
A typical day at the San Ysidro Port of Entry | Photo: Elizabeth Hensley Chaney
Californias border with Baja California is a complex region with unique environmental issues. Our Borderlands series takes a deeper look at this region unified by shared landscapes and friendship, and divided by international politics.
Just north of the ramp, one of the last remnants of the old border-crossing footbridge, pedestrians cluster in the shade of a plastic tarp as they wait to enter the San Ysidro Port of Entry Pedestrian Facility. Meters west of the sidewalk is a temporary wall built of OSB and two-by-fours, painted white and coated in grey dust. The wall was installed in 2012 to separate southbound pedestrians from vehicular traffic. On the other side of the buckling temporary wall, 25 lanes of traffic, with vehicles ranging from chocolate autos to diesel buses to street bikes and hybrids, idle as passengers wait to reach the customs inspection booths.
The San Ysidro Port of Entry facility processes around 50,000 private vehicles daily. From 7:00 a.m. to 5:00 p.m. weekdays, wait times range from one to two and a half hours. As the waiting vehicles idle, they produce a copious variety of toxicants. They include nitrogen oxides, which are associated with respiratory ailments benzene, which increases the risk of cancer and other illnesses carbon monoxide, which reduces the oxygen-carrying capacity of blood and particulate matter (a.k.a. soot), known to cause respiratory and cardiovascular disease. Pedestrians waiting on the other side of the OSB wall breathe it all in, for up to four hours at a time.
Three miles north of the San Ysidro Port of Entry, Guillermo Cornejo carries lemons from his backyard tree to the kitchen sink. Washing the lemons has been an everyday ritual in Guillermo's household. The soot that coats them probably comes from diesel vehicles travelling along State Route 905, just a quarter of a mile north of the home. SR 905 travels between Interstate 5 and the Otay Mesa Port of Entry, a checkpoint for commercial traffic going between Baja and Alta California.
--
--
San Ysidro, the community closest to Guillermo's home, is a colonia of San Diego. Though it's 12 miles south of downtown San Diego, with the cities of Chula Vista and National City in between, San Ysidro was annexed by San Diego in 1957. It is a community with two distinct faces. On the one hand, it is seen as a great site for retailers because of its location near the international boundary. At the same time, residents face a whole host of challenges due to the community's location next to the most heavily transited land Port of Entry in the world. These challenges are seldom addressed by decision makers, whether in San Diego, Sacramento, or Washington.
Guillermo and his wife bought their home in 1981, motivated in large part by the property's ample backyard. When Guillermo, a retired engineer, purchased the home, he was aware of the potential inconvenience of living near a highway. But traffic along Interstate 5, which is 50 feet east of his backyard, was then very light. He recalls that in 1982, soon after he moved, an automobile would pass [only] around every 10 or so minutes. That was nothing like today's volumes along the Interstate that extends north from the international boundary, which he describes as a train of cars.
Lemons growing at the Cornejo residence in San Ysidro | Photo: Elizabeth Hensley Chaney
I met Guillermo at a community workshop in late August. The meeting was held to present to community members a set of air quality monitors which will be installed throughout San Ysidro, as part of a two-year study funded by the California Office of Environmental Health Hazard Assessment (OEHHA) and the California Environmental Protection Agency (CalEPA). The San Ysidro Air Quality and Border Traffic Study is conducted by researchers based at the University of Washington School of Public Health and the San Diego State University Graduate School of Public Health in consultation with members of the community of San Ysidro brought together by Casa Familiar, a local community development organization. The study's aim, in the words of the researchers, is to identify the sources and levels of air pollution with the goal of developing mitigation strategies that might reduce exposure in the community. Guillermo serves on the Community Steering Committee, formed to support the study in February 2016.
Related
Trumps Border Wall Would Be the Worlds Longest Concrete Dam
Endangered Sheep Need an Open Border
Habitat Restoration Kicks Off at Salton Sea
1 of 2
next
He learned about the study and the Committee from a friend who helps coordinate exercise classes he takes at the nearby San Ysidro Civic Center. His interest was piqued at the thought that participating in the study could help him to better understand his worsening allergies. Living near the freeway that leads to and from the most heavily used land Port of Entry, he's frequently exposed to nitrogen oxides. He worries that this exposure has affected his immune system, causing daily allergy attacks.
Guillermo started taking the exercise classes about three years ago, after he retired. The Civic Center, where the classes are held, is a city-owned building leased to Casa Familiar, a few minutes' walk from both I-805 and I-5. The building is also one of 13 sites where the Community Steering Committee has proposed placing one of the air quality monitors employed by the study. Curiously, the City of San Diego won't authorize placing a monitor on the property. At times during his exercise classes, Guillermo senses a faint aroma of gasoline, which he attributes to the location of the building between two busy freeways leading to the Port of Entry. He's concerned about the effect of exposu
Most recent headlines
05/01/2027
Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...
09/10/2026
September 10 2026, 06:00 (PDT) Dolby Expands Dolby OptiView Platform with New Capabilities at IBC 2026
New Sports Intelligence helps providers better unders...
07/10/2026
Dalet, a leading technology and service provider for media-rich organizations, today announced the latest Long-Term Supported (LTS) release of Dalet Flex. Build...
20/09/2026
COW Jobs: Video Editor, Motion Designer - Remote, PT, 6 Months
Brie Clayton September 20, 2026
0 Comments
Video Editor + Motion Designer (Remote | PT ...
19/09/2026
Three new rackmount power conditioners introduced
Yorkville Sound have announce the upcoming launch of three new RPC rackmount power conditioners from ART P...
19/09/2026
September 15, 2026
AMSTERDAM, SEPTEMBER 2026 - Colorfront (colorfront.com), the Academy and Emmy Award-winning developer of high-performance cinema mastering, ...
19/09/2026
Two High-Profile Professional Sports Franchises Renew creative.space Contracts with DigitalGlue
NFL team and Major League Soccer Club cite ease of use, secure ...
19/09/2026
Limited Edition Audio releases VoxSplit Pro for overlapping dialogue separation ...
18/09/2026
IBC 2026 Tech Moves Beyond the Gloss and Into the Rack If you spent any time in the halls of the RAI this year, you noticed a clear shift in conversation. The c...
18/09/2026
In-venue and creative video staffers at the professional and collegiate level ha...
18/09/2026
Qvest has appointed Jens Miedek as Senior Vice President Sales, Media and Entertainment. Before joining Qvest, Miedek spent 16 years at Riedel Communications an...
18/09/2026
Fonn Group has acquired full ownership of everviz, a cloud-native platform for interactive charts, maps, and data-driven graphics, and will rebrand it as Teikna...
18/09/2026
Other World Computing (OWC) has announced the acquisition of OpenDrives, a provider of software-defined video and rich media storage management solutions. The a...
18/09/2026
Kaltura and Verimatrix have announced a partnership integrating Verimatrix's Digital Rights Management and security capabilities into Kaltura's Cloud TV...
18/09/2026
The sixth edition of the World Nomad Games combined traditional sports, large-scale cultural performances, and some decidedly modern broadcast technology. Held ...
18/09/2026
DAZN and Super League Basketball (SLB) have extended their partnership for the 2026-27 season. Every Championship, Cup, and Play-Off fixture will be available l...
18/09/2026
Nielsen has announced that its Streaming Content Ratings (SCR) product will move from weekly to daily data delivery, with clients now receiving viewership data ...
18/09/2026
ESPN will present LALIGA's ElCl sico on ABC for the first time, with FC Barcelona vs. Real Madrid airing Sunday, October 25 at 4 p.m. ET. A one-hour pre-mat...
18/09/2026
The University of Pennsylvania's Division of Recreation and Intercollegiate ...
18/09/2026
The Charlotte Hornets have announced DAZN as their exclusive direct-to-consumer streaming partner for the 2026-27 NBA season. The service launches immediately, ...
18/09/2026
Broadcast sports' original medium will let drivers keep on hearing the plays thanks to a new bill set to pass the Senate....
18/09/2026
Fourteen iPhone 18 Pro devices - eight connected over a T-Mobile Private 5G Netw...
18/09/2026
The Minnesota Lynx have announced that their final local broadcast of the 2026 regular season will air free on FOX 9 following the shutdown of Victory . The Ly...
18/09/2026
Monumental Sports Network (MNMT) has announced that its Monumental+ streaming service is now available as a subscription through Prime Video, giving Capitals an...
18/09/2026
WTGL, the women's team golf league created by TMRW Sports in partnership with the LPGA, has announced its inaugural season schedule. The season premieres Su...
18/09/2026
Ratings Roundup is a rundown of recent ratings news and is derived from press re...
18/09/2026
Studio Network Solutions (SNS) has won Best Journal Article at the 2026 IAMT Impact Awards for What Video Editors Need When Everything Is Changing Around Them, ...
18/09/2026
10 new voice models join line-up
The latest expansion for IK Multimedia's AI-powered vocal-modelling software has arrived, delivering a set of 10 new vo...
18/09/2026
A day of hands-on synthesis, sound design & performance
On Saturday 26 September 2026, The Museum of Synthesisers will be hosting a full day of hands-on syn...
18/09/2026
HPA is supporting Fix It or Risk It, a non-commercial, industry-wide public-service campaign helping organizations across the media and entertainment supply cha...
18/09/2026
AgileTV has successfully wrapped up its participation at IBC 2026 in Amsterdam, following four days of conversations with customers, partners and industry profe...
18/09/2026
aconnic AG (ISIN: DE000A0LBKW6), Munich, invites its shareholders and investors to a Virtual Investor Conference on Tuesday, September 29th, 2026, at 11.00 am.
...
18/09/2026
DHD reports a high level of interest in its range of audio production equipment on all four days of the September 11-14 International Broadcasting Convention in...
18/09/2026
Sonnet Announces Thunderbolt 5 eGPU With 850-Watt Power Supply and Integrated Do...
18/09/2026
DeckBridge adds live Resolve playback and Fairlight controls to Stream Deck
Brie Clayton September 17, 2026
0 Comments
DeckBridge starting profiles ac...
18/09/2026
Learn to arrange tracks using Color With Live's Free Stencil Pack
Brie Clayton September 17, 2026
0 Comments
Stencils are Color With Live's or...
18/09/2026
Berklee Establishes Susan Tedeschi Scholarship in Honor of Grammy-Winning Alumna The scholarship is announced as Tedeschi returns to headline the Berklee Bloc...
18/09/2026
The inside scoop on attention-grabbing market assets from those in the know 17 September 2026
(L-R): Sophie Green, Todd Brown and Edwina Waddy
Find this episo...
18/09/2026
Senior Colorist Siggy Ferstl of Company 3 has been grading The Boys since the sh...
18/09/2026
Friday 18 September 2026
The new iPhone 18 Pro, iPhone 18 Pro Max, Apple Watch ...
18/09/2026
Senior Colorist Siggy Ferstl of Company 3 has been grading The Boys since the sh...
17/09/2026
Lions vs. Bills will also be the first regular-season game at new Highmark Stadi...
17/09/2026
Teradek has announced Bolt 7, a wireless video and data system that adds an integrated 900MHz radio to the Bolt's zero-delay video pipeline. The 900MHz chan...
17/09/2026
DAZN has announced three appointments to its executive leadership team, all reporting to CEO Shay Segev effective immediately.
Patrick Delany has been appointe...
17/09/2026
Monumental Sports and Entertainment (MSE) has announced a leadership restructuring. Zach Leonsis has been named President and Vice Chairman, a newly created pos...
17/09/2026
CP Communications has been named Best of Florida for Audio-Visual Services, and its subsidiary Red House Streaming has been named Best Movie and Recording Studi...
17/09/2026
Scripps Sports and ION have announced a broadcast partnership for the Shriners Children's East-West Bowl, the nation's oldest college all-star football ...
17/09/2026
The 17th annual espnW: Women + Sports Summit, presented by Toyota, will take place October 14-16 at the Ojai Valley Inn in Ojai, California, with virtual attend...
17/09/2026
The Professional Audio Manufacturers Alliance (PAMA) and Shure Incorporated have...
17/09/2026
Lithuanian broadcaster LNK Group has completed a migration of playout and media management for its five national television networks - LNK, BTV, TV1, InfoTV, an...