Diagnosis of cardiomyopathy is on the rise

Daniel Lindholm, cardiologist, researcher at the Department of Medical Sciences.
Photo Credit: Daniel Lindholm

Scientific Frontline: "At a Glance" Summary

• Main Discovery: A comprehensive longitudinal study reveals that the number of patients diagnosed with cardiomyopathy in Sweden has more than doubled over the past two decades, with these conditions linked to substantial excess mortality.
• Methodology: Researchers mapped all adult cardiomyopathy cases in Sweden from 2004 to 2023 using the National Board of Health and Welfare’s health registers, comprising 57,000 patients, and compared survival rates against the Human Mortality Database.
• Key Data: Mortality rates among the youngest patients were 32 times higher for women and 16 times higher for men compared to the general population, while mortality remained double the average even among the oldest patient cohorts.
• Significance: The results highlight a critical need for earlier detection and better management strategies, particularly given the disproportionately high relative mortality risk observed in younger women compared to their male counterparts.
• Future Application: These findings provide the epidemiological foundation required to refine diagnostic guidelines and develop targeted treatments aimed at reducing the high mortality associated with heart muscle diseases.
• Branch of Science: Cardiology and Epidemiology
• Additional Detail: The specific increase in diagnoses among women is notably driven by a rise in identified cases of Takotsubo cardiomyopathy, also known as stress-induced cardiomyopathy or broken heart syndrome.

Epidemiology: In-Depth Description

Epidemiology is the fundamental science of public health, defined as the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems. Its primary goals are to identify the etiology (cause) of diseases, determine the extent of disease burden in communities, study the natural history and prognosis of diseases, and evaluate preventive and therapeutic measures.

Childhood lead exposure associated with increased depressive symptoms in adolescence

Childhood blood lead concentrations with increased depressive symptoms in adolescence, with larger increases when exposure occurred later in childhood.
Image Credit: Scientific Frontline

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Higher concentrations of lead in blood throughout childhood are linked to increased depressive symptoms in adolescence, with exposure at age 8 showing a particularly strong association with symptom onset and severity.
• Methodology: Researchers analyzed data from 218 caregiver-child pairs in the Health Outcomes and Measures of Environment Study, measuring blood lead concentrations at ages 1, 2, 3, 4, 5, 8, and 12, and assessing anxiety and depression symptoms at approximately age 12.
• Key Data: Each doubling in mean childhood blood lead concentrations was significantly associated with an increased risk of elevated child-reported depressive symptoms.
• Significance: This study fills a critical gap by connecting low-level lead exposure—often from environmental sources like dust and aging pipes—directly to the prevalence of psychiatric conditions in U.S. adolescents, rather than just cognitive or behavioral issues.
• Future Application: Public health efforts must expand to prevent cumulative lead exposure and specifically target reduction strategies for older children, not just toddlers, to mitigate long-term mental health risks.
• Branch of Science: Epidemiology and Environmental Health
• Additional Detail: Proposed biological mechanisms for this link include altered neurotransmitter function, oxidative stress, and inflammation in brain regions responsible for mood regulation.

Low vitamin D levels shown to raise risk of hospitalization with potentially fatal respiratory tract infections by 33%

Photo Credit: Karyna Panchenko

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Severe vitamin D deficiency significantly increases the likelihood of hospitalization for respiratory tract infections such as bronchitis and pneumonia.
• Methodology: Researchers analyzed NHS data from 36,258 participants within the UK Biobank to correlate vitamin D serum levels with hospitalization rates for respiratory infections.
• Key Data: Individuals with severe deficiency (below 15 nmol/L) were 33% more likely to be hospitalized than those with sufficient levels (at least 75 nmol/L), with a 4% decrease in hospitalization rate observed for every 10 nmol/L increase in vitamin D.
• Significance: The findings provide empirical data supporting the critical role of vitamin D's antibacterial and antiviral properties in preventing severe respiratory illness and potentially reducing strain on healthcare systems.
• Future Application: Public health strategies may prioritize vitamin D supplementation and fortified food consumption during winter months, specifically targeting high-risk demographics like the elderly and ethnic minority communities.
• Branch of Science: Nutritional Epidemiology
• Additional Detail: Lower respiratory tract infections currently rank among the top leading causes of global mortality for adults over 50 years of age.

Old diseases return as settlement pushes into the Amazon rainforest

Yellow fever cases have begun to rise, spilling over the expanding border between the forest and urban areas.
Photo Credit: Thiago Japyassu

Scientific Frontline: "At a Glance" Summary

• Main Discovery: The expansion of human settlements into the Amazon rainforest, specifically the growing interface between urban areas and forests, is the primary driver behind the recent resurgence of human yellow fever spillover cases.
• Methodology: Researchers analyzed yellow fever case records from Brazil (2000–2021), Colombia (2007–2021), and Peru (2016–2021) alongside land-use data from the MapBiomas Project, modeling the relationship between disease rates and geographic metrics such as forest patch size, edge density, and forest-urban adjacency.
• Key Data: A 10% increase in forest-urban adjacency raised the probability of a spillover event by 0.09, equivalent to a 150% increase in the number of spillover events annually; notably, this high-risk borderland is expanding by approximately 13% per year.
• Significance: Proximity between human settlements and forest edges is a significantly stronger predictor of disease spillover than ecological forest fragmentation alone, raising critical concerns that urban transmission cycles—independent of non-human hosts—could reemerge.
• Future Application: Findings indicate a critical need to realign public health infrastructure and vaccination stockpiles to specifically target expanding forest-urban interfaces, rather than relying solely on broad ecological conservation metrics.
• Branch of Science: Disease Ecology and Epidemiology
• Additional Detail: Recent data highlights the urgency, with confirmed yellow fever cases in 2025 showing a threefold increase compared to 2024 and shifting geographically to areas outside the Amazon basin.

Alcohol consumption increases the risks of over 60 diseases

Photo Credit: Taylor Friehl

Alcohol consumption increases the risks of over 60 diseases in Chinese men, including many diseases not previously linked to alcohol, according to a new study by researchers from Oxford Population Health and Peking University, published in Nature Medicine.

Alcohol consumption is estimated to be responsible for about 3 million deaths worldwide each year, and it is increasing in many low- and middle-income countries such as China. The harmful effects of heavy drinking for certain diseases (such as liver cirrhosis, stroke and several types of cancer) are well known, but very few studies have systematically assessed the impact of alcohol use on an extensive range of diseases within the same population.

The study shows that alcohol use increases the risks of 61 diseases in men in China, including many non-fatal diseases not known to be alcohol-related due to limited previous evidence. The findings of this study demonstrate the influence that alcohol intake may have on the risk of disease in populations around the world.

The researchers used data from the China Kadoorie Biobank (CKB), a collaborative study of over 512,000 adults recruited during 2004-08 from ten diverse urban and rural areas across China. Study participants were interviewed about their lifestyle and behaviors, including detailed alcohol drinking patterns. About a third of men, but only 2% of women, drank alcohol regularly (ie at least once a week). The researchers comprehensively assessed the health effects of alcohol use on over 200 different diseases in men identified through linkage to hospital records over a period of about 12 years. Importantly, they also undertook a genetic analysis to clarify whether or not alcohol intake was responsible for causing disease.

Exposure to “forever chemicals” during pregnancy linked to increased risk of obesity in kids

Toxic "forever chemicals" are used in oil- and water-repellant textiles, personal care products, firefighting foams, food packaging, medical products and many other household products.
Photo Credit: Stijn Dijkstra

A federally funded study led by researchers at Brown University showed links between prenatal exposure to per- and polyfluoroalkyl substances and slightly higher body mass indices in children.

The risks of exposure to “forever chemicals” start even before birth, a new study confirms, potentially setting up children for future health issues.

Exposure to per- and polyfluoroalkyl substances (PFAS) during pregnancy was linked to slightly higher body mass indices and an increased risk of obesity in children, according to a new Environmental Health Perspectives study led by Brown University researchers.

While this link has been suggested in previous research, the data has been inconclusive. The new study, which was funded by the Environmental Influences on Child Health Outcomes program at the National Institutes of Health, involves a much broader data set with research sites across the country, said lead author Yun “Jamie” Liu, a postdoctoral research associate in epidemiology at the Brown University School of Public Health.

“The findings were based on eight research cohorts located in different parts of the U.S. as well as with different demographics,” Liu said. “This makes our study findings more generalizable to the population as a whole.”

Can Artificial Intelligence Predict Spatiotemporal Distribution of Dengue Fever Outbreaks with Remote Sensing Data?

Image Credit: Sophia University
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Researchers train machine learning model with climatic and epidemiology remote sensing data to predict the spatiotemporal distribution of disease outbreaks

Cases of dengue fever and other zoonotic diseases will keep increasing owing to climate change, and prevention via early warning is one of our best options against them. Recently, researchers combined a machine learning model with remote sensing climatic data and information on past dengue fever cases in Chinese Taiwan, with the aim of predicting likely outbreak locations. Their findings highlight the hurdles to this approach and could facilitate more accurate predictive models.

Outbreaks of zoonotic diseases, which are those transmitted from animals to humans, are globally on the rise owing to climate change. In particular, the spread of diseases transmitted by mosquitoes is very sensitive to climate change, and Chinese Taiwan has seen a worrisome increase in the number of cases of dengue fever in recent years.

Like for most known diseases, the popular saying “an ounce of prevention is worth a pound of cure” also rings true for dengue fever. Since there is still no safe and effective vaccine for all on a global scale, dengue fever prevention efforts rely on limiting places where mosquitoes can lay their eggs and giving people an early warning when an outbreak is likely to happen. However, thus far, there are no mathematical models that can accurately predict the location of dengue fever outbreaks ahead of time.

Using sewage to forecast COVID-19 infections

Collecting samples at a wastewater treatment plant for the study
Photo Credit: provided by Masaaki Kitajima

Sifting through sewage for SARS-CoV-2 genetic material could help authorities tailor infection control policies.

A new mathematical model uses wastewater samples to effectively forecast the number of clinical COVID-19 cases in a community five days in advance. The approach was developed and validated by Hokkaido University environmental engineer, Masaaki Kitajima, and colleagues in Japan. It could help healthcare authorities better tailor infection control policies, especially when clinical surveillance is lacking. The researchers reported their findings in the journal Environment International. 

Testing wastewater samples for SARS-CoV-2 as a means to predict surges in clinical cases has been attracting attention. Scientists have been researching this approach since the beginning of the pandemic. However, current methods aren’t particularly sensitive and can only detect increasing cases without being able to forecast their numbers within a community.

Kitajima and his colleagues had already developed a method to detect SARS-CoV-2 RNA in wastewater samples. But this method requires solid material and does not work well with diluted wastewater on rainy days or with treated wastewater that has been clarified and is mostly liquid. So, they modified their approach. Instead of using low-speed centrifugation to create pellets from wastewater samples that then go on to be tested, they used special filters that can capture the viral RNA from diluted wastewater. This is followed by extracting RNA from the filter, amplifying it, and then running polymerase chain reaction (PCR) tests to detect it. They call the new method Efficient and Practical Virus Identification System with Enhanced Sensitivity for Membrane (EPISENS-M).

Nicotine exposure during pregnancy may increase risk of sudden infant death

SNUS
Photo Credit: Bengt Wiberg

Infants whose mothers have used snus (a moist oral tobacco product) during pregnancy run three times the risk of sudden infant death, according to a comprehensive registry study from Karolinska Institutet published in the journal Pediatric Research. The risk was much lower if the mother had stopped taking snus before the first antenatal visit. The researchers conclude that all types of nicotine products should be avoided during pregnancy.

“Fortunately, the incidence of sudden infant death is very low, but we can see that taking snus or smoking while pregnant is associated with an increased risk,” says Anna Gunnerbeck, pediatrician at the Astrid Lindgren Children’s Hospital and researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.

Studied two million babies

While it is known that smoking during pregnancy is a risk factor in sudden infant death, little research has been done on snus and other nicotine products. To address this, the researchers conducted a registry study comprising over two million babies born in Sweden between 1999 and 2019. During this time, only two out of 10,000 babies suffered sudden infant death, which is when death occurs suddenly for no apparent reason during sleep.

Risk of developing heart failure much higher in rural areas vs. urban

Photo Credit: Tumisu

Large NIH-supported study showed that rural-dwelling Black men are at greatest risk.

Adults living in rural areas of the United States have a 19% higher risk of developing heart failure compared to their urban counterparts, and Black men living in rural areas have an especially higher risk – 34%, according to a large observational study supported by the National Institutes of Health.

The study, one of the first to look at the link between living in rural America and first-time cases of heart failure, underscores the importance of developing more customized approaches to heart failure prevention among rural residents, particularly Black men. The study was largely funded by the National Heart, Lung, and Blood Institute (NHLBI), part of NIH, and the findings, produced in collaboration with Vanderbilt University Medical Center, Nashville, Tennessee, published today in JAMA Cardiology.

“We did not expect to find a difference of this magnitude in heart failure among rural communities compared to urban communities, especially among rural-dwelling Black men,” said Véronique L. Roger, M.D., M.P.H., the study’s corresponding author and a senior investigator with the Epidemiology and Community Health Branch in NHLBI’s Division of Intramural Research. “This study makes it clear that we need tools or interventions specifically designed to prevent heart failure in rural populations, particularly among Black men living in these areas.”

New study to tackle role of environmental contamination in the growing problem of antibiotic resistance

Photo Credit: Volodymyr Hryshchenko

Environmental factors, including pollution, that might help ‘superbugs’ become resistant to antibiotics is set to be investigated by the University of Surrey. Findings will help address this serious public health problem by identifying trends and emerging areas that require further research.

During this new eighteen-month study, funded by the One Health European Joint Project, Surrey researchers will embark on work to catalogue the evidence of the effects of environmental factors on antibiotic resistance.  

Dr Giovanni Lo Iacono, Senior Lecturer in Biostatistics and Epidemiology at the University of Surrey, said:

“The World Health Organization has declared antimicrobial resistance as one of the top 10 global public health threats facing humanity. The danger of it cannot be underestimated as it limits treatment options for those who need it most and means that certain infections can become uncontrollable.”

Antibiotic resistance, which is a form of wider antimicrobial resistance, is the ability of bacteria to withstand antibiotics and has led to increasing treatment failure for commonplace infections. Misuse and overuse of antibiotics were previously believed to be the sole cause of this threat. However, the role of environmental factors such as contamination of water or soil by antibiotics, potentially impacting the food chain, is now being recognized.

These pesticides may increase cancer risk in children

Julia Heck, associate research professor of epidemiology
in the UCLA Fielding School of Public Health.
Source: UCLA

Past research has shown that pesticide exposure increases the risk of cancer. Now, UCLA-led research has exposed which specific pesticides increase the risk of retinoblastoma — a rare eye tumor — in children.

The study, published in the August International Journal of Hygiene and Environmental Health, found that children prenatally exposed to the chemicals acephate and bromacil had an increased risk of developing unilateral retinoblastoma, or cancer in one eye, and that exposure to pymetrozine and kresoxim-methyl increased the risk of all types of retinoblastoma.

“What’s important is looking at specific bad actors and identifying them,” said Julia Heck, an adjunct associate professor in the department of epidemiology at the UCLA Fielding School of Public Health, who studies environmental causes of childhood cancers.

Identifying specific pesticides correlated with cancer is the first step toward banning or replacing them with less harmful options.

The researchers studied land use data and pesticide use reports — which provide information on where, when and in what quantity the chemicals are applied — to determine locations of possible pesticide exposure. They considered 132 pesticides that are associated with cancer.

They compared children with retinoblastoma to random children with California birth certificates and found that those with cancer were more likely to have been born in neighborhoods near applications of specific pesticides.

Study hopes to understand the impact of exposure to COVID-19 infection early in life on a child’s brain development

More than 650,000 babies are born every year [i] in the UK, and during the pandemic some of them will have been exposed to SARS-CoV-2, the coronavirus which causes COVID-19. A national study, funded by the charity Action Medical Research, will investigate the long-term impact of exposure to SARS-CoV-2 in the womb or shortly after birth.

It is known that exposure to certain viral infections shortly after birth or during pregnancy can impact a baby’s brain development or affect their development later in life, but it is not known if this is the case with SARS-CoV-2 infection. The SINEPOST (SARS-CoV-2 infection in neonates or in pregnancy) study, led by the University of Bristol in collaboration with researchers from the National Perinatal Epidemiology Unit (NPEU) at the University of Oxford, Imperial College London, and University of Leicester, aims to compare the impact of SARS-CoV-2 on the development of children who were exposed to the virus during pregnancy or shortly after birth to infants who have not been exposed to the virus.

Two hundred and fifty-seven infants have already been enrolled into the study, with recruitment ongoing until October 2022. The children will be followed up when they are 21 to 24 months old, with parents or carers being asked to complete questionnaires on how their child is developing.

The questionnaire will include the Ages and Stages Questionnaires (ASQ) used by professionals to monitor a child’s developmental progress; the Liverpool Respiratory Symptoms Questionnaire (LRSQ) which assesses patterns of wheezing and other respiratory symptoms in infants and preschool children; and additional questions about the child’s general health and use of health care services.

Bird Flu: How It’s Spreading and What to Know About This Outbreak

A feeding frenzy of western sandpipers during the mass migration via Cordova, Alaska, a key study site in the paper.
Credit: Wendy Puryear

When it comes to avian influenza, more commonly known as bird flu, all birds are not created equal.

“The scientific community has become accustomed to speaking about influenza viruses in birds as a group, but birds are an incredibly diverse taxa of animals with different natural history, physiology, and anatomy,” says Jonathan Runstadler, professor and chair of the Department of Infectious Disease & Global Health at Cummings School of Veterinary Medicine.

Runstadler is one of the authors of a new study, published today in the journal PLOS Pathogens, which takes a data-driven look at influenza viruses circulating among different groups of birds and characterizes which types of birds are involved in spreading the virus. The timing of this paper is impeccable, as a highly pathogenic strain of bird flu has been spreading across North America.

This lineage of bird flu originated around 1996 and was first found in a domestic goose in China. The virus mutated and persisted, and the first big wild bird outbreak happened around 2005 in a major wetland in central Asia. Subsequent changes in the virus led to a 2014 introduction to the U.S. via the Pacific Northwest, severely affecting the U.S. poultry industry and forcing the culling of about 40 million turkeys and chickens as a control measure.

World-leading simulation model to improve future pandemic quarantine response

A world-leading epidemiological simulation model to help improve future border quarantine practices for Australia and overseas has been developed by researchers at the University of Melbourne, the Peter Doherty Institute for Infection and Immunity and collaborating institutions.  

The team of researchers – who advised the Federal Government on its National Plan to Transition Australia's National COVID Response last August – have published their model findings in the journal Sciences Advances.

The simulation model combines a detailed representation of person-to-person contact and virus transmission among both travelers and the quarantine workforce, with an accurate simulation of how infectiousness and virus testing accuracy varies over the course of a person’s period of infection.

Researchers were able to include these factors into the simulation model by drawing on growing data from the operation of Australian hotel quarantine during the COVID-19 pandemic, and their inclusion can aid the design of quarantine systems to reduce the risk of virus transmission from infected arrivals in quarantine to the wider community.

Lead researchers Associate Professor Nic Geard and Dr Cameron Zachreson, from the University’s School of Computing and Information Systems (CIS), said the simulation model was developed to be adaptable and better calculate risks associated with various quarantine pathways including hotel quarantine, home quarantine and dedicated quarantine facilities such as the Victorian Quarantine Hub at Mickleham.

Spread of Delta SARS-CoV-2 variant driven by combination of immune escape and increased infectivity

 

Visualization of the Covid-19 virus 
Credit: Fusion Medical Animation via Unsplash

The Delta variant of SARS-CoV-2, which has become the dominant variant in countries including India and the UK, has most likely spread through its ability to evade neutralizing antibodies and its increased infectivity, say an international team of researchers.

The findings are reported today in Nature.

As SARS-CoV-2 replicates, errors in its genetic makeup cause it to mutate. Some mutations make the virus more transmissible or more infectious, some help it evade the immune response, potentially making vaccines less effective, while others have little effect. One such variant, labelled the B.1.617.2 Delta variant, was first observed in India in late 2020. It has since spread around the globe – in the UK, it is responsible nearly all new cases of coronavirus infection.

Professor Ravi Gupta from the Cambridge Institute of Therapeutic Immunology and Infectious Disease at the University of Cambridge, one of the study’s senior authors, said: “By combining lab-based experiments and epidemiology of vaccine breakthrough infections, we’ve shown that the Delta variant is better at replicating and spreading than other commonly-observed variants. There’s also evidence that neutralizing antibodies produced as a result of previous infection or vaccination are less effective at stopping this variant.

“These factors are likely to have contributed to the devastating epidemic wave in India during the first quarter of 2021, where as many as half of the cases were individuals who had previously been infected with an earlier variant.”

To examine how well the Delta variant was able to evade the immune response, the team extracted serum from blood samples collected as part of the COVID-19 cohort of the NIHR BioResource. The samples came from individuals who had previously been infected with the coronavirus or who had been vaccinated with either the Oxford/AstraZeneca or Pfizer vaccines. Serum contains antibodies raised in response to infection or vaccination. The team found that the Delta variant virus was 5.7-fold less sensitive to the sera from previously-infected individuals, and as much as eight-fold less sensitive to vaccine sera, compared with the Alpha variant - in other words, it takes eight times as many antibodies from a vaccinated individual to block the virus.

Consistent with this, an analysis of over 100 infected healthcare workers at three Delhi hospitals, nearly all of whom had been vaccinated against SARS-CoV-2, found the Delta variant to be transmitted between vaccinated staff to a greater extent than the alpha variant.

SARS-CoV-2 is a coronavirus, so named because spike proteins on its surface give it the appearance of a crown (‘corona’). The spike proteins bind to ACE2, a protein receptor found on the surface of cells in our body. Both the spike protein and ACE2 are then cleaved, allowing genetic material from the virus to enter the host cell. The virus manipulates the host cell’s machinery to allow the virus to replicate and spread.

Using 3D airway organoids – ‘mini-organs’ grown from cells from the airway, which mimic its behaviour – the team studied what happens when the virus reaches the respiratory tract. Working under secure conditions, the team used both a live virus and a ‘pseudo typed virus’ – a synthetic form of the virus that mimicked key mutations on the Delta variant – and used this to infect the organoids. They found that the Delta variant was more efficient at breaking into the cells compared with other variants as it carried a larger number of cleaved spikes on its surface. Once inside the cells, the variant was also better able to replicate. Both of these factors give the virus a selection advantage compared to other variants, helping explain why it has become so dominant.

Dr Partha Rakshit from the National Centre for Disease Control, Delhi, India, joint senior author, said: “The Delta variant has spread widely to become the dominant variants worldwide because it is faster to spread and better at infecting individuals than most other variants we’ve seen. It is also better at getting around existing immunity – either through previous exposure to the virus or to vaccination – though the risk of moderate to severe disease is reduced in such cases.”

Professor Anurag Agrawal from the CSIR Institute of Genomics and Integrative Biology, Delhi, India , joint senior author, added: “Infection of vaccinated healthcare workers with the Delta variant is a significant problem. Although they themselves may only experience mild COVID, they risk infecting individuals who have suboptimal immune responses to vaccination due to underlying health conditions – and these patients could then be at risk of severe disease. We urgently need to consider ways of boosting vaccine responses against variants among healthcare workers. It also suggests infection control measures will need to continue in the post-vaccine era.”

The research was largely supported in India by the Ministry of Health and Family Welfare, the Council of Scientific and Industrial Research, and the Department of Biotechnology; and in the UK by Wellcome, the Medical Research Council and the National Institute of Health Research.

Credit/Source: University of Cambridge

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Exposure to air pollution linked with increased mental health issues

 

Exposure to traffic-related air pollution is associated with increased mental health service-use among people recently diagnosed with psychotic and mood disorders such as schizophrenia and depression, a study on data from over 13,000 people has found.

Increased use of mental health services reflects mental illness severity, suggesting that initiatives to lessen air pollution could improve outcomes for those with these disorders and reduce costs of the healthcare needed to support them.

The research was published in the British Journal of Psychiatry and funded by the National Institute for Health Research (NIHR) Maudsley Biomedical Research Centre.

In 2019 119,000 people lived with illegal levels of polluted air in London. Previous research has found that adults exposed to high levels of traffic-related air pollution are more likely to experience common mental health disorders such as anxiety and mild depression but, until now, little was known about whether air pollution exposure contributes to the course and severity after the onset of more serious mental illness.

Researchers at King’s College London, University of Bristol and Imperial College London analyzed data from 13,887 people aged 15 years and over who had face-to-face contact with South London and Maudsley NHS Foundation Trust (SLaM) services between 2008 and 2012. Individuals were followed from the date of their first face-to-face contact for up to seven years.

Anonymized electronic mental health records were linked with quarterly average modelled concentrations of air pollutants (20x20 meter grid points) at the residential address of the participants. These included nitrogen dioxide and nitrogen oxides (NO2 and NOx) and fine and coarse particulate matter (PM2.5 and PM10).

The study found people exposed to higher residential levels of air pollutants used mental healthcare services more frequently in the months and years following their initial presentation to secondary mental healthcare services compared to those exposed to lower air pollution.

The researchers found that for every 3 micrograms per cubic meter increase in very small particulate matter (PM2.5) and 15 micrograms per cubic meter increase in nitrogen dioxide (NO2) over a one-year period there was an increased risk of having an inpatient stay of 11 per cent and 18 per cent. Results also showed increases in PM2.5 and NO2 were associated with a 7 per cent and 32 per cent increased risk of requiring community-based mental healthcare for the same period. These findings were also replicated over a seven-year period.

Dr Ioannis Bakolis, Senior Lecturer in Biostatistics and Epidemiology at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) King’s College London and lead author of the study, said: ‘There is already evidence linking air pollution to the incidence of mental disorders, but our novel findings suggest that air pollution could also play a role in the severity of mental disorders for people with pre-existing mental health conditions.’

He continued: ‘Our research indicates that air pollution is a major risk factor for increased severity of mental disorders. It is also a risk factor that is easily modifiable which suggests more public health initiatives to reduce exposure such as low emission zones could improve mental health outcomes as well as reduce the high healthcare costs caused by long-term chronic mental illness.’

According to the researchers, if the UK urban population’s exposure to PM2.5 was reduced by just a few units to the World Health Organization's recommended annual limit (10 micrograms per cubic metre), this would reduce usage of mental health services by around two per cent, thereby saving tens of millions of pounds each year in associated healthcare costs.

Dr Joanne Newbury, Sir Henry Wellcome Research Fellow, Bristol Medical School (PHS), and the study’s first author, added: ‘We observed these findings for both mood disorders and psychotic disorders, as well as for both inpatient and community-based mental healthcare, and over seven years follow-up. This suggests that air pollution may contribute to a broad range of mental health problems, across a wide spectrum of clinical need, and over long periods of time.

‘We now plan to examine whether air pollution is associated with a broader range of mental health, neurodevelopmental, and educational outcomes, particularly among children, who might be especially vulnerable to air pollution.’

South London and Maudsley NHS Foundation Trust provides comprehensive secondary mental healthcare to approximately 1.36 million people within the London boroughs of Croydon, Lambeth, Lewisham and Southwark. These are inner-city areas with high-traffic flows and high average air pollution concentrations compared to other UK urban areas that reflect London’s diversity in terms of ethnicity and wealth.

The researchers controlled the analyses for a number of potential variables that could influence the association between air pollution and service-use association, such as deprivation, population density, age, season, marital status and ethnicity. However, they cautioned that the study does not prove cause and effect, and further research needs to demonstrate exactly how air pollution might increase severity of mental health problems.

Dr Adrian James, President of the Royal College of Psychiatrists, said: ‘The environmental and climate emergency is also a mental health emergency. Our health is fundamentally linked to the quality of our environment, whether that's about cleaner air, access to green spaces or protection from extreme weather.

‘If air pollution is exacerbating pre-existing serious mental illnesses, such as schizophrenia, bipolar disorder and major depression, then improving air quality could reduce the pressure on mental health services. As we look ahead to our post-pandemic future, it is vital that we find ways to build back greener and prevent poor health. This important research presents a clear example where these go hand-in-hand.’

The research was funded by the National Institute for Health Research (NIHR), the NIHR Maudsley Biomedical Research Centre, Wellcome, the Economic and Social Research Council, and the UK Medical Research Council.

Press Release
Source / Credit: University of Bristol