Urbana Campus Research Calendar (OVCRI)

ABSTRACT 

Exposure to particulate matter (PM) is known to have an adverse health effect on human health, leading to increased mortality globally. Oxidative potential (OP) quantifies the ability of PM to induce oxidative stress and has emerged as an alternative metric that may better represent PM-induced toxicity than particle mass concentrations (PMC) alone. People spend over 85% of their time indoors, however, the OP of PM in this critical environment is understudied. 

We first quantified the OP of PM emissions from commonly used indoor sources spanning different emission mechanisms in a chamber environment. The intrinsic (mass-normalized) OP of emissions from several indoor sources was comparable to or exceeded those of ambient PM2.5. An exploratory exposure assessment revealed certain sources (i.e., incense, cigarettes, and toasters) could result in occupants being exposed to higher OP in less than 1 h of indoor operation than that resulting from inhaling typical ambient PM2.5 in the US over an entire day. Collectively, these results demonstrate the importance of indoor emissions, emphasizing the need for comprehensive health impact assessments to mitigate indoor PM exposure. 

Subsequently, we collected PM samples from occupied residences in the Champaign-Urbana Region (CUR) and measured their OP. Results from this work revealed that OP exposure in these residential environments was seven times higher than that in ambient environments in CUR, due to the higher proportion of time people spend in residences as compared to outdoors. Exposure to PM and OP in residential environments was influenced by real-world building characteristics such as floor area, window opening frequency, and type of ventilation, as well as source use characteristics such as cooking fuel, use of scented candles, and scented cleaning products. 

 Finally, we quantified the time- and size-resolved emission rates of PM mass and OP from indoor sources to enhance our understanding of the dynamics of OP evolution indoors and its respiratory deposition. The results from the time-resolved experiments revealed limited temporal variation of intrinsic OP across an emission experiment. Results from the size-resolved emission experiments demonstrated that particle size affected the intrinsic OP of indoor emissions. Respiratory deposition assessments revealed that only about a third to half of the inhaled particles eventually get deposited in the respiratory tract, and that Quazi-ultrafine particles under 250 nm in size disproportionately constitute about 80% of the particles that deposit in the alveolar regions of the lungs.

SPEAKER BIO

Ganesh received his B.Sc. and M.S. from the Indian Institute of Science, Bangalore, before joining Prof. Vishal Verma’s group in fall 2020 as a Ph.D. student in the EE&S program. At its core, Ganesh’s research focuses on understanding the health effects of particulate matter exposure in indoor environments. In recognition of his research, Ganesh has been fortunate to receive several prestigious awards and fellowships, such as the Engelbrecht Fellowship (2026), ASHRAE Grant in-Aid Award (2025), Air & Waste Management Association (A&WMA) Scholarship Award (2025), Mavis Future Faculty Fellowship (2024) and the Ravindar K. and Kavita Kinra Fellowship (2021), in addition to several conference presentation and travel grant awards. Ganesh aims to leverage his research on air pollution and its health impacts to reduce the overall health burden associated with poor air quality. He is grateful to the public for enabling his academic research career and strives to reciprocate through continued commitment to collaboration, teaching, science communication, outreach, and community-minded initiatives.