Tag Archives: quality

New Study Reveals Popular ‘Pink Noise’ Could Deteriorate Sleep Quality

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A recent study has revealed that while pink noise is popular for promoting better sleep, it may actually disrupt your rest, contradicting common beliefs.

Pink noise, akin to white noise, encompasses all audible frequencies but emphasizes lower frequencies. Various sounds used for brain stimulation are categorized into colors based on how their noise spectrum aligns with the spectrum of colored light. Notably, white noise plays all frequencies at equal intensity, similar to how white light combines all visible colors.

Pink noise resembles the soothing sounds of rain or ocean waves. However, findings suggest mixed effects on memory and sleep benefits.

Conducted at the University of Pennsylvania, a 7-day study evaluated sleep quality among 25 healthy adults, primarily young women, exploring the impacts of environmental noise, pink noise, and earplugs. Participants did not have any sleep disorders or frequently use sound machines.

Participants were instructed to turn off lights at 11 PM and rise at 7 AM.

During the sleeping hours, participants encountered various noise scenarios: no noise, isolated environmental noise, pink noise alone, a blend of pink and environmental noise at different volumes, or environmental noise with earplugs.

Environmental sounds ranged from traffic to sonic booms.

Sleep encompasses phases, including light eye movement, deep sleep, and REM sleep—where dreaming occurs.

Published in the journal Sleep, the study demonstrated that environmental noise notably disrupts stage 3 sleep, leading to an average reduction of 23.4 minutes in this crucial phase, which is essential for cognitive function and memory.

Moreover, pink noise was found to decrease REM sleep duration by 18.6 minutes, a vital phase for mood regulation and mental clarity.

Dr. Matthias Basner, lead author and professor of psychiatry at the University of Pennsylvania, expressed surprise at the significant disruption pink noise caused to sleep.

“While there’s existing literature on REM sleep reduction, it was overlooked until now,” he stated.

The researchers evaluated cognitive and physiological responses before and after each sleep session, alongside monitoring participants’ sleep and inquiring about their mood and fatigue levels.

Although losing 20 minutes of REM sleep may seem minor, Dr. Basner highlighted that these minutes accumulate over time.

“Losing just 10 minutes a night could total 70 minutes over a week, and over a year, that’s a significant 3,640 minutes,” he explained.

The study did not explore ambient noise impacts on infants or children. Dr. Basner cautioned that REM sleep loss may be even more critical in newborns, who spend 50% of their sleep in REM compared to only 25% for adults. He advised against using noise machines for infants and young children.

Adults typically require 7 hours of sleep each night, and each minute of lost REM sleep is significant, according to Basner.

“I won’t dismiss it as trivial; these disruptions can impact wellbeing,” he remarked.

Basner speculated that “constant auditory input” might interfere with the brain’s sleep processes, but the specific reasons why pink noise affects REM sleep remain unclear.

While pink noise aided in falling asleep amidst traffic sounds, earplugs proved more effective in blocking external noise.

The study has limitations; the small sample size of 25 adults was assessed over only seven nights. Over longer durations, participants might adapt to pink noise and revert to normal sleep patterns. Also, the environmental noise included atypical sounds like jet engines, which might also be acclimated to over time.

Noise levels fluctuated nightly, leading to inconsistent sleeping conditions. Even within a controlled lab environment, many participants had never previously slept there, possibly affecting their sleep quality.

Dr. Rafael Pelayo, a clinical professor at Stanford’s sleep medicine division, emphasized that lab study outcomes may not fully reflect typical home environments.

“Though sleep is a biological necessity, sleep habits are learned,” he remarked, suggesting that people can adapt to various sleeping circumstances, similar to managing a snoring partner.

If you find a sound machine beneficial, Dr. Basner recommends using it at a low volume and setting a timer to avoid it running all night.

“I don’t want to undermine its popularity; there may be valid reasons many individuals rely on it,” he concluded.

Source: www.nbcnews.com

Doctor Seeks Individuals with Exceptional Stool Quality for Health Study

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Infectious disease expert Elizabeth Homan with stool donor Dmitri

Elizabeth Homan with her valuable stool donor, Mr. Dmitri

Elizabeth Homan

Fecal transplants have become a vital treatment for Clostridioides difficile relapses. However, sourcing high-quality stool donors remains a significant challenge.

“This process can be quite frustrating; only about 1 percent of those who respond to donor ads are in optimal health,” states Elizabeth Homan, an infectious disease specialist at Massachusetts General Hospital in Boston. “Finding qualified donors is tough, so we really appreciate their generosity.” Over the years, some donors have contributed their stools over 100 times.

Homan has overseen the fecal transplant program at her hospital for 15 years. Her responsibilities include collecting donations, processing them into oral capsules, and administering them to patients suffering from challenging intestinal conditions, particularly recurrent C. difficile infections that are resistant to antibiotics. The beneficial gut bacteria in the donor’s stool help to eliminate harmful bacteria in the recipient’s gut, alleviating symptoms.

To recruit donors, Homan advertises online, offering $1,200 for a month’s worth of stool donations.

Potential donors undergo a rigorous screening process. Many do not advance past the initial phone interview due to health criteria, such as being a healthcare worker or recent travel to Southeast Asia, both of which heighten the risk of transmitting drug-resistant bacteria. Furthermore, donors need to be within a healthy weight range, as past experiences showed that stools from obese donors could cause adverse reactions in recipients.

Individuals who pass the initial screening undergo comprehensive testing, including blood tests to evaluate their overall health, screenings for infectious diseases like HIV and COVID-19, and rectal examinations to detect any intestinal abnormalities.

Homan’s most successful donors are often fitness enthusiasts with balanced diets. One notable donor is a “semi-professional athlete, personal trainer, and gym owner.” Generally, superior stools result from diets rich in natural foods while minimizing ultra-processed options. “We’ve considered using only vegan donors, but in reality, my best donors have been omnivores,” she notes.

Donation periods typically last from 2 to 4 weeks. During this time, donors are encouraged to make frequent visits to the hospital for donations. “They often have regular bowel movements, coming in around the same time daily after a coffee boost,” Homan explains. Each stool sample is collected in a plastic container and processed in the lab.

Fresh stool is quickly converted into capsules. “I blend it with saline and strain it through a graduated mesh filter,” Homan explains. After additional processing, the liquid is encapsulated. “It’s not pleasant, but you adapt,” she adds.

After each donation period, donors are screened again for any infections, making sure they are not exposed to pathogens like Salmonella. If they test positive, the capsules are discarded, and new donor sourcing begins.

Despite these hurdles, Homan expresses her passion for the job, highlighting the life-changing effects fecal transplants can have on patients. Recently, a patient who was unable to work has returned to a 30-hour work week thanks to the transplant capsules. “I continue this work because it makes a meaningful difference in people’s lives,” she remarks.

Sadly, Elizabeth Homan is nearing retirement and is struggling to find a replacement. “I keep asking my department, ‘Who’s willing to help?’ The response has been silence. It seems they’re overwhelmed with the basics and hesitant to take on this responsibility.”

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Source: www.newscientist.com

Unlock Better Sleep: How Dietary Fiber and Microbiome Research Connect to Enhanced Sleep Quality

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How Microbial Activity in the Gut Affects Sleep Quality

Oleksandra Troian / Alamy

Research indicates that diet, particularly dietary fiber, may significantly influence sleep quality.

Prior studies have revealed associations between various sleep states and the gut microbiome. Notably, a lack of bacterial diversity suggests that improving dietary habits could enhance sleep quality. However, no study has yet identified specific microbial species consistently linked to sleep quality and the exact foods that support their growth.

A new systematic review by Wang Che from China’s Shandong First Medical University analyzes 53 observational studies comparing the gut microbiota of individuals with sleep disorders to those without, encompassing 7,497 individuals with sleep disorders and 9,165 without.

The researchers discovered that the overall bacterial species diversity, termed alpha diversity, was significantly lower in individuals suffering from sleep disorders. Those with insomnia, obstructive sleep apnea, or REM sleep behavior disorder showed a notable decrease in anti-inflammatory, butyrate-producing bacteria like Faecalibacterium, alongside an increase in pro-inflammatory bacteria such as Collinsella.

This underscores the importance of dietary fiber, as Faecalibacterium produces butyrate, which provides energy for colon cells, strengthens the intestinal barrier, and reduces inflammation, according to recent studies.

Researchers highlighted that microbial signatures could serve as criteria to differentiate clinical symptoms from other sleep-related issues, thus enabling targeted treatments.

According to Catherine Maki from the National Institutes of Health in Maryland, this study aligns with her group’s ongoing research, which has found a similar connection between sleep and butyrate production from Faecalibacterium.

“Collectively, these consistent findings highlight plausible microbiome metabolic pathways that link sleep and host physiology, warranting direct testing in future mechanistic and interventional studies,” Maki notes.

“This meta-analysis supports the correlation between Faecalibacterium and insomnia,” states Elizabeth Holzhausen from Michigan State University. “However, since these studies are observational, causality cannot be established.”

One hypothesis is that insomnia may negatively impact dietary fiber intake, leading to reduced levels of Faecalibacterium. Alternatively, reduced butyrate from Faecalibacterium could influence sleep quality, as suggested by research findings.

Controlled intervention studies are essential for confirming the causal relationship, Holzhausen emphasizes.

The findings further highlight the vital role of the gut microbiome in our sleep health and reveal potentially significant changes in gut microbial signaling pathways related to sleep-influencing processes such as hormone release, metabolism, and inflammation.

Maki suggests that while it’s too early to recommend increasing fiber intake to improve sleep, there is emerging evidence regarding dietary aspects that may influence sleep.

Avoiding caffeine is advisable, as it may delay the onset of sleep, particularly in high doses or when consumed late in the day. Furthermore, alcohol can disrupt sleep, despite common misconceptions that it aids sleep. Additionally, eating too close to bedtime can impair sleep quality.

Some evidence suggests that certain foods, like tart cherry juice, can improve sleep quality. Improving overall dietary quality and increased fiber intake is linked to better sleep quality, though the specific dietary components influencing this relationship remain unclear.

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Source: www.newscientist.com

AirPods Pro 3 Review: Enhanced Battery, Superior Noise Cancellation, and Improved Sound Quality | Apple

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Apple’s highly acclaimed AirPods Pro Bluetooth earphones have returned in their third generation, featuring an improved fit, extended battery life, built-in heart rate sensors, and enhanced noise cancellation, all while maintaining a look similar to their predecessors.


Although three years have elapsed since the previous version, these earphones remain exclusively white. The differences between them and earlier generations are subtle and require close inspection.

Priced at £219 (249 Euros/$249/$429), the AirPods Pro 3 is £30 less expensive in the UK than its predecessor at launch and features compatibility with AirPods 4.

The earphones have undergone slight shape refinements to enhance comfort, especially during prolonged listening sessions exceeding three hours. The package includes five sizes of tips, but if you prefer non-silicone earphones, these won’t offer much difference.




The stems maintain their previous length, but the earphones’ shape has been optimized to better align the tips with the ear canal. Photo: Samuel Gibbs/The Guardian

Most functions are standard for modern earphones. Squeeze the stems for playback controls, swipe for volume adjustment, or remove them to pause music. They support features introduced with older Apple earphones, like the Shutter Remote Camera app and live translation using the translation app on your iPhone. The latter currently supports only English, French, German, Portuguese, and Spanish but works surprisingly well for casual conversations.

A notable drawback is that others still need to read translated speeches from their iPhones. This feature proves most useful for announcements and audio guides, especially for singular language translations in transportation hubs and museums.

One of the standout hardware features is heart rate monitoring through the sensors on the earbuds, similar to Apple’s PowerBeats Pro 2 fitness band. This can be utilized with over 50 workout tracking options via the Fitness app or select third-party apps on your iPhone. Its readings align closely with those from a Garmin Forerunner 970 or an Apple Watch during activities like walking and running. Additionally, the earphones boast an IP57 water resistance rating, making them more resilient to rain and sweat than previous models.

Battery life has improved, extending to at least 8 hours of playback, along with competitive noise cancellation on every charge, making them suitable for most listening durations.




The compact flip-top case provides two full charges for a combined playback time of 24 hours (6 hours shorter than the previous generation), with just 5 minutes of charging offering an hour of listening time. Photo: Samuel Gibbs/The Guardian

Specifications

  • Connectivity: Bluetooth 5.3, SBC, AAC, H2 chip, UWB

  • Battery life: 8 hours of ANC playback (24 hours in case)

  • Water resistance: IP57 (buds and case)

  • Earphone dimensions: 30.9 x 19.2 x 27.0mm

  • Earphone weight: 5.6g each

  • Charging case dimensions: 47.2 x 62.2 x 21.8mm

  • Charging case weight: 44g

  • Case charging: USB-C, QI Wireless/Magsafe, Apple Watch

Richer Sound and Exceptional Noise Cancellation




The silicone tips are designed to slightly expand for a better seal, enhancing both music quality and noise cancellation. Photo: Samuel Gibbs/The Guardian

The audio experience with the third-generation AirPods Pro is impressive, offering louder playback with an expansive soundscape. They maintain powerful, well-regulated bass while enhancing the spaciousness of larger tracks. The sound is detailed and balanced, catering to various genres, with ample power when needed. However, like other Apple headphones, they can occasionally feel a tad clinical, lacking warmth and rawness in some tracks, which may lessen the impact of deep bass notes. Nevertheless, few earphones can outshine these in terms of price and size.

Apple’s implementation of spatial audio for movies is unrivaled, and while its efficacy in spatial music remains mixed, it provides an immersive experience with compatible devices and services.




The AirPods Pro offers the ideal blend of earphones and compact carrier, easily portable in your pocket. Photo: Samuel Gibbs/The Guardian

Enhanced noise cancellation is arguably the most significant upgrade. Apple claims it’s twice as effective as the already excellent AirPods Pro 2. In direct comparisons, the AirPods Pro 3 effectively mitigates street noise, including traffic sounds and engine roars. It stands up impressively against the class-leading Sony WH-1000XM6, renowned for their over-ear design.

They also excel in dampening disruptive high frequencies, such as keyboard clicks and conversations, making them well-suited for commuting and office environments.

Apple’s leading transparency mode is equally outstanding, allowing for natural sound experiences, as if the earbuds aren’t being worn at all. Sudden loud noises can be managed, making them handy in busy streets and while using hearing aids.

Call quality is superb, with my voice sounding clear and natural, whether in quiet settings or bustling environments, with only minimal ambient sounds noticeable during calls.

Sustainability




The charging case supports USB-C, Magsafe, QI, or Apple Watch charging, and includes new features like Limit Charging to prolong battery life. Photo: Samuel Gibbs/The Guardian

Apple does not specify the expected battery lifespan. Typically, similar devices retain at least 80% of their original capacity after 500 full charge cycles. The earphones are not repairable, but Apple provides battery servicing for £49 per earphone or case, with replacement for lost or damaged items starting from £79. Repair specialist iFixit graded these earphones a 0 out of 10 for serviceability.

Both the AirPods and their cases include 40% recycled materials, including aluminum, cobalt, copper, gold, lithium, plastic, rare earth elements, and tin. Apple offers trade-in and recycling programs, detailing the environmental impact of its earphones in their reports.

Price

The price for the AirPods Pro 3 is £219 (249 Euros/$249/$429).

For context, AirPods 4 starts at £119, while Beats PowerBeats Pro 2 are priced at £250. The Sennheiser Momentum TW4 retails for £199, Google Pixel Buds Pro 2 cost £219, Sony WF-1000XM5 is available for £219, and the Bose QuietComfort Ultra Earbuds are priced at £300.

Verdict

AirPods Pro 3 takes an already impressive second-generation model and enhances virtually every aspect.

A longer battery life and a more comfortable fit for extended listening sessions are welcome improvements. Additionally, proper water resistance and integrated heart rate monitoring cater well to fitness enthusiasts, particularly for activities like powerlifting where wearing a watch may not be practical. The live translation feature performs better than anticipated, despite its conversational limitations.

The standout element is the remarkably effective noise cancellation, comparable to top-tier over-ear headphones, while being much easier to transport.

Audiophiles may notice a slightly clinical sound profile, and full functionality requires an iPhone, iPad, or Mac. Compatibility with Bluetooth devices like Android phones, PCs, and gaming consoles may not offer the same features. However, the significant drawback remains its difficult repairability, a common issue for true wireless earbuds, diminishing its rating.

Pros: Highly effective noise cancellation, excellent sound quality, industry-leading transparency, water resistance, integrated HR monitoring, seamless controls, advanced features when paired with Apple devices like spatial audio, remarkable comfort, and a premium case with excellent call quality.

Cons: Challenging to repair, premium price, lacks high-resolution audio support, minimal functionality with Android/Windows, similar appearance to its predecessor, and only available in white.




The AirPods Pro 3 is among the finest earphones available, especially for iPhone users. Photo: Samuel Gibbs/The Guardian

Source: www.theguardian.com

Incredible Workouts to Enhance Your Sleep Quality

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Yoga has emerged as the leading practice for enhancing sleep

ShutterStock/Drazen Zigic

After a poor night’s sleep, the last thing I feel like doing is working out, even though I know it could help me rest better. The idea of intense physical activity when I’m sleep-deprived doesn’t seem appealing. However, I was astonished to discover that pushing yourself at the gym may not be the most effective strategy for improving sleep.

A recent review of 22 studies involving over 1,300 adults suffering from insomnia evaluated how seven exercise-related interventions influenced sleep. It was found that gentler activities like yoga and Tai Chi contribute more positively to sleep quality than intense workouts, such as strength training and aerobic exercises.

Yoga (as shown in the image) has been linked with an increase in total sleep time by nearly 2 hours compared to the control group, surpassing the effects of cognitive behavioral therapy. Traditional insomnia treatments boost sleep by merely about an hour, while Tai Chi results in a 52-minute increase. Instead of helping individuals sleep longer, exercising diminished the frequency of awakenings and shortened the duration it took to fall asleep.

I must admit I found these findings surprising. I had thought one reason exercise helps improve sleep is because it tires you out. However, the results suggest this isn’t the case; intense physical activity had minimal impact on sleep.

Then what about those gentle exercises that are major contributors to better sleep? Their effectiveness may lie in their focus on breath control and bodily awareness. Research indicates that mindfulness practices, along with activities like Yoga and Tai Chi, diminish the activity of the sympathetic nervous system, which manages our fight or flight responses. This leads to reduced blood pressure, heart rate, and levels of the stress hormone cortisol, ultimately alleviating depression and anxiety symptoms that can disrupt sleep.

However, these findings don’t suggest that other types of exercise lack value for those with insomnia. In fact, walking and jogging showed the most significant reductions in insomnia severity index scores, which assess sleep quality alongside its effects on mood, attention, and memory. Although walking and jogging didn’t seem to improve sleep duration, the reduced severity scores might indicate that mild aerobic activities assist in mitigating the daytime impacts of insomnia.

I truly appreciate this kind of research. I believe that exercise encompasses more than just pushing your body to its limits. If I’m not physically drained, I can find myself thinking that my workouts don’t matter, but that’s simply not accurate! Interestingly, reducing the intensity seems to have its unique advantages, including enhanced sleep quality. Plus, unrolling my yoga mat feels more manageable after a night of poor sleep than logging miles on the treadmill.

Grace Wade is a health reporter for New Scientist based in the US

These articles are published weekly at NewsCientist.com/Maker

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Source: www.newscientist.com

A Blanket of Wildfire Smoke Triggers Air Quality Alerts for Millions Amidst Our Expansive Skies

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On Monday, air quality warnings were issued for millions across the upper Midwest and northeastern regions as smoke from wildfires in Canada moved into these areas.

Areas expected to experience hazy skies include Minnesota, Wisconsin, Michigan, Northern Indiana, Pennsylvania, New York, New Jersey, Connecticut, Massachusetts, Vermont, Rhode Island, New Hampshire, Delaware, and Maine. The National Weather Service reports.

In Canada, approximately 200 wildfires remain uncontrolled, including 81 in Saskatchewan, 159 in Manitoba, and 61 in Ontario. Data from Canada’s Interagency Forest Fire Centre indicates that over 16.5 million acres have been affected this year, which may lead to a record-breaking wildfire season.

High-pressure systems in the Midwest are trapping smoke, contributing to air quality issues that may last for several days. According to the Michigan Department of Environment, Great Lakes, and Energy.

The Air Quality Index on Monday across 14 Midwest and Northeastern states indicated conditions ranging from “moderate” to “unhealthy” for the general population.

Wildfire smoke is particularly hazardous as it contains fine particles measuring less than 2.5 micrometers in diameter, which is about 4% the width of an average human hair. This type of pollution can penetrate deeply into the lungs, exacerbating asthma, lung cancer, and other chronic respiratory conditions.

High levels of air pollution can lead to inflammation and weaken the immune system. Infants, children, the elderly, and pregnant women are especially at risk during poor air quality conditions.

Research indicates that climate change contributes to the frequency and intensity of wildfires. Elevated temperatures can desiccate vegetation, elevating the likelihood of wildfires igniting and spreading quickly.

Cities experiencing poor air quality on Monday included Milwaukee, Detroit, Buffalo, Albany (New York), Boston, and New York City. Multiple alerts are in effect until Tuesday, as reported by the Weather Bureau.

In the western regions, several wildfires are causing additional air quality concerns. Over 65,000 acres have burned in California’s Los Padres National Forest, where high temperatures and dry conditions are fueling the growth of wildfires.

In Colorado, the Air Quality Index also displayed “moderate” readings on Monday.

“If the smoke becomes thick in your area, we advise you to remain indoors,” stated the Colorado Department of Public Health and Environment. This recommendation particularly applies to individuals with heart diseases, respiratory issues, young children, and the elderly. If smoke levels are moderate to intense, consider reducing outdoor activities.

Source: www.nbcnews.com

Improved Air Quality Linked to Rise in Urban Heat Waves

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Heatwaves are increasing in frequency as global smog diminishes

Claudio Reyes/AFP via Getty Images

As the world works to eliminate harmful aerosol pollution, heatwaves are becoming more common, exposing the intensifying effects of greenhouse gases in the atmosphere. This warming trend is particularly pronounced in densely populated areas where air pollution typically rises.

“Mitigating aerosol pollution is imperative for public health,” states Geeta Persad from the University of Texas at Austin. “However, we must acknowledge that this reveals specific risks that become magnified in populated regions.”

Aerosol pollution, primarily stemming from fossil fuel combustion, has effects that generally counteract those of greenhouse gases. While gases like carbon dioxide trap heat, aerosols tend to cool the atmosphere by reflecting sunlight either directly or by altering cloud behavior. Some estimates suggest that aerosol pollution masks half of the global warming effect of greenhouse gases.

This interplay means that cleaning up air pollution can inadvertently amplify climate warming effects. However, the specific ways in which aerosol variations impact heat in populous regions have remained unclear until now.

To analyze this more precisely, Persad and her team utilized climate models to evaluate how aerosol levels influence the occurrence of land heatwaves, examining both historical data and future projections. They defined a heatwave as three consecutive days where temperatures would rank among the hottest 10% for that time of year in a pre-industrial context.

Throughout most of the 20th century, the team discovered that aerosols mitigated the rise in heat wave occurrence driven by increasing greenhouse gases. However, since 2005, this trend has shifted as aerosol reductions have accelerated the growth of global heatwaves by nearly two days each decade.

The researchers also found that aerosols exert a more significant influence on heatwave frequency in densely populated regions compared to less populated areas. In certain regions, the reduction of aerosol levels has proven to be more than twice as impactful as the increase in greenhouse gas concentrations. “If you examine the spatial distribution of aerosol concentrations, they correlate strongly with areas of high population,” remarks Persad.

In a scenario where greenhouse gas emissions rise significantly while aerosol levels gradually decrease, the team predicts a notable escalation in the frequency of heatwaves. By 2080, the number of heatwave days in densely populated regions could surge from about 40 to over 110 days annually.

“What sets this study apart is its focus on daily timescale data. You can genuinely perceive the decrease in aerosol levels across different areas of the globe,” says Shiv Priyam Raghuraman at the University of Illinois, Urbana-Champaign, who was not involved in the study. He highlights that these results arise from a single model under the most severe greenhouse gas emission scenario.

“These findings are compelling and enhance existing literature on the significant role aerosols play in climate extremes,” states Daniel Westerbert from Columbia University in New York. “It will be fascinating to see how other models might differ in their findings, and whether past observations support these results.”

Another significant uncertainty lies in the future trajectory of aerosol concentrations in the coming years, adds Persad. “Current emissions scenarios could determine aerosol trends over the next three decades,” she remarks.

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Source: www.newscientist.com

A Fruit and Vegetable-Rich Diet May Enhance Sleep Quality

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A recent study conducted by researchers at the University of Chicago School of Medicine and Columbia University revealed that increasing fruit and vegetable intake to five cups daily, as recommended by dietary guidelines, is linked to a 16% enhancement in sleep quality.

Borge et al. Increasing fruit and vegetable intake during the day was found to be associated with improved sleep that same night. Image credit: Guillermo Gavilla.

Observational studies have shown that diets of high quality correlate with better sleep quality.

Despite this, a deeper comprehension of this relationship is essential, as dietary changes could represent novel and natural methods for enhancing sleep.

“We have been striving to maximize our lives,” stated Dr. Esla Tasari, director of the Sleep Center at the University of Chicago.

“The temporal associations and objectively measured outcomes from this study are significant in addressing gaps in crucial public health knowledge.”

Earlier observational research indicated that higher consumption of fruits and vegetables was connected to improved self-reported overall sleep quality, but this latest study is the first to establish a temporal link between specific daily food choices and objectively measured sleep quality.

Healthy young adults in this study recorded their daily food intake through an app and wore wrist monitors to allow researchers to obtain objective measurements of their sleep patterns.

The researchers focused on sleep fragmentation, which indicates the frequency of awakenings during sleep or transitions into deep sleep throughout the night.

They discovered that meal choices had significant correlations with differences in sleep quality the following night.

Participants consuming more fruits and vegetables during the day experienced deeper, more uninterrupted sleep that night, similar to those who included healthy carbohydrates like whole grains.

Based on their findings and statistical modeling, scientists estimate that those who adhere to the CDC’s recommendation of five cups of fruits and vegetables per day could see a 16% improvement in sleep quality compared to those who do not consume these foods.

“A 16% difference is substantial,” said Dr. Tasari.

“It’s remarkable that such significant changes can be detected within just 24 hours.”

Future studies will aim to establish causal relationships, expand the findings to diverse populations, and explore the underlying mechanisms of digestion, neurology, and metabolism that may clarify the positive effects of fruits and vegetables on sleep quality.

Nevertheless, based on current evidence, the authors strongly recommend maintaining a diet rich in complex carbohydrates, fruits, and vegetables for optimal long-term sleep health.

“They are making a difference,” remarked Dr. Marie Pierre St. Onge, director of the Center for Sleep and Circadian Research at Columbia University Irving Medical Center.

“Minor adjustments can impact your sleep. It’s empowering to know better rest is within your control.”

The study was published in the journal Sleep Health this month.

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Header L. Boge et al. We anticipate that increased daytime intake of fruits and vegetables will lead to less disrupted nighttime sleep in younger adults. Sleep Health Published online on June 11th, 2025. doi: 10.1016/j.sleh.2025.05.003

Source: www.sci.news

Canadian Wildfire Smoke Impacts Air Quality in the Midwest and Northeast

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Smoke from Canadian wildfires is prompting air quality warnings across the Midwest and Northeastern US this Thursday as forests in North Korea continue to burn at a historic rate reminiscent of the extreme fire season of 2023.

Air pollution levels have surged in cities including Minneapolis, Green Bay, Indianapolis, Cincinnati, Columbus, Pittsburgh, Washington, Philadelphia, and New York due to smoke and ozone from the heat.

According to Canada’s Interagency Forest Fire Centre, the ongoing fire season in Canada has already resulted in the burning of around 8.6 million acres. With three months left in the season, this figure has exceeded the seasonal average since 1983, which stands at approximately 6.5 million acres.

The current burning rates in Canada are mirroring those from 2023, known as the year with the highest smoke exposure in modern American history, raising concerns that the current season may reflect that intensity.

“We’re facing significant challenges with our response,” stated Robert Gray, a wildfire ecologist in Chilliwack, British Columbia. “Most forecasts for Canada indicate above-average temperatures, while precipitation levels remain below normal.”

In past years, nearly 43 million acres burned in Canada by the end of the fire season.

Gray noted that much of the smoke this year originates from the densely packed boreal forests found in northern British Columbia, Alberta, and Saskatchewan. Wildfires typically occur in these regions during May and June, coinciding with longer days and rising temperatures. The subsequent developments depend heavily on weather conditions.

“It could be a brief two-week event. The huy starts burning, aspen gets involved, and then weather changes,” Gray explained, alluding to the common aspen trees in these forests. “If aspen and rain don’t clear out, the fires may persist.”

According to the BC Wildfire Service, parts of northern British Columbia have been experiencing drought conditions since 2022. Some forecasts predict an “increased likelihood of significant and challenging fires.”

Gray mentioned that drought, low snowfall during winter, and heightened “overwinter” fires are factors contributing to increasingly busy fire seasons.

These overwintering fires continue smoldering beneath forest debris and peat, reigniting in spring.

“There was a fire that started in 2023, lingering through winter into 2024,” Gray remarked. “Some of the same fires have reemerged this year.”

As northern British Columbia faces these wildfires, smoke is often transported to the US by the jetstream, a high-altitude air current that influences pressure and weather changes in the Northern Hemisphere.

“It’s a consistent pattern that remains stable. As long as central and northern BC are burning, this pattern channels smoke into the central and northeastern US,” Gray stated.

Sometimes the smoke stays aloft, creating hazy skies without significant ground-level air quality deterioration. However, it can pose a risk to health.

Wildfire smoke is increasingly hazardous across the US, reversing decades of improvements in air quality achieved under the Clean Air Act.

Inhaling wildfire smoke can cause inflammation, particularly as particles enter the lungs and bloodstream, compromising the immune system. This exposure can elevate the risks of asthma, lung cancer, and other chronic respiratory diseases, especially in vulnerable populations such as the elderly, pregnant individuals, infants, and children. Additionally, wildfire smoke is linked to respiratory illnesses, premature births, and miscarriages.

Evan Bush

Evan Bush is a science reporter for NBC News.

Kathryn Prosive I contributed.

Source: www.nbcnews.com

Report shows nearly 50% of Americans residing in areas with insufficient air quality

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A total of 156 million residents in the US, approximately 46% of the population, resided in areas with poor air quality that received an “F” grade from the American Lung Association due to ozone or particle pollution. This indicates a decline in the country’s air quality standards, as per the Association’s 26th Annual Air Quality Data Analysis.

An examination of data from 2021 to 2023 revealed a rise of about 25 million individuals living in unhealthy environments compared to the previous year’s survey results.

The report highlights the impact of climate change, such as increased heat, drought, and wildfire smoke, contributing to changes in air quality nationwide.

Katherine Pruitt, senior director of Clean Air Policy, expressed surprise at the significant increase in the number of people residing in areas with poor air quality, especially due to ozone degradation. She emphasized the influence of hot and sunny weather conditions on this deterioration.

In 2023, the final year of the Lung Association’s analysis, global temperatures recorded by the National Oceanic and Atmospheric Administration were among the highest on record. The US experienced the fifth-highest temperatures in its history.

The spike in ozone levels, particularly in states like Texas facing intense heatwaves in 2023, was evident. Pruitt pointed out how towns like Del Rio endured temperatures exceeding 100 degrees for extended periods.

Additionally, heavy wildfire smoke significantly impacted air quality, with regions like the northeast being exposed to the most smoke in modern American history due to wildfires in Canada.

The growing threat of wildfire smoke has hindered progress made under the Clean Air Act, releasing particles that pose health risks. Recent studies indicate that around 25% of Clean Air Act progress has been reversed due to increased wildfire smoke.

Pruitt warned of ongoing environmental degradation and its consequences, emphasizing the need to address emission sources to combat these challenges.

The EPA’s plans to roll back environmental regulations, including revisiting programs under the Clean Air Act, have raised concerns about future air quality standards.

Bakersfield, California, was identified as having the most polluted air in the country from 2021 to 2023, ranking high for both short-term particle pollution and ozone pollution.

Source: www.nbcnews.com

Unexpected connection between gut microbiota and quality sleep

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A bad night's sleep can be caused by many things, including screen time, stress, and drinking too much alcohol. Now, there's another culprit. It's the microorganisms in your intestines.

This article is part of a special series exploring important questions about sleep. Click here for details.

It's long been known that our microbiome has a powerful influence on our health, but new research has revealed that this extends to our sleep as well. But it's a complex two-way relationship. “The microbiome influences your sleep, and sleep influences the microbiome,” he says. elizabeth holzhausen At the University of Colorado Boulder. The good news is that there are ways we can intervene.

At first glance, the connection between your stomach and sleep patterns may not be obvious, but a growing body of research is revealing how they influence each other. For example, a 2023 study of 720 people found that: Diversity of microorganisms in the gut It was associated with improved sleep quality. Similarly, researchers at King's College London (KCL) and other institutions, in collaboration with personalized nutrition company Zoe, surveyed nearly 1,000 people and found that irregular sleep patterns are associated with sleep disorders. It turned out. Increase in the number of “undesirable” bacterial species It is associated with poor health.

Furthermore, changes in the composition of the gut microbiome are associated with several sleep states. For example, rapid eye movement sleep behavior disorder, in which sleepers physically act out their dreams during REM sleep, Decrease in intestinal bacteria It produces the short-chain fatty acid butyrate, which causes an increase in bacteria that worsens inflammation.

Source: www.newscientist.com

The importance of sleep quality and the challenges of measuring it

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How did you sleep last night? Your response may depend on how long you were in bed, how much of that time you spent tossing and turning, or whether you felt rested. However, it may also depend on whether you exercised today, the messages on your wearable device, or even when you were asked.

This article is part of a special series exploring important questions about sleep. Click here for details.

“Everyone has a different definition of sleep quality, and that’s the problem,” sleep researchers say. nicole tan At the University of Warwick, UK.

While sleep quality and what defines it is still a mystery that scientists are still trying to figure out, a good night’s rest involves a series of sleep cycles, or distinct sequences of stages of brain activity that you experience during sleep. We know that (see the image below). And for most of us, each stage of these cycles is necessary to wake up feeling refreshed. The average person experiences four to five complete menstrual cycles per night, and any disruption to this can have negative effects on your health in both the short and long term.

“Poor sleep quality is associated with many negative physical health effects,” he says. Jean-Philippe Chapou At the University of Ottawa, Canada. As with what you’d expect from not getting enough sleep (see Why your chronotype is key to knowing how much sleep you need), these include an increased risk of: cardiovascular disease, stroke, high blood pressure, type 2 diabetes and weight gain.

Although there is no clear consensus on what defines sleep quality, researchers and doctors often analyze sleep using electroencephalograms (EEGs), which track brain activity during sleep.

Source: www.newscientist.com

Lisa Nandy urges YouTube and TikTok to promote higher quality content for children

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Britain’s Culture Secretary Lisa Nandy has reached out to video-sharing platforms like YouTube and TikTok, urging them to prioritize the promotion of high-quality educational content for children.

Recent data indicates a substantial shift in children’s viewing habits, with a significant decrease in TV consumption over the past decade. Instead, children, aged between 4 and 8, are increasingly turning to platforms like YouTube and TikTok for entertainment, according to Nandy.

During an interview on BBC Radio 4’s Today program, Nandy mentioned the government’s intention to engage in dialogue with these platforms initially, but warned of potential interventions if they do not respond positively.

She emphasized the importance of the high-quality educational content produced in the UK, which plays a crucial role in informing children about the world, supporting their mental well-being and development, and providing entertainment. However, she expressed concerns about the lack of similar quality in content on video-sharing platforms compared to traditional broadcasters.

Former BBC presenter Floella Benjamin, acting as a guest editor on the show, described these platforms as a “wild west” filled with inappropriate content.

Nandy highlighted the government’s efforts to remove harmful content for children and stressed the need to address deeper issues related to the quality of content children consume.

She acknowledged the democratic nature of platforms like YouTube, where individuals can build careers from home, but also emphasized the responsibility to ensure the content is appropriate for young viewers.

Regarding the decrease in funding for children’s television, Nandy mentioned the Young Audiences Content Fund as a positive initiative to boost production. She believed that increasing investment might not be the solution, as the focus should be on reaching all children, including those who do not watch traditional TV.

Despite concerns raised by Benjamin about a crisis in children’s television, Nandy praised the sector as a valuable asset for Britain, from networks like CBeebies to beloved shows like Peppa Pig. She emphasized the government’s role in supporting and nurturing this content, even if it may not be highly profitable.

Nandy admitted the challenges of monitoring her own son’s online activities but commended the platform’s filtering mechanisms and highlighted the positive influence of educational content like news programs.

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Nandy confirmed contacting Ofcom to elevate the importance of children’s television in their regulatory considerations and urged a review of public broadcasting, anticipated in the summer.

She stressed the necessity of balancing the influx of investment from platforms like Netflix and Disney with preserving and promoting uniquely British content without overshadowing it.

This involves forming partnerships with public broadcasters to expand online content availability and ensure adequate recognition and support for their contributions, as per Nandy’s statements.

Source: www.theguardian.com

A recent review suggests that using weighted blankets can be beneficial for enhancing sleep quality

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Weighted blankets can help improve sleep in adults with insomnia and mental health conditions such as anxiety and depression, but results are mixed in children, one researcher says. new review paper Published in American Occupational Therapy Journal.

dawson others. We suggest that occupational therapists should consider offering or recommending weighted blankets as a sleep intervention option for all age groups, taking into account individual preferences. Image credit: Martin de Arriba.

“Sleep is a basic human need, and not getting enough sleep can increase or worsen the risk of chronic diseases such as heart disease, stroke, and mental health problems, as well as It can cause health problems.” Dr Suzanne Dawson, researcher at Flinders University.

“In occupational therapy, weighted blankets are becoming common among many age groups as an assistive technology, but there are no current clinical guidelines for their use.”

In a review study, Dr. Dawson and fellow authors considered 18 existing studies that investigated the overnight use of weighted blankets.

They found significant evidence supporting the use of weighted blankets to improve sleep in adults.

“Weighted blankets appear to offer a specific, non-drug intervention to improve sleep quality,” says Dr. Dawson.

“Adults who used the blanket reported improved sleep, reduced use of sleeping pills, and even improved mood and pain management.”

Despite strong evidence for use in adults, research on the use of weighted blankets in children is mixed, and there are limits to their ability to improve sleep in children with conditions such as ADHD and autism spectrum disorders.

“However, some parents report positive results with the use of weighted blankets, and some studies have shown that children’s daily functioning improves after using weighted blankets.”

“Parents often reported that when using blankets, their children seemed more relaxed, less anxious, and more focused in their daily lives. This has been shown to improve children’s overall health can have long-term effects,” Dr. Dawson said.

The authors note that for children and adults with cognitive impairments, the blankets used should be easy to remove on their own.

Although the findings indicate that overnight use of weighted blankets is recommended for adults and can be continued for children, the next step is to develop clear clinical guidelines for blanket use.

“This scoping study was conducted to inform change in practice and its findings were used to change state-wide protocols for the use of weighted blankets across South Australia’s public mental health services. I’m very happy about that,” Dr. Dawson said.

“Blankets come in many different types, including those with beads and chains, and those of varying weights, but there are still no standardized recommendations including type, weight, frequency of use, and duration. .”

“More rigorous research is needed to find out how best to use them, but the practical use of weighted blankets requires further research.”

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Suzanne Dawson others. 2024. Weighted Blankets as a Sleep Intervention: A Scope Review. American Occupational Therapy Journal 78 (5): 7805205​​160;doi: 10.5014/ajot.2024.050676

Source: www.sci.news

NASA Inspector General Criticizes Boeing’s Quality Control With Scathing Review

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Many of the deficiencies identified in the report were not addressed.

Boeing’s response processes for past defects have been ineffective, and the company has not been responsive in taking corrective action for recurring quality control issues,” the company stated.

When asked for comment, a Boeing representative directed NBC News to NASA.

In a written response included in the report, Katherine Corner, deputy administrator for NASA Headquarters’ Exploration Systems Development Mission Directorate, emphasized NASA’s commitment to the highest technical and programmatic standards.

NASA is dedicated to ensuring that its personnel and contractors are qualified, well-trained, and prioritize mission safety,” Corner expressed.

The report suggested various recommendations, such as imposing financial penalties on Boeing for not meeting quality control standards. However, NASA opted not to levy any financial penalties.

The Space Launch System, standing at 322 feet tall, along with the Orion spacecraft, aims to launch astronauts to the moon to establish a base on its surface.

NASA successfully conducted an uncrewed test flight of the Space Launch System rocket and Orion spacecraft in 2022 (Artemis I mission). The following year, four astronauts are scheduled for a crewed flight around the moon (Artemis II mission).

Aside from the first-generation SLS rocket, NASA is also working on a more powerful model capable of carrying more cargo to the moon, led by Boeing as the prime contractor for the enhanced upper stage, known as the Space Launch System Block 1B, with work commencing in 2014.

Originally, an improved rocket system was planned to transport Artemis 2 astronauts into lunar orbit, but this timeline adjustment delayed development and raised costs, as stated by the inspector general.

According to a new report, the Block 1B version of the SLS could potentially cost up to $5.7 billion per launch.

This assessment marks a setback for NASA’s lunar return program, plagued by delays and budget overruns. Over the span of more than a decade, the agency has invested over $42 billion in the Space Launch System and Orion spacecraft.

Last year, NASA’s inspector general estimated each Artemis launch to cost $4.2 billion.

Source: www.nbcnews.com

Cooking releases artificial flavors that enhance the quality of lab-grown meat

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Flavored cultured meat

Yonsei University

Lab-grown meat could potentially taste better thanks to aroma chemicals that activate when cooked and give off a meaty scent – or, if you prefer, coffee or potato.

Meat grown from cell cultures has already been produced in a variety of forms, such as steaks and meatballs, that resemble slaughtered meat, but matching the taste has proven harder: The flavor of traditional meat is too complex and unstable to withstand the lengthy lab process.

One of the key components of cooked meat's flavor is the Maillard reaction, named after the French chemist who discovered that temperatures between 140 and 165°C (280 and 330°F) give cooked foods their distinctive flavor. Jinkee Hong Researchers at Yonsei University in Seoul, South Korea, say they have devised a way to simulate the Maillard reaction by adding “switchable flavour compounds” (SFCs) to a 3D gelatin-based hydrogel called a “scaffold” that remains stable during meat cultivation.

When heated to 150°C, the chemicals “switch on” and release flavors, making the cultured protein more palatable: “When we heated SFC, it actually tasted like meat,” Hong says, though he declined to confirm whether the team actually ate meat.

These SFCs can also be used to create different flavor profiles. For example, the researchers say they tested three compounds, which produced flavors that mimicked roasted meat, coffee, roasted nuts, onion and potatoes. “You can diversify and customize the flavor compounds released from the SFCs,” Hong says.

One big problem is that the chemicals involved are not currently considered safe for human consumption. “Because the materials and culture media have not been approved as edible materials, we cannot guarantee their safety,” Hong says. “However, our strategy can be applied to conventional edible materials and we believe it would be safer than the materials we used in this study.”

Johannes Le Couteur Researchers at the University of New South Wales in Sydney, Australia, said they were skeptical of the study for a number of reasons, including that the flavor tests primarily used electronic noses to evaluate chemicals released, rather than humans judging whether a scent was appetizing.

“This type of material cannot feed humans,” Le Coutur said. “While cell-based meat is a promising technology concept, this particular flavoring method will never be able to provide safe, sustainable protein to low- and moderate-income communities in need.”

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Source: www.newscientist.com

Seven nations adhere to WHO air quality standards, US falls short

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A report released on Tuesday by Swiss air quality monitoring company IQAir suggests that the World Health Organization's air pollution ranking will increase in 2023 due to the continued reliance on fossil fuels and the impacts of climate change, posing a threat to human health. Only seven countries currently meet the WHO guidelines.

According to the report, Bangladesh, Pakistan, and India have the most polluted air, with particulate pollution levels exceeding the WHO’s recommendations by at least 10 times. More than 92% of countries and territories analyzed surpassed the guidelines for particulate matter pollution, including the United States.

The report also highlights that Canada has become the most polluted country in North America, primarily as a result of a record wildfire season that burned over 45 million acres. Smoke from Canadian wildfires has affected air quality in the United States and contributed to an overall increase in particle pollution from 2022 to 2023.

It is evident from this analysis that air pollution from fossil fuel combustion, coupled with other factors like wildfires exacerbated by climate change, is impacting human health globally. While some regions such as Western Europe are seeing improvements in pollution levels as economies shift towards electrification, in other areas, air pollution control measures are regressing. The report authors emphasize that air pollution transcends national borders, making it a global issue even for countries making efforts to reduce emissions.

According to IQAir, this data is based on inputs from over 30,000 air quality monitors in 134 countries and territories. The company installed monitoring devices to assess average annual pollution levels in cities and calculate people’s exposure to particulate matter around 2.5 microns in size, known as PM2.5, which is considered a crucial indicator of pollution’s impact on human health.

“PM2.5 particles can penetrate every cell in our bodies, from skin cells to lung and brain cells,” stated IQAir Global CEO Frank Hames at a press conference.

Air pollution is linked to approximately 6.7 million premature deaths annually, according to the World Health Organization. In the United States, air pollution levels experienced a slight increase, with Canadian wildfires causing a 30 to 50% rise in average annual pollution in cities like Milwaukee, Minneapolis, and Detroit in the upper Midwest.

A study by Stanford University researchers published in Nature last year revealed that smoke from wildfires in some parts of the US has reversed decades of air quality progress achieved through the Clean Air Act, with the situation now deteriorating.

In 2023, Americans, on average, inhaled more wildfire smoke compared to any other year on record, as per Stanford University researchers.

Wildfire smoke can deeply penetrate lungs and enter the bloodstream, increasing the risk of asthma, lung cancer, and other chronic respiratory diseases. Studies have also linked exposure to wildfire smoke to premature births and miscarriages.

Source: www.nbcnews.com

3D Printed Ice Blood Vessels Could Enhance the Quality of Artificial Organs

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3D printed blood vessel ice template

Philip LeDuc and others/Carnegie Mellon University

Complex artificial organs can be created by 3D printing molds of veins, arteries, and capillaries in ice, casting them in organic materials, and melting the ice to form delicate, hollow networks. This leaves space for the complex vascular grafts required for the development of laboratory-cultured internal organs.

Researchers have been working for decades to develop artificial organs to meet the high global demand for transplants such as hearts, kidneys and livers. However, creating the vascular network necessary to keep them alive remains a challenge.

Existing technology can grow artificial skin and ears, but the meat and organ materials disappear when they are more than 200 micrometers away from blood vessels. Philippe Leduc at Carnegie Mellon University in Pennsylvania.

“It's about twice the width of a hair. Once you get through that, and you can't access nutrients anymore, your cells start dying,” he says. Therefore, new processes will be needed to produce internal organs cheaply and quickly.

LeDuc and his colleagues experimented with printing blood vessels with meltable wax, which requires fairly high temperatures and can leave behind residue. “One day, out of the blue, a student of mine said, 'What if we tried using water, the most biologically compatible substance in the world?'” he says. “And I'm like, 'Oh, yeah.' It still makes me laugh. It's that simple.”

They developed a technique that uses a 3D printer to create a mold of the inside of an organ's blood vessels in ice. In the test, they embedded them in a gelatin material that hardens when exposed to ultraviolet light before the ice melts away.

The researchers used a platform cooled to -35°C and a printer nozzle that ejected hundreds of drops of water per second, allowing them to print structures as small as 50 micrometers in diameter.

LeDuc says the process is conceptually simple, but requires complete coordination. If the droplet is ejected too quickly, the droplet will not solidify quickly enough to create the desired shape, but if it prints too slowly, it will just form a clump.

The system is also affected by weather and humidity, so researchers are looking into using artificial intelligence to adjust the printer to different conditions.

They also used a version of water in which all the hydrogen was replaced with deuterium, a stable isotope of the element. This so-called heavy water has a high freezing point and helps create a smooth structure by avoiding unwanted crystallization. Deuterium is not radioactive, unlike some isotopes, and tests have shown it to be safe for creating artificial organs, LeDuc said.

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Source: www.newscientist.com

The Unseen Impact of Christmas Trees on Indoor Air Quality

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NIST researchers studied VOC emissions from living Christmas trees and their interaction with ozone. They found that monoterpenes were the main VOCs emitted, decreasing over time and reacting with ozone to produce low levels of formaldehyde. The study concludes that Christmas trees have minimal impact on indoor air quality for most people. Credit: SciTechDaily.com

  • Living Christmas trees emit chemicals called volatile organic compounds (VOCs).
  • Some of these VOCs can react with ozone, a reactive gas, to create chemical irritants in your home.
  • Levels of chemical irritants are low, but may be a potential concern for people who are sensitive to chemical irritants.

Every year during the holiday season, Americans purchase approximately 30 million live Christmas trees. Many families enjoy not only having a live tree in their home, but also smelling the fresh scent it produces. That odor comes from chemicals called volatile organic compounds (VOCs). However, little is known about how much is excreted and whether it affects health.

“Our noses are excellent chemical sensors,” says Dustin Poppendieck, an environmental engineer at the National Institute of Standards and Technology (NIST). “We know these trees are emitting something, but the question is how big is the source? We are investigating which chemicals and how much they are emitting. “We wanted to compare that to other chemical sources in the home,” he said.

To answer these questions, Poppendieck and his colleagues at NIST took a common type of Christmas tree (Dog pine) and sealed it inside a room. They then measured the amount and type of VOCs emitted over a 17-day period. They also investigated whether VOCs react with other components of indoor air to form new compounds.

The team’s findings were published in the journal indoor environment.

NIST researchers placed a common type of Christmas tree in a sealed room for 17 days and monitored and measured the chemicals released from it. These chemicals are called volatile organic compounds (VOCs), which give the smell of pine and can react with ozone to produce byproducts. Researchers found low amounts of these chemicals, which could be a potential concern for people who are sensitive to chemicals. Credit: M. King/NIST

The refreshing scent commonly associated with Christmas trees comes from a group of VOCs called . monoterpenesIt is also found in air fresheners, candles, and some personal care products. In the outdoors, conifer, a group of plants, including most Christmas trees, emit monoterpenes and can affect outdoor air quality. However, little is known about how much monoterpene is released when trees are cut down and placed indoors.

Research also shows that monoterpenes can react with ozone. Ozone in the upper atmosphere acts as a protective barrier against the sun. On the ground, chemical reactions with light produce ozone, which can cause symptoms such as coughs and throat irritation. Ozone also easily reacts with other chemicals in the air to form new compounds. Researchers were therefore interested in observing the effects of ozone in the presence of indoor trees.

They placed it inside an environmentally controlled room so they could measure the chemicals released by the tree in real time. Using a technique that can detect airborne organic compounds, known as proton transfer reaction mass spectrometry (PTR-MS), they measured the VOCs emitted over a 17-day period.

In the experiment, the researchers simulated a home environment. They decorated the tree with a typical holiday lighting setup and illuminated it with bright lights to mimic the day/night cycle. They turned off the lights every 12 hours and watered the tree daily. They brought in outside air at rates typical of a typical home and constantly measured chemicals in the indoor air.

Monoterpenes were the most abundant VOCs emitted by trees. They peaked on the first day and then decreased significantly by the third day. Poppendieck said the concentrations were initially similar to those found in plug-in air fresheners and new homes, but quickly dropped to nearly 10 times the original concentration. Researchers detected 52 different monoterpenes.

The researchers then injected ozone into the chamber to see how it affected indoor air chemistry. They found that ozone reacts with monoterpenes, producing byproducts such as formaldehyde, another type of VOC, and other reactive chemicals. It was found that the introduction of ozone further reduced monoterpene concentrations and increased formaldehyde levels, affecting indoor air chemistry. However, the amount of formaldehyde produced was relatively small at approximately 1 ppb. Formaldehyde concentrations in typical homes in the United States range from 20 to 30 ppb.

For people who are sensitive to VOCs, Christmas trees can be another source of watery eyes and noses, especially if you first bring them indoors. In that case, Poppendieck suggests opening a window near the tree to reduce exposure. In addition, the emission intensity naturally decays over time, so a newly cut tree can be left outdoors or in the garage for three days before bringing it into the house.

“But for most people, this shouldn’t be a big concern,” Poppendieck says. I will continue to decorate the Christmas tree at home. ”

Reference: “Jingle Bells, what do they smell like?” Indoor VOC Emissions from Living Christmas Trees,” by Dustin Poppendieck, Riley Robertson, and Michael F. Link, December 22, 2023. indoor environment.
DOI: 10.1016/j.indenv.2023.100002

Source: scitechdaily.com