ASU Researchers Tackle Valley Ozone Challenges to Enhance Air Quality Solutions

Phoenix’s air quality has reached alarming levels, ranking fifth among the most ozone-polluted cities in the United States, according to the American Lung Association. In response, researchers at Arizona State University (ASU) are spearheading a study to better understand ozone precursors and potential solutions to this pressing issue.

“In the Phoenix area, we are in violation of ozone standards,” said Professor Pierre Herckes from ASU’s School of Molecular Sciences. “This raises the critical question: What can we do against it?” Ozone forms when sunlight interacts with nitrogen oxides from vehicle emissions and volatile organic compounds (VOCs). These VOCs, which can be detected through scent, originate from both human activities and natural sources.

Human sources include gasoline, perfumes, and cleaning products, while natural sources are primarily plants. Understanding these components, especially the natural ones, is the focus of the ASU research team, supported by a grant from the Arizona Board of Regents.

The study, led by Herckes and Matthew Fraser alongside PhD candidates Trinity Olguin and Gabby Cano, aims to investigate how VOC emissions fluctuate with rising temperatures during the Valley’s scorching summers. “We can control human-generated emissions through regulations, but we cannot simply eliminate natural sources such as vegetation,” Herckes noted.

Researchers argue that this aspect of air quality has yet to be explored in Phoenix’s unique climate. “The gases emitted by natural systems like vegetation change with temperature,” Olguin explained. The team is currently installing monitoring equipment in three locations across the Valley to collect 24-hour data on VOC levels.

Recently, they completed measurements in a West Phoenix neighborhood and are now gathering data in a more natural desert setting in Mesa, with plans to assess an agricultural site next. “Different plants emit various compounds, so it’s critical to understand how native desert species differ from agricultural crops,” Olguin said.

Ultimately, the research aims to refine recommendations to improve air quality by quantifying the contribution of natural VOCs to ozone levels in the Phoenix area. “This study can inform strategies to combat air pollution while acknowledging factors we cannot control,” Herckes emphasized, highlighting the need for a balanced understanding of all contributing elements.