Category: Environmental Effects

Categories : Cardiovascular Disease Environmental EffectsTags :

Urinary Metal Exposure Linked to Increased Risk of Heart Failure, Landmark Study Finds

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In addition to cadmium, molybdenum and zinc found to have particularly high risk increases

Right side heart failure. Credit: Scientific Animations CC4.0

A new multi-cohort study at Columbia University Mailman School of Public Health, has found that exposure to certain metals, detected in urine, is associated with a higher risk of heart failure (HF). Published in the Journal of the American College of Cardiology, it is the largest investigation of its kind to date, reinforcing the importance of reducing environmental metal exposure to reduce heart failure risk. While environmental metals are recognised as cardiovascular disease risk factors, until now the role of metal exposure in heart failure risk had remained understudied.

“Most previous studies have assessed individual metals in isolation. By examining metals as a mixture, our analysis more closely reflects real-world exposure patterns,” said Irene Martinez-Morata, MD, PhD, postdoctoral research scientist in Environmental Health Sciences at Columbia Mailman School, and lead author. “In our analysis of over 10 000 adults across diverse geographic, racial, and ethnic backgrounds, we observed consistent associations between elevated urinary metal levels and increased HF risk over long-term follow-up after accounting for other established traditional risk factors for the disease such as diabetes and obesity.”

The study pooled data from three large cohorts with more than 20 years of follow-up:

  •  MESA (Multi-Ethnic Study of Atherosclerosis), U.S. adults aged 18–85 from six urban-suburban areas in Maryland, Illinois, North Carolina, California, Minnesota and New York.
  • SHS (Strong Heart Study), American Indian adults aged 18–65 in the U.S. from Oklahoma, Arizona, North Dakota and South Dakota.
  •  Hortega Study, a general population cohort in Spain

Among the 10 861 participants, a thousand people developed heart failure. In a subset, researchers assessed left ventricular function, which measures how effectively the heart pumps blood.

Metals were measured in urine samples, which can indicate how much metal is in the body and how much is being eliminated from it. Health and lifestyle data – including medication use, cholesterol levels, blood pressure, glucose, BMI, and more – were collected via questionnaires, lab tests, and physical exams. The team used advanced machine learning models to evaluate the combined effects of five urinary metals as a mixture.

Key findings included:

  •  Higher levels for the mixture of five metals in urine: arsenic, cadmium, molybdenum, selenium, and zinc, was associated with a 55% higher risk of heart failure in rural American Indian adults (SHS), a 38% higher risk in urban and suburban diverse populations (MESA) and a 8% increased risk in adults in Spain (Hortega).
  •  In the analysis of metals individually, a doubling in the levels of urine cadmium, a toxic metal found in tobacco products, foods and industrial waste, was associated with 15% higher risk of heart failure.
  • Similarly, a doubling in the levels of molybdenum and zinc was associated with 13% and 22% higher risk of heart failure across the three cohorts. These metals have an essential function in the body, but high levels can be toxic.

“The strongest association between the 5-metal mixture and HF risk was seen in the SHS cohort,” said Martinez-Morata. “This population faces a historically high burden of contaminant metal exposure and cardiovascular disease and public health action is urgently needed.”

The sources of exposure to these metals can vary from urban and rural environments. Toxic metals such as arsenic, cadmium, and tungsten can occur as a result of mining and industrial activity leading to contamination of drinking water, foods that grow in contaminated soils, and air pollution. Many of these metals are also present in smoking devices, consumer products, and certain foods, observes Martinez and her co-authors. “Essential metals such as zinc and selenium are needed for biological functions, but high levels can be toxic.”

“We consistently found higher urinary levels of cadmium, molybdenum and zinc linked to increased heart failure risk,” noted Ana Navas-Acien, MD, PhD, Columbia Mailman School professor and chair of the Department of Environmental Health Sciences. “Even after adjusting for diabetes – a known HF risk factor – the zinc association remained significant.”

These results support the relevance of metal exposures as contributors to heart failure risk. “In ongoing research, we aim to clarify biological mechanisms and to explore the role of environmental interventions in cardiovascular disease prevention,” said Navas-Acien, who also is senior author.

“This study’s strengths include its large, diverse sample size, high-quality data, and robust, long-term follow-up,” said Martinez-Morata. “Our findings underscore the importance of continuing efforts to monitor and reduce environmental metal exposures, particularly in communities with historically high exposure levels as an innovative approach to improve cardiovascular health.”

Source: Columbia University Mailman School of Public Health

Categories : Environmental EffectsTags :

How Microplastics Are Spreading from Soil to Salad to Humans

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Photo by FLY:D on Unsplash

A review from Murdoch University has stressed that agricultural soils now hold around 23 times more microplastics than oceans.

Amongst the revelations in the comprehensive evaluation is that plastics in soil may be exposed to up to 10 000 chemical additives, most of which are unregulated in agriculture.

“These microplastics are turning food-producing land into a plastic sink,” said PhD candidate Joseph Boctor, who led the study, which appears in Environmental Sciences Europe.

Both microplastics and nanoplastics have now been found in lettuce, wheat and carrot crops. This happens through various means, from plastic mulching, fertilisers and even through being dropped by clouds.

This is particularly concerning when combined with findings of these plastics in the human lungs, brain, heart, blood, and even placenta.

“And BPA-free does not equal risk free,” Mr Boctor said.

“Replacement chemicals like BPF and BPS show comparable or greater endocrine-disrupting activity.”

The challenge is that regulations are slower than science, and industry is faster than both.

In addition to this, assessing additive toxicity is often overlooked, Mr Boctor said, due to the lack of transparency in the plastic industry and large number of additives produced.

“This makes the plastic crisis unchecked, and human health exposed,” he said.

“This review tries to bring this creeping danger under the radar and shine a flashlight on regulators.”

Alongside endocrine disruptors, the review pinpointed other additives in soil such as Phthalates (linked to reproductive issues), and PBDEs (neurotoxic flame retardants).

These additives have been linked with neurodegenerative disease, increased risks of stroke and heart attack and early death.

“These are not distant possibilities – they are unfolding within biological systems – silently and systematically,” Mr Boctor said.

To address this crisis, Mr Boctor is working alongside his colleagues at the Bioplastics Innovation Hub to create a type of plastic that is not only safe, but also decomposes in soil, land and water, leaving behind no legacy.

One innovation currently under development is the Smart Sprays Project – which will demonstrate and test a non-toxic, bioplastic-based spray for soil which forms a water barrier to harvest rainfall and reduce evaporation that can be easily applied with existing farm equipment.

The hope is that through the Hub’s work, they will introduce a green plastic to the market that will minimise and eventually negate the need for non-sustainable plastic production worldwide.

“This review highlights the urgent need for coordinated scientific and regulatory efforts,” Joseph said.

“Regulators, scientists and industry must collaborate to close the loopholes before plastic pollution further entrenches itself in the global food chain.”

Source: Murdoch University

Categories : Ageing Environmental EffectsTags :

Intense Heat Changes Biology and Can Accelerate Ageing

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Photo by Amanda María on Unsplash
By Rongbin Xu

Heat takes it out of you. After a long, hot day, we feel tired and grumpy.

But sustained periods of heat do more than that – they age us faster. Cumulative heat stress changes our epigenetics – how our cells turn on or off gene switches in response to environmental pressure.

Now, new research from the United States explores the pressing question of how extreme heat affects humans. The findings are concerning. The more days of intense heat a participant endured, the faster they aged. Longer periods of extreme heat accelerated ageing in older people by more than two years.

As the climate heats up, humans will be exposed to more and more heat – and our bodies will respond to these stresses by ageing faster. These findings are especially pertinent to Australia, where heatwaves are expected to become more frequent and intense in a warmer world.

How, exactly, does heat age us?

Ageing is natural. But the rate of ageing varies from human to human. As we go through life, our bodies are affected by stresses and shocks. For instance, if we don’t get enough sleep over a long period, we will age faster.

While heat can directly sicken or kill us, it also has a long tail. Sustained heat stresses our bodies and make them less efficient at doing the many jobs needed to stay alive. This is what we mean when we say it accelerates biological ageing. This deterioration is likely to precede the later development of diseases and disabilities.

What does that look like on a genetic level? You might think your genes don’t change over your life, and this is mostly true (apart from random mutations).

But what does change is how your genes are expressed. That is, while your DNA stays the same, your cells can switch some of its thousands of genes off or on in response to stresses. At any one time, only a fraction of the genes in any cell are turned on – meaning they’re busy making proteins.

This is known as epigenetics. The most common and best-understood pathway here is called DNA methylation (DNAm). Methylation here refers to a chemical our cells can use to block a DNA sequence from activating and producing proteins with various functions.

Cellular changes in DNAm can lead to proteins being produced more or less, which in turn can flow on to affect physiological functions and our health status. This can be both bad or good.

Heat stress can alter the pattern of which genes are turned off or on, which in turn can affect our rate of ageing.

Severe heat stress can be remembered in cells, leading them to change their DNAm patterns over time. In laboratory testing, the effect is pronounced in fish, chickens, guinea pigs, and mice.

To date, much research on how heat affects epigenetics has focused on animals and plants. Here, the evidence is clear – even a single episode of extreme heat has been shown to have a long-lasting effect on mice.

But only a couple of studies have been carried out involving humans, and they have been limited. This is the gap this new research is intended to help fill.

Sustained heat changes how our cells express genes – accelerating ageing. Photo: aleks333/Shutterstock

What did the study find?

The study by researchers at the University of Southern California involved almost 3700 people, with an average age of 68 years.

Heat affects older people more than younger people. Our ability to control our body temperature drops as we age, and we are less resilient to outside stresses and shocks. We also know periods of extreme heat trigger a wave of illness and death, especially among older people.

The study set out to better-understand what happens to human bodies at a biological level when they’re exposed to intense heat over the short, medium, and longer term.

To do this, the researchers took blood samples and measured epigenetic changes at thousands of sites across the genome, which were used to calculate three clocks measuring biological age, named PcPhenoAge, PCGrimAge, and DunedinPACE.

Ageing is natural, but the speed at which we age can change. Photo: Bricolage/Shutterstock

Then, they looked at the levels of heat each participant would have been exposed to in their geographic areas over the preceding six years, which was 2010-16. They used the US heat index to assess heat, from caution (days up to 32°C), extreme caution (32–39°C), and danger (39–51°C). They used regression modelling to see how much faster people were ageing over the normal rate of ageing.

The effect of heat was clear in the three biological clocks. Longer-term exposure to intense heat increased biological age by 2.48 years over the six-year period of the study, according to PCPhenoAge; 1.09 years, according to PCGrimAge; and 0.05 years, according to DunedinPACE.

Over the period of the study, the effect was up to 2.48 years faster than normal ageing, where one calendar year equals one biological year of ageing. That is, rather than their bodies ageing the equivalent of six years over a six-year period, heat could have aged their bodies up to 8.48 years.

Importantly, the biological clocks differ quite substantially, and we don’t yet know why. The authors suggest the PCPhenoAge clock may capture a broader spectrum of biological ageing, covering both short-term and longer-term heat stress, while the other two may be more sensitive to long-term heat exposure.

The way these researchers have conducted their study gives us confidence in their findings – the study sample was large and representative, and the use of the heat index rather than air temperature is an improvement over previous studies.

However, the findings don’t account for whether the participants had airconditioning in their homes or spent much time outside.

We need to know more

Perhaps surprisingly, there’s been little research done to date on what heat does to human epigenetics.

In 2020, we conducted a systemic review of the science of how environment affects human epigenetics. We found only seven studies, with most focused on the effect of cold rather than heat.

Now we have this new research that sheds light on the extent to which heat ages us.

As we face a warmer future, our epigenetics will change in response. There’s still a lot of work to do to see how we can adapt to these changes – or if we even can, in some parts of the world.
The Conversation
This article originally appeared on The Conversation, and was co-authored with Shuai Li, University of Melbourne.

This article was first published on Monash Lens. Read the original article

Categories : Environmental EffectsTags :

Martian Dust Could be a Health Hazard to Future Astronauts

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Photo by RDNE Stock project

Don’t breathe in the dust on Mars.

That’s the takeaway from new research from a team of scientists, including researchers from the University of Colorado Boulder. The findings suggests that long-term exposure to Martian dust could create a host of health problems for future astronauts – leading to chronic respiratory problems, thyroid disease and more.

The study, published in the journal GeoHealth, is the first to take a comprehensive look at the chemical ingredients that make up Martian dust, and their possible impacts on human health. It was undertaken by a team from the worlds of medicine, geology and aerospace engineering.

“This isn’t the most dangerous part about going to Mars,” said Justin Wang, lead author of the study and a student in the Keck School of Medicine at the University of Southern California in Los Angeles. “But dust is a solvable problem, and it’s worth putting in the effort to develop Mars-focused technologies for preventing these health problems in the first place.”

Wang, a CU Boulder alumnus, noted that Apollo era astronauts experienced runny eyes and irritated throats after inhaling dust from the moon. Apollo 17’s Harrison Schmitt likened the symptoms to hay fever.

But scientists know a lot less about the potential harms of Martian dust. To begin to answer that question, Wang and his colleagues drew on data from rovers on Mars and even Martian meteorites to better understand what makes up the planet’s dust. The group discovered a “laundry list” of chemical compounds that could be dangerous for people—at least when inhaled in large quantities and over long periods of time.

They include minerals rich in silicates and iron oxides, metals like beryllium and arsenic and a particularly nasty class of compounds called perchlorates.

In many cases, those ingredients are present in only trace amounts in Mars dust. But the first human explorers on Mars may spend around a year and a half on the surface, increasing their exposure, said study co-author Brian Hynek.

“You’re going to get dust on your spacesuits, and you’re going to have to deal with regular dust storms,” said Hynek, a geologist at the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder. “We really need to characterize this dust so that we know what the hazards are.”

Into the bloodstream

One thing is clear, he added: Mars is a dusty place.

Much of the planet is covered in a thick layer of dust rich in tiny particles of iron, which gives the planet its famous red colour. Swirling dust storms are common and, in some cases, can engulf the entire globe.

“We think there could be 10 metres of dust sitting on top of the bigger volcanoes,” said Hynek, a professor in the Department of Geological Sciences. “If you tried to land a spacecraft there, you’re going to just sink into the dust.”

Wang found his own way to Martian dust through a unique academic path. He started medical school after earning bachelor’s degrees from CU Boulder in astronomy and molecular, cellular and developmental biology, followed by a master’s degree in aerospace engineering sciences. He currently serves in the Navy through its Health Professions Scholarship Program.

He noted that the biggest problem with Martian dust comes down to its size. Estimates suggest that the average size of dust grains on Mars may be as little as 3 micrometers across, or roughly one-ten-thousandth of an inch.

“That’s smaller than what the mucus in our lungs can expel,” Wang said. “So after we inhale Martian dust, a lot of it could remain in our lungs and be absorbed into our blood stream.”

An ounce of prevention

In the current study, Wang and several of his fellow medical students at USC scoured research papers to unearth the potential toxicological effects of the ingredients in Martian dust.

Some of what they found resembled common health problems on Earth. Dust on Mars, for example, contains large amounts of the compound silica, which is abundant in minerals on our own planet. People who inhale a lot of silica, such as glass blowers, can develop a condition known as silicosis. Their lung tissue becomes scarred, making it hard to breath—symptoms similar to the “black lung” disease that coal miners often contract. Currently, there is no cure for silicosis.

In other cases, the potential health consequences are much less well-known.

Martian dust carries large quantities of highly oxidising compounds called perchlorates, which are made up of one chlorine and multiple oxygen atoms. Perchlorates are rare on Earth, but some evidence suggests that they can interfere with human thyroid function, leading to severe anaemia. Even inhaling a few milligrams of perchlorates in Martian dust could be dangerous for astronauts.

Wang noted that the best time to prepare for the health risks of Martian dust is before humans ever make it to the planet. Iodine supplements, for example, would boost astronauts’ thyroid function, potentially counteracting the toll of perchlorates – although taking too much iodine can also, paradoxically, lead to thyroid disease. Filters specifically designed to screen out Martian dust could also help to keep the air in living spaces clean.

“Prevention is key. We tell everyone to go see their primary care provider to check your cholesterol before it gives you a heart attack,” Wang said. “The best thing we can do on Mars is make sure the astronauts aren’t exposed to dust in the first place.”

Source: University of Colorado at Boulder

Categories : Allergies Environmental EffectsTags :

How is Climate Change Affecting Seasonal Allergies?

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Photo by Caroline Hernandez on Unsplash

A review published in The Laryngoscope indicates that climate change’s effects on pollen seasons and concentrations are contributing to increasing rates of allergic rhinitis.

When investigators assessed research published between 2000 and 2023, they identified 30 studies that reported on the current epidemiological state of allergic rhinitis, described factors related to climate change, and observed how global warming is affecting pollen seasons and allergy symptoms.

Sixteen studies reported longer pollen seasons and/or higher pollen concentrations related to climate change. As an example, total pollen emissions in the U.S. are projected to increase by 16–40% by the end of the century and pollen season length to increase by 19 days. Four studies reported an increase in allergic rhinitis–related health care usage, particularly among low-income residents. Two studies reported that health care professionals want more education on climate change. 

“Physicians are uniquely positioned to witness the impact of allergic rhinitis on patient outcomes and can adapt their practice as climate change intensifies,” said corresponding author Alisha R. Pershad, BS, a third-year medical student at the George Washington University School of Medicine and Health Sciences. “As trusted voices in the community, they should leverage their frontline experience to advocate for meaningful change in addressing the climate crisis.”

Source: Wiley

Categories : Cardiovascular Disease Environmental EffectsTags :

Cardiovascular Disease Deaths Worldwide Linked to Widely Used Phthalates

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Phthalates are commonly used in plastic medical equipment

Photo by Marcelo Leal on Unsplash

Daily exposure to certain chemicals used to make plastic household items could be linked to the more than 356 000 global deaths from cardiovascular disease that occurred in 2018 alone, a new analysis of population surveys shows.

Although the chemicals, called phthalates, are in widespread use globally, the Middle East, South Asia, East Asia, and the Pacific bore a much larger share of the death toll than others – about three-fourths of the total.

For decades, experts have connected health problems to exposure to certain phthalates found in cosmetics, detergents, solvents, plastic pipes, bug repellents, and other products. These chemicals break down into microscopic particles and are ingested, and studies have linked such exposure to an increased risk of conditions ranging from obesity and diabetes to fertility issues and cancer.

Led by researchers at NYU Langone Health and published in eBioMedicine, the current study focused on a kind of phthalate called di-2-ethylhexyl phthalate (DEHP). This chemical is used to increase the flexibility and softness of food containers, medical equipment, and other plastic items. Exposure has been shown in other studies to prompt inflammation in the heart’s arteries, which over time is associated with increased risk of heart attack or stroke. In their new analysis, the authors estimated that DEHP exposure contributed to 356 238 deaths, or more than 13% of all global mortality from heart disease in 2018 among men and women ages 55 through 64.

“By highlighting the connection between phthalates and a leading cause of death across the world, our findings add to the vast body of evidence that these chemicals present a tremendous danger to human health,” said study lead author Sara Hyman, BS, an associate research scientist at NYU Grossman School of Medicine.

In a past study from 2021, the research team tied phthalates to more than 50 000 premature deaths each year, mostly from heart disease, among older Americans. Their latest investigation is believed to be the first global estimate to date of cardiovascular mortality, or indeed any health outcome, resulting from exposure to the chemicals, said Hyman, who is also a graduate student at NYU School of Global Public Health.

For the research, the team used health and environmental data from dozens of population surveys to estimate DEHP exposure across 200 countries and territories. The information included urine samples containing chemical breakdown products left by the plastic additive. Mortality data was obtained from the Institute for Health Metrics and Evaluation, a research group in the United States that collects medical information worldwide to identify trends in public health.

Among the key findings, the study showed that losses in the combined region of East Asia and the Middle East and the combined region of East Asia and the Pacific accounted, respectively, for about 42% and 32% of the mortality from ardiovascular disease linked to DEHP. Specifically, India had the highest death count, at 103 587 deaths, followed by China and Indonesia. The larger heart death risks in these populations held true even after the researchers adjusted their statistical analysis to take into account population size within the studied age group.

A possible explanation, the authors say, is that these countries face higher rates of exposure to the chemicals, possibly because they are undergoing a boom in plastic production but with fewer manufacturing restrictions than other regions.

“There is a clear disparity in which parts of the world bear the brunt of heightened heart risks from phthalates,” said study senior author Leonardo Trasande, MD, MPP. “Our results underscore the urgent need for global regulations to reduce exposure to these toxins, especially in areas most affected by rapid industrialisation and plastic consumption,” added Dr Trasande, Professor of Pediatrics at NYU Grossman School of Medicine.

Dr Trasande, who is also a professor in the Department of Population Health, cautions that the analysis was not designed to establish that DEHP directly or alone caused heart disease and that higher death risks did not take into account other types of phthalates. Nor did it include mortality among those in other age groups. As a result, the overall death toll from heart disease connected to these chemicals is likely much higher, he says.

Dr Trasande says that the researchers next plan to track how reductions in phthalate exposure may, over time, affect global mortality rates, as well as to expand the study to other health concerns posed by the chemicals, such as preterm birth.

Source: NYU Langone Health / NYU Grossman School of Medicine

Categories : Environmental Effects Mental HealthTags :

Nature-based Activity is Effective Therapy for Anxiety and Depression, Study Shows

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Photo by Charlotte Thomas on Unsplash

A prescription of gardening an allotment in the UK has shown promise as a means of improving health and well-being outside of conventional medical treatments. 

Green social prescribing is a practice whereby a healthcare professional refers a patient to community-based nature activities to help improve health and well-being beyond medical treatments. Currently these programmes are in a testing phase, but evidence is now pointing to the need for investment in this area to make it an additional option for patients across the country.

More than 220 participants were included in the programme, and their mental health status was evaluated before and after exposure to an organised programme of nature-based activities, such as horticultural and care farming, sport and exercise, and outdoor mindfulness and craft-based activities.

The majority of participants took part in the programme weekly between one and four weeks, five to eight weeks, and others between nine and 12 weeks.  The team used the Office of National Statistics  measures of personal well-being, as well as the hospital anxiety and depression scale (HADS) to understand if participants had made improvements.

Horticulture

Across the board, participants reported improvements in well-being and mental health. But participants in longer programmes – typically nine to 12 weeks – or took part in activities related to horticulture and care farming, showed greater improvements in mood and anxiety levels compared with those involved in shorter programmes – one to four weeks – or in activities such as outdoor crafts, creative and mindfulness-based sessions, or sport and exercise.

The signs of improvement were similar to those seen in short-term cognitive behavioural therapy (CBT), where someone might meet one-to-one with a therapist over a period ranging from six weeks to a year or more.

Professor Peter Coventry, Director of the University’s Mental Health and Addiction Research Group, said: “We have known for some time that nature has a positive impact on health and wellbeing, but in more recent years, a stronger evidence-base has grown that proves this to be true for mental health in particular.

“The fact that activities such as gardening, tending allotments, and care farming had the most impact on the participants in our study, demonstrated that it is not just about being passive in nature, but connecting with it in a meaningful way.  

“There is also something to be said for connecting with nature in the company of other people who live in the same place as you.  Anxiety and depression can often be born out of loneliness and feelings of disconnectedness, so it makes sense that taking part in shared activities close to home  – especially those that involve caring for and improving your local environment – can help lift mood and reduce anxiety.”

All ages

The study showed that these positive impacts were seen in all ages, which ranged from age 18 to age 85, and across genders.  Researchers are now calling for more investment to be made to support these community activities and the employment of green social prescribers that GPs and other health and social care professionals can refer their patients to.

Trish Darcy, research associate from the University’s Mental Health and Addiction Research Group, said: “This intervention might not work for everyone, but through an initial exploratory conversation a social prescriber will discuss with a patient or user of the service if nature-based activities would be suited to them, and for that choice to happen we need more investment to support these community-based activities”. 

“In our study 65% of participants were from low socioeconomic groups and we now know that not only can it help improve their mental health, but participation was high for  horticultural based activities in particular, meaning that not only is it good for the individual, but for the local community environment too.”

Test and learn

The evaluation, published in the journal Health & Social Care in the Community, was conducted in partnership with The HEY Smile Foundation and NHS Humber and North Yorkshire Integrated Care Board (ICB).

Dr Hannah Armitt a Clinical Psychologist and Clinical Lead for the Humber and North Yorkshire ‘test and learn’ programme said: “The research conducted in our region has the potential to enhance service delivery by connecting statutory services with local providers of nature based and outdoors activities. 

“It is important to evidence the potential of green space and nature to ensure clinicians and patients alike can harness the benefits of this wonderful free natural resource we have in abundance in Yorkshire and Humber.”

Positive outcomes

Anthony Hurd, Humber and North Yorkshire Green Social Prescribing Programme Manager, said “This work has not only shown the positive outcomes that nature-based activities have on mental health, it has also highlighted the role that community-based organisations play in supporting the health and wellbeing of communities. 

“As healthcare begins to move more into the community, and with a focus on prevention, the community-based organisations delivering activities such as gardening, care farming and walking groups need to be recognised as key players in our national health service and be resourced appropriately.”

Source: University of York

Categories : Environmental EffectsTags :

Heat Levels That Humans can Tolerate are Lower than Previously Thought

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Photo by Amanda María on Unsplash

A study from the University of Ottawa’s Human and Environmental Physiology Research Unit (HEPRU) has confirmed that the limits for human thermoregulation – the ability to maintain a stable body temperature in extreme heat – are lower than previously thought.

This research, led by Dr Robert D. Meade, former Senior Postdoctoral Fellow and Dr Glen Kenny, Director of HEPRU and professor of physiology, highlights the urgent need to address the impacts of climate change on human health.

The study, published in the journal PNAS, found that many regions may soon experience heat and humidity levels that exceed the safe limits for human survival. “Our research provided important data supporting recent suggestions that the conditions under which humans can effectively regulate their body temperature are actually much lower than earlier models suggested,” states Kenny. “This is critical information as we face increasing global temperatures.”

Utilizing a widely used technique known as thermal-step protocols, Meade and his team exposed 12 volunteers to various heat and humidity conditions to identify the point at which thermoregulation becomes impossible. What made this study different, was that participants returned to the laboratory for a daylong exposure to conditions just above their estimated limit for thermoregulation. Participants were subjected to extreme conditions, 42°C with 57% humidity, representing a humidex of approximately 62°C. “The results were clear. The participants’ core temperature streamed upwards unabated, and many participants were unable to finish the 9-hour exposure. These data provide the first direct validation of thermal step protocols, which have been used to estimate upper limits for thermoregulation for nearly 50 years”, says Meade.

“Our findings especially timely, given estimated limits for thermoregulation are being increasingly incorporated into large scale climate modelling,” explains Meade. “They also underscore the physiological strain experienced during prolonged exposure to extreme heat, which is becoming more common due to climate change.”

The implications of this research extend beyond academia. As cities prepare for hotter summers, understanding these limits can help guide health policies and public safety measures. “By integrating physiological data with climate models, we hope to better predict and prepare for heat-related health issues,” adds Kenny.

As the world grapples with the realities of climate change, this research aims to spark important conversations about our safety and adaptability in increasingly extreme environments.

Source: University of Ottawa

Categories : Environmental EffectsTags :

Cold Plunges Fire up Repair Functions in Cells

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Photo by Yaroslav Shuraev

Investigating the effects of trendy ice baths, scientists at the University of Ottawa have made an interesting discovery on the beneficial way they affect cell functions, and have published their findings in Advanced Biology.

A new study conducted at the Human and Environmental Physiology Research lab (HEPRU) at the University of Ottawa has unveiled significant findings on the effects of cold water acclimation on autophagic (the cells’ recycling system, which promotes cellular health) and apoptotic (the programmed cell death that gets rid of damaged cells) responses in young males. The research highlights the potential for cold exposure to enhance cellular resilience against stress.

The study, conducted by Kelli King, postdoctoral fellow, and Glen Kenny, Full Professor at uOttawa’s School of Human Kinetics and Director of HEPRU, involved ten healthy young males who underwent cold-water immersion at 14°C for one hour across seven consecutive days. Blood samples were collected to analyse the participants’ cellular responses before and after the acclimation period.

“Our findings indicate that repeated cold exposure significantly improves autophagic function, a critical cellular protective mechanism,” says Professor Kenny. “This enhancement allows cells to better manage stress and could have important implications for health and longevity.”

The research revealed that while autophagy was initially dysfunctional after high-intensity cold stress, consistent exposure over a week led to increased autophagic activity and decreased cellular damage signals.

“By the end of the acclimation, we noted a marked improvement in the participants’ cellular cold tolerance,” explains King, the study’s first author. “This suggests that cold acclimation may help the body effectively cope with extreme environmental conditions.”

The implications of this study extend beyond athletic performance. Cold water immersion has gained popularity for its potential health benefits, and this research provides some scientific backing for its efficacy. The findings suggest that proper autophagic activity could not only extend cellular longevity but also prevent the onset of various diseases.

As the use of cold exposure becomes increasingly mainstream, understanding its effects on cellular mechanisms is vital. Professor Kenny emphasises, “This work underscores the importance of acclimation protocols in enhancing human health, especially in contexts where individuals are exposed to extreme temperatures.”

“We were amazed to see how quickly the body adapted,” notes King. “Cold exposure might help prevent diseases and potentially even slow down aging at a cellular level. It’s like a tune-up for your body’s microscopic machinery.”

These results apply to young males and more research is needed to see if it would also apply to other cohorts.

Source: University of Ottawa

Categories : Environmental EffectsTags :

New Evidence for a Chronic Disease Link with Microplastics

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Tiny fragments of plastic have become ubiquitous in our environment and our bodies. Higher exposure to these microplastics, which can be inadvertently consumed or inhaled, is associated with a heightened prevalence of chronic noncommunicable diseases, according to new research being presented at the American College of Cardiology’s Annual Scientific Session (ACC.25).

Researchers said the new findings add to a small but growing body of evidence that microplastic pollution represents an emerging health threat. In terms of its relationship with stroke risk, for example, microplastics concentration was comparable to factors such as minority race and lack of health insurance, according to the results.

“This study provides initial evidence that microplastics exposure has an impact on cardiovascular health, especially chronic, noncommunicable conditions like high blood pressure, diabetes and stroke,” said Sai Rahul Ponnana, MA, a research data scientist at Case Western Reserve School of Medicine in Ohio and the study’s lead author. “When we included 154 different socioeconomic and environmental features in our analysis, we didn’t expect microplastics to rank in the top 10 for predicting chronic noncommunicable disease prevalence.”

Microplastics—defined as fragments of plastic between 1 nanometre and 5 millimetres across—are released as larger pieces of plastic break down. They come from many different sources, such as food and beverage packaging, consumer products and building materials. People can be exposed to microplastics in the water they drink, the food they eat and the air they breathe.

The study examines associations between the concentration of microplastics in bodies of water and the prevalence of various health conditions in communities along the East, West and Gulf Coasts, as well as some lakeshores, in the United States between 2015-2019. While inland areas also contain microplastics pollution, researchers focused on lakes and coastlines because microplastics concentrations are better documented in these areas. They used a dataset covering 555 census tracts from the National Centers for Environmental Information that classified microplastics concentration in seafloor sediments as low (zero to 200 particles per square meter) to very high (over 40 000 particles per square metre). 

The researchers assessed rates of high blood pressure, diabetes, stroke and cancer in the same census tracts in 2019 using data from the U.S. Centers for Disease Control and Prevention. They also used a machine learning model to predict the prevalence of these conditions based on patterns in the data and to compare the associations observed with microplastics concentration to linkages with 154 other social and environmental factors such as median household income, employment rate and particulate matter air pollution in the same areas.

The results revealed that microplastics concentration was positively correlated with high blood pressure, diabetes and stroke, while cancer was not consistently linked with microplastics pollution. The results also suggested a dose relationship, in which higher concentrations of microplastic pollution are associated with a higher prevalence of disease. However, researchers said that evidence of an association does not necessarily mean that microplastics are causing these health problems. More studies are required to determine whether there is a causal relationship or if this pollution is occurring alongside another factor that leads to health issues, they said.

Further research is also needed to determine the amount of exposure or the length of time it might take for microplastics exposure to have an impact on health, if a causal relationship exists, according to Ponnana. Nevertheless, based on the available evidence, it is reasonable to believe that microplastics may play some role in health and we must take steps to reduce exposures, he said. While it is not feasible to completely avoid ingesting or inhaling microplastics when they are present in the environment, given how ubiquitous and tiny they are, researchers said the best way to minimise microplastics exposure is to curtail the amount of plastic produced and used, and to ensure proper disposal.

“The environment plays a very important role in our health, especially cardiovascular health,” Ponnana said. “As a result, taking care of our environment means taking care of ourselves.”

In a separate study presented at ACC.25, researchers from a different group reviewed the scientific literature and found that studies showed a strong correlation between microplastics in plaques in the heart’s arteries and the risk of adverse cardiovascular events, suggesting that the presence of microplastics could play a role in the onset or exacerbation of serious heart problems.

Source: American College of Cardiology