Category: Environmental Effects

Categories : Cardiovascular Disease Environmental EffectsTags :

Exposure to Chronic Occupational Noise Drives up Blood Pressure

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Noise exposure is a known occupational hazard in some jobs, particularly for hearing loss, physical and psychological stress, and reduced concentration. A new study presented at the ACC Asia 2024 conference found in adult power loom weavers, chronic noise exposure not only increased their blood pressure overall, but also each year of exposure increased their odds of having high blood pressure by 10%.

“While the mechanism is still not well-explored, it is thought that the stress response by the body to chronic sound exposure causes hormonal imbalances that gradually leads to a permanent elevation of blood pressure,” said Golam Dastageer Prince, MBBS, MPH, medical officer at DGHS Bangladesh and the study’s lead author. “High blood pressure impacts more than a billion people worldwide and just 1 in 5 have it under control, yet it is a major cause of premature death. In addition to treating the high blood pressure through appropriate means, we must find ways to mitigate the exposure to the noise if we want to reduce the cardiovascular risk of these patients.”

Researchers at the Directorate of General Health Services in Bangladesh looked at 289 adult workers in selected weaving factories in the Araihazar sub-district of Narayanganj, Bangladesh, from January to December 2023. Participants took a face-to-face interview to complete a questionnaire covering sociodemographic variables, behaviour, dietary habits and family medical history. Blood pressure, height, weight and noise intensity were measured following standard procedures by the researchers.

The study cohort was predominantly male and married and were about 34 years of age on average. According to the researchers, a notable proportion of the cohort was illiterate. Workplace exposure duration averaged nearly 16 years, with noise intensity ranging from 96–111 decibels. In the United States the National Institute for Occupational Safety and Health has established the recommended exposure limits for occupational noise exposures to be 85 decibels on average over an eight-hour workday. Sounds at or below 70 decibels are generally considered safe.

According to Prince, none of the study population was found to be wearing ear protection personal protective equipment.

“Hopefully we can raise awareness of not only noise-induced hearing loss, but the impact of noise on blood pressure and workers’ behaviors and attitudes towards using personal protective equipment,” Prince said. “Pushing for structural improvements to industries may also help us improve the health safety of these workers.”

The study population had a 31.5% rate of high blood pressure with an additional 53.3% being prehypertensive. The study also found a positive correlation between blood pressure and noise exposure duration. Each year of exposure was found to increase high blood pressure odds by 10%, even after adjusting for age, body mass index and smoking status.

“As the study focused on workers exposed to more than 85 decibels noise for long periods of time, any profession causing workers to experience similar exposure might experience similar blood pressure impacts,” Prince said. “We definitely need more exploratory studies to reveal more information about the potential mechanisms and long-term health outcomes.”

Recent studies have shown that living near noise pollution, including highways, trains and air traffic, can have an impact on cardiovascular health. However, the current study may not apply to noise experienced during daily life. Noise pollution experienced near home typically ebbs and flows, while the industrial exposures in the study are typically continuous in pattern due to the machinery and remain at a constant sound level, according to Prince.

Source: American College of Cardiology

Categories : Cardiovascular Disease Environmental EffectsTags :

Benefits of UV Exposure may Outweigh Risks in Low-sunlight Countries

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The health benefits of spending time in the sun could outweigh the risks for those living in areas with limited sunshine, a UK study suggests. In low-sunlight locations such as parts of the UK, exposure to higher levels of ultraviolet (UV) radiation was linked to a drop in deaths due to cardiovascular disease and cancer.

Adapting public health advice to reflect both the risks and benefits of UV exposure may help to reduce disease burden and improve life expectancy in low-sunlight countries, the research team says.

Experts caution that measures should still be taken to protect the skin when UV levels are high, to prevent sunburn and the development of skin cancer.

Volunteer data

University of Edinburgh scientists used genetic and health information from the UK BioBank – an anonymised database of health details from volunteers – to examine the UV exposure of 395 000 people across the UK. Participants were restricted to those of white European descent, due to the role skin pigmentation plays in the body’s response to UV exposure.

The team applied two measures to identify those exposed to higher levels of UV. They used the geographical location of participants to calculate their average annual exposure to solar energy and, separately, whether they used sunbeds.

The findings were adjusted for other factors that might influence health – including smoking, exercise, social deprivation and gender – to reduce the chance that these factors were responsible for any of the changes observed.

Health impact

Living in locations with higher UV levels, for example Cornwall, was associated with a lower risk of death from cardiovascular disease and cancer – 19% and 12%, respectively – than living in areas with lower UV levels, such as Edinburgh or Glasgow.

Sunbed use was linked to a 23% lower risk of death from cardiovascular disease and a 14% lower risk of death from cancer, compared to non-users. It is possible that people who use sunbeds may also seek out greater sun exposure and so this result may reflect broader sun seeking behaviour, the team says.

Those with a higher estimated UV exposure had a slightly increased risk of being diagnosed with melanoma, but their risk of dying from the condition was not raised.

As the study is based on UK data from a white European population, the findings are of most relevance to similar groups in low-sunlight countries. Further research into locations with higher UV exposure is needed to build a clearer picture of the potential benefits to health, experts say.

The study, funded by Health Data Research UK, is published in the journal Health and Place.

Our paper adds to a growing body of evidence suggesting that in lower light environments, relatively higher exposure to UV is good for your health. Though there may be an increased risk of skin cancer incidence with higher UV exposure, this risk appears to be outweighed by a larger reduction in the risk of death from cancer and cardiovascular related disease.

Professor Chris Dibben, University of Edinburgh’s School of GeoSciences

Dermatologists have traditionally only considered possible harm to the skin caused by sunlight, much of which dates from the experience of white-skinned individuals in sunny countries such as Australia. When the UV index is very high, protecting skin is important.

However, this research shows that in the UK, the balance of benefit and risk from sunlight exposure is probably very different from that in sunnier countries.

Professor Richard Weller, University of Edinburgh’s Centre for Inflammation Research

Source: The University of Edinburgh

Categories : Environmental Effects Obstetrics & GynaecologyTags :

Pesticide Use Within 500m of Pregnant Women Linked to Stillbirth Risk

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Living less than 500m from pesticide use prior to conception and during early pregnancy could increase the risk of stillbirths, according to new research published in the American Journal of Epidemiology.

Researchers from the University of Arizona found that during a 90-day pre-conception window and the first trimester of pregnancy, select pesticides, including organophosphates as a class, were associated with stillbirth.

“In this study, some specific ingredients stood out due to their significant associations with stillbirth risk,” said first author Melissa Furlong, PhD, who studies the chronic health effects of environmental contaminants as an assistant professor and environmental epidemiologist at the Zuckerman College of Public Health. “These findings underscore the importance of considering individual pesticides rather than just the overall pesticide class, as specific chemical compounds may pose unique risks. It also highlights the potential for pre-pregnancy exposures to affect reproductive outcomes.”

To conduct the study, researchers linked Arizona pesticide use records for 27 different pesticides with state birth certificate data that included 1 237 750 births and 2290 stillbirths from 2006 to 2020.

They found that living within 500m of specific pyrethroid, organophosphate or carbamate pesticide applications during a 90-day pre-conception window or the first trimester was associated with an increased risk of stillbirth. 

Specifically, the pesticides cyfluthrin, zeta-cypermethrin, organophosphates as a class, malathion, carbaryl and propamocarb hydrochloride were linked to increased stillborn births pre-conception. During the first trimester, fenpropathrin, permethrin, organophosphates as a class, acephate and formetanate hydrochloride were associated with stillbirths.

“Among organophosphates, acephate showed the strongest effect estimates on stillbirth, so that exposure to acephate in the first trimester was associated with a doubling of risk,” said co-author Paloma Beamer, PhD, a professor and interim associate dean at the Zuckerman College of Public Health.  “Within the pyrethroid class, cyfluthrin exposure during the 90 days prior to conception almost doubled the risk of stillbirth.”

Pesticides are chemical substances used to control pests in various settings. They are commonly categorized into different classes, such as organophosphates, pyrethroids and carbamates. The primary route of exposure for most people is through diet, but household use, agricultural drift and occupational exposure are also significant pathways.

Researchers say while some pesticides may not have been directly implicated in this study, they could still pose risks to maternal and foetal health.

Pregnant women may be particularly vulnerable to the adverse effects of pesticide exposure due to physiological changes during pregnancy, such as increased metabolic rate, altered hormone levels and changes in the immune system. The developing foetus may be more susceptible to the toxic effects of pesticides during this period of rapid growth and development.

“Further research is essential to fully understand the safety profiles of various pesticides and to understand the underlying mechanisms of pesticide-induced stillbirth,” Furlong said. “This study underscores the need to develop strategies for mitigating exposure to protect maternal and foetal health.”

Source: University of Arizona Health Sciences

Categories : Environmental EffectsTags :

Climate Anomalies may Play a Major Role in Driving Cholera Pandemics

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Global climate change could create more opportunities for rise and spread of new cholera strains

Scanning electron micrograph image of cholera bacteria.

New research suggests that an El Niño event may have aided the establishment and spread of a novel cholera strain during an early 20th-century pandemic, supporting the idea that climate anomalies could create opportunities for the emergence of new cholera strains. Xavier Rodo of Instituto de Salud Global de Barcelona, Spain, and colleagues present these findings in the open-access journal PLOS Neglected Tropical Diseases.

Since 1961, more than 1 million people worldwide have died in an ongoing cholera pandemic, the seventh cholera pandemic to have occurred since 1817. The drivers of past cholera pandemics have been unclear, but one hypothesis holds that anomalous climate conditions may act synergistically with genetic changes of Vibrio cholerae—the bacterium that causes the disease—to facilitate the spread and dominance of new strains.

To help clarify potential links between climate and cholera, Rodo and colleagues applied a variety of statistical and computational tools to historical records of climate conditions and cholera deaths in various regions of former British India during the sixth cholera pandemic, which lasted from 1899 to 1923. They also compared past conditions with climate and cholera data for the ongoing pandemic.

This analysis revealed that anomalous patterns of cholera deaths from 1904 to 1907 occurred alongside out-of-the-ordinary seasonal temperatures and rainfall levels associated with an El Niño event; the timing of these occurrences correlates with the establishment of a new invasive strain during the sixth pandemic. In addition, these historical climate conditions show similarities to strong El Niño events that have been associated with cholera strain changes during the ongoing pandemic.

These findings support the possibility that anomalous climate events could help facilitate the establishment and spread of new cholera strains.

The researchers then explored future possibilities for climate-facilitated emergence of new cholera strains using standard climate prediction models. They found that climate change-driven increases in climate variability and extremes could boost the chances of emergence of novel strains through the end of the current century.

Meanwhile, to deepen understanding of this deadly disease, the scientists call for further research focused on the interplay of cholera evolution and climate anomalies.

Dr Rodó and co-author Dr Mercedes Pascual summarise: “Variation in climate conditions or the evolutionary change of a pathogen can be important drivers of major epidemics and pandemics. But these two drivers are typically considered separately in studies seeking to explain the emergence of unusually large outbreaks…here, we present indirect evidence that the two can act together to synergistically underlie the establishment and widespread transmission of a new strain.”

Provided by PLOS

Categories : Diseases, Syndromes and Conditions Environmental EffectsTags :

Does Air Pollution Affect Lupus Risk?

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New research published in Arthritis & Rheumatology indicates that chronic exposure to air pollutants may increase the risk of developing lupus, an autoimmune disease that affects multiple organs.

For the study, investigators analysed data on 459 815 participants from the UK Biobank. A total of 399 lupus cases were identified during a median follow-up of 11.77 years. Air pollutant exposure was linked with a greater likelihood of developing lupus. Individuals with a high genetic risk and high air pollution exposure had the highest risk of developing lupus compared with those with low genetic risk and low air pollution exposure.

“Our study provides crucial insights into the air pollution contributing to autoimmune diseases. The findings can inform the development of stricter air quality regulations to mitigate exposure to harmful pollutants, thereby reducing the risk of lupus,” said co–corresponding author Yaohua Tian, PhD, of the Huazhong University of Science and Technology, in China.

Source: Wiley

Categories : Environmental EffectsTags :

Sanitech Celebrates 50 Years with a Commitment to Community and Future Growth

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Robert Erasmus, Managing Director of Sanitech

Sanitech, a leader in integrated hygiene and sanitation solutions, recently celebrated its 50th anniversary. Reflecting on the company’s journey from a small plumbing business to a comprehensive sanitation provider, Sanitech’s Managing Director, Robert Erasmus, shares insights into the company’s history, recent initiatives, and future aspirations.

The Sanitech name was registered in 1974 by Grant Murray in KwaZulu-Natal. Initially, it was a small plumbing business, but Murray quickly identified a market for portable sanitation services. Over the years, Sanitech expanded, albeit on a limited scale, by partnering with various agents. The significant transformation began in the 1990s and early 2000s when private equity ownership enabled national growth. In 2007, the business continued to expand following the acquisition of Sanitech, which marked the beginning of global support for WACO International.

Erasmus joined Sanitech in 2008, marking a pivotal moment. “My role was to transform Sanitech into a corporate entity aligned with WACO International’s standards in health, safety, policies, and procedures,” Erasmus explains. Under his leadership, Sanitech expanded from eight locations to 24 and diversified its services beyond portable toilets to include integrated hygiene services, water and waste treatment, and pest control. Today, Sanitech employs over 3,000 people, a substantial increase from 350 in 2008.

Instead of a traditional celebration event for its 50th anniversary, Sanitech chose to invest in Corporate Social Investment (CSI) projects. Sanitech sponsored 50 Khusela sanitation units across various regions in South Africa. These units were installed in disadvantaged  schools in areas such as Witbank, Johannesburg, Durban, Port Elizabeth, and Cape Town, providing proper sanitation facilities and meals for the day. “It was a school-focused initiative, ensuring that learners have access to clean and safe sanitation, which is crucial for their health and education.”

Looking ahead, Erasmus envisions Sanitech continuing its trajectory of growth and innovation. “We aim to expand our product and service offerings in the hygiene and sanitation sector, especially as we face new challenges like the potential water crisis. Sub-Saharan Africa presents significant opportunities, and we’ve already established a presence in Mozambique,” he notes. Sanitech plans to enhance its contributions to clients’ Environmental, Social, and Governance (ESG) requirements by expanding its hygiene, cleaning, and pest control services.

Reflecting on the impact of their CSI projects, Erasmus shares a poignant experience: “Visiting the school in Palm Ridge where we installed new sanitation units was eye-opening. The conditions these young learners face are challenging, yet their discipline and resilience are incredible. It was a humbling reminder of the importance of our work.”

Categories : Dermatology Environmental EffectsTags :

Toxic Chemicals from Microplastics can be Absorbed through Skin

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Toxic chemicals used to flame-proof plastic materials can be absorbed into the body through skin, via contact with microplastics, new research shows. The study offers the first experimental evidence that chemicals present as additives in microplastics can leach into human sweat, and then be absorbed through the skin, into the bloodstream.

Many chemicals used as flame retardants and plasticisers have already been banned, due to evidence of adverse health effects including damage to the liver or nervous system, cancer, and risks to reproductive health. However, these chemicals are still present in the environment in older electronics, furniture, carpets, and building materials.

While the harm caused by microplastics is not fully understood, there is increasing concern over their role as conduits of human exposure to toxic chemicals.

The research team demonstrated in a study published last year, that chemicals were leached from microplastics into human sweat. The current study now shows that those chemicals can also be absorbed from sweat across the skin barrier into the body.

In their experiments, the team used innovative 3D human skin models as alternatives to laboratory animals and excised human tissues. The models were exposed over a 24-hour period to two common forms of microplastics containing polybrominated diphenyl ethers (PBDEs), a chemical group commonly used to flame retard plastics.

The results, published in Environment International, showed that as much as 8% of the chemical exposed could be taken up by the skin, with more hydrated – or ‘sweatier’ – skin absorbing higher levels of chemical. The study provides the first experimental evidence into how this process contributes to levels of toxic chemicals found in the body.

Dr Ovokeroye Abafe, now at Brunel University, carried out the research while at the University of Birmingham. He said: “Microplastics are everywhere in the environment and yet we still know relatively little about the health problems that they can cause. Our research shows that they play a role as ‘carriers’ of harmful chemicals, which can get into our bloodstream through the skin. These chemicals are persistent, so with continuous or regular exposure to them, there will be a gradual accumulation to the point where they start to cause harm.”

Dr Mohamed Abdallah, Associate Professor of Environmental Sciences at the University of Birmingham, and principal investigator for the project, said: “These findings provide important evidence for regulators and policymakers to improve legislation around microplastics and safeguard public health against harmful exposure.”

Professor Stuart Harrad, co-author of the paper, added “the study provides an important step forward in understanding the risks of exposure to microplastics on our health. Building on our results, more research is required to fully understand the different pathways of human exposure to microplastics and how to mitigate the risk from such exposure.”

In future research, the team plan to investigate other routes through which microplastics could be responsible for toxic chemicals entering the body, including inhalation and ingestion.

Source: University of Birmingham

Categories : Environmental EffectsTags :

Study Tallies Heatwave Deaths over Recent Decades

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Between 1990 and 2019, more than 150 000 deaths around the globe were associated with heatwaves each year, according to a new study published May 14 in PLOS Medicine by Yuming Guo of Monash University, Australia, and colleagues.

Heatwaves, periods of extremely high ambient temperature that last for a few days, can impose overwhelming thermal stress on the human body.

Studies have previously quantified the effect of individual heatwaves on excess deaths in local areas, but have not compared these statistics around the globe over such a prolonged period.

In the new study, researchers used data from the Multi-Country Multi-City (MCC) Collaborative Research Network that included daily deaths and temperatures from 750 locations across 43 countries.

With the MCC data, the researchers estimated excess heatwave deaths around the world spanning 1990 to 2019 and mapped the variance in these deaths across continents.

During the warm seasons from 1990 to 2019, heatwave-related excess deaths accounted for 153 078 deaths per year, a total of 236 deaths per 10 million residents or 1% of global deaths.

While Asia had the highest number of estimated deaths, Europe had the highest population-adjusted rate, at 655 deaths per 10 million residents.

A substantial burden of estimated deaths was seen in southern and eastern Europe as well as the area between Northern Africa, the Arabian Peninsula and Southern Asia.

At the national level, Greece, Malta, and Italy had the highest excess death ratios.

Overall, the largest estimated rates of heatwaves deaths were seen in areas with dry climates and lower-middle incomes.

Understanding the regional disparity of heatwave-related mortality is key to planning local adaptation and risk management towards climate change.

“Heatwaves are associated with substantial mortality burden that varies spatiotemporally over the globe in the past 30 years,” the authors say.

“These findings indicate the potential benefit of government actions to enhance health sector adaptation and resilience, accounting for inequalities across communities.”

The authors add, “In the context of climate change, it is crucial to address the unequal impacts of heatwaves on human health. This necessitates a comprehensive approach that not only tackles immediate health risks during heatwaves but also implements long-term strategies to minimize vulnerability and inequality. The strategies include: climate change mitigation policy, heat action plans (e.g., heat early warning system), urban planning and green structure, social support program, healthcare and public health services, education awareness, and community engagement and participation.”

Provided by PLOS

Categories : Environmental Effects Respiratory DiseasesTags :

Extreme Heat Linked to Children’s Asthma Hospital Visits

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For children seeking care at a California urban paediatric health centre, extreme heat events were associated with increased asthma hospital visits, according to research published at the ATS 2024 International Conference.

“We found that both daily high heat events and extreme temperatures that lasted several days increased the risk of asthma hospital visits,” said corresponding author Morgan Ye, MPH, research data analyst, Division of Pulmonary and Critical Care Medicine, University of California, San Francisco School of Medicine. “Understanding the impacts of climate-sensitive events such as extreme heat on a vulnerable population is the key to reducing the burden of disease due to climate change.”

Ms Ye and colleagues looked at 2017-2020 electronic health records from the UCSF Benioff Children’s Hospital Oakland, which included data on asthma hospital visits by patients of the hospital, some of whom are from Benioff Oakland’s Federally Qualified Health Center, and demographics including patients’ zip codes. They used data from the PRISM Climate Group of Oregon State University to determine the timing of daily maximum (daytime heat waves) and minimum (nighttime heat waves) for each zip code. The researchers restricted their analyses to the region’s warm season (June to September). To evaluate the potential range of effects of different heat wave measurements, they used 18 different heat wave definitions, including the 99th, 97.5th and 95th percentile of the total distribution of the study period for one, two or three days.

They designed the study in a way that allowed them to determine the association between each heat wave definition and a hospital visit. They repeated the analysis for Bay Area and Central California zip codes.

The team discovered that daytime heat waves were significantly associated with 19% higher odds of children’s asthma hospital visits, and longer duration of heat waves doubled the odds of hospital visits. They did not observe any associations for night-time heat waves.

According to Ye, “We continue to see global temperatures rise due to human-generated climate change, and we can expect a rise in health-related issues as we observe longer, more frequent and severe heat waves. Our research suggests that higher temperatures and increased duration of these high heat days are associated with increased risk of hospital visits due to asthma. Children and families with lower adaptation capacity will experience most of the burden. Therefore, it is important to obtain a better understanding of these heat-associated health risks and susceptible populations for future surveillance and targeted interventions.”

The authors note that past research has suggested positive associations between extreme heat and asthma, but findings regarding hospitalisations and emergency room visits have been conflicting. Additionally, many other studies have focused on respiratory hospitalizations and not hospitalizations for asthma, specifically, and have not included or had a focus on children. This study is also unique because it investigated the effect of daily high temperatures but also the effects of persistent extreme temperatures.

The San Francisco Bay Area and California overall are unique areas of interest because the state is considered a coastal region with less prevalence of cooling units, such as air conditioners. While temperatures may not reach the extremes experienced in other parts of the country, this study demonstrates that even milder extreme heat temperatures may significantly impact health. These effects are more pronounced in climate-susceptible populations, including children and those who are medically vulnerable, such as those served by the urban paediatric health centre in this study. The authors hope these study results will lead to more equitable health outcomes and reduce racial/ethnic disparities observed in climate-sensitive events.

“These results can be used to inform targeted actions and resources for vulnerable children and alleviate health-related stress during heat waves,” they conclude.

Source: American Thoracic Society

Categories : Environmental EffectsTags :

How do the Myriad Smells of Nature Benefit Health?

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Contact with nature can lift our well-being by affecting emotions, influencing thoughts, reducing stress and improving physical health, as shown by studies. Even brief exposure to nature can help. One well-known study found that hospital patients recovered faster if their room included a window view of a natural setting.

Knowing more about nature’s effects on our bodies could not only help our well-being, but could also improve how we care for land, preserve ecosystems and design cities, homes and parks. Yet studies on the benefits of contact with nature have typically focused primarily on how seeing nature affects us. There has been less focus on what the nose knows. That is something a group of researchers set out to change, publishing their approach in Science Advances.

“We are immersed in a world of odorants, and we have a sophisticated olfactory system that processes them, with resulting impacts on our emotions and behaviour,” said Gregory Bratman, a University of Washington assistant professor of environmental and forest sciences. “But compared to research on the benefits of seeing nature, we don’t know nearly as much about how the impacts of nature’s scents and olfactory cues affect us.”

Bratman and colleagues from around the world outline ways to expand research into how odours and scents from natural settings impact our health and well-being. The interdisciplinary group of experts in olfaction, psychology, ecology, public health, atmospheric science and other fields are based at institutions in the US., the UK, Taiwan, Germany, Poland and Cyprus.

At its core, the human sense of smell, or olfaction, is a complex chemical detection system in constant operation. The nose is packed with hundreds of olfactory receptors, which are sophisticated chemical sensors. Together, they can detect more than one trillion scents, and that information gets delivered directly to the nervous system for our minds to interpret – consciously or otherwise.

The natural world releases a steady stream of chemical compounds to keep our olfactory system busy. Plants in particular exude volatile organic compounds, or VOCs, that can persist in the air for hours or days. VOCs perform many functions for plants, such as repelling herbivores or attracting pollinators. Some researchers have studied the impact of exposures to plant VOCs on people.

“We know bits and pieces of the overall picture,” said Bratman. “But there is so much more to learn. We are proposing a framework, informed by important research from many others, on how to investigate the intimate links between olfaction, nature and human well-being.”

Nature’s smell-mediated impacts likely come through different routes, according to the authors. Some chemical compounds, including a subset of those from the invisible realm of plant VOCs, may be acting on us without our conscious knowledge. In these cases, olfactory receptors in the nose could be initiating a “subthreshold” response to molecules that people are largely unaware of. Bratman and his co-authors are calling for vastly expanded research on when, where and how these undetected biochemical processes related to natural VOCs may affect us.

Other olfactory cues are picked up consciously, but scientists still don’t fully understand all their impacts on our health and well-being. Some scents, for example, may have “universal” interpretations to humans — something that nearly always smells pleasant, like a sweet-smelling flower. Other scents are closely tied to specific memories, or have associations and interpretations that vary by culture and personal experience, as research by co-author Asifa Majid of the University of Oxford has shown.

“Understanding how olfaction mediates our relationships with the natural world and the benefits we receive from it are multi-disciplinary undertakings,” said Bratman. “It involves insights from olfactory function research, Indigenous knowledge, Western psychology, anthropology, atmospheric chemistry, forest ecology, Shinrin-yoku – or ‘forest bathing’ – neuroscience, and more.”

Investigation into the potential links between our sense of smell and positive experiences with nature includes research by co-author Cecilia Bembibre at University College London, which shows that the cultural significance of smells, including those from nature, can be passed down in communities to each new generation. Co-author Jieling Xiao at Birmingham City University has delved into the associations people have with scents in built environments and urban gardens.

Other co-authors have shown that nature leaves its signature in the very air we breathe. Forests, for example, release a complex chemical milieux into the air. Research by co-author Jonathan Williams at the Max Planck Institute for Chemistry and the Cyprus Institute shows how natural VOCs can react and mix in the atmosphere, with repercussions for olfactory environments.

The authors are also calling for more studies to investigate how human activity alters nature’s olfactory footprint — both by pollution, which can modify or destroy odorants in the air, and by reducing habitats that release beneficial scents.

“Human activity is modifying the environment so quickly in some cases that we’re learning about these benefits while we’re simultaneously making them more difficult for people to access,” said Bratman. “As research illuminates more of these links, our hope is that we can make more informed decisions about our impacts on the natural world and the volatile organic compounds that come from it. As we say in the paper, we live within the chemical contexts that nature creates. Understanding this more can contribute to human well-being and advance efforts to protect the natural world.”