A weekly roundup of public health news
Research links environmental metals to heart failure
People who are exposed to metals in their surrounding environments are at higher risk of heart failure, a new study finds.
Published in the Journal of the American College of Cardiology, the research looked at health data collected from several distinct groups of people, finding links between exposure to metals in soil, water and air and heart failure at varying levels. The highest risks were for rural American Indian people, who had a 55% higher likelihood of heart failure when exposed to an environmental mix of arsenic, cadmium, molybdenum, selenium and zinc.
The data on American Indian adults came from the Strong Heart Study, which includes people living in Arizona, North Dakota, Oklahoma and South Dakota. Rural American Indian and Alaska Native populations have a higher risk of being exposed to environmental metals because of their proximity to abandoned mining sites, poorer housing and cultural food practices, among other factors.
But researchers also linked environmental metals to increased risks for heart failure for other Americans. Using health data from the Multi-Ethnic Study of Atherosclerosis — which involves adults in urban and suburban areas of California, Illinois, Maryland, Minnesota, North Carolina and New York — researchers found a 38% higher risk of heart failure for people exposed to the mix of environmental metals.
The scientists also examined the impact of cadmium exposure on heart failure, finding a 15% higher risk for people who had double the average levels of the metal in their urine samples. People are usually exposed to cadmium through tobacco use and by consuming food crops grown in soil containing the metal, though exposure may also come from industrial waste.
Wildfire smoke harmful for immune system, heart health, pregnancies
As exposure to wildfire smoke continues to increase for Americans, more research is warning of its dangerous and deadly effects on human health.
A new study led by researchers at Harvard T.H. Chan School of Public Health finds exposure to wildfire smoke can cause harm at the cellular level, damaging the immune system. The study, published June 26 in Nature Medicine, also found changes in cells related to asthma and allergies. The cellular damage could account for some of the many health risks that come from wildfire smoke exposure, researchers suggested.
Among those risks is heart failure, new science in the Journal of the American College of Cardiology shows. Researchers in that study found repeated exposure to fine-particle pollution, also known as PM2.5, from wildfire smoke can raise risks for heart failure, especially for older adults, women and other vulnerable populations. And as wildfire air pollution increases, so does the risk of developing heart failure.
For every 1 microgram increase in wildfire-related PM2.5 per cubic meter —roughly equivalent to the size of a dishwasher — the risk of heart failure among older adults grew by 1.4%, the study said. At that level, wildfire smoke exposure could be linked to over 20,000 annual heart failure cases among older U.S. adults.
Wildfire smoke is also connected to smaller newborn size, according to a new study in Environmental Science & Technology. Women exposed to wildfire smoke and excessive heat in the month before they became pregnant and the first trimester of their pregnancy were more likely to have babies that were small for their gestational age. The research, which looked at data on residents of Los Angeles, a city often affected by wildfire smoke, found women in some neighborhoods had twice the risk of having a smaller baby.
Previous research has found the number of Americans exposed to unhealthy levels of PM2.5 pollution from wildfire smoke at least one day a year has climbed 27-fold in the past decade. At one point in 2023, when smoke from Canadian wildfires spread across the U.S, more than 120 million Americans were under air quality alerts. Exposure to wildfire smoke is expected to worsen significantly in the next 30 years as the world becomes hotter and drier with human-caused climate change.
The health impacts of wildfires go beyond smoke, however. New findings in Nature Communications Earth & Environment show wildfires can threaten water quality for up to eight years after they burn. Researchers examined water samples from 500 river basins in Northern California, a common region for wildfire activity, finding high levels of contaminants such as phosphorus and nitrogen years after fires. The results showed water sources can take longer to recover after wildfires than previously thought, researchers said.
COVID-19 pandemic eroded trust in public health
Public trust in federal public health agencies plummeted during the early years of the COVID-19 pandemic, new research shows.
Published June 26 in PLOS Global Public Health, the study examined data taken from public surveys conducted from February 2020, a month before the pandemic was declared, through October 2024, when it had substantially ebbed.
Researchers found public trust in agencies such as the Centers for Disease Control and Prevention, Food and Drug Administration and National Institutes of Health dropped significantly from February through May 2020, and then again from May 2020 to June 2022. For CDC, public trust dropped from 82% in February 2020 to a low of 56% in June 2022. Trust in all of the agencies had begun to climb back up as of 2024.
While faith in local health departments also dipped from 2020 to 2022, it rebounded substantially last year, trending higher in October 2024 than it did even before the pandemic. The results show that local health officials can play an important role in reestablishing trust in public health, researchers said.
The findings overlap the beginning of the pandemic under the Trump administration in 2020 as well its peak of deaths in winter 2021 and general trend toward decline under the Biden administration.
Other recent public health news of note includes:
• Nitrate from fertilizers and groundwater runoff can make its way into drinking water supplies, raising risks for preterm births and low birth weights, new findings in PLOS Water show.
• A new analysis in Science of Food confirms food packaging is a significant source of micro- and nanoplastics in food. Normal use of plastic food packaging and plastic food-related items, such as bottles or cutting boards, can contaminate food with microplastics, the systemic analysis of more than 100 studies found.
• Teens of color are less likely to have access to mental health care, including mental health visits or medications, according to new research in JAMA Network Open.
• While deaths of newborns have fallen overall in the U.S. in recent decades, deaths from malnutrition and slow growth during pregnancy have increased by nearly 2% a year, with poor prenatal nutrition a possible cause, says a new study in JAMA Pediatrics.
The Watch is written by Michele Late, who has more than two decades of experience as a public health journalist. more than two decades of experience as a public health journalist.
