6.1 Biodiversity sets limits to human existence

The terrestrial and aquatic ecosystems promote biomass production, stability, and pollination success, produce raw material for processing and manufacturing, support water circulation and freshwater resources, ensure food and support agriculture, sequestrate carbon from the atmosphere, prevent soil erosion, and provide a place for recreation. A long-term manipulative field experiment in Germany showed that about 45% of different types of ecosystem processes were affected by plant species richness.117 However, the positive biodiversity effect seems to result from several mechanisms acting simultaneously, and functional diversity is even a stronger predictor of a healthy ecosystem than the structural one.118 Loss of biodiversity reduces ecosystem productivity and stability.119, 120 Now, we are also increasingly aware of the adverse health effects of nature/biodiversity loss, allergic diseases, and asthma as examples.

Human kind has evolved from natural environments, that is from soil and natural waters, but is increasingly affected by built environment and urban space. The fuel for immunological resilience is exposure to biotically diverse life.5 Human interaction with macro- and microdiversity is decisive.121 Urban populations are short of natural experience, not only of exposure to micro-organisms but also to biogenic compounds.122, 123 The total exposure is also called the exposome that can help predict biological responses of the organism to the environment over time.124

Immunological resilience is dynamic and derived from exposure through life. The importance of diverse microbial exposure in early life to prevent allergy risk has been reported in both humans and mice.125, 126 Children, who live on farms, are exposed to a greater variety of environmental micro-organisms and have a lower prevalence of asthma and allergic disorders than children in reference groups.10, 37 In mouse models of allergic asthma, intranasal instillation of dust extracts from homes with high levels of endotoxins significantly inhibited airway hyperresponsiveness and eosinophilia.37 Furthermore, exposure of mice to microbially rich and diverse soil modified composition of the intestinal microbiota, increased anti-inflammatory signaling in the intestinal epithelium, and protected against experimentally induced allergic asthma.72 Skin and epithelial barrier has a constant crosstalk with the environment and dysfunctional barrier predisposes to various health risks.127

Resilience is central not only to individuals but to societies and populations by and large.128, 129 It is strengthened by an environment of multiple options giving room for choices. This is called redundancy in the biodiversity discussion. If one option fails, the other may succeed. In a biological or psychological monoculture, the failure of one may mean a failure of all. Biodiversity denotes abundance and even waste instead of extreme effectiveness. Paradoxically, waste creates buffers, that is, resilience. If a population is homogenous in the lack of immunity against COVID-19, it may face extinction. Unpredictable chaos is characteristic to nature. Order and efficacy are the dreams of man.

Prevention is always more cost-effective that medical treatment. World Allergy Organization published already in 2013 a position statement advocating a Global Allergy Plan to improve prevention and tolerance.130 The Finnish nationwide, real-world intervention, controlled biodiversity interventions, and recent data on environmental epidemiology, microbiome, and epigenetics give credibility to the statement. Several initiatives for prevention are ongoing and new insights presented.131-133 The next step should be systematic implementation studies. Digital transformation in health and care may speed up to obtain results.134

Avoidance of allergens causing severe symptoms will remain as good clinical practice but does not solve the public health problem. Probiotic bacteria protect somewhat against atopic eczema, but not generally against IgE-mediated allergies, respiratory outcomes in particular. There are still a number of unknown nutritional135 and microbial factors that play a role in building immunological tolerance. For example, rhinovirus infections are associated with exacerbations of asthma. However, early rhinovirus infections as well as certain other enterovirus infections have associated with decreased risk of IgE-mediated sensitization.136 In secondary (tertiary) prevention, allergen specific immunotherapy is effective, but not applicable at population level.

Along with allergy prevention, also measures for other chronic non-communicable diseases have been discussed for a good reason. For example, Nurminen and coworkers found recently that exposure to biodiverse agricultural environment in early life delays the onset of β-cell damaging process among genetically predisposed children and reduces the risk for type 1 diabetes.137 Local communities and citizens need guidance to consider both human health and the environment.138, 139 The Finnish city of Lahti (120 000 inhabitants) is the Green Capital of European Union in 2021.140 The city is preparing an educational 10-year plan to implement the best practices of public health and environmental care in the spirit of Planetary Health, which interconnects human health and the health of the planet.141 The UN Agenda 2030 promotes individual-, community-, and system-level resilience for population well-being to reach the Sustainable Development Goals (SDGs).142

6.2 Money talks

In 2011, the total value of global ecoservices was estimated $125–145 trillion. They contributed more than twice as much to human well-being than global gross domestic product (GDP).143 Furthermore, more than half of the world's total GDP is fundamentally dependent on ecosystem services.144 Their loss from 1997 to 2011 was worth of $4.3–20.2 trillion per year.143 Only 0.19–0.25% of global GDP is yearly invested to sustain biodiversity.145 This discrepancy makes no sense ecologically or economically. By protecting global biodiversity, we protect our health, general well-being, as well as our wallets.146 Although the positive outcome of the Finnish allergy programme initiative was due to several factors, the cumulative, deferred savings of around €1,2 billion during the period from 2007 to 2018 tell of the potential of disease prevention in the health care.147