美国国家公共电台 NPR NPR Investigation: Low-Income Urban Areas Are Often Hotter（在线收听）

ARI SHAPIRO, HOST:

In big cities across the U.S., low-income neighborhoods are hotter than wealthier ones. That's the finding of a joint investigation by NPR and the Howard Center for Investigative Journalism at the University of Maryland. As NPR's Meg Anderson reports, that heat can be deadly.

MEG ANDERSON, BYLINE: In a vacant lot in her West Baltimore neighborhood, Shakira Franklin is describing the first asthma attack she's had in nearly five years. It happened a few days earlier when temperatures hit 100 degrees.

SHAKIRA FRANKLIN: In this neighborhood, that feels like 110.

ANDERSON: For Franklin, that's a big deal. Her asthma is triggered by heat.

FRANKLIN: You know, I didn't really come outside, but I had to go to work. And before I know it, I was gasping for air.

ANDERSON: Breathing felt like trying to drink water through a pinched straw.

FRANKLIN: You're gasping at this point. You're trying to bring your air through as much as you can.

ANDERSON: She says when she drives out of her neighborhood to her job by the city's harbor, she can actually feel the breeze get cooler.

FRANKLIN: Like, I can actually feel me riding out of heat. Like, when I get to a certain place when I'm on my way, I'll turn off my air, and I'll roll my windows down to save gas.

ANDERSON: And so people know that.

FRANKLIN: Yeah. When you from this area, yeah, you know it.

ANDERSON: Franklin isn't imagining that change in temperature. Her neighborhood, Franklin Square - no relation to her name - is hotter than about two-thirds of the neighborhoods in Baltimore. It's also in one of the city's poorer areas. That's according to an analysis by NPR and the Howard Center.

Citywide in Baltimore, the hottest neighborhoods can differ by as much as 10 degrees from the coolest, and the hottest parts of the city also have higher rates of poverty. We wanted to see just how common that pattern is across the country. We mapped 97 major U.S. cities by heat and income. The vast majority have that same pattern, to varying degrees. And more than two-thirds had an even stronger link between heat and income than Baltimore did. That matters because heat can have potentially fatal consequences. And, our analysis shows, the people exposed to that extra heat in the hottest parts of town are often the city's poorest and disproportionately people of color. On top of that, cities already tend to be hotter than their rural surroundings.

BRIAN STONE: If you have less green cover, you will almost always have higher temperatures and greater exposures to heat.

ANDERSON: Brian Stone, director of the Urban Climate Lab at the Georgia Institute of Technology, says trees and green space cool the air and provide shade. Pavement, on the other hand, absorbs heat and holds it in. At night, a large city can be as much as 22 degrees warmer than its surroundings. Plus, common features of cities, like major roadways, create even more heat.

STONE: So all of the pollution that comes out of the tailpipe of our vehicles - there's also a lot of waste heat.

ANDERSON: Stone says it makes sense that low-income neighborhoods often suffer more because compared to wealthier areas, they tend to have even fewer trees, even more concrete and even more waste heat from nearby factories or highways. That means as the planet warms, the urban poor will actually experience more heat simply by virtue of where they live.

We went to the places in Baltimore where our data said it was the hottest, and residents there described oppressive summer heat.

LEE LEWIS: It's like the sun just comes in and sit right here.

HANNAH TRENT: It was so hot that you could smell the heat.

JOE BOSTON: When it's hot like it is now, most of the time, I stay in.

IANTHIA DARDEN: I can feel the wheezing coming and I need to go someplace where I know I need to get cool.

ANDERSON: That was Ianthia Darden, Joe Boston, Hannah Trent and Lee Lewis.

Living day after day in the heat isn't just uncomfortable; it can be deadly. The Howard Center obtained EMS and hospital data in Baltimore and compared it to the city's heat patterns. When the heat index reached dangerous levels last summer, EMS calls increased citywide for heat stroke. But calls also increased for chronic conditions, including several cardiovascular and respiratory conditions.

And even when controlling for income, there were differences across the city. From 2013 to 2018, Medicaid patients in Baltimore's hottest areas visited the hospital with those conditions at higher rates than Medicaid patients in the cooler areas, according to the Howard Center analysis.

AMIT CHANDRA: A lot of times, the heat played a factor in making a chronic condition acutely worse.

ANDERSON: Dr. Amit Chandra runs the emergency room at an inner-city University of Maryland hospital. He says that's especially true for heart conditions because the body has to work harder to cool off. Respiratory conditions can increase, too, because heat can actually worsen air quality. Chandra says even looking at a patient's medical records won't necessarily tell you how heat could be harming their health.

CHANDRA: We wouldn't diagnose them at the end of the day with heat exhaustion or heat stroke, necessarily, unless their temperature went up. So there's probably quite a few folks that are affected by the heat, and we're not really tracking or measuring.

ANDERSON: In the ER at Bon Secours Hospital in West Baltimore, James Batson is wheezing and unable to catch his breath.

REGINALD BROWN: How you feeling, sir?

ANDERSON: The heat index, which factors in humidity, is nearly 90 degrees.

BROWN: Mind if I take another listen to your...

JAMES BATSON: Yeah.

BROWN: ...To your chest here?

ANDERSON: Dr. Reginald Brown examines him.

BROWN: Deep breath.

ANDERSON: Batson has asthma and chronic obstructive pulmonary disorder, or COPD. He's wearing an oxygen mask over his nose and mouth.

Do you feel like your asthma and COPD gets worse in the summertime?

BATSON: Only when the humidity's high.

ANDERSON: What does that feel like?

BATSON: It just - you can't breathe. Just feel like it - chest going to bust open.

ANDERSON: He says when it's humid, he can't breathe, and it feels like his chest is going to bust open.

Most patients who come to Bon Secours Hospital are low-income, and many are underinsured. People in poverty are more vulnerable to many chronic conditions, including some that are made worse by heat. And having less money can make it harder to cool off in the first place. Air conditioning, for instance, might be a pricey luxury for a family struggling to buy groceries.

GEORGES BENJAMIN: People with money, of course, can do that a lot better than people with less money.

ANDERSON: Dr. Georges Benjamin is executive director of the American public health association.

BENJAMIN: Folks with less money - they're going to be in their one home, and they're going to have to deal with the conditions in their one home. And if they're going to be in an area where it's real hot, they're going to have to find other ways to adapt, but they can't escape it.

ANDERSON: The urban poor, already often in hotter environments and already at higher risk for health problems, will have a harder time escaping climate change.

BENJAMIN: It is the most significant public health problem that we have. It's going to be here for a long time, and it's getting worse.

ANDERSON: There are ways to cool down a city - investing in public transit, designing roofs that reflect sunlight, planting trees. In Baltimore, city officials are working on planting trees in the city's low-income neighborhoods. The neighborhood where Shakira Franklin lives has increased its tree canopy over time, but in recent years, it's still been among the city's lowest.

FRANKLIN: The city has a lot of responsibility, and I think that we would be close to the bottom of the list, to be honest.

ANDERSON: So she's not waiting. Franklin and the organization where she works as a landscaping crew supervisor are planning to build a splash park in a lot near her house.

FRANKLIN: Our kids - they deserve it. And I just feel like it's a long time coming to just have something to say that we built this here for us. This is ours.

ANDERSON: On a hot Saturday this summer, they threw a party there, complete with a pop-up water fountain for kids to cool off.

UNIDENTIFIED CHILD: Look what I can do.

ANDERSON: But worldwide heat waves are getting hotter and more frequent, and the last five years have been the hottest ever recorded.

Meg Anderson, NPR News.

SHAPIRO: You can see the 97 U.S. cities NPR mapped as part of our investigation into heat, health and income at npr.org. And our City Heat series continues tomorrow with a look at why one of the best ways to combat urban heat is also one of the most challenging to maintain - tree cover.