Posted on 14 October 2024 by Moa Morency, our first guest blogger. She is studying a master’s degree in public health and has a bachelor’s degree in environmental science at Lund University.
The views expressed in this publication are those of the author and do not necessarily represent those of the Agenda 2030 Graduate School or Lund University. The present document is being issued without formal editing.
I have always been annoyed with how most environmental sustainability issues are communicated. It too often sounds like we should care about the environment for the environment’s sake. I care about people. That is why I studied environmental science and that is why I’m now studying public health. I specialized in soil science, agriculture ecology and ground pollution. In this blog I will tell you why I believe investing in soil health could be the most important public health intervention of our time.
Soil is not dirt. Soil develops slowly over many years creating a distinct structure and conditions functioning as the habitat for an extremely complex ecosystem of different organisms, or at least, it used to. About 40 % of soils worldwide are moderately to severely degraded and the trend is nowhere near slowing down (UNCCD, 2022).
Healthy soil for our food system
A healthy soil is crucial for the nutritional value of our food. Our current nutrient poor soils are unable to produce food with the necessary nutrients needed for a healthy life. Over 2 billion people in the world suffer from micronutrient deficiencies (FAO, 2022). Healthy soils that provide a nutrient-rich and an aggregated growth medium result in plant tissues that contain most of the elements required for human life (Brevik & Burgess, 2014).
It is not only the lack of necessary nutrients in the soils that pose a direct threat to human health, but also an even bigger issue is that soils and agriculture ecosystems contain high amounts of harmful substances. It is estimated that about 385 million people suffer of unintentional, acute pesticide poisoning every year globally (Boedeker et al., 2020). Soil pollution is estimated to cause more than 500,000 premature deaths globally each year (Landrigan et al., 2018). These are only the directly affected people whose issues where possible to connect to a pesticide with known health effects. Pesticides also interact and spread into surrounding waterways which suggests large hidden numbers. Pollution is estimated to be responsible for 9 million premature deaths yearly. That is three times more deaths than from tuberculosis, malaria and AIDS combined (Fuller et al., 2022).
In a living soil the diversity of organisms acts like a natural armour against pests and weeds much like how the gut microbiome is needed for a functioning bowel in humans (Rodbarry, 2023). Unhealthy soils are much like the body of a sick person taking multiple medicines where the drugs interact and cause side effects and symptoms that the person then needs more medication to treat. Soils in today’s conventional agriculture are addicted to pesticide input and need continually higher doses to keep running. I’m not saying we should stop using pesticides altogether, just like I’m not saying we should forget about amazing medical inventions like antibiotics, but I am saying we need to stop giving all soils what can be compared to continually higher daily doses of antibiotics, just in case they get sick.
Drought and flood resistance
An arguably even more important concept for soil health is to practice less or no tillage. Tillage is the conventional way of preparing the soil for planting by digging, stirring, and overturning the soil. It might look like the soil gets a better structure for planting after this, easier to get seeds into the soil. The problem is that tilling destroys the distinct structure and thus destroy the habitats within the soil ecosystem that the diversity of microorganisms depends on. Even worse is that the tilling cuts of the bloodstream of the soil, the mycelium, a network of fungi, transporting nutrients from the soil to the plants.
In addition, healthy soil is more like a sponge than a flat surface, making it more resistant to drought and flooding. This ability to store water also lowers the risk for nutrient and pesticide runoff. I’ve previously highlighted the harmful effects of pesticides in our waterways, but excess nutrients in waterways also pose a significant risk to public health. Nutrient runoff causes eutrophication which in turn cause harmful algal blooms, dead zones, and kills fish. This is an issue of both food safety, and food security.
Finally, and perhaps most importantly, healthy soil is a store of greenhouse gases. Plants absorb CO2 from the atmosphere and store it as biomass in the soil and as global warming is seen by many as the greatest threat to global health of our time, this is of utmost importance. The climate crisis is estimated to cost over two billion healthy life years by 2050 (World Economic Forum, 2024). Healthy soil practices have the potential to absorb over 6.5 billion metric tons of carbon equivalents per year. This is equivalent to the annual emissions of over 1,400 coal-fired power plants (Sha et al., 2022).
References
Boedeker, W. et al. (2020) ‘The global distribution of acute unintentional pesticide poisoning: estimations based on a systematic review’, BMC Public Health, 20(1). doi:10.1186/s12889-020-09939-0.
Brevik, E. C. & Burgess, L. C. (2014) The Influence of Soils on Human Health. Nature Education Knowledge 5(12):1
Fuller, R. et al. (2022) ‘Pollution and health: a progress update’, The Lancet Planetary Health, 6(6), pp. e535–e547. doi:10.1016/S2542-5196(22)00090-0.
UNCCD (2022). Global Land Outlook 2nd edition https://www.unccd.int/sites/default/files/2022-04/UNCCD_GLO2_low-res_2.pdf
Rodbarry, L. (2023). HOW HEALTHY SOIL MAKES HEALTHY PLANTS AND ECOSYSTEMS
Sha, Z. et al. (2022) ‘The global carbon sink potential of terrestrial vegetation can be increased substantially by optimal land management’, Communications Earth and Environment, 3(1). doi:10.1038/s43247-021-00333-1.
Steffan, J.J. et al. (2018) ‘The effect of soil on human health: an overview’, European Journal of Soil Science, 69(1), pp. 159-171–171. doi:10.1111/ejss.12451.
World Economic Forum (2024). Quantifying the Impact of Climate Change on Human Health