Whoever wishes to investigate medicine properly, should proceed thus: in the first place to consider the seasons of the year, and what effects each of them produces for they are not at all alike, but differ much from themselves in regard to their changes. Then the winds, the hot and the cold, especially such as are common to all countries, and then such as are peculiar to each locality. We must also consider the qualities of the waters, for as they differ from one another in taste and weight, so also do they differ much in their qualities.
— Hippocrates (460 BCE-370 BCE), “On Airs, Waters, and Places”, translated by Francis Adams.
As the quote by Greek physician Hippocrates tells us, the idea that human well-being is closely linked to the state of the natural environment can be traced back to many ancient civilizations. In the Indian context, such linkages between ecosystems and health have been highlighted in Ayurvedic texts such as the Charaka Samhita (believed to be composed in the 1st century CE) which discusses the impact of environmental change on health. Similarly, many ethnomedical systems practised in Adivasi communities—most of which traditionally entail the oral transmission of knowledge—emphasize the influence that natural forces and non-human beings wield on human wellbeing.
In modern times, the interest in such connections resurfaced in ecological literature from the late 1800s onwards and by the 1970s and ‘80s, the term ‘ecosystem services’ began to gain substantial traction. Defined by the global initiative on The Economics of Ecosystems and Biodiversity, as “the direct and indirect contributions of ecosystems to human well-being”, this concept of ecosystem services provided a common vocabulary for scientists (principally ecologists and the economists then) to discuss the question of what is sustainable development and how to value nature in the context of rapid economic growth. Such inquiry became necessary because ecosystems (and their services) were being routinely undervalued during economically driven decision-making—resulting in overwhelmingly negative impacts not only on the environment but on public health indicators too.
Although public health is an intersectoral domain, the role of the natural environment in enabling it is often overlooked. Yet, all four types of ecosystem services—be they provisioning, regulating, cultural or supporting—contribute to human wellbeing. Access to ecosystem services is doubly important for communities that lack access to formal and quality healthcare—due to their social, economic or geographic positions—because in such cases, ecosystem services serve as basic and free health care systems.
A Brief History of ‘Ecosystem Services’
In the decades that followed the institutional conception of ‘ecosystem services’ in the 1980s, discussions abounded on whether a monetary value should be assigned to ecosystems for both the goods and services that they provide, or only the former—since it is much harder to develop a valuation framework for the often intangible latter. Debates further ensued on how exactly the monetary value of an ecosystem should be calculated and if the methods used to measure value could be the same for tangible versus intangible services: for example, the value of clean water produced by an ecosystem versus its spiritual value to a community.
Ecosystem services as a buzzword intensified with the first Millennium Ecosystem Assessment undertaken between 2001 and 2005, when over a thousand experts from across the world worked together to evaluate how changes in ecosystem services were likely to affect human wellbeing. They categorised all ecosystem services into four types—that is provisioning, regulating, cultural and supporting services—and finally developed a set of recommendations to promote sustainable development. To translate these recommendations into policy, the Intergovernmental Panel on Biodiversity and Ecosystem Services was set up in 2012 as a wing of the United Nations Environment Programme.
In spite of its popularity in global environmental policymaking circles, the concept of ecosystem services also has its fair share of sceptics who have identified some shortcomings. For example, it promotes an overly materialistic understanding of nature, not all ecosystem services are beneficial to humanity, and the valuation frameworks are anthropocentric.
Yet, despite these flaws, ecosystem services as a concept has proven to be an effective means to emphasize the close connection between the state of the environment and the state of human well-being—much as the ancient medical texts did.
The most significant contribution of the concept of ecosystem services, as it evolved in the late 20th century, was that it provided a clear and simple means to foreground the value of nature to both the lay public and policymakers. More importantly, ecosystem services were positioned as public goods—that is, in economic terms, they were things that could benefit all of humanity and in principle, no one could be excluded from accessing them. As a result, the interest in understanding and protecting ecosystems was no longer the preserve of conservationists or the State: it became important to all sections of society in modern nation-states.
With ecosystems now being viewed as valuable at local and global scales, there is also an improved understanding of how deeply marginalised populations depend on ecosystem services.
Provisioning Services and Nutritional Security
One of the most obvious ways in which ecosystems contribute to human wellbeing is by supplying materials that meet the requirements of human populations such as fuelwood, medicine, fibre, and water. Arguably, the most important of these is food.
Although improvements in agriculture have certainly contributed to enhancing the nutritional status of communities in many rural or remote areas, forests and other ecosystems continue to play an important role by supplying wild food plants (WFPs) that have high nutritional value. Moreover, many of these sources provide key micronutrients and thereby prevent ‘hidden hunger’—or micronutrient deficiencies wherein “the quality of food that people eat does not meet their nutrient requirements (..) for their growth and development.
For example, a study conducted in 2015-16 found that people of the Soliga and Beda Gampana communities living in Karnataka’s Male Mahadeshwara Hills Wildlife Sanctuary together consumed 124 species of wild food plants. The communities, who are respectively classified as scheduled tribe and other backward class, collect these plants from both farmed and forested lands and consume them up to five times a week. The study further noted that WFPs are a “vital source of nutrition especially, for the Beda Gampana community who have a strictly vegetarian diet.” Along similar lines, during the compilation of a People’s Biodiversity Register for a joint community conservation area in Nagaland, researchers found that people in Ghukuyi, a Sema village, cultivated 64 types of fruits and vegetables and 22 types of WFPs. The researchers noted that “these locally grown plants are used by the indigenous population to deal with several ailments.”
These studies clearly indicate that wild foods continue to play an important role in the diet of communities across different parts of the country. Access to such provisioning services helps people achieve a balanced diet, especially during periods when they are unable to cultivate or purchase the different types of foods they need.
The Relationship Between Regulating Services and Flooding and Landslides
Ecosystems play a critical role in regulating the climate, water, pollination, and air quality, among other things. For instance, ecosystems stabilize the climate by enhancing rainfall and, at the same time, slowing down the flow of rainwater and protecting the topsoil. The relevance of these services to human health is very high—especially in the case of weather-related disasters, which cause significant damage to life and property in India each year, with a disproportionate impact on poor and marginalised communities.
Weather-related disasters are precipitated by cyclones and storms, floods, landslides, heat waves, and forest fires. Various parts of the country are also more geographically prone to these disasters. In the context of regulatory ecosystems services, almost all contribute to mitigating the impacts of weather-related disasters, and hence also towards reducing disaster-related injury, disease, and death.
If there are disruptions to these services, there is an immediate impact on human well-being—after all, the full impact of these weather-related events is also dependent on the adaptive capacities of the local populations.
For instance, the ecosystem disruption caused by deforestation in hilly areas contributes to flooding and landslides following storms. Such occurrences have become common in the Western Ghats, the Himalayan states, and in the northeastern states of India. A recent example is the case of Maharashtra, where deforestation in combination with heavy rains were thought to have caused the landslides that claimed over 130 lives in August of this year. Between 1996 and 2005, floods were linked with over 1,600 deaths in India, and over ₹4,000 crores’ worth of damage to property, including crops. Floods also displace the most vulnerable communities and expose them to a greater risk of vector-borne diseases. Flood-related deaths increased between 1978 and 2006, with the principal cause of this worsening trend reported to be the destruction of forests and grasslands.
In contrast, flood-related damages are often less in areas with tree cover—trees act as a natural flood control measure by improving water absorption and anchoring the soil. Evidently, the protection of ecosystems needs to be viewed as an investment towards protecting human lives and reducing the cost of healthcare.
Cultural Services and Mental Health
While it is widely recognised that ecosystems provide cultural services in the form of spaces for worship, education, recreation, and tourism, it is less commonly known that they contribute substantially to mental health—ecopsychology is an emerging field which examines this relationship.
Recent studies indicate that time spent in natural environments promotes stimulation of the senses and helps the human body moderate its response to stress, thereby promoting an overall sense of wellbeing. The beneficial effects of this phenomenon could range from alleviating depression, to regulating blood pressure, to boosting the immune system.
The importance of this ecosystem service in particular becomes marked when we consider that underlying mental illnesses are now being increasingly diagnosed,often afflicting vulnerable populations of women and youths. For example, a survey conducted by the National Institute of Mental Health and Neuro Sciences in 2015-16 found that nearly 150 million Indians suffer from some form of mental illness that requires medical intervention. Simultaneously, it is evident that with increasing urbanization as well as biodiversity loss, people’s access and exposure to nature is steadily declining, especially on an everyday level—this could exacerbate the issue.
On the other hand, there is also documentation on how communities close to and dependent on ecosystems suffer ‘ecological grief’ when they witness environmental degradation and the loss of local species. This is relevant to the experience of several Adivasi and fisher communities in India whose livelihoods and culture are deeply embedded in nature. Such intense distress may also be experienced by communities in the context of, say, mining and hydroelectric projects that have swallowed forests and human settlements in Madhya Pradesh. An urban example is the distress that the Warli and other local communities experienced during the tree felling at Aarey forest in Mumbai, for a metro rail project.
Ideally, these concerns should be factored into project planning, through community participation and health impact assessments, but these processes are neglected in India. Some inspiration can be drawn from the developed world in the meantime, where a range of experts from urban planners to doctors and educators have begun to advocate for regular ‘nature hours’. In some countries, such as Denmark, Sweden, and the United Kingdom, ‘forest schools’ expose young children to natural landscapes and in the process, help them acquire the foundational social, emotional and mental skills required to become resilient adults. In India, especially in areas facing the brunt of extractive development models, we need to draw on the diversity and richness of our Adivasi cultures to develop an ecosystem-attuned approach and mitigate the physical and mental illnesses caused by unbalanced development.
Supporting Services and Habitable Conditions
Supporting services refer to ecosystem services such as habitat maintenance, genetic diversity, soil formation and primary productivity. In simpler terms, these services provide the supportive framework for the other ecosystem services—provisioning, regulating, and cultural.
From a human health perspective, the linkage with supporting services may seem abstract. The linkages are largely indirect but are also critically important for wellbeing. For instance, the emergence of COVID-19 itself is often hypothesised to be linked to trade in wild meat at a wet market in Wuhan, China, wherein pathogens from the animal transferred onto a human, eventually spreading to others as well. This example indicates that the destruction of animal habitats may contribute to emerging diseases, due to increased proximity between wildlife, livestock, and human populations.
The destruction of habitats can also benefit vector species—or the species “that transmits an infectious agent from an infected animal to a human or another animal”—at the cost of species that prevent the transmission of disease. This has been observed in the case of mosquito-borne diseases such as malaria.
For instance, in Assam’s Sonitpur district, an elevated rate of malaria cases, and a change in the density and types of mosquito vectors that can transmit malaria was recorded alongside deforestation in the district. Such changes in vector habitat and ecology may have contributed to a wider transmission period for malaria in these areas.
For several decades, national programmes have struggled to control malaria, with its spread curtailed at varied degrees of success across the country. However, as the evidence above shows, even these gains may be partially jeopardised due to habitat destruction and climate change—which compromise ecosystem services at large.
Towards Eco-sensitive Public Health
There are strong contemporary connections between the state of the ecosystems and public health. This connection is particularly pronounced when we consider communities that live in the social, economic, or geographic regions of the country: here, the cost of ecosystem degradation and the loss of ecosystem services greatly adds to the burden borne by communities and by the health system at large. To address these concerns, we need to develop a more ecologically rooted imagination of public health in India. Such a vision will not only lighten the load on the current health system but also have a sizable positive impact on population health, especially the health of underserved populations and the ecosystems they reside in.
Acknowledgements: The authors thank Drs. Arima Mishra and Harini Nagendra for their suggestions on an earlier draft, and Dr. Mahesh Mathpati for information on Ayurvedic texts.
Featured image: the gathering of fresh food from Kodagu district, Karnataka; (L) a Kuruba woman cleans nucchi kumm, a variety of mushroom often found amongst leaf litter; (M) tender shoots of a thorny bush, ende mullu, found mostly across wastelands, used to prepare a medicinal chutney; (R) a woven bamboo fishing net called mande poda used between paddy fields. Images by Pooja Uthappa, reproduced with permission.