Polluted soil and water are fueling a global heart disease epidemic

Polluted soil and water are fueling a global heart disease epidemic

Toxic chemicals and microplastics in soil and water are fueling a global heart disease crisis - but researchers say solutions are within reach.

A study recently published in the journalAtherosclerosisreviewed the links between water and soil pollution and human health.

Clean water and healthy soil are essential for human health, well-being and the environment. Healthy soils underpin ecosystems by supporting food production, water retention, biodiversity and carbon storage. Soil degradation threatens the health of 40% of the world's population. Additionally, as of 2021, more than two billion people lived in water-prone regions. In 2019, pollution-related diseases caused nine million premature deaths. Additionally, pollution accounted for approximately 268 million life years (DALYS).

Air and soil pollution significantly impacts Daly's life stages, although the latter mainly affects older people. In addition, water pollution drives child mortality. Notably, more than two-thirds of pollution-related diseases are non-communicable diseases (NCDs), and cardiovascular diseases (CVDs) account for 60% of this burden. However, the global action plan for the prevention and control of NCDs lacks environmental pollution mitigation. The study also highlights that environmental factors such as pollution can trump genetic predispositions in promoting NCDs, highlighting a critical gap in current health strategies.

Soil pollution results from harmful compounds such as synthetic chemicals, heavy metals, pathogens, pesticides, micro/nanoplasts (MNPs) and plastics, mainly from mining, industry, agriculture, waste mismanagement and fossil fuel consumption.

MNPs, an emerging contaminant, release toxic additives such as phthalates and bisphenols that disrupt cellular function and worsen cardiovascular risks. The paper highlights that MNPs act as carriers for other toxic chemicals, amplifying their deleterious effects on cardiovascular and metabolic health. While less visible than air pollution, water and soil pollution remains critical. The present study examined the interaction between water and soil pollution and human health and emphasized the CVDs.

Main effects of soil contaminants on human health, indicating the organs or systems affected and the contaminants that cause them. PCBs, polychlorinated biphenyls; PBDEs, polybrominated diphenyl ethers; PFAs, per- and polyfluoroalkyl substances; Pops, persistent organic pollutants; BTEX refers to the chemicals benzene, toluene, ethylbenzene and xylene. Adapted from the Food and Agriculture Organization report of the United Nations (created from data in the Agency for Toxic Substances and Disease Registry and Campanale et al.fao.org/3/cb4894en/online/src/html/chapter-04-3.html​​​​​​​

Chemical pollution

Contamination of water and soil threatens public health through toxic chemical exposure. Hazardous substances include polycyclic aromatic hydrocarbons, heavy metals, organic solvents, pesticides, and per- and polyfluorinated substances (PFAs). Heavy metals such as lead, mercury, arsenic and cadmium cause cancer, neurodevelopmental disorders and CVDs.

Arsenic is a major cause of water-related deaths, while lead and cadmium are linked to ischemic heart disease and hypertension. Even low exposure to heavy metals increases the risk of CVD. Persistent organic pollutants such as pesticides, dioxins, and polychlorinated biphenyls accumulate in tissues and disrupt endocrine pathways.

Bisphenol A and PFAs are endocrine disruptors that increase the risks of CVDs, obesity, and dyslipidemia. Endocrine disruptors are also involved in disrupting circadian rhythms and metabolic homeostasis, contributing to CVD risk.

MNPs, derived from plastic degradation, induce oxidative stress, endothelial dysfunction and atherosclerosis. Recent human studies show that MNPs accumulate on arterial plaques and increase the risk of cardiovascular events.

Mounting evidence links water and soil pollutants to cardiovascular outcomes. Lead exposure is a known cause of high blood pressure and higher cardiovascular mortality. In addition, blood levels of lead are reportedly associated with atherosclerosis in the carotid arteries in a Swedish cohort, which was also confirmed by a study in the United States (US).

Impact of chemical pollution from various sources on the global burden of premature deaths. Estimated global annual deaths from all sources of chemical pollution (A) and the disease companies associated with these deaths (B). (C) Deaths from all chemical pollution – ranking of top 20 countries. Population fatality rates for death and disability life years (DALYS) for lead pollution as a typical soil pollutant (D) and water pollution (unsafe water source including chemical hazards) (e) reported for 20 representative countries from different WHO regions.​​​​​​​

Ecodisruptive causes of water and soil pollution

The Food and Agriculture Organization has highlighted the crucial role of soil as a carbon sink. However, climate change is affecting global land conditions and the European Environment Agency has highlighted increased risks of desertification, erosion, altered coastal soils and reduced soil moisture due to rising sea levels. In addition, rising temperatures have serious impacts on agricultural productivity.

Overproduction disrupts nitrogen cycles and contributes to PM2.5 formation and CVD mortality. Excess nitrogen from fertilizers and livestock reacts with pollutants to form toxic particles linked to strokes and heart disease.

Deforestation through logging, mining, agricultural expansion and urbanization disrupts ecosystems, exacerbates climate change and threatens human communities and wildlife. Forests form critical carbon sinks, and their clearance releases greenhouse gases and reduces the planet's ability to absorb them. Deforestation also disrupts the hydrological cycle, leading to changes in rainfall patterns, floods and droughts, and accelerated losses of biodiversity.

Poorly designed cities with high traffic, limited green spaces and industrial zones increase pollution exposure. Urban heat islands and contaminated runoff exacerbate cardiovascular risks, while sedentary lifestyles are associated with poor infrastructure-related health burdens. In addition, inadequate waste management in urban areas leads to persistent soil and water pollution with heavy metals and hazardous chemicals, further increasing cardiovascular risks.

Communities that rely on forests for cultural practices, food and traditional medicines face enormous challenges, including food insecurity, loss of livelihoods and displacement. In the Amazon, wildfires are accelerating greenhouse gas emissions and biodiversity loss, further destabilizing the region's hydrological system. In addition, airborne dust arises from soil disturbance caused by construction, unpaved roads, wind erosion from deserts, and agriculture.

Inhalation dust induces inflammation, oxidative stress, and cardiovascular and respiratory system damage. Smaller dust particles can enter the bloodstream and worsen immune responses and CVDs. Studies have linked desert dust exposure to a higher risk of cardiovascular and respiratory deaths. As climate change accelerates desertification, extreme weather and drought conditions, airborne dust is likely to become a significant contributor to air quality degradation, justifying mitigation measures.

Closing remarks

Water and soil pollution significantly reduces biodiversity and threatens human health and the ecosystem. Exposure to heavy metals, toxins, pesticides, MNPs and plastics induces endothelial dysfunction, disruptive circadian rhythm disruption, inflammation and oxidative stress. MNPs synergize with chemical additives and worsen cardiovascular injury through mechanisms such as pyroptosis and NLRP3 inflammasome activation. Chemical pollutants could synergize with other health factors and exacerbate NCD burden. However, reducing water and soil pollution is associated with cardiovascular health benefits.

Mitigation strategies include limiting exposure to chemicals through air purification, water filtration, smoking cessation, and avoiding contaminated food, among others. The paper emphasizes that medical interventions such as chelation therapies, including EDTA-based treatments, are effective in removing heavy metals such as lead and cadmium and reducing cardiovascular risk.

Public health interventions, such as those successfully implemented in high-income countries to reduce lead and cadmium exposure, have significantly reduced CVD mortality. Policy initiatives such as the European Commission's Zero Pollution Vision aim to reduce pollution to safe levels by 2050, while the EU Soil Treaty prioritizes soil restoration and pollution reduction.

The EU also aims to prevent soil sealing, improve soil biodiversity, reduce desertification and improve soil organic carbon stocks as part of broader restoration goals. In addition, nutritional and lifestyle interventions provide protective cardiovascular effects. While pollution drives several diseases, it is preventable and not a byproduct of economic development, as high-income countries have shown that replicable, low-cost solutions can control pollution.

Sources: