Soil pollution: a hidden threat to cardiovascular health
Researchers have found that soil polluted by heavy metals, pesticides and plastics has a significant impact on human health and cardiovascular disease.
A new paper published in Cardiovascular Research by researchers from the University Medical Center Mainz (Germany) reviews the effects of soil and water pollution on human health. The evidence shows that soil, air and water contamination have clear links to various cardiovascular diseases.
When we think of threats to human health, generally our thoughts go to disease, disaster or accidents. Soil pollution isn’t usually top of the list but in 2015, contaminated soil, air and water were responsible for approximately 9 million premature deaths. 70% of these deaths were by non-communicable diseases, of which 60% were caused by cardiovascular diseases.
More and more research is showing that healthy soil is vital for human health and wellbeing. “Soil contamination is a less visible danger to human health than dirty air, but evidence is mounting that pollutants in soil may damage cardiovascular health through a number of mechanisms including inflammation and disrupting the body’s natural clock,” explains author Thomas Münzel, Professor at the University Medical Center Mainz. Soil is essential to produce nutrient-rich food, supports ecosystems that we rely on, stores and filters water, and is the largest carbon storer after the oceans, thereby slowing climate change.
Macro- and microplastics, pesticides and heavy metals are the main points highlighted by this paper to affect soil health and, with it, human health. These contaminants affect the body by causing oxidative stress, inflammation and disrupting the natural circadian rhythm. They create a heavy burden on the body, leading to illness and disease.
Depression increases the risk of cardiovascular disease
Depression and stress were discovered to impact cardiovascular disease and the effectiveness of cholesterol-lowering treatment in a mouse study.
Pesticide use has been linked to an increased risk in developing chronic diseases, such as diabetes or asthma, and approximately 25 million agricultural workers are affected every year by pesticides. Heavy metals such as cadmium, lead and arsenic are common soil contaminants and have been linked to elevated risks of stroke, hypertension and heart disease. The paper points out that “although soil pollution with heavy metals and its association with cardiovascular diseases is especially a problem in low- and middle-income countries since their populations are disproportionately exposed to these environmental pollutants, it becomes a problem for any country in the world due to the increasing globalisation of food supply chains and uptake of these heavy metals with fruits, vegetables and meat.”
The paper also discusses the effect of airborne pollution with regards to contaminated soil being released into the air as dust. Annually, 400,000–500,000 deaths are linked to natural events where dust travels long distances (e.g., desert dust and volcanic eruptions). This contaminated dust can irritate the respiratory tract and, if the particles are small enough, enter the bloodstream and cause inflammation. Examples of this include a 20.8% increase in Japanese cardiovascular emergency department visits on days when there was Asian dust exposure from China and Mongolia.
The production of plastic has increased rapidly over the years. In 2015, 448 million tons of plastic were produced and this number is expected to double by 2050. In water and soil, plastic degrades as a result of light and environmental exposure. A significant portion of plastic is made of additives and heavy metals, which are carcinogens and toxins. As the plastic degrades, these leach into the environment. Although there are no population studies, research shows that plastic reaches humans through the ingestion of contaminated water and seafood, entering the bloodstream and leading to the development of cardiovascular diseases.
“More studies are needed on the combined effect of multiple soil pollutants on cardiovascular disease since we are rarely exposed to one toxic agent alone. Research is urgently required on how nano- and microplastic might initiate and exacerbate cardiovascular disease. Until we know more, it seems sensible to wear a face mask to limit exposure to windblown dust, filter water to remove contaminants, and buy food grown in healthy soil,” explains Münzel.
