COVID-19 Research Spotlight: Brenda Eskenazi on Risks to California Farmworkers

By Hope Henderson | August 31, 2020

Farmworkers packing lettuce in the field in Salinas Valley, CA.

This article was originally published on the Innovative Genomics Institute website.

Brenda Eskenazi was a Professor of Public Health at UC Berkeley for 35 years, and Director of the Center for Environmental Research and Children’s Health for 22 years. Despite “retiring,” she is co-leading an IGI-funded research project, looking at COVID-19 infection rates and risks for California farmworkers. In August, she talked with IGI science writer Hope Henderson about this project.

Under normal circumstances, what does your research focus on?

I was a professor at Berkeley for 35 years. My research has been on the effects of environmental toxicants on human health. I studied the effects of pesticides on farmworker families in the Salinas Valley for close to 25 years, with a focus on child and maternal health. I’m actually retired now. I thought I was going to spend my retirement doing art!

Tell me about your COVID-19 research project.

Brenda Eskenazi, Ana María Mora, and Joseph Lewnard.

We are studying COVID-19 infections in farmworkers in the Salinas Valley, near Monterey. Right now our main goal is to assess the positivity rate in the population using qPCR diagnostic testing. The second goal is to understand what the seropositivity rate is, because we don’t know if we’re coming close to herd immunity. The third goal is have people do a very detailed questionnaire to help us identify how they may have gotten exposed. The final goal is to store blood and saliva samples to build a biorepository so that we can look at things like what makes one person develop severe disease when another is asymptomatic.

How did the project get started?

My team had done thousands of farmworker home walk-throughs. We knew the conditions people live in and work under. And we said, “This is going to be bad.”

I know everything about working with farmworkers, but nothing about infectious disease. So I called Joe and said, I need you. Can we put our heads together? And then I brought in Ana María Mora, who is a physician from Costa Rica and is also an environmental epidemiologist. She and I have studied farm working together in multiple countries. So Joe, Ana, and I formed this triumvirate and realized that we work really well together!

Will each farmworker be tested once, or are you following them over the course of time?

It’s a one-shot deal, for many reasons, including cost. It’s especially tricky just to be able to follow people when you’re dealing with a hidden population. Many farm workers are here on H-2A visas and may be going back to Mexico at the end of the season.

And we are struggling right now with the issue of trust. The clinic we are working with is very trusted, but some of the workers are undocumented, and when you say, “We’re giving you results to the County, and the County is going to call you and find out who you’ve been in contact with” —  imagine if you’re undocumented and you’re living in this administration. They don’t want to get into the system at all.

Brenda Eskenazi romping in a lettuce field in Salinas Valley, CA.

What particular COVID-19 risks does this population face?

I hypothesize that infection is mostly due to housing conditions. It’s typical to see a family in each bedroom and 12 single men on the living room floor. My students can’t afford the rent in this area — imagine if you were a poor farmworker with Silicon Valley beginning to encroach on Salinas Valley and all these wealthy people moving down further and driving up the rents higher. They don’t have much farmworker housing. So, farmworkers live in crowded conditions, which is like a Petri dish for infection.

Another hypothesis is that people working in the produce packing sheds are at higher risk because it’s indoors and they’re working closely together, versus people working or packing produce in the fields; for instance, lettuces usually get boxed in the field itself.

What is the current status of the project?

Tomorrow we’ll be going to farmworker housing to collect samples in the field for the first time. These are mostly Mexican farm workers that have come for the season legally.

The study is much more difficult than previous studies because we’re in the middle of COVID-19. First off, whenever you’re doing your human subjects research, there’s a lengthy consent form. The form is scary to a person who is not well versed in the litigious nature of the United States and things like mandated reporting. And how do you get signatures in the middle of COVID-19? We have to sterilize the pens! And we can’t do a half hour questionnaire in person anymore. But how do you reach someone over the telephone when their only number they have is an international number? There’s a lot to figure out.

I don’t have preliminary results from our study, but I can tell you the clinics we’re based in have done surveillance testing of over 5,000 people, with a positivity rate of 22 percent.

Do you have a personal connection to farm work that got you interested in studying farmworkers?

I’m from New York City. You can probably tell from my accent! And I’m from a lower income family. My sister and myself were the first generation to get educated. I’ve always worked with the people that were underdogs or the populations that are hidden, or whose voices are ignored. Whether they are children or undocumented farmworkers, that’s what public health is about.

Working with the population in the Salinas Valley, I have come to really love the people. Of course it’s a broad generalization, but seeing how they are with their children — seeing people with no money, but their children will be immaculately dressed and clean because that’s what they value. They value each other. And the values they hold are values that I keep.

COVID is bringing into light how dependent we are on each other, and how much we all depend on farmworkers. What I want to be able to say to policymakers is that it’s time: we have to have good farmworker housing. Being an eternal optimist, I think this gives us a chance to shed the light on these complex interrelationships and maybe in a way that allows us to problem solve in a more cooperative fashion.