Connecting the dots between redlining and heat resilience in Phoenix

ASU's Knowledge Exchange for Resilience examines how the historical legacy of redlining affects communities’ vulnerability to extreme temperatures

June 22, 2021

Juneteenth — now a federal holiday — commemorates the end of slavery in America. But the historical events that followed, ushering in an era of Jim Crow laws and redlining across the country, impacted our cities and towns substantially and are reflected in our present-day experiences in urban spaces.  

In many cities, people can tell when they have entered a low-income neighborhood. They can tell by the quality of the roads, the lack of grocery stores and, particularly in redlined neighborhoods, a higher percentage of people of color. Historical map of redlining in Phoenix Historical map of redlining in Phoenix, made available by the University of Richmond. Download Full Image

Here in the Phoenix metro area, such neighborhoods also are marked by a lack of trees, disinvestment in infrastructure and deadly health consequences.

With Arizona experiencing its hottest summer on record last year, identifying heat-mitigation strategies and solutions is already a complex issue, and the lasting effects of racially based redlining implemented throughout the 20th century only add to its complexity.

Redlining was the practice of denying loans to people of color and low-income individuals based on the financial risk of the area where they chose to live. Essentially, this process aided in the active separation of races during segregation.

On the Mapping Inequality: Redlining in New Deal America website, a map of Phoenix shows how the city’s neighborhoods were categorized by lenders in 1940. One of the “hazardous” areas it highlights is section D4, described at the time as being“very ragged, occupied by Mexicans, Negroes and the low class of white people. There is no sale for property herein.” In another section, the original mapmakers wrote “in the Negro section are some very good homes, considering their occupancy by colored people.”

Map of Phoenix neighborhoods that were historically redlined

Created by ASU’s Knowledge Exchange for Resilience (KER), this map overlays historically redlined areas onto modern-day Phoenix. It is based on a historical map of redlining in the city made available by the University of Richmond’s Digital Scholarship Lab.

While redlining is no longer legal, the legacy of this practice in Phoenix and across the country makes finding thermal justice solutions a priority.

Very often redlined areas had less infrastructure investment, fewer green spaces and fewer resources overall, leading to those areas being disproportionately harder hit by extreme heat.

ASU researchers are using spatial data and partnerships to work toward heat equity for all people.

Patricia Solis, executive director of the Knowledge Exchange for Resilience (KER) at Arizona State University, convenes efforts across ASU and with community partners to address heat resilience.

“When you have hundreds of deaths every year, that’s like a (Hurricane) Katrina every year,” Solis said. “It is so slow-moving, and chronic, and spread out all over the city; you see the storm coming, and you know exactly where it’s going to hit.” 

The Utility Assistance Network led by Wildfire, an advocacy group aimed at ending poverty, asked KER to examine vulnerable communities in order to better offer services and ultimately save lives.

Solis and her team began by mapping and formulating a rich dataset. By linking heat-associated deaths, state programs, cooling centers, utility bills and more, Solis discovered that people who live in mobile homes were disproportionately affected by extreme heat. 

“When you map it, you can see it clearly,” Solis said. “... The type of housing matters. Are they living in a single-family home, or are they living in a mobile home? An older mobile home? You can have the same income, but your housing structure and the site where it is plays a big factor in determining your exposure to that heat.”

Additionally, people who work in a job that exposes them to the outdoors, such as construction and landscaping, are often excessively exposed to heat. People experiencing homelessness are also especially vulnerable.

“There was a spike in outdoor heat deaths last year,” Solis said. “And if you look at the demographics, Black men aged 50–60 are extremely overrepresented among people experiencing homelessness. There are also lower-income immigrant communities or people who don’t speak English as a first language who live in housing that may not be heat resilient. Native Americans here in Arizona are also very overrepresented in terms of health outcomes for heat.” 

Many of the places where minority and economically disadvantaged communities reside in Phoenix coincide with historically redlined neighborhoods, where the legacy of disinvestment continues. This coincides with higher land surface temperatures given housing and infrastructure differences.

Map of land surface temperatures and redlining in Phoenix

In Phoenix, areas that were historically redlined today experience some of the highest land surface temperatures in the city. Map courtesy of KER

Exposure to higher temperatures in the built environment can lead to greater risk for heat-related illness.

According to Melissa Guardaro, assistant research professor with KER and co-leader of the Arizona Heat Preparedness and Resilience Workgroup (AHPRW), evidence of the correlation between socioeconomically disadvantaged communities and heat-related deaths in the Phoenix area is evident through the historical side effects of redlining. 

“Redlining has created a historical legacy of underspending in the area,” Guardaro said. “You can just see it. … You can just drive through the different neighborhoods and see the difference in tree plantings and public spaces for cooling. It is starkly apparent.”

Map of heat-related illnesses compared to historically redlined areas

Present-day heat-related illnesses (yellow) among the population (gray) living now in the historically redlined neighborhoods of Phoenix (red). Much of the area around Buckeye Road has since been depopulated given the proximity of Phoenix Sky Harbor International Airport to the east. Data from Maricopa County Department of Public Health, various years.

The AHPRW sprung into existence when de facto cooling centers and public spaces like libraries, movie theaters and community centers abruptly closed during COVID-19. The group worked to try to open more cooling centers in neighborhoods that needed it the most.

Through the use of an optimization map, the team connects factors such as age, socioeconomic status, percent of greenness in the area and past heat mortality and morbidity statistics to figure out where the most vulnerable people are. This process allows groups such as the Arizona Faith Network to fill in the gaps to ensure cooling centers and hydration stations are available.

Though this work is essential, Guardaro says public officials also have a role to play.

“I think that local officials should use a data-driven approach to where they prioritize cooling, spending and heat-mitigation adaptation programs,” Guardaro said. “And if you’re trying to decrease deaths and heat mortality and morbidity, you need to disproportionately spend in those communities that have a lesser tree canopy, that rely on public transportation and where children who are walking to school are not taking the bus or being transported.”

There are intersecting systems contributing to the lack of thermal justice and hope for future reform. 

“You’ve got the housing system, the energy system, infrastructure, trees and then this historical legacy of redlining,” Solis said. “Not only do you have to solve the present problem, but you have to somehow overcome disinvestment, and in some cases the active lack of investment historically.”

Still, there is cause to hope.

“Phoenix is a case of how people are thriving in a very hot city,” Guardaro said. “We need to be really hopeful that we can beat this and that we can learn to thrive with urban heat and at the same time try to lower the number of deaths.”

As the heat season resumes, recognizing where history meets the present can provide a map for where to invest in solutions like infrastructure and housing improvements. By addressing current needs in urban spaces for the most vulnerable, a community can increase the potential for recovering from some of the long-lasting effects of racially based redlining.

Elise Miller

Written by Elise Miller,
freelance journalist and activist

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A nomad finds a home in viruses

June 22, 2021

ASU virologist Arvind Varsani pursues research of all kinds on all continents

When Arvind Varsani arrived in the Antarctica for the first time a decade ago, he noted that the world looked black and white — from the sheet ice to the sky to the snippets of Earth peeking out from under the snow-covered mountains. That is, with the exception of an oversized vermilion bus that ferried him and other researchers to a nearby camp. The sounds of a wind farm and heavy machinery reverberated.

“It was a very surreal experience,” Varsani recalled.

So was the spectacle of thousands of penguins gathered in nearby Cape Crozier for breeding season. Their sounds replaced the din of the camp, and so did their smell, the smell of guano, at least for a while.

“Once you’ve been there for a while, you don’t think about that smell again,” Varsani said.

“But you can’t ignore the sounds the penguins emit during breeding season. It’s a constant cacophony of calling and squeaking that can be heard from as far as a kilometer away (0.6 miles).” 

The penguins try to breed in the same place every year and identify “who’s who” through their calls, Varsani explained. Penguin parents recognize their offspring by the sound of their squeaks. Afterall, the chicks look alike, a veritable sea of fluffy gray bodies waddling about.

Varsani made his first journey to Antarctica from his lab in New Zealand to find out why penguin chicks were losing their feathers. He knew of a virus, a circovirus, that similarly affected parrots. Could it be possible that a related pathogen was responsible for this disorder in penguin chicks?  

A nomad gone viral

Varsani calls himself a “nomadic 'viral' scientist,” both in person and on Twitter. He also calls himself an adventurer, and with good reason. To date, he has pursued research of all kinds on all seven continents.

Born and raised in Kenya, Varsani moved to England to pursue his undergraduate studies, then he headed to South Africa to pursue his doctoral degree in molecular and cell biology. Later, he accepted a faculty position in New Zealand, making him the department’s lone virologist. Now, he calls Arizona State University home, where he’s an associate professor in the School of Life Sciences. He said that he chose ASU for its intellectual stimulation and for its respect for interdisciplinary research.

In addition to studying the aforementioned penguins, Varsani has studied cactus, maize, blueberries, geese, fish, microbiomes, good viruses, bad viruses, gila monsters, brains, bees, beetles, dolphins, seals, whiteflies, parrots, pigeons and marmots.

He encountered marmots years ago while investigating tiny viruses in their feces. He says that if you happen to be hiking in Colorado or the Pacific Northwest, you’re apt to hear chirping and whistling coming from the rocky outcrops. That whistling and chirping are the marmots who are putting up a racket to alert their neighbors of impending disaster.

“They’re pretty cute,” Varsani said. “They have a bit of an overbite. They’re like big rodents with a little bit of character. They hang out in the daisies during the spring bloom. It reminds one of being back in the ‘60s.”

Varsani acknowledges that he has a keen interest in psychology, which has had him thinking about whether and how certain viruses rewire the brain. (Yes, they do. Rabies is a classic example, he said.) He currently studies viruses in ecosystems. His research group is unique in that they don’t work on one thing at a time but in parallel with multiple projects related to virus ecology and evolutions across the spectrum, from tropics to polar regions and from plants to animals and bacteria.

Varsani attributes his diverse interests and explorations to growing up with limited resources, both as a child and as a young researcher. But it was his parents who emphasized that education was “the best thing you can ever get in life,” he said.

“When I was stationed in South Africa, a really big name in virus research came out to a conference that I had helped organize there. He said, ‘Listen, Arvind, you’re too broad in your research. You need to focus on one thing and one key question.’ But in different parts of the world, the resources aren’t there to do this.”

As an undergraduate, Varsani said he read “a lot of books about viruses,” and later worked on designing human papillomavirus vaccines with an aim to produce them cheaply in plants. Plant-infecting viruses can be used to produce a lot of these vaccines. 

As a new faculty member at University of Canterbury in Christchurch, New Zealand, Varsani happily and necessarily collaborated with scientists in other fields, like zoologists, geologists, ecologists and freshwater biologists.

“Being the only virologist there meant that I had to interact with other people,” he explained. “You look at your environment and you adapt. That’s the best thing you can do. Thinking of viruses from an evolutionary angle just kicked in.”

Much like the viruses Varsani was studying, he began adapting, too.

He explained that you can’t study just one virus and apply its traits to all the other viruses out there. And there are a lot of viruses out there, on land and water. Varsani himself has identified thousands so far in his career.

It should be noted that as abundant as bacteria are, viruses have them beat. There are ten times more viruses than bacteria, and oceans are teeming with both.

And humans? “We ourselves are an ecosystem of bacteria and human cells, given what we know about our gut system,” Varsani said.

So, how much of us are viruses? “Nobody has figured that out, but it would probably be 10 times the amount as the bacteria.”

Varsani acknowledges that the notion of being composed of 90% bacteria, and who knows how many viruses, is an unsavory one. But he said that’s because of the narrow way we think about them.

Viruses doing good

“We’ve always had this negative connotation of viruses because we study them from the disease side of things,” he said. “We study diseases in things we care dearly about. But if all viruses caused disease that were fatal, then there would be no organisms living on the planet today. So, they must be doing something right.”

And indeed, they do. Varsani will be the first to tell you so. Viruses will protect bacteria by infiltrating their chromosomes. That, in turn, will alter the physiology of the outer surface of the bacteria so intruders can’t get inside the bacteria and harm them. 

“There are many beautiful examples of good viruses,” Varsani said.

One of his favorite examples can be found in Wyoming’s Yellowstone National Park and involves a grass that can grow in temperatures as high as 55 degrees Celsius (131 Fahrenheit).

“What’s beautiful about that grass is that it’s infected by a fungus, and the fungus is infected by a virus,” Varsani said.

The fungus “rewires” the grass’s physiology allowing it to tolerate extreme soil temperatures often found in geyser basins.

“If you take the virus away, the fungus grows rapidly and kills the grass,” Varsani explained. “But the virus modulates the fungus’s growth, so the fungus can help the grass tolerate the high soil temperature. That is beautiful.”

When asked whether he has a favorite virus, Varsani pauses.

“Everyone asks me that. It’s kind of difficult to have a favorite virus when they’re all so unique and amazing.”

To be sure, viruses come in different forms, different sizes and different shapes. They’re beautiful and diverse.

“They constantly keep you on your toes,” he said.

Varsani described a type of virus that operates in groups of eight. That is, eight parts of the virus, which are all independent, come together to cause an infection. 

“They deliver segments of the virus to different parts of the plant, and then they come together to operate as one,” Varsani explained. “You can even get into philosophical discussions about cooperation in these pathogens. What about conflict? If you have a co-infection with five different viruses, do they come together to interact with one another?”

The answer is yes, at least when it comes to HIV and the herpesviruses, Varsani said. Herpesvirus infections can suppress HIV infection and, in mice, have been shown to protect against some bacterial infections.

arvind in the lab

Arvind Varsani (pictured in his lab) looks foward to getting out into the field after the pandemic. In the meantime, his lab is still carrying on studying the Antarctica viruses from afar. Photo by Deanna Dent/ASU News

Viruses and a changing climate

However, when it comes to climate change and increasing levels of carbon dioxide, some viruses have been found to replicate more efficiently than normal, Varsani said. Researchers are also looking at whether insects that fare better in warmer, more carbon dioxide-rich environments will be better able to transmit viruses more easily and at a higher rate, for better or worse.

What’s more, climate change has reduced breeding grounds for animals, including the Antarctic. Animals now are being forced into new territories and have to fight for that territory, which has been occupied by other animals that arrived before them.

“That also means there’s an increase in conflict, and we know that when you’re stressed, your immune system slightly declines,” Varsani said. “You’re in close contact, and species that have not traditionally come into contact with one another now are. So, it increases the chances that viruses can jump from one species to another.”

But scientists know little yet about how virus transmission works in the Antarctic. So, Varsani and his colleagues put together an assessment about the risk of COVID-19 there, taking into account both research and tourism activities. The assessment was published earlier this year.

They found that seals and birds seem to have a lower risk of becoming infected with the virus. But it’s the tourists and wildlife researchers who pose the greatest risk of transmitting the virus to Antarctic fauna. The researchers are recommending SARS-CoV-2/COVID-19 testing and robust sanitation practices to reduce the risk to the area’s fauna.

Meanwhile, Varsani is readying for the COVID-19 pandemic to wane so he can head out into the field again. In the meantime, his lab is still carrying on studying the Antarctica viruses from afar.

“There are so many projects to do, the excitement never runs out.”

Top photos by Deanna Dent/ASU News