FedOSHA) has jurisdiction. In addition, as LLNL is run by LLNS for the DOE, additional contractual requirements are in place to ensure workers performing the tasks that benefit national R&D are well protected. For industrial hygiene (IH), the contract requires the lowest established occupational exposure limit (OEL) for a given chemical, physical, or biological exposure. Therefore, the ACGIH ® Threshold Limit Values (TLVs) often meet this specification and therefore

Eleven years (by publication) years after the development and application of the control banding (CB) Nanotool for the qualitative assessment and control of engineered nanoparticles (ENP), there remains no quantitative gold standard to serve as an alternative to the qualitative assessment. Many CB models have been developed during the years subsequent to the initial development of the CB Nanotool and the literature continues to blossom with comparisons and applications of these various tools; however, these developments have hitherto been made in the absence of validating and verifying their effectiveness using existing, albeit limited, quantitative methods. This paper reviews the existing literature on the CB Nanotool to evaluate its effectiveness in a variety of settings and presents a summary of qualitative and quantitative information from its application in a broad range of ENP handling activities performed in two different research institutions. A total of 28 ENP activities were assessed using the CB Nanotool (Version 2.0). Due to the lack of guidance on a single exposure assessment methodology, a combination of real-time monitoring, filter analysis, and microscopic analysis was used to assess various quantitative metrics, including mass concentration, particle number concentration, and particle speciation. All the results indicated that the control outcomes from the CB Nanotool qualitative assessment were sufficient to prevent workers from being exposed to ENP at levels beyond established exposure limits or background levels. These data represent an independent quantitative validation of CB Nanotool risk level outcomes and give further credence to the use of the CB Nanotool to effectively control worker exposures in the absence of quantitative air monitoring results.

An understanding of the scaling laws governing aerosol sampler performance leads to new options for testing aerosol samplers at small scale in a small laboratory wind tunnel. Two methods are described in this paper. The first involves an extension of what is referred to as the "conventional" approach, in which scaled aerosol sampler systems are tested in a small wind tunnel while exposed to relatively monodisperse aerosols. Such aerosols are collected by test and reference samplers respectively and assessed gravimetrically. The new studies were carried out for a modified, low flowrate version of the IOM personal inhalable aerosol sampler. It was shown that such experiments can be carried out with a very high level of repeatability, and this supported the general validity of the aerosol sampler scaling laws. The second method involves a novel testing system and protocol for evaluating the performances of aerosol samplers. Here, scaled aerosol samplers of interest are exposed to polydisperse aerosols, again in a small wind tunnel. In this instance, the sampled particles are counted and sized using a direct-reading aerodynamic particle sizer (the APS). A prototype automated aerosol sampler testing system based on this approach was built and evaluated in preliminary experiments to determine the performance of another modified version of the IOM personal inhalable aerosol sampler. The design of the new test system accounts for the complex fluid mechanical coupling that occurs near the sampler inlet involving the transition between the external flow outside the sampler and the internal airflow inside the sampler, leading in turn to uncontrolled particle losses. The problem was overcome by the insertion of porous plastic foam plugs. where the penetration characteristics are well understood, into the entries of both the test and the reference samplers. Preliminary experiments with this new system also supported the general validity of the aerosol sampler scaling laws. In addition, they demonstrated high potential that this approach may be applied in a standardised aerosol testing method and protocol.

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