Monday, May 11, 2026

Causes of excess deaths in the US compared with other high-income countries

JAMA Network Open

About The Study:

In this repeated cross-sectional study of cross-national mortality, the U.S. had substantially higher death rates than other high-income countries between 1999 and 2022, despite having similar access to advanced medical technology. Many of these excess U.S. deaths could likely be avoided by adopting health and social policies that have benefited other high-income countries. These descriptive findings should be interpreted in light of uncertainty arising from differences in death coding, data completeness, and other aspects of data comparability across countries.

Corresponding Author: To contact the corresponding author, Jacob Bor, PhD, email jbor@bu.edu.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2026.6147)

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About JAMA Network Open: JAMA Network Open is an online-only open access general medical journal from the JAMA Network. On weekdays, the journal publishes peer-reviewed clinical research and commentary in more than 40 medical and health subject areas. Every article is free online from the day of publication.

Journal

JAMA Network Open

Cardiovascular and metabolic diseases are primary drivers of excess US deaths compared to other high-income countries

Between 1999 and 2022, the US had substantially higher death rates than other wealthy nations, largely due to cardiovascular disease, metabolic diseases, Alzheimer’s disease and related dementias, and drug and alcohol complications

Boston University School of Public Health

Between 1999 and 2022, the US had substantially higher death rates than other wealthy nations, largely due to cardiovascular disease, metabolic diseases (including diabetes), Alzheimer’s disease and related dementias, and drug and alcohol complications. Policies are needed to address the underlying health, social, and economic conditions that increase Americans’ risk of developing these diseases.

Despite having similar access to advanced medical technology, the United States has substantially higher death rates than other high-income countries (HICs), and the gap has been growing for decades. Cardiovascular diseases were the leading cause of excess US deaths, according to a new study led by researchers at Boston University School of Public Health (BUSPH).

Published in JAMA Network Open, the study found that between 1999-2022, the annual number of excess US deaths—deaths that would not have occurred had the mortality rate in the US been the same as in other HICs—increased steadily through 2019 and then rose rapidly during the COVID-19 pandemic. By 2022, all-cause mortality rates in the US were 38 percent higher than in other HICs. An estimated 12.7 million US deaths could have been averted during this period if US mortality rates mirrored those of its peers. The authors refer to these excess US deaths as “missing Americans.”

The study investigated the causes of these excess US deaths, and found that cardiovascular diseases, including heart disease, hypertension, and stroke, were the leading cause of excess mortality nearly every year of this period. Together, cardiovascular and metabolic diseases accounted for over half of all excess US deaths in 2022. Drug poisonings, alcohol-related diseases, and suicides emerged as another major cause of excess mortality during this period, particularly among men and people under 45 years old. Homicide and HIV/AIDS also had mortality rates many times higher in the US than in other HICs; however, these causes were responsible for only a small share of excess US deaths.

The study builds upon previous findings by the researchers which showed that excess US deaths have increased since 1980 and continued to increase even after the COVID-19 pandemic. The new analysis is the first study to identify all leading causes responsible for these excess US deaths—what the authors refer to as a “population autopsy.” Quantifying causes of the US mortality disadvantage can reveal opportunities for intervention, including policies to prevent these fatal conditions from occurring in the first place.

“In public health, we know that death certificates only list the most proximate cause of death and not the full causal chain. Differences in social factors between the US and other HICs can lead to differences in behavioral risk factors, which in turn can lead to higher risks of specific causes of death,” says study lead and corresponding author Dr. Jacob Bor, associate professor of global health and epidemiology at BUSPH. “These findings pinpoint the issues that we should be focusing on if we want to address the US mortality disadvantage relative to peer countries.”

For the study, Dr. Bor and colleagues from BUSPH, Harvard Medical School, and Hunter College at the City University of New York analyzed US excess deaths by sex, age, and year. They utilized cause-of-death data from the World Health Organization Mortality Database for all deaths occurring from 1999-20222 in the US and 17 other HICs, including Australia, Canada, France, Japan, and the United Kingdom. The team compared excess mortality among the countries used three metrics: excess deaths, which is the difference between reported deaths and deaths that would have occurred if the US had the mortality rate of other HICs; years of life lost, which is the years of potential life lost due to premature deaths; and mortality rate ratios, which compare the risk of different causes of death between the US and other countries.

Among more than 63.5 million total deaths that occurred during this period, the US experienced an estimated 12,675,646 more excess deaths than would have occurred if their death rates were equal to other HICs. Despite declining between 1999-2009, cardiovascular diseases remained the leading cause of excess deaths during the entire study period, except for 2010, before rising sharply and continuously through 2022. Diabetes, kidney, and metabolic conditions also rose sharply from 2010-2022, following no significant increases from 1999-2009. In 2022, mental health and nervous system disorders such as Alzheimer’s disease and other dementias were the leading cause of excess death among people 85 and older. Respiratory illnesses, transportation accidents, and homicides were also major causes of US excess deaths. COVID-19 was a leading cause of US excess deaths from 2020-2022, representing 1 in 5 US excess deaths in 2020 and 2021, and also coinciding with sharp increases in other diseases.

Importantly, the study findings revealed stark differences in the burden of these causes of deaths, depending on whether they were viewed in absolute or relative terms. For example, in 2022, excess deaths from drug poisonings were 7.48 times higher in the US than in other countries, but only accounted for 10 percent of US excess deaths, while cardiovascular diseases were 1.63 times as high in the US than in other countries, but accounted for 40 percent of US excess deaths.

“In US population health research, examining the stagnation in US life expectancy that began in 2010 usually focuses on drug overdoses, alcohol-related deaths, and suicide, known as ‘deaths of despair,’” say study senior author Dr. Andrew Stokes, associate professor of global health at BUSPH. ”One dramatic finding from this study is that on an absolute scale, cardiometabolic diseases are key contributors to the increase in US death rates. If there was one thing we could address on a population scale, tackling cardiometabolic diseases would substantially reduce the US mortality gap with other wealthy nations.”

Drug poisonings are still a critical component of the US excess death conversation, the researchers note, particularly in terms of years of life lost, as this measure focuses on premature deaths and captures the societal burden of losing young people. These deaths represented the fastest increase in excess US deaths, rising from a near-equivalent level with peer countries in 1999 to more than 130,000 excess deaths in 2022, with a particular rise in 2013 after fentanyl entered the US drug supply. These causes also contributed to excess deaths among people ages 45-65.

The US did outperform peer countries in a couple of categories, comprising fewer excess deaths in 2022 for cancers (excluding lung cancer) and influenza, which Dr. Stokes attributes partly to advancements within the US healthcare system. “We’ve come a long way with medical innovations to screen and treat cancers,” he says.

The team says that more research is needed to understand the sharp rise in excess deaths after 2010, but that federal policy changes that address the root causes of these excess deaths with evidence-based interventions will help alleviate the current national mortality burden.

“While new therapeutics such as GLP-1s could make a major dent in cardiometabolic mortality, our findings suggest that other policies should be considered too,” says Dr. Bor. “Countries that have the same, or even worse, access to advanced medical technology perform far better on these metrics than the US. We need to identify the policies that other countries have implemented, and think about how we can emulate those policies in the US.”

About Boston University School of Public Health

Founded in 1976, Boston University School of Public Health is one of the top ten ranked schools of public health in the world. It offers master's- and doctoral-level education in public health. The faculty in six departments conduct policy-changing public health research around the world, with the mission of improving the health of populations—especially the disadvantaged, underserved, and vulnerable—locally and globally.

Journal

JAMA Network Open

DOI

10.1001/jamanetworkopen.2026.6147

Method of Research

Observational study

Subject of Research

People

Article Title

Causes of Excess Deaths in the US Compared with Other High-Income Countries

Article Publication Date

8-May-2026

Ethics & Human Research, May-June 2026

Digital twins in translational research and health care and more

The Hastings Center

Digital Twins in Translational Research and Health Care: An Anthropological Perspective
Jennifer K. Wagner

The race to build “digital twins”—computational models of people’s biological and physiological systems—has accelerated. The promise is huge: predict disease, personalize care, and test treatments without risk. This essay points out that the ethics of the technology isn’t keeping pace.

Also in this issue:

Ten Questions for Ethics Committees Evaluating the Strength of Evidence in Support of Early Phase Trials

Spencer Phillips Hey, Mark Fedyk, Jonathan Kimmelman

Human Research Protections during Emergencies: An Integrative Review

Lauren M. Sauer, Megan K. Singleton, Andrew Stolbach, Jonathan M. Links, Beth Resnick, Lainie Rutkow

Perspectives of Information Access in the Informed Consent Process for Clinical Research Participation in Australia

Fleur O'Hare, Lauren N. Ayton, David Foran, Camille Paynter, Michelle Gallaher, Kelly Schulz, Myra B. McGuinness, Lauren Barina, Steven Y. C. Tong, Tessa Saunders

Table of Contents • Risk‐benefit analysis for early phase trials • Research during societal emergencies: Ethics & Human Research: Vol 48, No 3

Journal

Ethics & Human Research

DOI

10.1002/eahr.70029

Method of Research

Content analysis

Subject of Research

People

Gentoo penguin is actually four distinct species, one new to science. Three are threatened.

Biologists argue that gentoo penguins should be divided into four separate species, including a newly recognized “cryptic” species.

University of California - Berkeley

The four-foot-tall Emperor penguin of Antarctica may be the most iconic member of this unique family of birds, but 17 other species of penguins populate the Southern Hemisphere, many of them confined to isolated islands that make them hard to study.

That’s likely why an entirely new species of gentoo penguin has been overlooked on the Kerguelen Islands — or, as the French refer to them, the Desolation Islands — located nearly 2,000 miles from any permanently inhabited landmass. An international team of penguin experts led by Chilean and University of California, Berkeley biologists announced the discovery — the first new penguin species named in more than 100 years — in a paper published last month in the journal Communications Biology.

The scientists provided genetic evidence that what was once thought to be one widely dispersed species is actually four separate species of gentoo penguin. One of these was previously unrecognized because, except for slight differences in size and vocalization, it looks like every other gentoo: a white underside and black back, which are optimal for escaping predation while enabling prey capture in an ocean environment. Yet it is clearly genetically different — what scientists refer to as a cryptic species.

The researchers also concluded that three previously recognized subspecies of gentoo penguins are genetically distinct and should be elevated to full-fledged species status.

The fate of the newly recognized species — the southeastern gentoo penguin, Pygoscelis kerguelensis — and two others are uncertain as global warming affects the Antarctic and sub-Antarctic regions they occupy. Only the southern gentoo, now called Pygoscelis ellsworthi and the only species to reside in Antarctica, is predicted to be minimally affected or possibly even advantaged because of an expanded distributional range.

“In Antarctica, of course, other species, not the gentoo, are threatened by climate change,” said Juliana Vianna, one of the paper’s senior authors and a professor of ecosystems and environment at Andrés Bello National University in Santiago, Chile. “But the gentoo is of most concern in the sub-Antarctic region,” an area of widely separated islands north of Antarctica governed by numerous countries, including Chile, South Africa, France, the Netherlands, Australia and New Zealand,

“It's very important that conservation institutions in all the different countries involved recognize and take appropriate action to save these three gentoo penguin species,” she added.

Biologists reach a consensus

Vianna and co-senior authors Rauri Bowie, a professor of integrative biology at UC Berkeley, and Elie Poulin, a professor at the University of Chile in Santiago, corralled penguin experts from around the world to collaborate on a new genomic analysis of gentoo penguin populations. Several of the authors had previously described subspecies of the gentoo — as many as six — though not all of them were in agreement. The paper represents a consensus, based on new whole genome sequences of 64 individuals from 10 breeding colonies, for the first time spanning nearly the entire geographical range of the gentoo penguin. The study also includes comparisons of physical characteristics, ranging from coloration and vocalizations to the timing of breeding, diet and feeding behaviors.

“There's probably no species of penguin where the taxonomy has been more debated than the gentoo penguin,” said Bowie, a curator in UC Berkeley’s Museum of Vertebrate Zoology. “For over 100 years it's been controversial as to how many species or how many subspecies there are. What this paper does is try to address that question using cutting-edge integrative approaches.”

Bowie and Vianna have worked together for nearly 10 years to understand the origins and diversity of penguins. In 2019, they published a landmark paper showing that penguins first arose around Australia and New Zealand about 22 million years ago, with Emperor and King penguins splitting off and occupying Antarctica and the sub-Antarctic, respectively. About 12 million years ago, with the rise of the circumpolar current, other penguins were carried throughout the sub-Antarctic, occupying many small islands and archipelagoes and spreading as far north as the African and South American continents.

Gentoos differ from most other penguin species in having a generalized diet, eating essentially anything they can chase down in the water. Today, with plunging krill populations, this generalized strategy is a survival advantage. Penguins that eat more specific food items, like Emperors and Adélies, are declining in numbers, while the gentoos that coexist with them on the Antarctic peninsula are increasing in population size.

The gentoos’ generalized diet indirectly led to the evolution of the new species, the researchers argue. Because the birds are content to eat what’s in front of them — including fish, krill, squid and cuttlefish — they don’t travel far from their breeding colony and nest in the same place year after year. As a result, the populations on isolated islands developed behavioral and ecological adaptations to their specific region that over time have been reinforced through selection across the genome. This led to speciation during the past 300,000 to 500,000 years, aided by the isolation of these remote islands and by the Antarctic Polar Front, a temperature and salinity barrier in the Southern Ocean that also is a barrier to animal movement.

North of the Polar Front, where the water is warmer and saltier, there’s now the eastern lineage — Pygoscelis taeniata — on the Crozet, Marion and Macquarie Islands, and the northern lineage — Pygoscelis papua — which is restricted to the Falkland/Malvinas and Martillo Islands in South America.

Right on the Polar Front lies the newly described, though low-population, southeastern lineage — Pygoscelis kerguelensis — which evolved on Kerguelen Island and likely nearby Heard Island. Below the Polar Front is found the southern and most populous lineage — Pygoscelis ellsworthi — which thrives on the Antarctic Peninsula, coastal Antarctica and South Georgia Island.

Genomes reveal genetic adaptations

The genomic analysis, which was led by the paper’s lead author, University of Chile graduate student Daly Noll, incorporated a more representative sample of genes across the entire genome than previous studies. It also involved thousands of genetic variations called single nucleotide polymorphisms (SNPs). The analysis showed how these species evolved to adapt to their environments. For example, the southern gentoo that is thriving in Antarctica shows genetic changes associated with adaptation to extreme polar environments, with a larger number of genes related to heat generation, fat and lipid storage and light perception. The latter likely reflects adaptations to seasonal daylight variation and ice reflectivity.

In contrast, the eastern gentoo has an increased number of genes linked to energy-efficient carbohydrate metabolism and enhanced diving capacity. These genes, which are associated with oxygen transport and use, blood vessel formation, mitochondrial activity and lung development, likely support prolonged underwater activity in low-productivity oceans.

The northern gentoo of South America, however, showed gene enrichment for digestion-related processes and pathways involved in cardiac contraction and muscle excitation. The researchers suggest that these patterns reflect metabolic and physiological adaptations that support sustained foraging activity in the water.

To assess how the gentoo penguins will adapt to climate change, the researchers used climate prediction models to see where the animals’ preferred habitat will be in 2050. Under a moderate climate change scenario, all of the island-inhabiting sub-Antarctic species will find their current islands uninhabitable, with few or no nearby suitable islands to which they can move. The Antarctic species, however, is likely to expand deeper into the continent as other Antarctic species — Emperor, Adélie and chinstrap penguins — decline because of the disappearance of sea ice and the krill that grow under the ice.

Vianna noted that many other non-Antarctic penguins are expected to suffer from habitat loss because of climate change and the increasing impacts of warming oceans, habitat destruction, predation by rats and dogs, competition from commercial fisheries and entrapment in nets.

“In terms of climate change, island species that have really low population sizes could be compared with the sub-Antarctic gentoo penguins,” she said. “Galapagos and other island penguin species, because they’re endemic to these islands, will find no place to go after a change in their environment. Those islands are very isolated, and these penguins cannot adapt easily to colonize any other region.”

The amount and variety of data acquired for the study is unprecedented and will have other uses, Bowie said. Vianna is already searching through penguin genomes to find the genetic changes associated with survival from avian influenza, which is now ravaging penguin, bird and mammal populations worldwide. Such studies could help identify populations most at risk from the disease.

“Whole genome sequencing has transformed our ability to not only look at adaptation from a perspective of how things diversify, but it has really important conservation value,” Bowie said.

Co-authors with Bowie and Vianna include biologists from Australia, Spain, Venezuela, South Africa, the United Kingdom, France, Argentina, Monaco and Brazil. Daly Noll of the University of Chile in Santiago is first author of the paper.

A gentoo penguin with chick.

Credit

Claudia Ulloa

Gentoo penguins engaged in a swimming technique known as porpoising.

Credit

Keith Barnes

Journal

Communications Biology

DOI

10.1038/s42003-026-10081-7

Subject of Research

Animals

Article Title

Integrative evidence reveals adaptive divergence and speciation in gentoo penguins

Smartwatches and GPS show promise for tracking environmental impacts on health in real time

CUNY pilot study demonstrates a new approach bridging wearable technology and environmental epidemiology

The Graduate Center, CUNY

NEW YORK, May 8, 2026 — As climate change drives more frequent extreme heat and worsening air pollution, researchers are seeking better ways to understand how these exposures affect health in real time. A new pilot study led by researchers at The City University of New York demonstrates the feasibility of combining wearable devices, smartphone location data, and real-time surveys to capture individuals’ environmental exposures and their immediate physical and emotional effects.

The newly published study, “Feasibility of Integrating Wearable Devices and Ecological Momentary Assessment for Real-Time Environmental Exposure Estimation,” appears in the journal JMIR Formative Research. The study was co-authored by Sameera Ramjan and Melissa Blum (co-first authors), Rung Yu Tseng, Katherine Davey, and Duke Shereen, with Yoko Nomura as senior author.

“People move through many different environments each day, and this approach lets us capture that in real time,” said Ramjan, a doctoral student in the CUNY Graduate Center Psychology program. “We were struck by how quickly the data revealed patterns — changes in heart rate variability, shifts in mood — that lined up with where participants had been and what they were exposed to.”

For the study, participants wore Fitbit smartwatches for roughly a month while completing short mood surveys known as ecological momentary assessments several times a day. Researchers combined these data with smartphone location tracking to estimate exposure to heat and air pollutants such as nitrogen dioxide, particulate matter, and sulfur dioxide based on where participants spent time throughout the day.

The findings suggest that this integrated approach is not only feasible but also revealing. On days with higher exposure to heat and nitrogen dioxide, participants showed changes in heart rate variability, a marker of the body’s ability to recover from stress. Higher exposure to sulfur dioxide was associated with increased feelings of nervousness and hopelessness. Interestingly, higher heat exposure was linked to lower self-reported sadness, a counterintuitive finding that may reflect seasonal patterns in outdoor activity and social engagement during warmer weather, underscoring the need for larger studies to disentangle these effects.

“Even in a small pilot, we could see that the relationship between environmental conditions and people’s physiological and emotional responses is more complex than traditional methods can capture,” said Blum, a medical student at the Icahn School of Medicine at Mount Sinai. “By combining wearable sensors, GPS data, and real-time surveys, we’re able to build individualized exposure profiles that move with people throughout their day. That’s a real shift from relying on stationary monitors or home addresses.”

“To our knowledge, this is the first study to combine wearable devices, ecological momentary assessment, and continuous GPS tracking to measure environmental exposures and their immediate health impacts,” said senior author Nomura, a distinguished professor of Psychology at the CUNY Graduate Center and Queens College with an appointment at the Icahn School of Medicine at Mount Sinai. “It’s a small pilot, but it demonstrates an integration between consumer technology and environmental epidemiology that could open the door to personalized approaches for preventive medicine.”

The pilot study also identified areas for improvement, including simplifying the system and increasing participant adherence — lessons that have already been incorporated into the next phase of the research. Building on these findings, Nomura’s team is now applying the refined system to a larger, National Institutes of Health (NIH)-supported study examining how prenatal and current environmental exposures affect brain development and mental health in adolescents.

The work comes at a critical moment. Exposure to extreme heat and air pollution is increasing, with disproportionate impacts on vulnerable populations, including children, pregnant individuals, people experiencing homelessness, and those with lower socioeconomic status. Children are particularly at risk because environmental exposures can have lasting effects on brain development and behavior.

Beyond research, the approach could have clinical applications. Real-time environmental exposure monitoring could one day help clinicians make more informed decisions about patient care, particularly for individuals with conditions sensitive to heat or air quality.

“This is still early-stage work, and we’re cautious about reading too much into a small sample,” Nomura said. “But improving how we measure exposure is a critical step toward protecting public health, and these results give us confidence that the approach can scale.”

The study was supported by a Professional Staff Congress–City University of New York (PSC-CUNY) research grant. For further information about the study, contact Yoko Nomura (yoko.nomura@qc.cuny.edu) or Melissa Blum (Melissa.blum@icahn.mssm.edu).

About the Graduate Center of The City University of New York The CUNY Graduate Center is a leader in public graduate education devoted to enhancing the public good through pioneering research, serious learning, and reasoned debate. The Graduate Center offers ambitious students nearly 50 doctoral and master’s programs of the highest caliber, taught by top faculty from throughout CUNY — the nation’s largest urban public university. Through its nearly 40 centers, institutes, initiatives, and the Advanced Science Research Center, the Graduate Center influences public policy and discourse and shapes innovation. The Graduate Center’s extensive public programs make it a home for culture and conversation.

Journal

JMIR Formative Research

DOI

10.2196/86615

Method of Research

Experimental study

Subject of Research

People

Article Title

Feasibility of Integrating Wearable Devices and Ecological Momentary Assessment for Real-Time Environmental Exposure Estimation

Article Publication Date

8-May-2026

Drones match farm planning effectiveness of more expensive tech, study finds

Researchers demonstrated that maps made using photos taken by a drone-born camera can be nearly as accurate showing hydrologically sensitive spots as those made using more expensive technology

Penn State

researcher launches a drone in a farm field — image:
Study first author Jhony Armando Benavides-Bolaños, who earned his doctoral degree in soil science and international agriculture and development at Penn State, launches a drone in a farm field.
view more
Credit: Penn State

UNIVERSITY PARK, Pa. — Environmental scientists and water resource managers need precise, high-resolution maps to reveal areas that farmers should avoid when planting crops, to limit polluting waters with phosphorus from fertilizer or manure. Making those maps has depended on an expensive, sometimes unavailable technology, but a team led by Penn State researchers has developed a cheaper approach that can be just as effective.

The researchers’ novel system, detailed in a paper available online ahead of publication in the June issue of Computers and Electronics in Agriculture, uses drones and photogrammetry, a technology that develops reliable 3D spatial information by analyzing overlapping 2D photographs. With this system, the team can map hydrologically sensitive areas — locations where water tends to collect or flow, creating high runoff risk — and phosphorus critical source areas, where phosphorus is likely to wash into streams and pollute them. They found that the drone-photogrammetry approach was cheaper, more accessible and nearly as accurate as conventional mapping.

The team tested the accuracy and resolution of maps created with the new method against maps made using a technology called LiDAR, which stands for light detection and ranging. It is a remote-sensing technology deployed from aircraft or satellites that uses laser pulses to measure distances to the Earth, creating precise, high-resolution maps. LiDAR is accurate but expensive and not always accessible, according to study co-author and team leader Patrick Drohan, professor of pedology in Penn State’s College of Agricultural Sciences.

“Our new technique uses a small drone to take hundreds and hundreds of photographs, essentially duplicating what a LiDAR model does,” Drohan said, explaining that the LiDAR model is only as accurate as the most recent data obtained from an overflight, but the new approach can obtain new data as needed. “We employed a technique called ‘Structure from Motion’ photogrammetry — stitching photographs together that are taken from many different angles and slightly different positioning to create a three-dimensional surface of a landscape.”

The drone-based approach could allow water resource managers worried about sediment and nutrient pollution to analyze agricultural landscapes even if a LiDAR overflight has not occurred in recent years, or if landscape alterations have happened since the last LiDAR flight, Drohan pointed out.

“It doesn't take very long to fly over a typical size farm in Pennsylvania, so this is a way that we can more rapidly update areas that might be being targeted for best-management practice implementation, or a property that is eligible for financial assistance to install some type of runoff attenuation feature, such as a riparian buffer,” he said. “Most phosphorus losses originate from a small proportion of watershed areas, following the established 80:20 rule where approximately 80% of phosphorus losses originate from 20% of watershed area.”

The team studied four farm sites in eastern Pennsylvania and created elevation models from drone imagery and compared them to existing LiDAR data from 2017. They checked accuracy using 400 to 1,000 ground control points per site. Then the researchers used both datasets to map hydrologically sensitive areas and phosphorus critical source areas.

They found that drone maps matched LiDAR very closely. In elevation accuracy, the correlation was 0.999 — almost perfect. In the mapping of hydrologically sensitive areas and phosphorus critical source areas, maps from drones and LiDAR were nearly identical, with differences less than 1.53%.

“The drone method gives almost the same answers as LiDAR, meaning that drones plus structure from motion photogrammetry are a viable, cheaper alternative to LiDAR,” Drohan said. “Our approach can be used for farm planning, reducing nutrient runoff and environmental protection. Instead of paying for expensive LiDAR scans, farmers and researchers can use drones and photogrammetry to map runoff and pollution-risk areas with nearly the same accuracy, making precision agriculture more accessible.”

The research was conducted within the U.S. Department of Agriculture’s experimental watershed in Northumberland County, a sub-catchment of the Mahantango Creek Watershed that ultimately drains to the Chesapeake Bay.

Study first author Jhony Armando Benavides-Bolaños, a researcher and professor at the Universidad del Valle in Cali, Colombia, earned his doctoral degree in soil science and international agriculture and development at Penn State. He was advised by Drohan in the Department of Ecosystem Science and Management.

Contributing to the research were Daniel Guarín, Carboneers, Utrecht, Netherlands; Dimitrios Bolkas, associate professor of surveying engineering at Penn State Wilkes Barre; and Alejandro Pérez Y Soto-Domínguez, Universidad Nacional de Colombia.

This work was funded by the Pennsylvania Department of Agriculture, and the Broadening Extension Through Student Training program, the Harrar Scholarship, and the International Agriculture and Development Competitive Grant Program Award.

Farmers and researchers can use drones and photogrammetry to map runoff and pollution-risk areas with great accuracy, making precision agriculture more accessible.

It doesn't take very long to fly over a typical size farm in Pennsylvania, the researchers say, so the drone method enables more rapid updates of areas that might be being targeted for best-management practice implementation, or a property that is eligible for financial assistance to install some type of runoff attenuation feature, such as a riparian buffer.

These two maps from the study were made from photos taken by a drone-carried camera using the Structure from Motion photogrammetry method. Drone positions are shown in blue above the top image.

Credit

Jhony Armando Benavides-Bolaños / Penn State.

Journal

Computers and Electronics in Agriculture

DOI

10.1016/j.compag.2026.111704

Method of Research

Imaging analysis

Subject of Research

Not applicable

Article Title

Unmanned Aerial Vehicle photogrammetry for mapping hydrologically sensitive and phosphorus critical source areas