More than half of the victims of violent deaths in Brazil had consumed alcohol or drugs shortly before

Postmortem analyses of 3,577 cases in four state capitals reveal a consistent association between psychoactive substances and homicides, accidents, and suicides, with distinct regional patterns.

Fundação de Amparo à Pesquisa do Estado de São Paulo

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A Brazilian study based on postmortem toxicological analyses found that 53% of violent death victims had alcohol or drugs in their systems shortly after death. The study examined 3,577 cases in Belém (North), Recife (Northeast), Vitória (Southeast), and Curitiba (South), representing the four regions of the country. “The goal was to produce standardized and comparable data on the role of psychoactive substances in deaths from external causes in Brazil,” says Henrique Silva Bombana, a biomedical toxicologist, postdoctoral researcher at the University of São Paulo’s School of Pharmaceutical Sciences (FCF-USP), and the first author of the study.

The study was published in the journal Toxics.

Bombana explains that the study was made possible by a 2020 agreement between USP and the National Secretariat for Drug Policy and Asset Management (SENAD) to map the relationship between alcohol and drug use and violent deaths. The four state capitals were chosen based on two criteria: the magnitude of the problem and strategic relevance. “These cities were selected based on the mortality rate from external causes and because they’re strategic points along the drug trafficking route,” the researcher explains. The selection also considered the country’s role as an international transit corridor. “Often, drugs come from other countries and pass through Brazil to be distributed to the United States, Europe, and Africa.”

Data collection took place between 2022 and mid-2024. “We assembled and trained teams of four researchers in each city to collect blood samples during autopsies. This material was frozen and sent to our laboratory at USP, where a team of five researchers performed the analyses,” Bombana explains.

The profile of the victims reflects the most common face of violent mortality in the country: 89.7% were male, 56% were 30 years of age or older, and 67.3% died from homicide. This last figure is especially relevant when compared to the percentages of deaths from traffic accidents (14.7%) and suicides (9.2%). In the North and Northeast regions, the highest percentage was of individuals classified as “brown,” according to the nomenclature adopted by the Brazilian Institute of Geography and Statistics (IBGE), while in the Southeast and South regions, the majority were “white.”

Of all the victims, 53% tested positive for at least one psychoactive substance. The most commonly detected substances were cocaine (29.6%), alcohol (27.7%), benzodiazepines (6.8%), and cannabis (2.2%). “The prevalence of cocaine was very significant in homicide cases, while alcohol was the most detected substance in traffic accident deaths. Benzodiazepines were prevalent in suicides,” reports Bombana.

The laboratory analyses included alcohol and a range of illicit drugs and psychoactive medications using standardized protocols. The team also implemented operational precautions to minimize losses due to degradation. “Especially in the case of alcohol, if the sample isn’t stored properly, the substance can degrade and skew the results,” the researcher notes.

“The association between the substance and violent death in the case of homicide is very complicated, because we’re only looking at the victim, not the perpetrator. Still, it’s possible to attribute the high presence of cocaine not only to acute use of the substance but also to the social and economic context in which the illegal market operates – the environment of trafficking, selling, and buying that characterizes what we call structural violence,” Bombana argues.

The presence of alcohol in traffic fatalities is a longstanding problem in the country. “The issue has been discussed for at least 30 years without a solution being found. The legislation is quite robust, but what may be lacking is greater control over the sale of alcohol. Some countries have much stricter and more restrictive rules for sales,” the researcher notes.

The cross-sectional research does not allow for the establishment of cause-and-effect relationships. This type of study collects data at a single point in time, providing a snapshot of reality.

In the study, the researchers recorded the type of death (homicide, traffic accident, suicide, etc.) and the results of the postmortem toxicological analysis (cocaine, alcohol, benzodiazepines, etc.) for each victim. The researchers then compared the two sets of data. This makes it possible to measure prevalence – for example, “53% had some substance in their blood” – and to identify associations – for example, cocaine was more common in homicides, and alcohol was more common in traffic deaths. However, the study does not allow us to prove that cocaine “caused” the homicide through cause and effect. Similarly, the cross-sectional design alone does not “close” the causal chain between alcohol consumption and traffic fatalities. “What can be stated with certainty is the existence of consistent risk signals,” notes Bombana.

When analyzing police records associated with homicide cases, the team found that approximately 85% of deaths were caused by gunshot wounds. “This occurred at a time when, through decrees and ordinances, the federal government at the time relaxed rules for purchasing and carrying firearms, increased limits on weapons and ammunition, expanded authorized categories, and reduced control and enforcement mechanisms – a context that helps explain the observed pattern of lethality,” Bombana emphasizes.

The prominence of benzodiazepines in suicides raises questions about medication use, self-medication, and vulnerability. The researcher suggests a plausible hypothesis without attributing direct causality: “The use of these substances may end up serving as a trigger to transition from suicidal ideation to actual action.”

More broadly, this observation summarizes a mechanism common to different forms of violent death: substance use can lead individuals to place themselves in more dangerous environments (in the case of homicides) or act more recklessly (in the case of traffic accidents).

The pattern of fatal incidents is not uniform. There are differences in patterns among the four state capitals studied: Recife has a high prevalence of alcohol-related deaths (either alone or in combination with other substances); Vitória and Belém have a higher concentration of deaths associated with illegal drug use (without alcohol); and Curitiba has a higher prevalence of alcohol-related deaths than illegal drug-related deaths. “Brazil is a vast country, and each city has its own social, cultural, health, and safety characteristics. Substance use patterns reflect these specificities,” comments Bombana. According to the researcher, this heterogeneity should inform tailored interventions and public policies focused on the reality of each city or region.

Although he emphasizes that he is not a public policy specialist, Bombana argues that addressing the problem is more effective when centered on public health and harm reduction rather than repression. “Perhaps the criminalization policy, the so-called ‘war on drugs,’ isn’t the best option. Portugal decriminalized drug use and saw a decrease in the number of users, petty crimes, homicides, and overdoses. The differences between Portugal and Brazil are enormous, of course. Starting with the size of the territories and populations. Still, the Portuguese example suggests that a harm reduction policy may be the most promising path.”

The study was conducted by the “Alcohol, Drugs, and Violence” group at the USP Medical School (FM) and was coordinated by Bombana and Professor Vilma Leyton, who is also an author of the article. The study received support from FAPESP through a postdoctoral fellowship awarded to Bombana.

About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

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Journal

Toxics

DOI

10.3390/toxics14010103 

Article Title

Prevalence of Psychoactive Substance Use and Violent Death: Toxicological and Geospatial Evidence from a Four-Metropolitan-Area Cross-Sectional Study in Brazil

 

New study: One of world’s rarest mouses is adapting to climate change

San Diego Zoo Wildlife Alliance

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This week, Science Advances will publish a new study on climate adaptation in the Pacific pocket mouse—North America’s most endangered mouse. The research highlights a major challenge for endangered species, as many lack the genetic diversity needed to survive changing climates.

Once thought extinct before being rediscovered in 1994, the Pacific pocket mouse faces significant threats from habitat loss and climate change. Researchers analyzed the genomes of these mice, collected over the past century, and identified 14 genes associated with adaptation to temperature and moisture. They then tracked these genes in a population reintroduced to the wild from a conservation breeding program. The genetic variation in these climate-associated genes shifted as predicted for the new environment, suggesting that adaptation to changing climates is ongoing.

Beyond its implications for the Pacific pocket mouse, this research provides a broader framework for how conservation programs can support endangered species as climates continue to change.

An embargoed manuscript and interviews are available. Visuals can be found here. Embargo will lift at 2:00 pm U.S. Eastern Time Friday, April 17, 2026.

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Journal

Science Advances

Method of Research

Observational study

Article Title

Historical and contemporary genomes of an endangered rodent reveal shifts in environmentally associated genes

Article Publication Date

17-Apr-2026

 

You talkin’ to me? Parrots use names in a variety of ways

University of Pittsburgh

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A sample of parrots living with humans showed the ability to correlate names with individuals, but also to use proper names in ways humans typically don't.

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Credit: Lauryn Benedict

Like many animals, parrots make sounds that suggest they are talking with each other, maybe even calling out to a specific parrot. But do they truly have names in the same way people do? To find out, Lauryn Benedict, a biology professor at the University of Northern Colorado, didn’t set up shop in the tropics to record parrot chatter, as they’ve done in the past. She instead found birds who spoke her language–birds that live with humans and mimic what they hear, including people’s names. 

Working with long-time collaborator Christine Dahlin from University of Pittsburgh at Johnstown and a team of researchers from Austria, Benedict analyzed vocalizations from more than 880 captive parrots. They heard many of the birds using names in ways that seemed similar to people, to identify individuals. They also found some unusual ways names popped up in the recordings.

Their work was published in the journal PLOS ONE.

Contact Christine Dahlin at: crdahlin@pitt.edu | cell: 575-642-7166 | office: 814-269-2910

One of the benefits people get from using proper names is the ability to more readily organize complex social interactions. Plenty of animals in nature use sounds in ways that are at least analogous to names, and for seemingly the same reason. Although animal researchers have been studying these vocalizations, Dahlin said, ”We cannot conclude that they are analogous to human names both because animals signals are often so different and because we don’t understand the full intent behind the signals.”

Thankfully, plenty of parrots do speak of our language. To find them, Benedict and team used data from the ManyParrots project, a network of researchers who study parrot vocal learning and cognition by collecting survey data and audio recordings.

The researchers sorted through survey data on over 889 parrots. For a subset of those birds, the survey respondents provided additional context that allowed the research team to better understand how the birds were using names.

Nearly half of the survey takers included examples of parrots using names. Of those 413 clips, 88 seemed to be birds using names as labels for people and animals. The research team also found strong evidence that some birds applied names not only to a particular category, such as “people,” but to a single individual.

On the other hand, many of the birds also used these labels in ways that people typically wouldn’t. For instance, parrots sometimes said their own name just so they could get some attention.

Ultimately, Dahlin said, this research suggested that parrots do have the cognitive and vocal skills to use names in different ways, from communicating with people to even talking about someone who isn’t there. The variation across species and even across individuals of the same species, however, leaves room for plenty of questions about how, when and why animals do or don’t use these skills to call out another creature by name.

This work was funded in part by the Vienna Science and Technology Fund (WWTF) project ANIML (LS23-014) to MH. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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Journal

PLOS One

DOI

10.1371/journal.pone.0346830 

Method of Research

Survey

Subject of Research

Animals

Article Title

Name use by companion parrots

Article Publication Date

17-Apr-2026

 

Fiber optic cable captures minute slip events deep within Taiwan landslide

Seismological Society of America

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Researchers deploy fiber optic cable in a borehole to monitor landsliding in Lantai in northern Taiwan.

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Credit: Courtesy of Hsin-Hua Huang

Placed within a borehole drilled deep through the layers of a landslide, a fiber optic cable captured tiny, periodic stick-slip events that offer a unique glimpse at the complex movements within the landslide’s shear zone.

At the Lantai site in northern Taiwan, researchers concluded that the timing and pace of these stick-slip events was linked strongly to typhoon rainfall and earthquake shaking, they reported at the 2026 SSA Annual Meeting.

Recurring stick-slip events at the base of a deep-seated landslide like Lantai, where the sliding interface extends to the bedrock, have been detected on a few exceptional occasions using ground-based sensors prior to large failures, said Hsin-Hua Huang of Academia Sinica. In those cases, the stick-slip events were thought to be precursors to a major landsliding event.

“In contrast, our findings suggest that these stick-slip events are persistent rather than episodic—they are simply too minute to be detected by surface instrumentation under normal conditions,” Huang explained. “By leveraging borehole DAS sensing, we can now clearly ‘see them’ and characterize their spatiotemporal patterns for the first time.”

“Continuous monitoring of these repeating events may therefore offer a practical framework for developing accurate landslide early warning systems to mitigate future hazards,” he added.

DAS uses the tiny internal flaws in a long optical fiber as thousands of seismic sensors. An interrogator at one end of the fiber sends laser pulses down the cable that are reflected off the fiber flaws and bounced back to the instrument. When the fiber is disturbed by movement, researchers can examine changes in the reflected pulses to learn more about the resulting seismic waves.

Researchers are using a host of geophysical instruments to monitor the Lantai site, but most of their observations are confined to the ground surface. And compared to other borehole instruments, DAS is easier and less expensive to deploy to the depths where the overburden of rock and soil slides against bedrock.

“These deep interfaces also entail a massive volume of material, and consequently, the resulting damage is catastrophic upon failure,” said Huang.

The research team at Lantai wanted to study the possible interaction between extreme environmental events such as typhoons and changes in the landslide’s structure. When a typhoon alert is issued for the area, the team deploys the DAS interrogator to the Lantai borehole for two weeks to a month.

During five of these DAS deployments, Huang and colleagues captured both accelerated landslide movements and recurring stick-slip events at the soil-bedrock interface, 20 to 30 meters deep.

Rainfall can trigger shallow landslides or debris flows, but “while rainfall is also considered a primary factor driving deep-seated landslides, the correlation is not as direct or immediate due to the depth of the interfaces,” said Huang. “Rather, it involves a complex network of fractures and fluid pathways that evolve dynamically during rainfall and are difficult to predict.”

DAS deployments like the one at Lantai can help scientists analyze how rainfall impacts frictional changes and other landslide mechanics at the landslide shear plane itself, which was “unattainable in the past,” said Huang.

 

Treetops glowing during storms captured on film for first time

Weather phenomenon that eluded scientists for decades captured in nature as corona discharges glow on tips of leaves

Penn State

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The glow of coronae are much easier to see in the nearly pitch-dark environment of a meteorology and atmospheric science lab at Penn State, left. On right, the spruce branch produces coronae during a thunderstorm, yet there is too much visible light from the sun to see these coronae glows with our eyes. 

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Credit: William Brune / Penn State

UNIVERSITY PARK — In a converted 2013 Toyota Sienna affixed with a hand-built telescopic weather device protruding from the roof, Penn State experts in meteorology and atmospheric science made their way down the nation’s eastern coast in June 2024 in search of Florida’s famed near-daily summer thunderstorms.

They were hoping to catch corona discharges, a long-hypothesized atmospheric weather phenomenon where miniscule pulses of electricity dance at the tips of tree leaves, causing the canopy to glow in the ultraviolet (UV). For more than 70 years, scientists have suspected treetops might emit these corona electrical discharges because of odd electric field activity in and over forests during storms, yet they have never been documented outside the lab.

The team, consisting of William Brune, distinguished professor of meteorology and atmospheric science; Patrick McFarland, a doctoral candidate in meteorology and atmospheric science; Jena Jenkins, assistant research professor; and David Miller, a former associate research professor who is now at the Penn State Applied Research Lab; worked to be the first to document this effect.

They chose the Sunshine State because of its propensity to produce frequent thunderstorms. However, as is often the case during research endeavors, the typical weather proved atypical.

For three weeks in Florida, McFarland and Brune chased pop-up storms that left as quickly as they formed.

The researchers had little to show for their efforts until, as they made their way back to Penn State, massive and sustained storms began cropping up just west of Interstate 95. The team caught an exit, nestled in a parking lot at the University of North Carolina at Pembroke, and trained their instruments to the top branches of a sweetgum tree that the rangefinder logged as 100 feet from their van.

The thunderstorm flashed lightning and poured rain for nearly two hours, giving them time to also observe corona on a nearby long needle loblolly pine tree as the storm waned. The results, which were the first directly-observed corona discharges occurring in nature, were recently published in Geophysical Research Letters.

“This just goes to show that there’s still discovery science being done,” said McFarland, lead author on the paper. “For more than half a century, scientists have theorized that corona exists, but this proves it.”

Corona discharges take shape during storms, the researchers said, because clouds build up strong negative charges that attract the opposite positive charge on the ground below. Opposites attract and this positive electrical ground charge rises up through the trees to the highest point, causing an electric field on the tiny, hair-like tips of leaves that is great enough to create the weak corona glow in both visible and UV form. This UV from the corona breaks apart water vapor, producing hydroxyl.

Hydroxyl is the atmosphere’s main oxidizer. Oxidizers clean the air by reacting with chemicals emitted into the air, making other chemicals that are easier to remove. These chemicals include volatile organic compounds emitted by trees or human activities and the greenhouse gas methane. The team’s prior research found corona discharges to be a substantial source of atmospheric cleansers in the forest canopy.

The chemical conversion is what researchers keyed in on. Several years ago, the team applied high-voltage, low-current electrical impulses to tree branches and found a strong correlation between the UV emissions from corona discharges and the creation of hydroxyl compounds. In that project and the more recent observations, researchers noted leaf damage at the point corona was emitted.

To capture the phenomena in nature and make use of this correlation, the team developed the Corona Observing Telescope System, a Newtonian telescope that feeds into a UV camera. It’s geolocated, equipped with a device for measuring atmospheric electricity and calibrated for UV emissions using a mercury lamp. The solar UV wavelength band is completely blocked, leaving corona, lightning and fire as the only sources of UV in the field.

In North Carolina, this system captured 859 coronae events on the sweetgum tree and 93 on the loblolly pine. Events ranged from a blink to several seconds, McFarland said. During the field campaign, researchers observed coronae in four additional thunderstorms and on four additional tree species.

“It’s nearly invisible to the naked eye but our instruments give rise to a vision of swaths of scintillating corona glowing as thunderstorms pass overhead,” McFarland said. “Such widespread coronae have implications for the removal of hydrocarbons emitted by trees, subtle tree leaf damage and could have broader implications for the health of trees, forests and the atmosphere.”

While the researchers have confirmed the phenomena, they said they still don’t know much about the potential impacts of these corona discharges and have more questions, such as: Are trees harmed during this process? Or do they benefit in some way? Have they evolved to withstand it? Does the atmospheric cleansing have a benefit to the forest? The researchers are beginning collaborations with interested tree ecologists and biologists to answer these questions, thus blazing new paths of discovery into the natural world around us.

This work was supported by the U.S. National Science Foundation. Brune, Jenkins and Miller were co-authors on the research.

 

The research team points the periscope on top of the Toyota Sienna van at a palm tree under a thunderstorm in Florida. 

Credit

Patrick McFarland / Penn State

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Journal

Geophysical Research Letters

DOI

10.1029/2025GL119591 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Corona Discharges Glow on Trees Under Thunderstorms

WAIT, WHAT?!

Eating fruits, vegetables and whole grains may increase chance of early onset lung cancer

Pesticide residue may play a role in increased rates of lung cancer in non-smokers under age 50

University of Southern California - Health Sciences

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Jorge Nieva, MD, is a medical oncologist and lung cancer specialist with Keck Medicine of USC and lead investigator of the study.

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Credit: Ricardo Carrasco III

LOS ANGELES — A diet rich in fruit, vegetables and whole grains is generally recommended for better health and to lower the risk of cancer and other diseases.  

However, new research from USC Norris Comprehensive Cancer Center, part of Keck Medicine of USC, presented at the annual meeting of the American Association for Cancer Research suggests that this type of diet may put non-smoking Americans under the age of 50 at greater risk of developing lung cancer.  

“Our research shows that younger non-smokers who eat a higher quantity of healthy foods than the general population are more likely to develop lung cancer,” said Jorge Nieva, MD, a medical oncologist and lung cancer specialist with USC Norris and lead investigator of the study. “These counter-intuitive findings raise important questions about an unknown environmental risk factor for lung cancer related to otherwise beneficial food that needs to be addressed.”  

Nieva and his fellow researchers speculate that this risk factor may be the pesticides used to keep crops pest-free. Commercially produced (non-organic) fruits, vegetables and whole grains are more likely to be associated with a higher residue of pesticides than dairy, meat and many processed foods, according to Nieva. He also notes that agricultural workers exposed to pesticides typically have higher rates of lung cancer, which adds credence to the theory.  

The study also showed that young women who don’t smoke have a higher incidence of lung cancer than men, and that women tended to also have a diet higher in produce and whole grains than men.  

A New Epidemic of Lung Cancer 

Lung cancer has typically been a disease that affects older adults (the average age of lung cancer onset is 71), men more than women, and smokers. 

Smoking rates have fallen since the mid-1980s, which has led to fewer lung cancer cases across the United States, except for one unique group — non-smokers age 50 and younger, especially women, who are now more likely to get lung cancer than men.  

To investigate this trend, researchers launched the Epidemiology of Young Lung Cancer Project, which surveyed 187 patients who were diagnosed with lung cancer by age 50. Patients provided details on demographics, diet, smoking history and lung cancer diagnosis.  

Most patients had never smoked and had a form of lung cancer biologically different from lung cancer caused by smoking. A 2021 study from the Epidemiology of Young Lung Cancer Project, the Genomics of Young Lung Cancer Project, found that the subtypes of lung cancer seen in people under 40 were distinct from lung cancer in older adults.  

Researchers used the Healthy Eating Index (HEI), a ranking of the overall quality of Americans’ diet on a scale of 1-100, to compare patients’ diets with the broader United States population. Young non-smoking lung cancer patients had an average HEI score of 65 out of 100, compared to the national average of 57. Among participants in the study, women had higher HEI scores than men. 

On average, the young lung cancer patients ate more daily servings of fruit, vegetables and whole grains than the general population. For example, participants averaged 4.3 servings of dark green vegetable and legumes and 3.9 servings of whole grains per day, while the average U.S. adult eats 3.6 servings of dark green vegetables and legumes and 2.6 servings of whole grains per day. 

More Research Needed 

The link between pesticides and lung cancer in young people, especially women, needs more research, said Nieva. 

In the study, researchers did not test specific foods for pesticides. Instead, they used published data on average pesticide levels for food categories such as fruits, vegetables and grains to estimate exposure. The next step, said Nieva, is to confirm the link by directly measuring pesticide levels in blood or urine samples from patients. This could also help reveal whether or not some pesticides increase lung cancer risk more than others. 

“This work represents a critical step toward identifying modifiable environmental factors that may contribute to lung cancer in young adults," said Nieva. “Our hope is that these insights can guide both public health recommendations and future investigation into lung cancer prevention.”  

The research is supported by the Addario Lung Cancer Medical Institute, a nonprofit focused on advancing lung cancer research and care, as well as AstraZeneca, the Beth Longwell Foundation, Genentech, GO2 for Lung Cancer and Upstage Lung Cancer.  

Researchers also received funding from the National Institutes of Health, grant number R25CA225513 and the National Cancer Institute, grant number P30CA014089. 

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For more information about Keck Medicine of USC, please visit news.KeckMedicine.org. 

Disclosure: Dr. Nieva has received consulting payments from AstraZeneca and Genentech.