Publications by authors named "P DeCarlo"
Modelling indoor radical chemistry during the HOMEChem campaign.
Environ Sci Process Impacts
January 2025
In the indoor environment, occupants are exposed to air pollutants originating from continuous indoor sources and exchange with the outdoor air, with the highest concentration episodes dominated by activities performed indoors such as cooking and cleaning. Here we use the INdoor CHEMical model in Python (INCHEM-Py) constrained by measurements from the House Observations of Microbial and Environmental Chemistry (HOMEChem) campaign, to investigate the impact of a bleach cleaning event and cooking on indoor air chemistry. Measurements of the concentrations of longer-lived organic and inorganic compounds, as well as measured photolysis rates, have been used as input for the model, and the modelled hydroxyl (OH) radicals, hydroperoxyl radicals, and nitrous acid (HONO) concentrations compared to the measured values.
View Article and Find Full Text PDFIn 2018, the ATHLETIC campaign was conducted at the University of Colorado Dal Ward Athletic Center and characterized dynamic indoor air composition in a gym environment. Among other parameters, inorganic particle and gas-phase species were alternatingly measured in the gym's supply duct and weight room. The Indoor Model of Aerosols, Gases, Emissions, and Surfaces (IMAGES) uses the inorganic aerosol thermodynamic equilibrium model, ISORROPIA, to estimate the partitioning of inorganic aerosols and corresponding gases.
View Article and Find Full Text PDFThe prevailing view for aqueous secondary aerosol formation is that it occurs in clouds and fogs, owing to the large liquid water content compared to minute levels in fine particles. Our research indicates that this view may need reevaluation due to enhancements in aqueous reactions in highly concentrated small particles. Here, we show that low temperature can play a role through a unique effect on particle pH that can substantially modulate secondary aerosol formation.
View Article and Find Full Text PDFArticle Synopsis
- EPFRs are significant pollutants linked to air quality issues, especially in Fairbanks, Alaska, where they were studied during winter 2022.
- High concentrations of EPFRs were found during temperature inversions and were associated with markers of incomplete combustion, including carbon monoxide and elemental carbon.
- Exposure to EPFR levels can be comparable to smoking 0.4-1 cigarette daily, and they may induce oxidative stress in the respiratory system based on their strong correlation with hydroxyl radical formation.
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.