
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 ...
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...
06/09/2026
June 9 2026, 23:00 (PDT) Dolby and MagentaTV Bring Fans Closer to the FIFA Worl...
04/08/2026
Dalet, a leading technology and service provider for media-rich organizations, t...
01/08/2026
Latest free Vaults instrument released
The Crow Hill Company's Vaults collection offers a continually rotating selection of virtual instruments and samp...
01/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
01/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
01/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
01/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
01/08/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
01/08/2026
COW Jobs: Lead Generation Representative - Animation Services
Brie Clayton July 31, 2026
0 Comments
Lead Generation Representative - Animation Service...
01/08/2026
Emilie Lowe Shoots Award Winning Short Film Where Dead Things Grow with Blackmag...
01/08/2026
Early Registration Opens for the 2026 SMPTE Media Technology Summit
Brie Clayton July 31, 2026
0 Comments
Initial Program Announced Alongside New Medi...
31/07/2026
With an emphasis on local, the league is looking beyond the initial four teams t...
31/07/2026
The 2026 Sundance Institute Directors Lab fellows in Estes Park, Colorado (Photo by Gabe Rovick)
Dear Friends,
This has been an extraordinary year for our ar...
31/07/2026
Offers 360-degree sound placement in any DAW
Audiocube have just announced the launch of a new plug-in that embeds a complete 3D acoustic environment inside...
31/07/2026
10 new Chinese C-Pop voices introduced
While Sonarworks are best known to many for their room-correction software, their product range also includes an inno...
31/07/2026
Reimagines the vintage BBD sound character
PSPaudioware have now officially launched the new delay plug-in that they were previewing at GearExpo UK. Said to...
31/07/2026
The Savannah Bananas has built its reputation on refusing to play baseball by traditional rules, and the team's production arm Banana Ball TV (BTV) has draf...
31/07/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
31/07/2026
SMPTE, the home for media professionals, technologists and engineers, today opened early registration for the 2026 Media Technology Summit (MTS) and announced i...
31/07/2026
Clear-Com announced that Central Christian Church has transformed communication across its live production operations by implementing Clear-Com's LQ Seri...
31/07/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
31/07/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
31/07/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
31/07/2026
IBC has unveiled the finalists for the IBC2026 Innovation Awards, recognising collaborative projects from around the world that solve real-world challenges and ...
31/07/2026
From focus puller to colourist
Caroline Shawley July 30, 2026
0 Comments
Ana Mar a Ormaza shares her story of instinct, storytelling and finding a cre...
31/07/2026
Amazon Prime Documentary Andata e Ritorno Relies on Blackmagic Design
Brie Clayton July 30, 2026
0 Comments
DaVinci Resolve Studio and Blackmagic Clou...
31/07/2026
Krotos Launches Video to Sound Plugin for DaVinci Resolve
Brie Clayton July 30, 2026
0 Comments
AI-assisted workflow helps editors add synchronized, p...
31/07/2026
Athletics, Camogie, the Dublin Horse Show, the FAI Cup, Golf, Hockey, the UEFA C...
31/07/2026
Luxembourg, July 31, 2026 - Pursuant to the liquidity contract entered into by SES with BNP Paribas as of 7 April 2026, please see the below update on the progr...
31/07/2026
Luxembourg, July 31, 2026 - SES today published a restatement of its FY2025 EU Taxonomy (Article 8) disclosure. The restatement updates the FY2025 EU Taxonomy d...
31/07/2026
RT Commercial has today announced Mercedes-Benz Ireland will return as the offi...
31/07/2026
RT Supporting the Arts is delighted to spotlight a diverse range of arts, culture and heritage events taking place across Ireland this August. From major festi...
30/07/2026
CP Communications provided RF audio, RF video, communications, RF coordination, ...
30/07/2026
OpenDrives has been included in CRN's 2026 Storage 100 list in the Software-Defined Storage category. The annual list, selected by the CRN editorial team, r...
30/07/2026
LATAM Airlines has selected SES to provide multi-orbit inflight connectivity to its fleet of Airbus and Embraer aircraft. More than 60 aircraft - including Airb...
30/07/2026
Tagboard has launched the Producer API, an open interface that allows key commands in Tagboard's live production environment to be triggered from external d...
30/07/2026
FOX Sports and the New York Racing Association (NYRA) have announced a multi-year agreement with Del Mar Thoroughbred Club that will make FOX Sports the exclusi...
30/07/2026
ABC Commercial has launched four free ad-supported streaming television (FAST) channels on LG Smart TVs across North America, Great Britain, and select countrie...
30/07/2026
The Six Kings Slam exhibition tennis tournament will return to Riyadh on October 21, 22, and 24, streaming live on Netflix at no additional cost to subscribers....
30/07/2026
Central Christian Church in Mt. Vernon, Illinois has deployed Clear-Com's LQ...
30/07/2026
Blackmagic Design has released the UltraStudio Express 3G family, a pair of USB4 capture and playback devices compatible with Mac, Windows, and Linux computers ...
30/07/2026
ESPN has reached a media rights agreement with the Women's Pro Baseball League (WPBL), making ESPN the national streaming home of the league's 2026 seas...
30/07/2026
Most Valuable Promotions (MVP) and the Professional Fighters League (PFL) have announced a merger that will operate under the MVP banner. PFL CEO John Martin wi...
30/07/2026
The Columbus Blue Jackets will simulcast all game broadcasts across television and radio beginning with the 2026-27 NHL season. Under the new format, the televi...
30/07/2026
TMRW Sports has selected Populous as architect for a purpose-built stadium for its professional flag football league, being developed in partnership with the NF...
30/07/2026
SiriusXM has announced SiriusXM Sports Pass, a new subscription plan launching September 1 that bundles the company's sports audio programming into a single...
30/07/2026
Leagues, broadcasters, and technologists gather to tackle cloud economics, distr...
30/07/2026
A major player in the cloud-based solutions, Amazon Web Services (AWS) has conti...