Originally published by UC Research and Innovation on October 30, 2024
By Janet Byron

By Janet Byron
Farmworkers are among the Californians most vulnerable to climate change. That’s especially true for those toiling in California’s semiarid Imperial Valley.
“We have extreme heat, up to 120 degrees in the summer,” says Briana Sugey Toji. Toji is a promotora, or community health worker, who works with farmworkers for the nonprofit Líderes Campesinas. Toji and colleague Ana Solorio have lived in Brawley, an irrigated farming area south of the Salton Sea, for most of their lives, and Solorio has worked in the fields herself. But when the two visited farmworkers to help recruit for a UC-funded climate study, they were both stunned by just how hot it was out in the fields.
“We were suffering from the heat and we were only out there for an hour,” Solorio says. “They are out there for 8 to 12 hours a day.”
Multiple studies funded by the California Climate Action Seed Grant program are developing interventions to improve farmworker health in the face of climate crises. One project, led by San Diego State University assistant professor Nicolas Lopez-Galvez, is working with community organizations such as Líderas Campesinas to study the health impacts of heat stress and chemical exposures among farmworkers in the Imperial Valley.
Maria F. of Brawley has worked as a farmworker for about 14 years among all kinds of California crops, including dates, figs, lettuce, onions, cilantro, olives, grapes, cabbage, garlic, and broccoli. “The heat and the humidity this year have been stronger than in past years and it’s affecting agriculture,“ Maria F. says. “The heat makes me feel weaker and more tired.”
She is participating in Lopez-Galvez’s research, she says, because “Líderes Campesinos cares about agricultural workers and learning about their experiences, and I like going to the information meetings.”

A second project led by Matthew Sparke, UC Santa Cruz politics professor and co-director of the Global and Community Health Program, aims to empower farmworkers to protect themselves with knowledge of farm and environmental conditions, worker protections, and health information.
Funding for the projects comes from $100 million allocated by the state legislature to the University of California to invest in research across the state supporting community climate resilience. Both projects also received a $20,000 Community-Engaged S/Hero Supplement, which engages research teams in workshops to share best practices and provide leadership, resources, and mentoring on community engagement.
“These projects were meant to actually address problems faced by the most-vulnerable Californians and not be just traditional research that creates academic articles,” Sparke says. “We’re meant to make meaningful interventions that protect people.”
Heat vulnerability
Farmworkers already struggle to eke out a living in California. A 2022 UC Merced survey found that the average California farmworker’s income was less than $22,000 per year; about two-thirds fear deportation and have difficulties paying for food and household expenses; and half did not have health insurance during the previous year.
Climate change adds a host of health risks to their plight. For example, extreme heat increases the risk of dehydration and kidney disease. When the body’s core temperature rises to dangerous levels, heat cramps, heat exhaustion, and heat stroke can ensue. More agricultural workers die from such heat-related illnesses—and 20 times more frequently—than any other U.S. occupation.
“We see climate change impacts in these communities in relation to an already existing set of social, economic, and political vulnerabilities that range from chronic poverty, job insecurity, the constant threat of deportation, cultural marginalization, and exclusion from many health care services,” Sparke says.
Meanwhile, wildfire smoke can result in lung damage and inflammation in outdoor workers, while diminished water quality increases risk of exposure to carcinogens. Flood damage and crop failures that put farmworkers’ livelihoods at risk can in turn lead to mental health problems such as stress, anxiety, and depression.
Higher temperatures also make it easier for toxic airborne chemicals to volatilize, increasing farmworker exposures, Lopez-Galvez says. “When it’s hot, you tend to breathe heavier, your lungs expand, you sweat more, and your pores are open, so there’s definitely a lot more chances to be exposed to these toxic chemicals, many of which are potential carcinogens or have been linked to reduced cognitive functioning.”

Empowering farmworkers
Sparke’s two-year, $2 million Climate Action project aims to share information and advice on protections through community health workers and support farmworkers to know and claim their rights to a safe and healthy workplace.
A key component of Sparke’s project is developing an app called Campo-Sano that farmworkers and their advocates can use to crowdsource information about problems ranging from extreme heat, to air pollution from wildfires, to water quality. The app aggregates this data from myriad state sources, and integrates it with localized housing and farmworker services information.
“It is also aimed to give farmworkers a voice by enabling them to put their experiences on the map,” Sparke says. “If enough problems show up listed by location where the incident happened, then it flags that area for people who care about these problems.”
The app can be accessed via smartphone, a technology ubiquitous among farmworkers, Sparke says. “Phones are important for them like they are for virtually all Americans, but they are absolutely critical for farmworkers because they often don’t have desktops at home and it’s a way of connecting with the community.”
In addition, Sparke’s team is developing educational outreach tools on community health protections in multiple languages. Farmworkers and employers can use these aids to identify protective measures such as wearing masks to protect against smoke, and empower employees to take advantage of required rest breaks, shade, and water on the job.
By law, California employers must provide rest breaks, shade, and good quality, cool water. But for farmworkers, access to adequate water supplies in the fields and at home may be compromised. The wells in many Central Valley towns produce low-quality or even dangerous water when toxic chemicals leach from farm fields into groundwater. In the fields, drinking water often sits in plastic barrels in the sun so it not only tastes bad but may contain harmful chemicals from their containers.
Although drinking water can help cool overheated workers, many drink less on the job to avoid the need to relieve themselves. “Farmworkers are desperate to make income from picking as many crops as possible because they’re paid by the piece, and they often refrain from taking necessary water breaks,” Sparke says. The required porta-potties (which he says are often “disgusting”) may be a long walk from where they are working.
“Many employers try to do the right thing, but others don’t,” Sparke says. “We don’t want to alienate growers but rather support those who seek to protect their workers. We hope our app will create an incentive structure where it shows areas where farmworkers’ protections are available as well as showing the ones where they are not.”

Community-centered climate research
The project brings together multiple groups interested in farmworker health. Partners include colleagues from UC Berkeley, UC Riverside, and California State University, Monterey Bay, as well as 10 community-based groups.
The community engagement aspect of Sparke’s project focuses on three “Rs”: risks, remedies, and retraining. The app will collect and share data on the health risks that farmworkers face. Farmworkers and their advocates can then use the information to develop practical remedies as well as nature-based solutions for reducing the health impacts of climate change in agriculture. Such solutions can include biocontrols for pest management, alternatives to fumigation, robotization of farm tasks, and installing drip irrigation.
The retraining component will offer tools to help farmworkers find educational options such as adult education, community college, and English as a second language classes. “There’s an interest in widening job opportunities and the roles that farmworkers can play in their communities, and providing income that will cover the times in the year when there’s less work because of climate change,” Sparke says.
The project is building regional partnerships in the Pajaro, Salinas, and San Joaquin valleys to identify strategies for improving farmworker health statewide. To foster a climate-aware workforce, project leaders are mentoring UC Santa Cruz undergraduate researchers such as Gisselle Castillo. Castillo is a premed UC Santa Cruz senior who worked in the fields around McFarland during school breaks alongside her parents and younger brother.
“I got exposed pretty early on as to what life working in the fields is like every day and learned about the intense labor and day-to-day tasks that farmworkers have to do just to be able to survive,” Castillo says.
Castillo was encouraged by one of Sparke’s co-investigators, UC Santa Cruz Molecular, Cell, and Developmental Biology Professor Grant Hartzog, to help develop a climate change curriculum for community health workers.
“I was instantly drawn to it because I wanted to start getting involved in research and this is research that I can relate to,” Castillo says. “A lot of these people don’t have the proper medications or the health care that they need. I hope one day to be able to give back and work in a free clinic in a low-income community like mine.”