A5046075790- Indoor Air Quality and Microbial Exposure
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Vehicle emissions and performance
- Building Energy and Comfort Optimization
- Infection Control and Ventilation
- Aerosol Filtration and Electrostatic Precipitation
- Toxic Organic Pollutants Impact
- Odor and Emission Control Technologies
- Fire dynamics and safety research
- Wind and Air Flow Studies
- Groundwater flow and contamination studies
- Noise Effects and Management
- Conservation Techniques and Studies
- Microbial bioremediation and biosurfactants
- Silicone and Siloxane Chemistry
- Atmospheric and Environmental Gas Dynamics
- Advanced Chemical Sensor Technologies
- Gas Sensing Nanomaterials and Sensors
- Fire effects on ecosystems
- Analytical chemistry methods development
- Advanced Sensor Technologies Research
- Analytical Chemistry and Sensors
- Evacuation and Crowd Dynamics
- Scientific Measurement and Uncertainty Evaluation
National Institute of Standards and Technology
2016-2025
National Institute of Standards
2014-2025
The University of Texas at Austin
1999-2023
Humboldt State University
2010
University of North Dakota
2001-2002
Recent interest in commercial devices containing germicidal ultraviolet lamps with a peak emission wavelength at 222 nm (GUV222) has focused on mitigating virus transmission indoors while posing minimum risk to human tissue. However, light can produce ozone (O3) air. O3 is an undesirable component of indoor air because health impacts from acute chronic exposure and its ability degrade quality through oxidation chemistry. In seven 4 h experiments, we measured the production single filtered...
Wildfires are increasing in frequency, raising concerns that smoke can permeate indoor environments and expose people to chemical air contaminants. To study transformations evaluate mitigation strategies, we added a test house. Many volatile organic compounds (VOCs) persisted days following the injection, providing longer-term exposure pathway for humans. Two time scales control VOC partitioning: faster one (1.0 5.2 hours) describes reach equilibrium between adsorption desorption processes...
Soil and sediment samples from oil gas (OG) coal (CG) manufactured plant (MGP) sites were selected to represent a range of PAH concentrations (150−40 000 mg/kg) sample matrix compositions. Samples varied vegetated soils lampblack soot had carbon contents 3 87 wt %. SFE desorption (120 min) water/XAD2 days) curves determined fit with simple two-site model determine the rapid-released fraction (F) for PAHs ranging naphthalene benzo[ghi]perylene. F values greatly among samples, ca. 10% >90%...
Human exposure to airborne ultrafine particles (UFP, < 100 nm) has been shown have adverse health effects and can be elevated in buildings. In-duct electrostatic precipitator filters (ESP) an effective particulate control device for reducing UFP concentrations (20-100 buildings, although they the potential increase indoor ozone concentrations. This study investigated residential ESP reduce between 4 15 nm quantified resulting generation. ESPs were operated central air handling unit of a test...
The Chemical Assessment of Surfaces and Air (CASA) study aimed to understand how chemicals transform in the indoor environment using perturbations (
Over one-quarter of the world's population relies on fuel-based lighting. Kerosene lamps are often located in close proximity to users, potentially increasing risk for respiratory illnesses and lung cancer. Particulate matter concentrations resulting from cook stoves have been extensively studied literature. However, characterization particulate lighting has received minimal attention. This research demonstrates that vendors who use a single simple wick lamp high-air-exchange market kiosks...
ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTWhy Indoor Chemistry Matters: A National Academies Consensus ReportRima HabreRima HabreUniversity of Southern California, Los Angeles, California 90089, United StatesMore by Rima Habre, David C. DormanDavid DormanNorth Carolina State University, Raleigh, North 27695, Dorman, Jonathan AbbattJonathan AbbattUniversity Toronto, Ontario M5S 3H6, CanadaMore Abbatt, William P. BahnflethWilliam BahnflethPennsylvania University Park, Pennsylvania 16802,...
Devices using 222 nm germicidal ultraviolet light (GUV222) have been marketed to reduce virus transmission indoors. However, GUV222 generates ozone which can react with gases and surfaces create undesirable air byproducts.
Removal rates of polycyclic aromatic hydrocarbons (PAHs) from manufactured gas plant (MGP) soils were determined using water desorption for 120 days and mild supercritical carbon dioxide extraction (SFE) 200 min. Both techniques used to compare the changes in individual PAHs untreated treated that obtained a field biotreatment unit after 58, 147, 343 days. Water profiles (plotted days) SFE minutes) very similar regardless whether PAH was rapidly or slowly removed. fit with simple two-site...
Indoor surfaces play a key role in indoor chemistry, including modification of oxidant concentrations. This study utilises the INdoor CHEmical Model Python (INCHEM-Py) to investigate impact surface transformations and their on gas-phase chemistry. INCHEM-Py has been developed simulate deposition ozone hydrogen peroxide onto nine six individual respectively typical bedroom, kitchen office for normal concentrations absence household activities. The results show that 91 96% these oxidants are...
Energy-efficient residential building standards require the use of mechanical ventilation systems that replace indoor air with outdoor air. Transient pollution events can be transported indoors via system and other entry pathways impact chemistry. In spring 2022, we observed elevated levels NOx (NO + NO2) originated outdoors, entering National Institute Standards Technology (NIST) Net-Zero Energy Residential Test Facility through system. Using measurements NOx, ozone (O3), volatile organic...
In response to the COVID-19 pandemic, air cleaning technologies were promoted as useful tools for disinfecting public spaces and combating airborne pathogen transmission. However, no standard method exists assess potentially harmful byproduct formation from cleaners. Through a consensus development process, draft test portable cleaner performance was developed, suite of cleaners employing seven different tested. The quantifies not only removal efficiency challenge chemical ultrafine...
Vaporous hydrogen peroxide (VHP) has been used to disinfect a wide range of biological contaminants in buildings. It attracted renewed attention for inactivation the SARS-CoV-2 virus on N95 respirators, allowing their subsequent reuse, as well potential use decontamination indoor spaces frequented by those who have COVID-19. Knowledge VHP removal materials and associated emissions organic compounds not widely reported but would be valuable disinfection planning. Twenty-three building were...
The chemical composition of indoor air is strongly driven by the and properties surfaces. At Chemical Assessments Surfaces Air (CASA) campaign, we performed controlled additions ammonia (reaching up to 297 ppb 662 ppb) investigate impacts changing surface basicity on fate gaseous particulate acids bases in an unoccupied house. In response injections, nitrogen-containing compounds (C2–7H3–11N1O0–3) were emitted from surfaces gas phase with signals increasing 101% 104% compared their prior...
The National Institute of Standards and Technology constructed the Net-Zero Energy (NZE) Residential Test Facility to support development adoption cost-effective NZE designs technologies. In indoor air quality goals, contaminant source control approaches were implemented that minimized use products containing urea-formaldehyde resin utilized with relatively low volatile organic compound emissions. Indoor outdoor concentrations formaldehyde acetaldehyde measured approximately monthly for 15...
Abstract. Proton-transfer-reaction mass spectrometry (PTR-MS) using hydronium ion (H3O+) ionization is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. Unlike more energetic methods (e.g., electron impact), H3O+ can leave a target VOC molecule mostly intact thus in PTR-MS spectrum be identified by its mass-to-charge ratio corresponding to proton-transfer product (MH+). However, ionization, associated chemistry reactor, known generate other ions...
Gas chromatography paired with proton transfer reaction mass spectrometry allows for a more accurate assessment of gas-phase chemicals in indoor air.
Abstract. Methane emissions from natural gas appliances and infrastructure within buildings have historically not been captured in greenhouse inventories, leading to under-estimates, especially urban areas. Recent measurements of these post-meter indicated non-negligible residences, with impacts on both indoor air quality climate. As a result, methane losses residential included the latest US national inventory, emission factors determined single study homes California. To facilitate future...