Part 1: Introductory Concepts in Planetary Health

3 Defining ECO-Health

Authors: Sarkar, A., & Atkinson, S.

Learner Outcomes

After reading this chapter you should be able to:

  • Describe the relevance of Eco-health to clinical practice
  • To learn the application of eco-health perspectives in disease prevention and promotion of health and wellness
  • To understand nature as therapy in an evidence-based context


Key words associated with this chapter include:

  • ecosystem health
  • ecological determinants
  • social prescribing
  • nature prescribing

Part 1: What is ECO-Health

A. Sarkar, Associate Professor, Faculty of Medicine, Memorial University


The significant developmental challenges for the 21st century have been improving people’s health while promoting thriving, resilient communities and environmental sustainability. Globalization, overexploitation of the earth’s resources, climate change, and extreme weather conditions, widespread pollution have all contributed to our awareness of the interdependency of the fate of human societies and the well-being of our planet. Overall carrying capacity of the earth is being exceeded, and preventing us from living healthy and productive lives now, and threatening similar conditions for future generations. An ecosystem approach distinguishes that health and well-being result from complex and dynamic interactions among various determinants, such as people, social and economic conditions, and ecosystems. It is worth noting that an ecosystem approach to health focuses on improving human health by going beyond existing biomedical or epidemiological methods to health policy. Thus the ecosystem approaches to health (or Ecohealth) focus on the interactions between the ecological and socioeconomic dimensions of a given situation and their influence on human health, as well as how people use or impact ecosystems, their implications for the quality of ecosystems, the provision of ecosystem services, and sustainability. While improving livelihoods and economic conditions with inadequate attention to the environment and inequities can endanger health and become unsustainable over time, ignoring the existing environmental and social needs when trying to improve health can be ineffective. 


Ecohealth awareness influences investigators and their students to engage in ecohealth-related research projects, partnering with multiple stakeholders, including the affected communities. Indeed the ongoing planetary health crises affect the poor the most, and most of the existing ecohealth approaches focus on the global south. But, it is undeniable that the problems are escalating in scale and are increasingly co-occurring in every corner of the plant. Severe drought, flood, heat waves, forest fire, and the spread of vector-borne infectious diseases have become routine phenomena in Europe and North America. In this regard, people from low socioeconomic status, Indigenous backgrounds and people of colors, and people living in remote and rural areas are more disadvantaged. The cocktails of endocrine disrupting chemicals in human blood resulting in a steady decline in sperm counts and rising infertility and the recent discovery of nano-plastics in the blood of the European population are examples of putting commercial interest before public health and eventually exerting enormous financial burden on the health system. The study shows that the member countries of the European Union spend an additional 50 billion Euros on health care for the additional burden of illnesses due to endocrine-disrupting chemicals. The Millennium Ecosystem Assessment (MEA) represents a landmark attempt to link human health and well-being with conservation and more sustainable use of ecosystems. The MEA conceptual framework articulates the relationships between human health and well-being in our ecosystems. However, WHO’s International Health Regulations (WHO 2005) and Commission on the Social Determinants of Health (CSDH 2008) only peripherally addressed the contributions of ecosystems to health, despite their inclusion as part of the Millennium Development Goals (MDGs) and the links made in the MEA. Understanding how people and their health are related to ecosystems is very complex. However, involving medical communities in ecohealth is still very insufficient. Therefore, awareness of the transdisciplinary approach among medical learners has become a top priority in leading medical schools across the continent. The following section will briefly overview various methods to enhance the knowledge and skills about ecohealth.


  1. System approach to assessing health risks and actions

Systems thinking considers the relationships among ecological, social-cultural, economic, and governance dimensions and helps apply some order to the complex reality of health in the context of social-ecological systems. For health professionals, systems thinking can lead to a better understanding of the limits of the problem, its scale, and its dynamics. The behavior of individuals in a household, and their interactions within groups in a community, may be determined by gender, ethnicity and culture, residence, and socioeconomic status. For example, the rapidly spreading urban sprawl to rural and forest areas may result in more exposure to ticks and disease-causing mosquitoes. These exposures might also be determined by socioeconomic, ethnicity, and cultural factors, such as preference and affordability to spend more time in outdoor activities, dress codes, and complexion. Thus systems thinking can lead to changes in policies and practices and health promotion activities. The health officials can team up with local veterinarians, town and park officials, family physicians, microbiologists, public health officials, local school district officials, tour operators, media, and prominent community members. The collective efforts will include regular entomological (tick) surveillance, case surveillance, identification of high-risk areas, notification to the public in parks and trails, and public awareness via media, schools, clinics, and tour operators.


  1. A transdisciplinary approach to designing health care

A transdisciplinary approach integrates different scientific perspectives, community representatives, and other stakeholders’ knowledge about the health problem and ecosystem perspectives based on their experiences. A transdisciplinary approach while addressing ecohealth perspectives of any diseases will enhance innovations and design strategies to improve health care and environmental conditions in a sustainable, contextually appropriate way. The transdisciplinary approach also provides more opportunities to establish an acceptable process for discussion and negotiation among stakeholders pursuing a new understanding of a given health problem or situation. To achieve a practical transdisciplinary approach, health professionals must draw on a wide range of skill sets that are not usually part of their academic training, including consensus building, negotiation, communication, facilitation, and strategic planning. To lead a multi-stakeholder process, the health professional can develop a framework for group dialogue, social inquiry for development, multi-criteria evaluation for conflict management, and outcome mapping. For instance, endocrine disrupting chemicals wreak havoc worldwide, causing infertility, hypothyroidism, cancer, and poor immune responses – need the active involvement of family physicians, endocrinologists, obstetricians, and public health professionals, laboratory medicine, environmental toxicologists, and analytical chemists. While routine testing of EDCs for infertility and hypothyroidism patients, pregnant women, and infants can generate more substantial evidence of causal relations, eco-toxicological and epidemiological studies will give clear evidence of sources and existing risk factors. Eventually, the transdisciplinary team can play a decisive advocacy role in developing the right developmental policy, including case management protocol, antenatal care, banning or restricting the use of high-risk products, etc.


  1. Ensuring sustainability in ecohealth approach

Any ecohealth approach will aim to make it ethical and positive, and its sustainability should be given priority. By sustainability, the initiative implies that these changes be environmentally sound, socially and culturally responsible and appropriate, and economically less burdensome. There may be the possibility of the initiative slipping back into previous negative patterns or relationships; any forms of setbacks or any new forms of problems may arise. The policymakers may face ethical quandaries when people’s short-term needs and priorities are inconsistent with a longer-term process for improving health and the environment. Therefore, ecohealth proponents should anticipate these dynamics and be prepared to learn from them. It is important to note that seeking sustainability is fundamentally challenging and maybe a very lofty goal, mainly when the health issues are complex, multi-sectoral, and multi-generational. For example, addressing food insecurity issues in the Indigenous communities cannot be solved by improving the supply chain and price control due to external factors that cannot be controlled at the local levels (such as global gas prices, poor yields in traditional food production areas). On the other hand, local food production can be a promising solution if scientifically sound. Still, it can only be sustainable if the initiative is participatory, provides economic incentives, and is based on equity and justice.


  1. Gender and social equity as a foundation for an ecosystem approach

Any ecosystem approach to health should explicitly address gender and social equity and mainly focus on vulnerable groups in the society based on gender, age, race, ethnicity, socioeconomic conditions, occupation, habitat, and so on. Considerable evidence shows that the differences between members of different socioeconomic classes, ages, and ethnic or gender groups in all societies are reflected in their relationships with ecosystems, exposure to different health risks, health status, and well-being goals. Therefore, the health professionals who lead the ecohealth approach will not only address the existing social inequity affecting the health status of the vulnerable population but should make sure to reduce the gap in the process. Otherwise, any health promotion or disease prevention initiative can be ineffective or counterproductive. For example, imposing a sugar tax on packaged sweet beverages can be a novel approach to reducing obesity and chronic diseases. However, it can be financially challenging for the Indigenous communities living in remote locations without a clean drinking water supply. Perhaps, these communities are compelled to spend on sweetened beverages for drinking since bottled water is more expensive. Therefore, the sugar tax will put an additional financial burden on vulnerable communities.


Ecohealth action may generate unintended consequences (either favorable or unfavorable), which can influence the future course of action. Gathering knowledge from ecohealth activities and translating it for further follow-up actions is essential. Knowledge translation is paramount for operational research and developing and assessing interventions’ effectiveness.

Below is a video published by the UK newspaper: the Daily Mail showing some 39000 tons of unsold clothing made in China, India and other parts of the world ends up in the Chilean Atacama Desert.

PUBLISHED: 04:14 EDT, 11 November 2021 | UPDATED: 03:50 EDT, 12 November 2021; Downloaded November 9, 2022.


Dominique F. Charron (editor). Ecohealth Research in Practice: Innovative Applications of an Ecosystem Approach to Health. Ottawa. 2012. Springer – International Development Research Centre. ISBN 9781461405160.

Jean Lebel. Health: An Ecosystem Approach. Ottawa. 2003. International Development Research Centre. ISBN 1-55250-012-8.

Part 2: Biophilia — Understanding the evolution of our relationship with nature

S. Atkinson, Clinical Assistant Professor of Surgery, Memorial University

Biophilia is proposed by Edward Wilson as the innate human tendency to focus on and seek connection with other life and life-like processes (1986).  This may be evolutionary and born out of human ancestors’ need to identify food, shelter, and threat for survival. The ever presence of the human desire to form a relationship with the natural world can be seen in historical artifacts, writings, and art from cultures all over the world. In the last millennia, as humans came indoors and many cultures evolved through technology, the industrial revolution, and the modernization of medical practice, many of the most important aspects of the relationship faded from view. There are, of course, exceptions to that; indigenous cultures in Canada and around the world have continued to foster beautiful reciprocal relationships with nature that have flourished despite the threat of cultural loss under the guise of modernization (I think it would be a good idea to have an excerpt here from an indigenous perspective). That said, polls carried out by numerous organizations indicate that Canadians, like their counterparts in the USA, UK, and Europe, are spending little time in nature. A company specializing in indoor living environments polled more than 16,000 adults living in 15 countries and found that we are spending up to 90% of our time indoors with 52% of respondents stating that in the preceding month they had spent less than one hour per day outdoors (Velux, 2019). Similarly in 2017 the Coleman Canada Outdoor Report revealed that among the 1500 Canadians surveyed, 30% of Canadians were spending less than 30 minutes outdoors per week.


Despite spending such little time outdoors, Institut Publique de Sondage d’Opinion Secteur (Ipsos) conducted a poll in 2018 on behalf of Nature Conservancy Canada that found more than 85% of Canadians polled agreed that they are happier when spending time in nature. In fact, the majority who answered the poll indicated that when spending time in nature they noticed improvement in their creativity, focus at work, and sleep (IPSOS, 2018). In fact these reported benefits are just the tip of the iceberg. An expanding body of evidence is just beginning to uncover the vast and significant health benefits nature can provide to humans across the lifespan. Physicians are, therefore, beginning to prescribe time in nature as a therapeutic intervention supporting mental and physical health.


Supporting mental health through nature prescribing

The Ipsos report touches on the mental health benefits afforded by nature; people feel better, perform better, and sleep better. Beyond the vastly important subjective reports of individuals reporting feeling better in nature, science has begun to report more objective measurements of the benefit of nature on stress.  Cortisol, a glucocorticoid hormone produced by adrenal gland, is released in abundance during times of stress. Persistently high levels of cortisol can result in sustained hyperglycemia, dulled immune response, and disrupted sleep leading to the numerous health conditions associated with chronic stress. A study measuring salivary cortisol has shown that it decreases in subjects having nature experiences of ten minutes or more (Hunter, Gillespie, Chen, 2019). This decrease was measured at 21.3% per hour and was noted to be most significant between 20-30 minutes in nature (Hunter, Gillespie, Chen, 2019). A similarly objective and compelling measurement of the mental health benefits afforded by nature is heart rate variability (HRV). HRV is a way of measuring balance between sympathetic and parasympathetic nervous system activation; when a subject is in a state of rest, growth, and digestion their parasympathetic nervous system is activated and sending signals to decrease heart rate. Conversely, in a state of stress or exercise their sympathetic nervous system is activated and sending signals to increase the heart rate. HRV is the resulting variation in heart rate from these two autonomic competitors among other influences. Increases in a subject’s HRV are suggestive of increased parasympathetic effect and less sympathetic activation due to stress. Time in nature has been found to result in just that; an increased HRV among healthy subjects viewing a forest landscape when compared to those viewing an urban landscape (Kobayashi et. al., 2015)!


Beyond decreasing stress and the ensuing negative affects it has on human health, physicians and health care providers should be aware of its numerous other impacts on mental health and wellbeing. Among children who have ADHD, 85% indicated that it improved their day (Barfield and Driessnack, 2018). Furthermore, a 20 minute walk in the park was found to elevate attention performance for children with ADHD in a manner that rivalled some stimulant medication (Taylor and Kuo, 2009). Time in nature has been shown to improve memory (Koselka et. al. 2019), reduce prefrontal cortex activation and rumination Bratman et. al, 2015), and, among elder adults, connecting with the natural world through gardening decreases their risk of dementia by more than 30% (Simons et. al, 2006).

Supporting physical health through nature prescribing.

The mental health benefits of nature are bountiful but there are countless other representations of how spending time in nature positively influences health. For example, we know that trees have an enormous role to play in the livability of our environments; they play a direct role in the degradation and removal of pollutants from the air and their overstory reduces air temperature. These functions of trees within our ecosystem and particularly in urban areas provides cleaner and cooler air to breath (Nowak, Crane & Stephens, 2006). It is unsurprising then that living in an area with more trees is associated with a decreased risk of respiratory illness and associated morbidity and mortality (Twohig-Bennett & Joneas, 2018; Donovan et. al., 2013). The benefits of spending time in nature are farther reaching in that it cuts patients’ risk of cardiovascular disease, diabetes, stroke(Twohig-Bennett & Joneas, 2018); it helps manage hypertension, hyperglycemia, and promotes meeting physical activity goals(Ochiai et. al, 2015; Ohtsuka, Yabunaka and Takayama, 1998;

Faka et. al, 2019). Some of the positive outcomes seen from spending time in nature may be from increasing physical activity, however it is even shown that adults who exercise outdoors reduce their stress levels and improve their energy and mood more than adults who exercise indoors (Coon et. al, 2011).


Physician advocacy.

When it comes to primary prevention, disease management, or overall health maintenance advocating for urban green spaces and promoting time in nature is well within the purview of health providers. In fact, in the interest of practicing evidence based medicine, as the breadth and strength of evidence mounts it appears remiss to negate the powerful potential health benefits nature affords our patients at little to no cost. In fact promoting nature as therapy stands to improve individual health but also potentially decreasing the cost of health care to the system while giving the planet and society the gift of a stronger relationship between humans and the rest of the planet. People who feel connected with nature are more likely to protect it and, for children in particular, participate in environmentalism later in life (Wells and Lekies, 2006). Promoting nature as therapy, therefore, is a step toward improved planetary health and toward ensuring nature is available as therapy for generations to come.


Foundations of nature as therapy in clinical practice.

So how is this being incorporated into clinical practice? What recommendations should we be making? There are aspects of this that are somewhat dependant on specialty, practice, location, and patient population but the foundations can be the same. We know the endless benefits of green spaces; advocating for conservation of existing natural spaces and forests while incorporating more rewilding and planting of trees in urban living areas are valuable recommendations from a population health perspective. From an individual health perspective, research supports the recommendation that 120 minutes in nature per week promotes health and wellbeing (White, 2019). There is also evidence supporting the greatest reduction in cortisol level between 20 and 30 minutes (Hunter, Gillespie and Chen, 2019). These can be the foundations of nature prescribing in clinical practice that can be further tailored to meet the needs of individual patient populations.


In fact, nature is being prescribed across the world already and in some places for many years; In New Zealand physicians have been prescribing nature since the ‘green prescriptions’ program began in 1998 (How the Green Prescription Works, 2017)! In the United Kingdom after a pilot program in 2017 physicians have been providing Nature Prescriptions across all regions of Scotland (Nature Prescriptions RSPB Scotland, 2017). In the United States physicians are prescribing nature in 35 states through multiple programs including Park Rx, a national nature prescribing program that inspired a similar program here in Canada (Murdoch, 2022; James, Christiana and Battista, 2019). The PaRx ( program here in Canada began as a trial in British Colombia and has now expanded across the country.


As the evidence supporting nature based social prescribing is expanding so too do the burden of disease affecting humans and the threats to planetary health. As members of the health care community, knowledge of how vast nature’s health benefits are can and should inform our advocacy work and clinical practice and help us to make choices with our patients that will benefit us all.



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