Abstract. Dust events are an important and complex constituent of the atmospheric system that can impact Earth's climate, the environment, and human health. The frequency of dust events in the Southern High Plains of West Texas has increased over the past 2 decades, yet their impact on air quality in this region is still unclear. This is due to the fact that there is only one air quality monitoring station that measures only PM2.5 concentrations (particulate matter with an aerodynamic diameter < 2.5 µm), and there is no information on other PM sizes or the particle size distribution. The Aerosol Research Observation Station (AEROS) unit provides insight into the local variation in particle concentration during different dust events and allows for a better understanding of the impact of dust events on air quality. As this area is prone to dust events, we were wondering if dust events generated by different meteorological causes (synoptic vs. convective) would present similar particle concentrations or particle size distributions. Thus, in this project, three different dust events were measured by AEROS and compared. Each dust event originated from a different direction and lasted a different duration. One of the dust events was synoptic (10 April 2019) and two were convective (5 and 21 June 2019). Measurements of particle mass and number concentration, size distribution, and meteorological conditions for each dust event were compared. The synoptic dust event (on 10 April) was longer (12 h) and had stronger wind speed conditions (up to 22.1 m s−1), whereas the two respective convective dust events on 5 and 21 June lasted only 20 and 30 min and had lower wind speeds (up to 16.5 and 13.4 m s−1). Observation of PM based on daily and hourly values showed an impact on air quality, yet measurements based on daily and hourly values underestimate the impact of the convective dust events. Observations based on a shorter timescale (10 min) reveal the true impact of the two convective dust events. A comparison of the particle size distribution showed that all three dust events presented an increase in particles in the 0.3–10 µm size range. Comparisons of the particle concentration for particles > 5 and > 10 µm show very high values during the dust events. Some particle sizes even increase in concentration by ∼ 2 orders of magnitude compared with the time before the dust event. This leads us to speculate that the impact of convective dust events on air quality in this region is underestimated with the current (hourly basis) method.

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This program was designed to begin the process of educating health care providers about the unique health care issues of military LGBT Service Members and their beneficiaries. This program was the first to address the disparities in LGBT health care needs within the Department of Defense. It also provided a platform for facilitating open communication among providers regarding LGBT population health needs in the military.

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Abstract. Information on atmospheric particles' concentration and sizes is important for environmental and human health reasons. Air quality monitoring stations (AQMSs) for measuring particulate matter (PM) concentrations are found across the United States, but only three AQMSs measure PM2.5 concentrations (mass of particles with an aerodynamic diameter of < 2.5 µm) in the Southern High Plains of West Texas (area ≥ 1.8 × 105 km2). This area is prone to many dust events (∼ 21 yr−1), yet no information is available on other PM sizes, total particle number concentration, or size distribution during these events. The Aerosol Research Observation Station (AEROS) was designed to continuously measure these particles' mass concentrations (PM1, PM2.5, PM4, and PM10) and number concentrations (0.25–35.15 µm) using three optical particle sensors (Grimm 11-D, OPS, and DustTrak) to better understand the impact of dust events on local air quality. The AEROS aerosol measurement unit features a temperature-controlled shed with a dedicated inlet and custom-built dryer for each of the three aerosol instruments used. This article provides a description of AEROS as well as an intercomparison of the different instruments using laboratory and atmospheric particles. Instruments used in AEROS measured a similar number concentration with an average difference of 2 ± 3 cm−1 (OPS and Grimm 11-D using similar particle size ranges) and a similar mass concentration, with an average difference of 8 ± 3.6 µg m−3 for different PM sizes between the three instruments. Grimm 11-D and OPS had a similar number concentration and size distribution, using a similar particle size range and similar PM10 concentrations (mass of particles with an aerodynamic diameter of < 10 µm). Overall, Grimm 11-D and DustTrak had good agreement in mass concentration, and comparison using laboratory particles was better than that with atmospheric particles. Overall, DustTrak measured lower mass concentrations compared to Grimm 11-D for larger particle sizes and higher mass concentrations for lower PM sizes. Measurement with AEROS can distinguish between various pollution events (natural vs. anthropogenic) based on their mass concentration and size distribution, which will help to improve knowledge of the air quality in this region.