Chemical Analysis of Exhaled Vape Emissions: Unraveling the Complexities of Humectant Fragmentation in a Human Trial Study.

Electronic cigarette smoking (or vaping) is on the rise, presenting questions about the effects of secondhand exposure. The chemical composition of vape emissions was examined in the exhaled breath of eight human volunteers with the high chemical specificity of complementary online and offline techniques. Our study is the first to take multiple exhaled puff measurements from human participants and compare volatile organic compound (VOC) concentrations between two commonly used methods, proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and gas chromatography (GC).

East Asian summer monsoon delivers large abundances of very-short-lived organic chlorine substances to the lower stratosphere.

Deep convection in the Asian summer monsoon is a significant transport process for lifting pollutants from the planetary boundary layer to the tropopause level. This process enables efficient injection into the stratosphere of reactive species such as chlorinated very-short-lived substances (Cl-VSLSs) that deplete ozone. Past studies of convective transport associated with the Asian summer monsoon have focused mostly on the south Asian summer monsoon.

Heparin versus normal saline locking for prevention of occlusion, catheter-related infections and thrombosis in central venous catheter in adults: Overview of systematic reviews.

Venous access devices are used in health care. To prevent occlusions the evidence confirmed the need for routine catheter flushing before and after infusion as well as at the end of use. To date, the efficacy of heparin has not been demonstrated.

Long-term variations of C-C alkyl nitrates and their sources in Hong Kong.

Investigating the long-term trends of alkyl nitrates (RONO) is of great importance for evaluating the variations of photochemical pollution. Mixing ratios of C-C RONO were measured in autumn Hong Kong from 2002 to 2016, and the average level of 2-butyl nitrate (2-BuONO) always ranked first. The C-C RONO all showed increasing trends (p < 0.

Atmospheric Acetaldehyde: Importance of Air-Sea Exchange and a Missing Source in the Remote Troposphere.

We report airborne measurements of acetaldehyde (CHCHO) during the first and second deployments of the National Aeronautics and Space Administration (NASA) Atmospheric Tomography Mission (ATom). The budget of CHCHO is examined using the Community Atmospheric Model with chemistry (CAM-chem), with a newly-developed online air-sea exchange module. The upper limit of the global ocean net emission of CHCHO is estimated to be 34 Tg a (42 Tg a if considering bubble-mediated transfer), and the ocean impacts on tropospheric CHCHO are mostly confined to the marine boundary layer.

Stable isotope profiles reveal active production of VOCs from human-associated microbes.

Volatile organic compounds (VOCs) measured from exhaled breath have great promise for the diagnosis of bacterial infections. However, determining human or microbial origin of VOCs detected in breath remains a great challenge. For example, the microbial fermentation product 2,3-butanedione was recently found in the breath of Cystic Fibrosis (CF) patients; parallel culture-independent metagenomic sequencing of the same samples revealed that Streptococcus and Rothia spp.

OH reactivity in urban and suburban regions in Seoul, South Korea - an East Asian megacity in a rapid transition.

South Korea has recently achieved developed country status with the second largest megacity in the world, the Seoul Metropolitan Area (SMA). This study provides insights into future changes in air quality for rapidly emerging megacities in the East Asian region. We present total OH reactivity observations in the SMA conducted at an urban Seoul site (May-June, 2015) and a suburban forest site (Sep, 2015).

Quantification of Aerosol Hydrofluoroalkane HFA-134a Elimination in the Exhaled Human Breath Following Inhaled Corticosteroids Administration.

Inhaled corticosteroids (ICS) and β2-agonists are the primary pharmacotherapies of asthma management. However, suboptimal medication compliance is common in asthmatics and is associated with increased morbidity. We hypothesized that exhaled breath measurements of the aerosol used in the inhaled medications might prove useful as surrogate marker for asthma medication compliance.

Air quality in Mecca and surrounding holy places in Saudi Arabia during Hajj: initial survey.

The Arabian Peninsula experiences severe air pollution, the extent and sources of which are poorly documented. Each year in Saudi Arabia this situation is intensified during Hajj, the Holy Pilgrimage of Islam that draws millions of pilgrims to Mecca. An initial study of air quality in Mecca and surrounding holy sites during the 2012 Hajj (October 24-27) revealed strongly elevated levels of the combustion tracer carbon monoxide (CO, up to 57 ppmv) and volatile organic compounds (VOCs) along the pilgrimage route-especially in the tunnels of Mecca-that are a concern for human health.

High-global warming potential F-gas emissions in California: comparison of ambient-based versus inventory-based emission estimates, and implications of refined estimates.

To provide information for greenhouse gas reduction policies, the California Air Resources Board (CARB) inventories annual emissions of high-global-warming potential (GWP) fluorinated gases, the fastest growing sector of greenhouse gas (GHG) emissions globally. Baseline 2008 F-gas emissions estimates for selected chlorofluorocarbons (CFC-12), hydrochlorofluorocarbons (HCFC-22), and hydrofluorocarbons (HFC-134a) made with an inventory-based methodology were compared to emissions estimates made by ambient-based measurements. Significant discrepancies were found, with the inventory-based emissions methodology resulting in a systematic 42% under-estimation of CFC-12 emissions from older refrigeration equipment and older vehicles, and a systematic 114% overestimation of emissions for HFC-134a, a refrigerant substitute for phased-out CFCs.

Air quality in the Industrial Heartland of Alberta, Canada and potential impacts on human health.

The "Industrial Heartland" of Alberta is Canada's largest hydrocarbon processing center, with more than 40 major chemical, petrochemical, and oil and gas facilities. Emissions from these industries affect local air quality and human health. This paper characterizes ambient levels of 77 volatile organic compounds (VOCs) in the region using high-precision measurements collected in summer 2010.

Source attributions of hazardous aromatic hydrocarbons in urban, suburban and rural areas in the Pearl River Delta (PRD) region.

Aromatic hydrocarbons (AHs) are both hazardous air pollutants and important precursors to ozone and secondary organic aerosols. Here we investigated 14 C6-C9 AHs at one urban, one suburban and two rural sites in the Pearl River Delta region during November-December 2009. The ratios of individual aromatics to acetylene were compared among these contrasting sites to indicate their difference in source contributions from solvent use and vehicle emissions.

Exhaled breath and fecal volatile organic biomarkers of chronic kidney disease.

Background: While much is known about the effect of chronic kidney disease (CKD) on composition of body fluids little is known regarding its impact on the gases found in exhaled breath or produced by intestinal microbiome. We have recently shown significant changes in the composition of intestinal microbiome in humans and animals with CKD. This study tested the hypothesis that uremia-induced changes in cellular metabolism and intestinal microbiome may modify the volatile organic metabolites found in the exhaled breath or generated by intestinal flora.