Effects of E-Cigarette Liquid Ratios on the Gravimetric Filter Correction Factors and Real-Time Measurements.

Electronic cigarettes (ECIGs) generate high concentrations of particulate matter (PM), impacting the air quality inhaled by humans through secondhand exposure. ECIG liquids are available commercially and some users create their own "do-it-yourself" liquids, and these liquids often vary in the amounts of their chemical ingredients, including propylene glycol (PG) and vegetable glycerin (VG). Previous studies have quantified PM concentrations in ECIG aerosol generated from liquids containing different PG/VG ratios.

Use of real-time monitors to evaluate the potential exposure of secondhand electronic cigarette particulate matter inside vehicles.

Electronic cigarette (ECIG) use continues to be highly prevalent, especially among youth and young adults. Potential exposure from secondhand ECIG particulate matter (PM) places bystanders in danger of inhaling harmful substances, especially in confined spaces. This study was conducted to measure the potential exposure from secondhand ECIG PM exposure in vehicles, with participants completing a 30-min ECIG use session in their own vehicle with their preferred ECIG device.

Secondhand electronic cigarette aerosol in vehicles impacts indoor air quality.

Background: Electronic cigarette (ECIG) use in vehicles represents a public health concern due to the potential for exposure to high concentrations of particulate matter (PM) and other toxicants. This study examined the impact of ECIG use on air quality in vehicles.

Methods: People who reported current ECIG use (n=60; mean age=20.

Heavy metal ecotoxicology of vervet monkeys (Chlorocebus pygerythrus) across field sites in South Africa.

Primatologists use ecological models for understanding nonhuman primate (NHP) behavior and biology. Yet few studies have focused on the impacts of naturally occurring and anthropogenically derived toxicants in NHP habitats. For humans and NHPs, toxic levels of heavy metals frequently result in poor health outcomes including improper neurological development, immune system depression, and endocrine disruption.

Laboratory Determination of Gravimetric Correction Factors for Real-time Area Measurements of Electronic Cigarette Aerosols.

Research on secondhand electronic cigarette (ECIG) aerosol exposure using aerosol monitors has demonstrated that ECIG use can generate high concentrations of particulate matter (PM) and impact indoor air quality. However, quantifying indoor air PM concentrations using real-time optical monitors with on-site calibration specifically for different PM exposures has not been established. Therefore, the ECIG aerosol filter correction factors were calculated for different PM sizes (PM, PM, and PM) and different aerosol optical monitors, the MiniWRAS, pDR, and SidePak.

Increased JUUL Emissions from Initial Puffs after Removing and Reinserting Pod.

Standard laboratory electronic cigarette (ECIG) puffing protocols that do not consider user behaviors, such as removing and resinserting a pod, may underestimate emissions. This study compared JUUL emissions from four 10-puff bout procedures. We generated ECIG aerosol in a chamber using a JUUL device and measured concentrations of particulate matter ≤2.

Speciation of chromium via laser-induced breakdown spectroscopy of ion exchange polymer membranes.

A new method for the speciation of ng/mL concentrations of Cr(III) and Cr(VI) solutions with analysis by laser-induced breakdown spectroscopy (LIBS) is reported. Speciation is achieved by pre-concentration of the chromium onto commercially available cation exchange polymer membranes. Chromium(III) is removed directly by cation exchange; chromium(VI) in the filtrate is reduced to Cr(III) and concentrated onto a second cation exchange membrane, affording independent measurement of both species.

Resonance-enhanced multiphoton ionization for real-time monitoring of trichloroethylene formed by degradation of tetrachloroethylene using zero-valent zinc.

Resonance-enhanced multiphoton ionization (REMPI) is investigated as a potential technique for real-time monitoring of selected volatile organochloride compounds (VOCs). In a proof-of-concept experiment, the progress of the reductive-degradation of tetrachloroethylene (PCE) to trichloroethylene (TCE) by zero-valent zinc was monitored by REMPI measurements performed in the headspace above the PCE solution. Two-photon resonant REMPI spectra of TCE and PCE were recorded over the wavelength range 305-320 nm.

Population consequences of fipronil and degradates to copepods at field concentrations: an integration of life cycle testing with leslie matrix population modeling.

The predominant data used in ecological risk assessment today are individual-based rather than population-based; yet environmental policies are usually designed to protect populations of threatened species or communities. Most current methods in ecotoxicology are limited by largely logistic/ technology-driven requirements that yield data for a relatively small number of test species and end points that focus on acute lethality or sublethal nonproduction-based parameters (e.g.

Dual-pulse laser-induced breakdown spectroscopy with combinations of femtosecond and nanosecond laser pulses.

Nanosecond and femtosecond laser pulses were combined in an orthogonal preablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS) configuration. Even without full optimization of interpulse alignment, ablation focus, large signal, signal-to-noise ratio, and signal-to-background ratio enhancements were observed for both copper and aluminum targets. Despite the preliminary nature of this study, these results have significant implications in the attempt to explain the sources of dual-pulse LIBS enhancements.