A weekly roundup of public health news
U.S. faces fast increases in dangerous heat stress
More people around the world are facing dangerous heat because of climate change, with the U.S. expected to see some of the fastest increases in heat stress in coming decades, according to new research.
Nearly 1 billion more people now experience at least one day of extreme heat stress each year than they did in the 1970s, according to a June 22 study in Nature Climate Change. Hotter days, warmer nights and longer heat seasons are exposing more people to conditions that can increase their risk of heat-related illness and death, the study found.
Researchers measured how hot conditions feel to the human body by accounting for temperature, humidity, wind and sunlight. They found that dangerous “feels-like” temperatures have become more common on every continent in the past half century. Some regions now experience up to 50 more heat stress days each year, with the Northern Hemisphere’s heat stress season lengthening by as much as 15 days, the study said.
Heat stress days occur when high temperatures, humidity and limited air movement prevent the human body from cooling itself off effectively, increasing risks for heat exhaustion, heat stroke and cardiovascular strain. Long stretches of hot days followed by warm nights further increase risks because the body has little chance to recover. Heat stress is already the leading cause of weather-related deaths globally, according to the World Health Organization.
The new study found that the hottest nights of the year are warming faster than the hottest days, making nighttime heat an increasing health concern. Population exposure has also climbed sharply. About 22% of the world’s people now experience at least one day of extreme heat stress each year, up from 16% in the 1970s.
In the U.S., population exposure to heat stress has increased 21% since the 1940s, a May study in Nature Communications finds. That study projected that if global warming reaches 2 degrees Celsius above mid-20th century levels, U.S. exposure to the most dangerous levels of heat stress could increase 273%, along with more dangerous nighttime heat and longer-lasting heat waves.
The greatest increases in dangerous heat exposure are expected across the eastern U.S. and Gulf Coast, where heat and humidity already approach dangerous thresholds. In the South, individual heat waves are projected to merge into month-long periods of extreme heat, while northern parts of the country are expected to have heat waves more often, researchers said.
Those periods of high heat could come at high financial cost, according to new projections from the Milbank Memorial Fund and Common Health Coalition. A June 30 issue brief estimates that U.S. heat waves could cost the nation more than $5 billion each year.
A five-day heat wave in a single state could lead to about 300 deaths, 4,000 emergency department visits and preventable hospitalizations, along with about $870 million in health and economic losses under current levels of public health preparedness, the brief estimated.
The new findings come as the nation is grappling with a major heat wave. More than 165 million Americans were expected to be hit with dangerously high temperatures through the Fourth of July holiday weekend and beyond, with the National Weather Service predicting heat indices as high as 115 degrees for some parts of the Midwest and East Coast.
Thousands of U.S. women face severe health problems after childbirth
Severe health complications are common for U.S. women after giving birth, especially among Black and low-income women, a new issue brief from the Commonwealth Fund says.
Released June 30, the brief reported that tens of thousands of women experience life-threatening pregnancy or childbirth complications each year, with conditions such as heart failure, sepsis, kidney failure and aneurysms among the most serious.
Women who experienced one of the complications were 31 times more likely to die within a year of giving birth than those who did not, the brief said. Their babies also face greater risks, with infants nearly four times more likely to die before or during their first year of life if their mothers experienced a severe complication.
Wide disparities exist. Rates of severe illness were consistently about 90% higher among Black women than among white women. They were also higher among women with lower incomes, those covered by public insurance such as Medicaid and people living in large metropolitan areas.
Age also played a role. Women ages 35 and older were about 70% more likely to experience severe pregnancy-related illnesses than younger mothers, the brief said.
About 650 U.S. women died of maternal causes during pregnancy or in the month and half after giving birth in 2024, according to the National Center for Health Statistics.
Healthcare spending may rise as Medicare swells, insurance coverage shrinks
National health spending is projected to continue to grow in the U.S. over the next eight years, even as rates of uninsurance increase among Americans.
By 2034, U.S. spending on health will reach $9 trillion, making up nearly 21% of the economy, compared to $5.3 trillion and 18% as of 2024, according to a new study in Health Affairs.
Published June 24, the study said new U.S. laws that affect insurance coverage and spending, as well as continued high use of medical services and goods, will play a factor in the increase.
Researchers projected that the share of Americans with health insurance will fall to about 91% by 2034, leaving about 33.5 million people uninsured. Much of the decline is tied to federal changes affecting Medicaid eligibility and the end of enhanced marketplace premium subsidies, the study said.
Health spending is expected to outpace growth in the overall economy throughout the projection period. Researchers attributed the increase to continued demand for healthcare services, particularly high-cost prescription drugs, an aging population and policy changes affecting Medicaid and private insurance.
Medicare is expected to see the fastest spending growth among the major insurance programs, averaging nearly 8% annually through 2034. As the older population continues to grow, more people are projected to enroll in Medicare and use home healthcare. Spending on prescription drugs is also expected to remain high because of continued demand for newer, high-cost medications, including drugs used to treat diabetes and obesity.
Women in poorer neighborhoods may face greater bone loss from air pollution
Women who live in lower-income neighborhoods may be more vulnerable to bone loss from air pollution, according to a June 30 study in Frontiers in Public Health.
Researchers analyzed data from more than 9,000 postmenopausal women across the U.S. They found women in disadvantaged neighborhoods experienced substantially greater bone mineral density loss linked to nitrogen oxides — pollutants linked to vehicle traffic and industrial emissions — than those in wealthier neighborhoods even when they were exposed to the same pollution levels.
The largest differences in bone loss were seen in the spine, hip and whole body. A 10% increase in nitrogen dioxide exposure was associated with nearly four times greater bone loss in the spine and about six times greater bone loss at the hip among women living in lower-income neighborhoods than among those in higher-income communities.
Several factors may help explain the findings, researchers suggested, including closer proximity to pollution sources, housing conditions that allow more outdoor pollution indoors and barriers to preventive healthcare and osteoporosis screening.
Other recent public health news of note:
• As U.S. droughts worsen and become less predictable, the nation needs to be better able to address them, a new report from the National Academies of Sciences, Engineering and Medicine says. Climate change is making droughts longer, more severe and faster to develop, the June 30 report said. Current drought monitoring systems were built for a more stable climate and don’t reflect today’s conditions, according to report committee members. They recommended strengthening monitoring systems, improving early warning capabilities and expanding research to better predict rapidly developing droughts.
The Watch is written by Michele Late, who has more than two decades of experience as a public health journalist.e than two decades of experience as a public health journalist.
