Planetary Health

 

Six scientists including Richard Hortoc, the editor of the journal, has published a manifesto in 8th of March 2014. Manifesto stated that it was no longer possible to protect human health without protecting the planetary health, and was a call for action for health and public health workers, politicians, international organizations, academicians, and for everyone who cares for the welfare of next generation. Manifesto stated that unlimited growth is not possible and inequalities are increasing and that we need immediate transformations in our values against the risks we faced and in our applications.

About a year after that, the Planet Health Commission, published an article entitled "Safeguarding Human Health in the Anthropocene epoch"(2). The word "anthropocene" in the beginning of the article which was first cited by Nobel Prize laureate chemist Paul Crutzen was a reference to the statement that the Holocene age was ending and that we have entered a new era due to the effects of the people on the planet (3). In this new era humanity was improved to a level never experienced before.

For example, the life expectancy which was 47 years in 1950-1955 has increased to 69 years in 2005-2010, while the rate of child mortality under the age of five has declined from 214 to 59 per thousand births, while the population has increased, poverty has decreased in world scale2. These achievements are a result of major advances in public health, health care, education, human rights, agriculture, infrastructure and technology. Our planet has supported this development with ecological and biophysical systems; enabling humans to access resources with vital resources such as clean air, food, potable water and energy. However, these sources are not limitless, and as a result of human activities, environmental changes take place all over the planet and the planet is gradually losing its power to support human health. It has been reported that at least 60% of the services provided by ecosystems, such as the regulation of the quality of the air, the purification of water, have deteriorated or have lost their sustainability.

 
 

Environmental changes due to human activities

 

Climate change is the most important of the environmental changes due to human activities4. Greenhouse gases arising from the use of fossil fuels in transport, at home, in agriculture and in industry, cause global warming by the heat trapping. Studies show that the main greenhouse gases (carbon dioxide, methane and nitrous oxide) have reached their highest levels in the last 800,000 years. The average global surface temperature has increased by 0.8 oC since 1880. It is predicted that the temperature increase will be between 2.6-4.8 oC at the end of 21st century.Consequently, it is anticipated that extreme heat, extreme precipitation, drought in some areas will emerge, causing significant changes in both plant and animal populations in terms of both number and distribution. One of the effects of the increase in temperature is the melting of the glaciers and associated in sea level rise. Accordingly, it is thought that the coastal strips will become inaccessible and the agricultural areas in these areas will be lost.

 
As the oceans absorb carbon dioxide in the atmosphere reducing the greenhouse effect to a certain extent, the slightly alkaline sea water pH becomes increasingly acidic as a result of this interaction. At the end of the twenty-first century, the acidification in the seas is predicted to increase 170%. Acidification disrupts the reproduction of marine animals, causing death of corals and hindering the ability of shellfishes to produce shell. It is inevitable that such effects lead to irreversible consequences on the food chain, and that many live species disappear.
Underground water supplies approximately half of the drinking water resources. Since the use of underground waters is much faster than the renewal rate, some areas have already suffered from water shortages. Most of these resources are used for agricultural purposes. It is therefore expected that water shortage will have serious effects on agriculture. Contamination of water resources with chemical agents also leads to a gradual decrease in water availability.
Only the United States, Canada and Mexico in 2009 had around 4.9 million tons of chemical emissions per annum, of which 1.5 million tons consisted of toxic, carcinogenic and reproductive chemicals 6. The main sources of chemical contamination include pesticides used in agriculture, heavy metals associated with cement production, dioxins that are released during the recycling of electronics, and chemicals used in the textile and pharmaceutical sectors. These chemicals affect human health directly (toxicity, cancer formation, inhibition of reproduction and development) and indirectly by affecting ecosystem functions (toxic substances, food chains, etc.).
The studies show that since 2000, 2.3 million km2 of forest area has been destroyed. Every year, 10,000 to 25,000 km2 of soil are deteriorated and increasingly desertified due to human activities and 55% of the desertification is related to humans. Deterioration in soil quality threatens food safety, causes floods and causes biodiversity to decrease 5. Soil also reduces the greenhouse effect by holding carbon in the atmosphere. The cultivated land can hold 25% to 75% less carbon than natural ecosystems. In addition, increasing use of nitrogen and phosphorus-based fertilizers in agriculture is causing serious ecological problems in the soil, as well as in the water systems they mix.
Although the diversity of species in nature is not fully known (especially at the microorganism level), the rate of extinction in known species has reached frightening levels. The greatest threats to biodiversity are; excessive consumption of biological resources (overfishing in fisheries, etc.), nitrogen and phosphorus contamination, invasion of foreign species, climate change and acidification of the oceans. Biodiversity has vital importance in maintaining the balance of ecosystems and thus of clean food and water supplies provided by the ecosystem, regulating the climate on a planetary scale and removing pollutants from the environment. Studies show that at least 90% of fish resources are consumed, the rate of species disappearance became 100 times higher compared to the fossil records, and the number of vertebrates has decreased by at least by 50% past 45 years.
   

Effects of environmental changes on health

 

Environmental changes disrupt ecosystems, affecting the services provided by them. These services include supply services such as food, water, fuel, medicine and novel chemical compounds provided by ecosystems to humans; regulatory services such as regulation of climate, water, pollution, air quality, diseases and erosion; supporting of the habitat by cultural services having aesthetic, recreational and spiritual dimensions, and support services such as sustainment of biodiversity and soil formation.

The first level consists of direct effects such as floods, extreme heat, thirst, landslides, exposure to ultraviolet rays and chemical pollutants. It is estimated that 1.6 billion people have been affected by drought and about 700 million people have been affected by storms in the last 30 years. It is predicted that in 2050, 50 to 350 million people will have to migrate due to climate-related reasons. It is also clear that this will increase violence incidents. Chemical substances can be passed on to people through ingestion, digestion and inhalation of contaminated water and food, through skin contact. Contaminants can also pass from mother to child during pregnancy via placenta or postnatal breastfeeding. Children are especially vulnerable to such contaminants. Children are especially susceptible to problems associated with heavy metals such as lead, mercury, or effects of chemicals on reproductive development.
These include nutritional and developmental problems due to reduced quantity and nutritional properties of food products. For example, it has been reported that the increase in carbon dioxide concentrations in the atmosphere will lead to a decrease in the content of zinc, iron and protein in grain products such as wheat and rice and in legumes 7. Another discipline to be affected by environmental changes is infectious diseases. Especially, diarrheal infectious diseases and zoonotic and vector infectious diseases came forward. Despite the treatment and preventive measures, diarrheal diseases are predicted to increase globally by 8-12% in 2040. It is estimated that the destruction of forests will increase the population of the mosquitoes and thus the diseases transmitted by vectors such as malaria.
The recent SARS epidemic is a typical example of this affliction.Destruction of ecosystems also leads to aesthetic and cultural impoverishment. An increase in anxiety, depression and suicide attempts in rural areas during the drought period lasting for about 10 years has been reported in Australia 8. The effects of environmental changes on human health can be indirect. These include immigration to cities and ensuing increase in slums as well as conflicts and adaptation problems.
 

The concept of planetary health and what to do

 

One of the basic elements that make up the concept of planetary health is the "ecological public health" model. The main argument of this model, which was put forward by Tim Lang and Geof Rayner, is that health depends on the successful combination of the natural world and social life 9. An important conceptual change introduced by this model is that the health sector needs to take responsibility not only for the health sector but also for the protection and development of health. Planetary health in this context is the health of human society as well as the natural systems where human civilization flourish 1,2. It is clear that human health cannot be protected without ensuring sustainability of natural systems. Therefore, there is a need for change in concepts (for example: measuring development not only with measures such as Gross Domestic Product but also with environmental indicators), information (such as prioritizing social and environmental determinants of medicine and transferring resources to transdisciplinary research) and practice (how institutions and states perceive and respond to threats, sustainable development, use of technology, etc.) 2.

The Faculty of Medicine of İzmir University of Economics aims to raise awareness of planetary health and its effects on human health among students and society through education and research, and regards this as a part of academic responsibility. Global environmental changes (I) can be direct (eg heat), (ii) secondary (due to the change of natural systems) or (iii) indirect (social turmoil).

Kaynaklar
  1. Horton R, Beaglehole R, Bonita R, Raeburn J, McKee M, Wall S. From Public to Planetary Health: A Manifesto. Lancet 2014; 383; 847.
  2. Whitmee S, Haines A, Beyrer C, et al. Safeguarding Human Health in the Anthropocene epoch: report of The Rockefeller Foundation- Lancet Commission on planetary health. Lancet 2015; 386: 1973-2028.
  3. http://www.smithsonianmag.com/science-nature/what-is-the-anthropocene-and-are-we-in-it-164801414/ (erişim tarihi 30 Nisan 2017)
  4. https://climate.nasa.gov/evidence/ (erişim tarihi 30 Nisan 2017)
  5. Lal R. Soil carbon sequestration impacts on global climate change and food security. Science 2004; 304: 1623–27.
  6. UNEP. Global chemicals outlook—towards sound management of chemicals. 2013. http://www.unep.org/hazardoussubstances/Portals/9/Mainstreaming/GCO/The%20Global%20Chemical%20 Outlook_Full%20report_15Feb2013.pdf (accessed Dec 23, 2014).
  7. Myers SS, Zanobetti A, Kloog I, et al. Increasing CO2 threatens human nutrition. Nature 2014; 510: 139–42.
  8. Albrecht G, Sartore GM, Connor L, et al. Solastalgia: the distress caused by environmental change. Australas Psychiatry 2007; 15 (suppl 1): S95–98.
  9. Lang T, Rayner G. Ecological public health: the 21st century’s big idea? An essay by Tim Lang and Geof Rayner. BMJ 2012;345: e5466.