Air quality experts from the United States and Mexico came together recently on the San Diego State University campus to bring a sense of urgency to the challenges of monitoring air pollution along the border.

The discussion, which involved professors from SDSU and the University of California San Diego, as well as educators at universities in Tijuana and Mexicali, covered the wide availability of homemade air sensors and the wisdom of crowdsourcing air pollution.

The experts, whose areas of focus spanned environmental health, urban studies and chemical engineering, came away with a commitment to continue the conversation about ways air quality data can be captured and what actions can be taken to correct persistently polluted segments of the border.

The discussion was hosted and moderated by inewsource, and sponsored by the Center for Science and Media at SDSU. It was a continuation of “What’s in the Air,” an interdisciplinary class that brought journalism and earth sciences students together to build air monitors, test air quality in San Diego and publish the results.

“We decided that it would be good to move our focus away from just San Diego in general and explore what the air quality is like along the San Diego-Mexico border,” said Amy Schmitz Weiss, an associate professor of journalism who co-taught the class and organized the roundtable.

“As a binational city, we should care about the air, which has no geographic boundaries or constraints,” she said, pointing out that the border has unique factors such as long lines of idle cars that can negatively impact air quality for pedestrians and residential areas.

Those concerns play into the the highly localized nature of air pollution.

“One thing we know now that we didn’t know when the air pollution laws were written in the 1970s is that air pollution is very, very spatial,” said Penelope Quintana, an environmental health professor at SDSU. “It can be regional, like ozone is a very regional air pollutant, but it can also be quite local, if you’re next to idling traffic.”

Crowdsourcing was suggested as a possibility for capturing data documenting highly localized pollution.

Jack Hegenauer, a former professor at UCSD, has become active in monitoring air quality in his community of Solana Beach. He uses his own electronic sensor, which he modeled after those built by students for “What’s in the Air.” He suggested using low-tech sensors spread out among “citizen scientists.”

“You put inexpensive machinery in the hands of people who may not themselves know a good deal about what goes into it …” he said. “You have a lot of people to supplement the very expensive instruments that seem to be required these days to make anybody take notice about air quality.”

Quintana, on the other hand, suggested some intermediate-level instruments between the federal Environmental Protection Agency’s sensors and cheap “off-the-shelf sensors.” Those middle options can be more accurate than the homemade variety, she said, and can cost around $15,000.

Looking at those intermediate options, she pointed to the success of  a recent study she co-authored.

“We measured what appeared to be higher emissions from the border crossing,” she said.

Those findings, Quintana said, helped persuade the San Diego Air Pollution Control District to place an air quality monitor at the San Ysidro Port of Entry as an experiment for two years.

“Showing data is helpful.” Quintana said. “Having numbers helps you make an argument.”

Some of the experts attending the discussion, including Quintana, also stressed that just having data isn’t enough if it doesn’t mean anything to residents.

From left to right: Lorie Hearn, executive editor at inewsource, Gabriela Muñoz Melendez from the COLEF in Tijuana, and Margarito Quintero from the UABC in Mexicali. Megan Wood, inewsource

Margarito Quintero, a chemical engineer at Autonomous University of Baja California (UABC) in Mexicali, said the residents there don’t need more sensors to identify problems with the air quality.

“As soon as you get out of your house in the morning, to a job or to your kids’ (school), you can easily feel and smell something which was burned last night,” he said. “When you go out and you see in the city street, you can easily feel as well the smell of the smoke.”

According to Quintero, there are plans and strategies in place to address air pollution in Mexicali, but nothing is being done to actually carry them out. Usually air quality is low on the priority list for residents.

“It has to do with what do you consider important in Mexico as a citizen: security, violence, economy, corruption, impunity, air quality,” he said.

Gabriela Muñoz Melendez is a professor at the Department of Urban and Environmental Studies at the College of the Northern Border (COLEF) in Tijuana.

“It is true we need data,” she said. But researchers need to translate that data for the community in a way that is understandable and that measures the problems community members are facing.

“I think that it has been overlooked by a lot of people that work on air quality,” Muñoz said.

Leonardo Castañeda was a reporter and economic analyst for inewsource. To contact him with tips, suggestions or corrections, please email leocastaneda [at] inewsource [dot] org.