A Hotter Planet Takes Another Toll on Human Health
A new hypothesis about heat waves, redlining, and kidney stones.
Shortly after the New Year, the Washington Post ran a story with a headline that would have seemed inexplicable, even runic, to most readers just a few years ago: “The world’s torrid future is etched in the crippled kidneys of Nepali workers.” But we’re growing used to the idea that the climate crisis, in Naomi Klein’s phrase, “changes everything,” so why not the internal organs of Nepalis? Remarkable reporting by Gerry Shih tells a series of unbearably poignant tales: young Nepali men, struggling to earn a living in their impoverished homeland, head to the Gulf states to do construction work in the searing heat, some without access to sufficient water, some until they collapse. (Other reporting also shows that some Nepalis who work abroad resort to the black market for a transplant that might keep them—and the families that depend on the money they earn—alive.) The piece ends with a man coming back to the care of his sister, who donates her own kidney to save him. The costs of the medical procedures require that he sell his half-built house, and that he give up his life’s dream, which was to get married.
The Post was right: the world’s future is likely encapsulated in this story. The planet is getting steadily hotter, and large swaths of it are moving past the point at which it’s safe to do heavy outside labor in the middle of the day. A 2022 study estimated that six hundred and seventy-seven billion working hours a year were already being lost because it’s too hot to go outside and build things or farm. The researchers assessed the cost at more than two trillion dollars annually, but, of course, it could also be measured in other units—in vital organs, or dreams.
But it’s not just the future that’s illuminated by such studies; it’s the past as well. Unless you’ve been keeping up with your issues of Current Opinion in Nephrology and Hypertension, you may have missed a recent article titled “Redlining has led to increasing rates of nephrolithiasis in minoritized populations: a hypothesis.” I saw it only because one of the medical experts who wrote it—David Goldfarb, who runs the dialysis unit at New York’s V.A. hospital and teaches at New York University’s School of Medicine—is an old family friend. He forwarded it to me, and it fairly blew my mind.
“Nephrolithiasis” is the technical term for the development of kidney stones, those small formations that, as they pass, can cause excruciating pain. (I’ve never had them, but I know more than one man who has said he came away from the experience with a newfound appreciation for what his wife had undergone during labor.) Doctors have long known that higher temperatures lead to more sweat, which reduces urine volumes and thus increases “the saturation of the insoluble salts that cause kidney stones.” During heat waves in the U.S., it takes just three days before emergency-room visits for kidney stones begin to spike.
For reasons that remain unclear, kidney stones have traditionally been more common among white people, but, in recent years, doctors have noted huge increases among Black Americans and a significant rise in Latino communities. The authors of the new article looked to the past for a possible explanation—particularly to the nineteen-thirties, when a federal agency, the Home Owners’ Loan Corporation, graded all of America’s neighborhoods and deemed some of them “hazardous” for investment, essentially because they were home to large minority communities. This grading system (from A for “best” and B for “still desirable” to C for “declining” and D for “hazardous”) underlay what came to be known as redlining. The grading system led to “chronic disinvestment” in the lower-rated neighborhoods, resulting, over time, in less of everything from parks and green spaces to street trees and air-conditioning in homes.
Now the results can be measured with a thermometer: in Portland, Oregon, the authors report, neighborhoods that were graded A in the nineteen-thirties now “average 8 degrees Fahrenheit lower than the city’s mean temperature, while D-graded neighborhoods average 4.8 Fahrenheit degrees warmer.” Actually, you don’t need a thermometer—that’s a thirteen-degree gap that anyone can feel just by walking across town. No one has carefully studied the incidence of kidney stones among these different neighborhoods, but the authors, in their hypothesis, point to research now under way. Similar work on asthma, another heat-related disease, has shown emergency-room visits are 2.4 times higher in redlined tracts.
Indeed, Goldfarb’s son Ben—an environmental journalist who this year will publish a book called “Crossings,” on the environmental impact of roads—writes that the HOLC grading program produced all kinds of deleterious health effects. In Syracuse, Miami, Minneapolis, and other cities, large parts of neighborhoods that the agency had redlined—and whose residents were mostly Black—were bulldozed to make room for interstate highways. He told me, “Minorities today disproportionately live near the urban freeways that displaced them, and suffer as a result. Air pollution causes asthma and cancer; noise pollution increases the risk of heart disease and stroke; and the physical fragmentation wrought by highways shatters local economies. It’s heartbreaking, though hardly surprising, that disastrous policy decisions made decades ago continue to destroy bodies and communities today.”
It’s true that everyone is going to pay some price as the planet cooks. The authors of the nephrology study predict a likely additional cost to the U.S. health-care system of at least a billion dollars a year. But some people are going to be hit much harder than others because of history. Doing justice in the present requires taking that past seriously—understanding how we ended up where we are, and why we must put those with the least first, as we try to address the future. But we’re at a moment in this country when the idea of historical responsibility is increasingly seen not as logical and obvious but as some kind of invidious political correctness.
In April, 2022, Governor Ron DeSantis, of Florida, signed the Stop Wrongs to Our Kids and Employees Act, or the Stop WOKE Act. (In introducing the bill, he had said, “In Florida we are taking a stand against the state-sanctioned racism that is critical race theory,” adding that “we won’t allow Florida tax dollars to be spent teaching kids to hate our country or to hate each other.”) A preliminary injunction was issued against the act, which includes a dictum against any school teaching that “a person, by virtue of his or her race, color, sex, or national origin, bears personal responsibility for and must feel guilt, anguish or other forms of psychological distress because of actions, in which the person played no part, committed in the past by other members of the same race, color, national origin, or sex.” But, even if you can silence teachers, legislation can’t muffle the effects of history. On a hot summer’s day in Jacksonville, Florida, where DeSantis was born, the temperature in A neighborhoods is 5.5 degrees below the mean, and it’s 4.4 degrees above the mean in the D-rated communities. ♦