A weekly roundup of public health news
Drought-flood whiplash intensifies as climate warms
Back-to-back droughts and floods under climate change are a growing threat in the U.S. A new study in PNAS Nexus raises alarms about such extreme weather whiplash, in which communities can rapidly swing from one devastating disaster to another.
Published Sept. 15, the research found that extreme shifts are becoming more frequent as temperatures rise. For every additional 0.9 degrees Fahrenheit of warming, the frequency of drought and flooding swings increased about 10% on average and the area affected grew about 9%.
The time between droughts and floods is also getting shorter, leaving communities with less time to recover and prepare for the next emergency. Drought and flooding swings can damage crops and vegetation and increase risks for mosquito-borne diseases.
Lower-income populations experience the largest relative increases in exposure to drought and flooding swings as temperatures rises, according to the research, which explored the impact of the phenomenon in China.
In the U.S., Florida, Texas and other central portions of the nation have been hit hard this year by drought and flooding whiplash. In Texas, parts of the state experienced a lengthy dry spell this summer, with the Dallas-Fort Worth area going nearly seven weeks without rain. Then on Sept. 1, a tropical storm hit the state, releasing 20 inches of rain in just a few hours in some communities and triggering flash flooding.
Data center boom poses growing risks to public health
Growing electricity demands from data centers pose significant risks to public health, but the U.S. is not keeping pace with protections, a new report from a group of environmental health scientists warns.
Released Sept. 10 by the nonprofit Environmental Protection Network, the report identified at least 30 federal actions since January 2025 that could increase pollution risks, weaken safeguards or reduce oversight as data centers rapidly expand. Examples include changing air permitting to speed construction of data centers and their power infrastructure, allowing backup generators to run for grid support, and fast-tracking reviews of chemicals used in data center projects.
The actions could increase health risks both near data centers and in communities farther away that are affected by power plant pollution, according to the network, which is made up of hundreds of former Environmental Protection Agency scientists. Under a high-growth scenario, data center-related air pollution could contribute to about 600,000 asthma symptom cases and 1,300 premature deaths by 2028, previous research has estimated.
At least 74 new gas-fired power plants have been proposed specifically to serve data centers, which are warehouse-like facilities filled with computing equipment that work nonstop to support digital processing. The centers have been rapidly expanding as the demand for artificial intelligence computing has boomed.
The U.S. has more than 3,000 operating data centers already and another 1,500 are in development. The centers, which generate noise and heat and require massive amounts of water for cooling, consumed almost 5% of U.S. electricity in 2024, a share projected to reach nearly 12% by 2030.
The coal- and gas-fired power plants that support the centers can release nitrogen oxides, soot, volatile organic compounds, mercury and other pollutants linked to asthma attacks, heart attacks, strokes and premature death. Nearly 190 schools are within three miles of proposed gas plants dedicated to data centers, posing dangers to children, the report said.
On Sept. 14, EPA announced that U.S. coal- and gas-fired power plants will no longer be required to limit their greenhouse gas emissions. While a wealth of expert, peer-reviewed science confirms the emissions contribute to climate change, the Trump administration has rejected those findings. A group of environmental and public health groups, including the Natural Resources Defense Council, American Lung Association and Environmental Defense Fund, filed a lawsuit Sept. 17 against the change.
Millions of young adults could lose Medicaid coverage under new policies
Recent changes in Medicaid procedures could leave millions of U.S. young adults without coverage, despite qualifying for the program.
Nearly half of all young adult Medicaid users in 41 states could lose their coverage because of new policies put in place under a 2025 federal funding law, according to a Sept. 14 issue brief from the Urban Institute.
The law requires most Medicaid users to work, attend school or participate in other qualifying activities for 80 hours a month and increases eligibility reviews to every six months. Participants may have to provide documentation of their activities or exemptions when states cannot verify them through existing data. The new requirements begin January 2027.
People ages 19 to 24 are more likely to move often, attend school and participate in gig work, making it hard for them to meet the reporting and verification requirements, the brief said.
As many as 2.3 million young adults could lose Medicaid coverage in 2028, a 48% decline, depending on how states implement the requirements. Even with policies designed to minimize coverage losses, about 1.1 million young adults could lose coverage, researchers said.
Losing health coverage as a young adult can disrupt access to care during a crucial period of brain development, making it harder to identify emerging health problems, manage chronic conditions and maintain ongoing care, according to the brief.
Among the 41 states that expanded eligibility for Medicaid under the Affordable Care Act, California could experience the largest decline, losing as many as 642,000 young adult enrollees. New York could lose up to 242,000, while Illinois and Washington could each lose more than 100,000 under the highest-loss scenario.
Young adults in the states that did not expand Medicaid eligibility could also be hurt by recent policy changes, a companion Urban Institute brief found. The end of enhanced federal premium subsidies that saved low-income people money on health coverage is projected to leave about 908,000 fewer young adults with subsidized marketplace plans in 2028. New eligibility restrictions and enrollment requirements could reduce enrollment by another 190,000, bringing the combined decline to nearly 1.1 million.
More than half of that loss would be concentrated in Texas, Florida and Georgia. Researchers projected subsidized marketplace enrollment among young adults could fall by 334,000 in Texas, 145,000 in Florida and 110,000 in Georgia.
Other recent public health news of note includes:
• Wildfire smoke may be more harmful to health than other fine-particle pollution, two new studies show. A Sept. 17 study in Nature Communications found people exposed to PM2.5 from wildfires were more likely to be hospitalized for lung and heart diseases than people exposed to the same level of other PM2.5 sources such as vehicle and power plant emissions. A related analysis released Sept. 15 in The Lancet Oncology found lung cancer patients were more likely to die after being exposed to wildfire PM2.5.
• Employer-based health insurance is the most common type of coverage for Americans, serving 60% of adults under age 65. But workers who have unstable employment are less likely to have it, new research in JAMA Network Open says. Workers who have changing weekly work hours, inconsistent income or temporary jobs have much lower odds of being able to get coverage through their employers. Such workers are more likely to be young, female and to have low incomes and more likely to rely on marketplace insurance plans. Nationwide, nearly a third of U.S. employees have low-quality work schedules, a 2025 Gallup poll found.
The Watch is written by Michele Late, who has more than two decades of experience as a public health journalist.has more than two decades of experience as a public health journalist.
