Development of ASTM International D8405-Standard Test Method for Evaluating PM Sensors or Sensor Systems Used in Indoor Applications.

Sensors and sensor systems for monitoring fine particles with aerodynamic diameters smaller than 2.5 µm can provide real-time feedback on indoor air quality and thus can help guide actions to manage indoor air pollutant concentrations. Standardized verification of the performance and accuracy of sensors and sensor systems is crucial for predicting the efficacy of such monitoring.

Towards the Development of a Sensor Educational Toolkit to Support Community and Citizen Science.

As air quality sensors increasingly become commercially available, a deeper consideration of their usability and usefulness is needed to ensure effective application by the public. Much of the research related to sensors has focused on data quality and potential applications. While this information is important, a greater understanding of users' experience with sensors would provide complementary information.

Long-term evaluation of a low-cost air sensor network for monitoring indoor and outdoor air quality at the community scale.

Given the growing interest in community air quality monitoring using low-cost sensors, 30 PurpleAir II sensors (12 outdoor and 18 indoor) were deployed in partnership with community members living adjacent to a major interstate freeway from December 2017- June 2019. Established quality assurance/quality control techniques for data processing were used and sensor data quality was evaluated by calculating data completeness and summarizing PM measurements. To evaluate outdoor sensor performance, correlation coefficients (r) and coefficients of divergence (CoD) were used to assess temporal and spatial variability of PM between sensors.

Deliberating Performance Targets: Follow-on workshop discussing PM, NO, CO, and SO air sensor targets.

The use of air sensor technology is increasing worldwide for a variety of applications, however, with significant variability in data quality. The United States Environmental Protection Agency held a workshop in July 2019 to deliberate possible performance targets for air sensors measuring particles with aerodynamic diameters of 10 μm or less (PM), nitrogen dioxide (NO), carbon monoxide (CO), and sulfur dioxide (SO). These performance targets were discussed from the perspective of non-regulatory applications and with the sensors operating primarily in a stationary mode in outdoor environments.

Development of a Performance Evaluation Protocol for Air Sensors Deployed on a Google Street View Car.

Performance evaluation studies of low-cost sensors (LCS) measuring air pollutants have been conducted by academic and governmental groups for stationary applications. In contrast, evaluation protocols are nonexistent for LCS used in mobile deployments, though LCS are used in this manner by research groups and may be employed to complement regulatory directives for community monitoring. Mobile measurements with LCS are a nascent but growing use-case, and questions of data quality will become increasingly important.

Development of a Network of Accurate Ozone Sensing Nodes for Parallel Monitoring in a Site Relocation Study.

Recent technological advances in both air sensing technology and Internet of Things (IoT) connectivity have enabled the development and deployment of remote monitoring networks of air quality sensors. The compact size and low power requirements of both sensors and IoT data loggers allow for the development of remote sensing nodes with power and connectivity versatility. With these technological advancements, sensor networks can be developed and deployed for various ambient air monitoring applications.

Secondary particles formed from the exhaust of vehicles using ethanol-gasoline blends increase the production of pulmonary and cardiac reactive oxygen species and induce pulmonary inflammation.

Background: Ethanol vehicles release exhaust gases that contribute to the formation of secondary organic aerosols (SOA).

Objective: To determine in vivo toxicity resulting from exposure to SOA derived from vehicles using different ethanol-gasoline blends (E0, E10, E22, E85W, E85S, E100).

Methods: Exhaust emissions from vehicles using ethanol blends were delivered to a photochemical chamber and reacted to produce SOA.

Variability in the primary emissions and secondary gas and particle formation from vehicles using bioethanol mixtures.

Unlabelled: Bioethanol for use in vehicles is becoming a substantial part of global energy infrastructure because it is renewable and some emissions are reduced. Carbon monoxide (CO) emissions and total hydrocarbons (THC) are reduced, but there is still controversy regarding emissions of nitrogen oxides (NO), aldehydes, and ethanol; this may be a concern because all these compounds are precursors of ozone and secondary organic aerosol (SOA). The amount of emissions depends on the ethanol content, but it also may depend on the engine quality and ethanol origin.

Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion.

Enstrophy is an intrinsic feature of turbulent flows, and its transport properties are essential for the understanding of premixed flame-turbulence interaction. The interrelation between the enstrophy transport and flow topologies, which can be assigned to eight categories based on the three invariants of the velocity-gradient tensor, has been analysed here. The enstrophy transport conditional on flow topologies in turbulent premixed flames has been analysed using a Direct Numerical Simulation database representing the corrugated flamelets (CF), thin reaction zones (TRZ) and broken reaction zones (BRZ) combustion regimes.

Inhaled ambient-level traffic-derived particulates decrease cardiac vagal influence and baroreflexes and increase arrhythmia in a rat model of metabolic syndrome.

Background: Epidemiological studies have linked exposures to ambient fine particulate matter (PM) and traffic with autonomic nervous system imbalance (ANS) and cardiac pathophysiology, especially in individuals with preexisting disease. It is unclear whether metabolic syndrome (MetS) increases susceptibility to the effects of PM. We hypothesized that exposure to traffic-derived primary and secondary organic aerosols (P + SOA) at ambient levels would cause autonomic and cardiovascular dysfunction in rats exhibiting features of MetS.

Effects of fresh and aged vehicular exhaust emissions on breathing pattern and cellular responses--pilot single vehicle study.

The study presented here is a laboratory pilot study using diluted car exhaust from a single vehicle to assess differences in toxicological response between primary emissions and secondary products resulting from atmospheric photochemical reactions of gas phase compounds with O₃, OH and other radicals. Sprague Dawley rats were exposed for 5 h to either filtered room air (sham) or one of two different atmospheres: (i) diluted car exhaust (P)+Mt. Saint Helens Ash (MSHA); (ii) P+MSHA+secondary organic aerosol (SOA, formed during simulated photochemical aging of diluted exhaust).

Development and evaluation of a countercurrent parallel-plate membrane diffusion denuder for the removal of gas-phase compounds from vehicular emissions.

Diffusion denuders have been commonly used to remove trace gases from an aerosol (mixture of gases and particles), while allowing the particles to remain suspended in air. We present the design and evaluation of a high-flow (16.7 L min⁻¹) countercurrent parallel-plate membrane diffusion denuder that has high removal efficiencies for both non-reactive gases such as carbon monoxide (89%), as well as volatile organic compounds (80-85%) from an automobile exhaust.

Laboratory evaluation of a prototype photochemical chamber designed to investigate the health effects of fresh and aged vehicular exhaust emissions.

Laboratory experiments simulating atmospheric aging of motor vehicle exhaust emissions were conducted using a single vehicle and a photochemical chamber. A compact automobile was used as a source of emissions. The vehicle exhaust was diluted with ambient air to achieve carbon monoxide (CO) concentrations similar to those observed in an urban highway tunnel.

The effects of rest and subsequent training on selected physiological parameters in professional female classical dancers.

The purpose of this study was to assess the effects of a six-week summer break and of dance preparations at the beginning of the new season following the break, on selected physiological parameters. Seventeen professional ballerinas (mean age 27.2 +/- 1.