Publications by authors named "S P Herndon"

Article Synopsis
  • Ethylene oxide (EtO) is a volatile organic compound and carcinogen, with limited reliable data on its ambient concentrations near production facilities, raising exposure concerns.
  • In February 2023, sensitive mobile measurements in southeastern Louisiana showed that 75% of sampled areas had EtO levels above the threshold associated with a 1-in-a-million cancer risk, with some locations exceeding levels indicating a 1-in-1,000 risk.
  • This study revealed higher EtO concentrations than previous EPA estimates and highlights the need for improved monitoring methods to assess exposure risks in industrial areas.
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Objective: Systemic lupus erythematosus (SLE) disproportionately affects patients from racial and ethnic minority groups. Medication adherence is lower among these patient populations, and nonadherence is associated with worse health outcomes. We aimed to identify factors that enable adherence to immunosuppressive medications among patients with SLE from racial and ethnic minority groups.

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Biomass burning particulate matter (BBPM) affects regional air quality and global climate, with impacts expected to continue to grow over the coming years. We show that studies of North American fires have a systematic altitude dependence in measured BBPM normalized excess mixing ratio (NEMR; ΔPM/ΔCO), with airborne and high-altitude studies showing a factor of 2 higher NEMR than ground-based measurements. We report direct airborne measurements of BBPM volatility that partially explain the difference in the BBPM NEMR observed across platforms.

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Wildfires emit large amounts of black carbon and light-absorbing organic carbon, known as brown carbon, into the atmosphere. These particles perturb Earth's radiation budget through absorption of incoming shortwave radiation. It is generally thought that brown carbon loses its absorptivity after emission in the atmosphere due to sunlight-driven photochemical bleaching.

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Tracer flux ratio (TFR) methodology performed downwind of 15 active oil and natural gas production sites in Ohio County, West Virginia sought to quantify air pollutant emissions over two weeks in April 2018. In coordination with a production company, sites were randomly selected depending on wind forecasts and nearby road access. Methane (CH), ethane (CH), and tracer gas compounds (acetylene and nitrous oxide) were measured via tunable infrared direct absorption spectroscopy.

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