In July of 1995, something unprecedented went down in Chicago–
a heat wave that ground the entire city to a halt.
The heat index, which measures how the temperature feels to us,
jumped to a record-setting 126 degrees Fahrenheit.
Chicago was unprepared. As residents cranked up their air conditioning,
the spike in electrical use led to power outages across the city.
Cars broke down and the city’s emergency response units were overwhelmed.
Ambulance services sometimes took two hours to arrive on the scene,
and then had trouble finding somewhere to take people
because hospitals were full and closing their doors to new patients.
The oppressive heat lasted about a week and it’s estimated
that up to 739 Chicago residents lost their lives from heat-related complications.
But follow-up reporting revealed that the impact wasn’t random.
A map of deaths showed that the communities most affected
were those that suffered from a lack of infrastructure and community resources,
mostly in the south and west of the city. 25 years later, Chicago found itself staring down
a different headline-grabbing crisis: the COVID-19 pandemic.
Early in the pandemic, a local news station in Chicago analyzed the number of covid deaths
in different neighborhoods across the city, and an interesting trend appeared.
The map that emerged showed similarities to the map
of Chicago’s death toll from the 1995 heat wave.
These maps describe two distinct health outcomes at two different moments 25 years apart.
Yet the story they tell is the same: people who live in certain neighborhoods
have faced measurably worse health outcomes than those in other neighborhoods.
To help understand why, we need to look at the role that our environment plays
in determining our health.
Hi, I’m Vanessa Hill and this is Crash Course Public Health!
[INTRO MUSIC]
We often think of our environment as the world outside our bodies.
Like, we think of ourselves as being in an environment.
Where our skin stops, our environment begins.
But we don’t always consider the ways that our environment is sort of part of our bodies.
Sure, my body is mainly made up of...me.
But all that oxygen and water that my body depends on comes from somewhere.
Our bodies are biological machines built to turn our environments into stuff we need to survive.
It’s what bodies do!
But when that environment becomes contaminated or conditions become too extreme,
our health may be put in jeopardy. The environmental factors that
affect our health outcomes are what we are calling the
environmental determinants of health. We can divide these
determinants into two major categories: the ones related to our natural environment,
and the ones related to our built environment.
Our natural environment is all that non-human-made stuff around us,
like forests and mountains. On the other hand, our built environment
is the environment we tend to think of as “human-made,” like our homes, streets,
or even miniature golf courses! When thinking about our environment,
public health experts generally consider how our built and natural environments
come together to influence a population’s overall health.
For example, while we know that the air we breathe and the water we drink aren’t human-made,
we can recognize that they are human-influenced!
Like, if we take a deep breath of air, we’re mostly breathing in nitrogen and oxygen;
but not only those things. A closer look reveals there’s a whole bunch
of other stuff in that breath, too. Air pollution is the stuff in the air
that is harmful to the health of both humans and the planet.
One major airborne pollutant on our public health radar is particulate matter, or PM.
These are particles like dust or smoke that are too small to be seen with the naked eye,
and can come from things like car exhausts and construction sites.
This is small enough to work its way into our lungs or even infiltrate our bloodstream.
The smallest of these particles can be 30 times thinner than a strand of human hair.
And it turns out when you’re that small and light,
you can hang around in the air for weeks at a time, sometimes traveling hundreds of miles.
Which is how smoke from a wildfire in California can travel over
2,000 miles to New York City, affecting the air quality across the U.S.
Now, when we picture air pollution, we tend to imagine cities full of
gas-guzzling cars and smoke-spewing factories. But air pollution can come from other,
less expected sources that aren’t right outside our front door.
One review found that, because of traffic-related pollution like car emissions,
children living as far as 500 meters, or about a third of a mile, of a busy road
can experience negative health outcomes, like exacerbated asthma.
The same report estimated that as much as 45%
of people in large cities in North America live within that distance from a busy road.
And the World Health Organization reports that 99% of the global population
breathes air that exceeds their guideline limits for outdoor air pollution,
which contributes to as many as 4.2 million deaths every year.
And air pollution isn’t just outdoors. It’s in our homes, too!
Some of that can come from outside elements coming in,
but some of it is introduced by the activities done inside our homes.
As we cook and clean, we’re actually introducing potentially harmful particles
and chemical compounds into the air, which can hang around long enough
to eventually work their ways into our bodies.
Gas-based cooking is one of the biggest culprits, because it releases things like smoke particles
and carbon dioxide that can stick around our homes.
Even baking a cake in a gas oven can emit up to double the levels
of the potentially dangerous gas nitrogen dioxide than US regulators
like the EPA consider safe for our lungs. Then there’s the problem of water.
You might have heard of it. It’s, you know, most of what you are.
Like air, water is part of our natural environment.
But the systems we’ve developed to deliver water to our homes,
like plumbing, come with their own set of risks.
Water pollution happens when our water supply becomes contaminated
with harmful substances. Some forms of water pollution feel pretty obvious,
like a Coca-Cola can bobbing down a river
or the oil spill in the Gulf of Mexico back in 2010.
But others aren’t so obvious, like when lead leaches out from our pipes
and into our drinking water, or when fertilizer runs off into a river.
When it comes to our water supply, one of the major pollutants that have
public health experts on high alert are per- and polyfluoroalkyl substances, or PFAS.
Sometimes called “forever chemicals,” these man-made pollutants have a super strong
chemical make-up that prevents them from breaking down naturally in the environment.
Over time, these chemicals can seep into groundwater,
eventually working their way into our drinking water.
And because they’re tough to break down, many household water filters struggle
to totally eliminate these chemicals from our water supply.
There’s a lot we still need to learn about the long-term effects of PFAS on the human body.
But early findings suggest that PFAS could trigger negative health outcomes
ranging from altered brain development to cancer.
More than 4,500 of these chemicals are currently used around the world,
in everything from non-stick pans to firefighting foam.
Now, when it comes to predicting and improving the health of a population,
one of the biggest factors to consider is the environment in which our homes exist:
our neighborhoods. For instance, we know that some people living in the West End of Chicago
had it worse than others during the 1995 heat wave,
but it wasn't the same in every neighborhood in that area.
Let's go to the Thought Bubble to see why.
In 2002, American sociologist and urban studies expert Eric Klinenberg published a book
comparing two neighborhoods impacted by the heat wave: North Lawndale and South Lawndale.
Both neighborhoods had similar populations of elderly people as well as similar levels of
people living in poverty–which are factors associated with higher heat-related deaths.
But when Klinenberg looked at the heat-related deaths in the two neighborhoods, he found that
North Lawndale experienced heat-related deaths at a rate 10 times higher than South Lawndale.
Compared to South Lawndale, North Lawndale had significantly more abandoned buildings,
empty lots, and shuttered storefronts. Fewer community buildings
like banks and grocery stores meant that
residents without air conditioners in their homes likely had difficulty locating air conditioning
in public places to find relief from the heat. In addition, North Lawndale had sidewalks
that were in far worse condition than South Lawndale,
which suggested that older residents who don’t drive
might have been reluctant to leave their homes for fear of falling while walking,
or unable to leave their homes because damaged sidewalks can be impossible
to navigate with a wheelchair. North Lawndale also had higher rates of violent crime,
which may have meant that residents were less likely to leave their homes
for fear of robbery while they were away. They were also less likely to crack open
the windows or sleep outside -- strategies that might’ve helped them cope with the heat wave.
These infrastructure challenges and high rates of violent crime also had social implications
that came into play during the heat wave. The absence of a connected community
meant that residents had fewer opportunities to build connections with their neighbors.
This lack of social cohesion put the residents at risk of severe social isolation, and made them
less likely to have a social network that they could lean on during the heat wave.
Faced with a lack of suitable options, residents remained in the sweltering heat of their homes.
And for many, this proved deadly. Thanks, Thought Bubble.
So there’s no escaping the influence our environment has on our health.
But we do have some say in how we manage and build our environments–
and in who those environments protect. Decades of studies have found that
marginalized and low-income populations are disproportionately exposed to environmental
pollutions, often because they don’t have the support from their government
or communities to escape or improve their environments, and because their communities
are often targets for things like hazardous waste sites. Enter: environmental justice!
American environmental justice activist Dr. Robert Bullard defines environmental justice
as the principle that “all people and communities are entitled to equal protection of environmental
and public health laws and regulations.” In short, the environmental justice movement
calls for us to address our shared history of racism, exploitation, and segregation
to create an environment that’s healthy for everyone. And just to be clear, this
means improving environments everywhere. Environmental justice also demands
that we find solutions for these unfair and preventable differences in health outcomes.
Not tomorrow. Not eventually. Right. Now.
What makes the environmental justice movement so urgent is climate change,
one of the biggest challenges facing our planet. Climate change is the change in average weather patterns
in a region over a long period of time. In the last two centuries alone, human activity
and growth has caused our climate to change at a faster pace than it has even in the
last 65 million years. In fact, the Union of Concerned Scientists estimates that
if humans continue to alter the climate at the rate we are now, we could see events
like that Chicago heat wave as often as three times per year by the end of the century.
Now, climate change is a global problem, and it affects all of us. But its effects
will always weigh most heavily on communities
not equipped with the same tools and support as others.
These are often groups that have ancestral ties to a particular location, who can’t afford
to relocate, or who face other health challenges on top of the ones presented by their environment.
The good news here is that today, public health researchers are working to make the environment
work for our health–not against it. Policymakers can work with scientists to create regulations
around what we put into our water and air. Communities can invest in cooling stations
and community centers where people can cool off on a hot summer day.
But maybe most importantly, we can continue to better understand and address the parts of
our society that make the environmental determinants of health
affect us unequally in the first place–
namely, the social determinants of health. More on that in the next episode.
Thanks for watching this episode of Crash Course Public Health,
which was produced by Complexly in partnership with the American Public Health Association.
If you want to learn even more about Public Health, head over to APHA’s YouTube channel
to watch “That’s Public Health” a series created by APHA and Complexly.
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