Worrying levels of lead detected in the indigenous population of the Amazon

Universitat Autonoma de Barcelona

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Researchers from the UAB and the UB are working with indigenous Amazonian communities to understand health issues from a holistic perspective, including people, wildlife and the ecosystem. "In recent years we have studied various viral and parasitic pathogens, such as malaria and Chagas, in Amazonian communities", explains Pedro Mayor, principal coordinator of the research and lecturer in the Department of Animal Health and Anatomy at the UAB. "On this occasion we have focused on the issue of lead, as recent studies suggest that the ammunition used by Amazonian communities for subsistence hunting could be an important route of lead exposure for indigenous peoples in the rainforest."
Lead is a highly persistent and widely distributed toxic metal on a global scale. It accumulates in the food chain and can affect several vital organs. In children, it limits neuronal development, while in adults it causes liver damage, as well as cardiovascular and fertility problems. The study analysed lead levels in humans, wild animals and fish, as well as its possible sources—including river water used for drinking and cooking, surrounding soils, and lead ammunition used in subsistence hunting—in a very remote indigenous region in the northeastern Peruvian Amazon, an environment of intact and well-preserved forests.
The study identified the main routes of lead exposure in this community. The results show that river water—used daily for drinking and cooking—and ammunition used in subsistence hunting are the two main sources of contamination. The average blood lead concentrations were 11.74 micrograms per deciliter. Although there is no safe level of lead exposure, levels above 5 micrograms per deciliter are already associated with adverse health effects. In the indigenous community studied, 95.8% of children under 12 years of age and 94.5% of adults exceeded this threshold, reflecting widespread population exposure to lead and a worrying health risk situation.
In addition, high concentrations of lead were detected in wild animals and in the river water used as a source of drinking water. In wild animals, concentrations reached up to 1.7 mg/kg of lead in liver, well above the limit of 0.1 mg/kg permitted in meat for human consumption according to European legislation. A total of 99% of wild animal samples exceeded the legal maximum permitted in meat for direct consumption.
"We have observed that the main sources of lead for humans are river water, which the indigenous population uses for drinking and cooking, as well as the ammunition they use to carry out subsistence hunting. Fish and wildlife transport lead from the water, and this fauna also acts as a transporter of lead from ammunition", warns Pedro Mayor. "This threat that affects human populations is also important for the health of wildlife and the ecosystem in general, since lead bioaccumulates and biomagnifies throughout the food chain. Furthermore, this problem transcends the Amazon forest, since in all tropical forests on the planet the main tool used by subsistence hunters is a shotgun with lead-based ammunition". Martí Orta, co-author of the article and researcher in the Department of Evolutionary Biology, Ecology and Environmental Sciences of the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the University of Barcelona,  points out that "the problem of lead goes beyond the Amazon and could have global implications for the health of indigenous populations, since currently shotguns and lead-based ammunition are the main tools used by communities that hunt and consume bushmeat as a means of subsistence".
 
Traditionally, lead pollution is associated with industrialised environments and with mining and waste recycling activities. Researchers warn that the evidence of high levels of lead in remote and non-industrialised areas demonstrates the urgency of implementing regional policies to prevent exposure to this metal through effective drinking water filtration systems and the use of non-toxic, lead-free ammunition.

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Journal

Toxics

DOI

10.3390/toxics13100826 

Method of Research

Randomized controlled/clinical trial

Subject of Research

People

Article Title

Unexpected High Blood Lead Levels in a Remote Indigenous Community in the Northeastern Peruvian Amazon

 

Scientists agree chemicals can affect behavior, but industry workers more reluctant about safety testing

New research exposes divide between industry scientists and academic scientists over testing chemicals for behavioral impacts

University of Portsmouth

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Results from the study 'Perceptions about the use of Behavioral (Eco)Toxicology to protect human health and the environment', published in Integrated Environmental Assessment and Management.

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Credit: University of Portsmouth

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• Survey of 166 international experts highlights concerns about protecting human and wildlife health from environmental pollutants

• Less than a third of industry scientists support including behavioural tests in chemical safety assessments, compared to 80 per cent of academics and 91 per cent of government scientists

• Despite almost all scientists (97 per cent) agreeing that chemicals can affect wildlife behaviour, most testing is done by universities rather than chemical companies, leaving gaps in safety assessment

Peer-reviewed, survey

An international study led by the University of Portsmouth has revealed reluctance from industry scientists to testing chemicals for their effects on human and wildlife behaviour, despite growing evidence linking environmental pollutants to neurological disorders and behavioural changes.

The researchers surveyed 166 scientists across 27 countries working in environmental toxicology and behavioural ecology. They found that whilst 97 per cent of experts agree that contaminants can impact wildlife behaviour and 84 per cent believe they can affect human behaviour, there remains a stark divide between sectors on how to address these risks.

Industry scientists were consistently more sceptical about the reliability and necessity of behavioural testing compared to their academic and government counterparts, raising questions about potential conflicts of interest in chemical safety assessment.

The findings, published in Integrated Environmental Assessment and Management, revealed 76 per cent of academics and 68 per cent of government scientists considered behavioural experiments reliable, compared to just 30 per cent from industry. 

When asked whether regulatory authorities should consider behavioural tests when assessing chemical safety, 80 per cent of academics and 91 per cent of government scientists agreed, but less than a third (30 per cent) of industry respondents supported this approach.

The connection between chemical exposure and behavioural changes is far from new. The English language shows evidence of these links in historical phrases like “mad as a hatter” - referring to hat-makers who suffered neurological damage from mercury poisoning - and “crazy as a painter,” describing the erratic behaviour of artists exposed to lead-based paints.

Today's concerns centre on whether modern pollution could be contributing to rising rates of dementia, Alzheimer's disease, autism, and even criminal behaviour. Recent studies have linked air pollution to neurological disorders, including Parkinson's and Huntington’s disease, whilst research continues to examine the role of environmental contaminants in neurodevelopmental conditions.

Professor Alex Ford from the University of Portsmouth's Institute of Marine Sciences, who led the research, expressed concern about industry attitudes: “What worries me is that industry appears apprehensive that testing chemicals for their behavioural effects will lead to increased costs and potentially uncover effects they'd rather not have to address. When we're talking about protecting human health and wildlife, surely using the most sensitive, and thereby most protective, data should take priority over profit margins.”

While the study found that industry respondents were significantly more likely to question the reliability and relevance of behavioural testing, the pharmaceutical industry extensively uses behavioural tests in drug development and there are regulations governing behavioural impairment from substances like alcohol and cannabis.

Recent studies have shown a 34-fold increase in research papers on behavioural effects in environmental toxicology since 2000, yet there’s still reluctance to incorporate these harm measurements into regulatory frameworks. 

“Our previous research shows that whilst European law doesn't prevent regulators from introducing behavioural tests for chemicals, there are very few official testing requirements in place,” explained Marlene Ågerstrand, co-author and researcher at Stockholm University.

“This means that most studies examining how chemicals affect behaviour are carried out by university researchers rather than chemical companies, resulting in incomplete coverage of potentially harmful substances.”

The new study builds on award-winning research from 2021, when Professor Ford and international colleagues won two best paper awards for their work on chemical behavioural studies.

The researchers want behavioural testing to become a standard part of chemical safety checks, with consistent testing methods and better cooperation between industry, government and academic scientists.

“The overwhelming majority of scientists - including those in industry - agree that contaminants can affect behaviour,” said Professor Ford. “The question now is whether we have the collective will to act on that knowledge to better protect human health and the environment.”

The study surveyed scientists from academia (47 per cent), government agencies (21 per cent), and industry/consultancy (27 per cent), with the remainder working in environmental NGOs and research institutions.

It was a collaboration between researchers from the University of Portsmouth in England, Stockholm University, Swedish University of Agricultural Sciences, German Environment Agency (UBA), Australian Environment Protection Agency, US EPA, Monash University in Australia), and Baylor University in the USA.

 

A graph from the paper ‘Perceptions about the use of Behavioral (Eco)Toxicology to protect human health and the environment’, published in Integrated Environmental Assessment and Management

Credit

University of Portsmouth

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Journal

Integrated Environmental Assessment and Management

DOI

10.1093/inteam/vjaf123 

Method of Research

Survey

Subject of Research

People

Article Title

Perceptions about the use of Behavioral (Eco)Toxicology to protect human health and the environment

Article Publication Date

7-Oct-2025

Libcom.orglibcom.org/article/our-synthetic-environment-murray-bookchin

Our Synthetic Environment - Murray Bookchin - Libcom.org

Dec 11, 2014 ... Our Synthetic Environment is a 1962 book by Murray Bookchin, published under the pseudonym "Lewis Herber".

 

Scientists create ChatGPT-like AI model for neuroscience to build one of the most detailed mouse brain maps to date

Artificial intelligence reveals undiscovered regions of the brain from large-scale spatial transcriptomics data

Allen Institute

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AI-produced rendering of mouse brain regionalization overlaid with network motifs, symbolizing the fusion of artificial intelligence and neuroanatomical discovery.  

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Credit: University of California, San Francisco

Seattle, WASH.—October 7, 2025—In a powerful fusion of AI and neuroscience, researchers at the University of California, San Francisco (UCSF) and Allen Institute designed an AI model that has created one of the most detailed maps of the mouse brain to date, featuring 1,300 regions/subregions. This new map includes previously uncharted subregions of the brain, opening new avenues for neuroscience exploration. The findings were published today in Nature Communications. They offer an unprecedented level of detail and advance our understanding of the brain by allowing researchers to link specific functions, behaviors, and disease states to smaller, more precise cellular regions—providing a roadmap for new hypotheses and experiments about the roles these areas play.  

“It’s like going from a map showing only continents and countries to one showing states and cities,” said Bosiljka Tasic, Ph.D., director of molecular genetics at the Allen Institute and one of the study authors. “This new, detailed brain parcellation solely based on data, and not human expert annotation, reveals previously uncharted subregions of the mouse brain. And based on decades of neuroscience, new regions correspond to specialized brain functions to be discovered.” 

At the heart of this breakthrough is CellTransformer, a powerful AI model that can automatically identify important subregions of the brain from massive spatial transcriptomics datasets. Spatial transcriptomics reveals where certain brain cell types are positioned in the brain but does not reveal regions of the brain based on their composition. Now, CellTransformer allows scientists to define brain regions and subdivisions based on calculations of shared cellular neighborhoods, much like sketching a city’s borders based on the types of buildings within it. 

“Our model is built on the same powerful technology as AI tools like ChatGPT. Both are built on a ‘transformer’ framework which excels at understanding context,” said Reza Abbasi-Asl, Ph.D., associate professor of neurology and bioengineering at UCSF and senior author of the study. “While transformers are often applied to analyze the relationship between words in a sentence, we use CellTransformer to analyze the relationship between cells that are nearby in space. It learns to predict a cell's molecular features based on its local neighborhood, allowing it to build up a detailed map of the overall tissue organization.” 

This model successfully replicates known regions of the brain, such as the hippocampus; but more importantly, it can also discover previously uncatalogued, finer-grained subregions in poorly understood brain regions, such as the midbrain reticular nucleus, which plays a complex role in movement initiation and release. 

 

What Makes this Brain Map Distinct from Others 

This new brain map depicts brain regions, versus cell types; and unlike previous brain maps, CellTransformer’s is entirely data-driven, meaning its boundaries are defined by cellular and molecular data rather than human interpretation. With 1,300 regions and subregions, it also represents one of the most granular and complex data-driven brain maps of any animal to date. 

 

Role of the Allen Institute’s Common Coordinates Framework (CCF) 

The Allen Institute’s Common Coordinate Framework (CCF) served as the essential gold standard for validating CellTransformer’s accuracy. “By comparing the brain regions automatically identified by CellTransformer to the CCF, we were able to show that our data-driven method was identifying areas aligned with known expert-defined anatomical structures,” said Alex Lee, a PhD candidate at UCSF and first author of the study. “Seeing that our model produces results so similar to CCF, which is such a well-characterized and high-quality resource for the field, was reassuring. The high level of agreement with the CCF provided a critical benchmark, giving confidence that the new subregions discovered by CellTransformer may also be biologically meaningful. We are hoping to explore and validate the results with further computational and experimental studies." 

The potential of this research to unlock critical insights reaches beyond neuroscience. CellTransformer’s powerful AI capabilities are tissue agnostic: They can be used on other organ systems and tissues, including cancerous tissue, where large-scale spatial transcriptomics data is available to better understand the biology of health and disease and fuel the discovery of new treatments and therapies. 

 

About the Allen Institute
The Allen Institute is an independent, 501(c)(3) nonprofit research organization founded by philanthropist and visionary, the late Paul G. Allen. The Allen Institute is dedicated to answering some of the biggest questions in bioscience and accelerating research worldwide. The Institute is a recognized leader in large-scale research with a commitment to an open science model. Its research institutes and programs include the Allen Institute for Brain Science, the Allen Institute for Cell Science, the Allen Institute for Immunology, and the Allen Institute for Neural Dynamics. In 2016, the Allen Institute expanded its reach with the launch of The Paul G. Allen Frontiers Group, which identifies pioneers with new ideas to expand the boundaries of knowledge and make the world better. For more information, visit alleninstitute.org

Three-dimensional representation of region/subregion in mouse brain map created by CellTransformer. Fewer regions are generated for visual clarity/simplicity 

Examples from 1300 regions/subregion in mouse brain created by CellTransformer

Credit

University of California, San Francisco 

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Journal

Nature Communications

DOI

10.1038/s41467-025-64259-4 

Method of Research

Computational simulation/modeling

Subject of Research

Animals

Article Title

Data-driven fine-grained region discovery in the mouse brain with transformers

Article Publication Date

7-Oct-2025