Soil pollution and health

Figure 20. Summary analysis: soil pollution and health 

Introduction

Healthy soils are critical for supporting human health. They are essential for food, biomass and fibre production, the production of certain medicines, and retaining and filtering water. Healthy soils also play a key role in carbon and nutrient cycles. Soil pollution affects soil fertility; this jeopardises food security, which is essential for human survival. It also poses risks to human health — both indirectly through the consumption of contaminated food and drinking water, and directly through exposure to contaminated soil.

Soils can become polluted in various ways. For example, repeated pesticide application is a significant issue because it lowers soil biodiversity and resilience, and could lead to the contamination of food and feed. The zero pollution action plan sets targets of a 50% reduction in the use of chemical pesticides and the risks they pose, and a 50% reduction in the use of more hazardous pesticides by 2030 (for more information, see the zero pollution production and consumption section). Excess nutrients are another source of soil pollution. They lead to ecosystem eutrophication and reduced biodiversity, and result from fertiliser and manure application or from the deposition of certain air pollutants. The zero pollution action plan sets a target to reduce nutrient losses related to excessive nutrient application by at least 50% by 2030 (for more information, see the zero pollution analysis on nutrient losses). Another target which will promote healthier soils requires a reduction of 25% in the area of land impacted by air pollution; this target is assessed in the air and ecosystems section.

The EU soil strategy for 2030 reiterates the zero pollution target that, by 2050, soil pollution should be so low that it no longer harms human health (EC, 2021). The strategy prioritises preventing pollution at its source, which aligns with the zero pollution hierarchy. The soil strategy proposes a future soil health law; this is expected to include provisions on identifying, keeping an inventory of and remediating contaminated sites — significantly reducing risks as a result.

Soils support human health

Heathy soils provide nutritious food, clean drinking water, raw materials and carbon sequestration functions — ecosystem services that are essential for guaranteeing food security, tackling climate change and safeguarding human health (Montanarella and Panagos, 2021).

Soil pollution affects food security in two ways. First, soil pollution can reduce crop yields; this is because toxic pollutants degrade soils over the long term. Second, soil pollution can make foods unsuitable for human consumption (Rodríguez-Eugenio et al., 2018).

Human exposure to soil pollution is estimated to contribute to more than 500,000 premature deaths globally each year (Landrigan et al., 2018). Most of these deaths occur in vulnerable groups, such as children and the elderly, affected by long-term exposure. Moreover, these deaths are related to exposure to only a limited range of pollutants; the impacts of all soil contaminants on health and well-being are likely to be greater.

Depending on the chemicals involved, soil pollutants can affect various organs, such as the lungs, skin, gut, liver and kidneys. These pollutants can also affect the immune, reproductive, nervous and cardiovascular systems, and more. Evidence suggests that the health impacts of soil pollution disproportionally affect poorer households; for example, poorer households have higher chances of living close to industrial sites and being exposed to contaminated soils (Morrens et al. 2012; Levasseur et al., 2021).

Human exposure to soil pollution

When spending time outdoors, people may be exposed to polluted soils through direct skin contact or by breathing in dust. In particular, children playing on the ground may consume or inhale polluted soil. Soils in urban areas, such as parks and home gardens, are a repository for contaminants (Li et al., 2018).

The degree of exposure is likely to depend on weather and soil conditions, as well as on the distance to sources of pollution. Sources include agricultural fields on which pesticides, fertilisers, wastewaters and sewage sludge may be applied; and industrial production, mining operation and waste management facilities, where hazardous materials may be used or stored — leading to emissions to air, water and soil.

People may also be indirectly exposed to soil pollutants through contaminated drinking or bathing water. They could also consume contaminated food grown in polluted soils, or products from animals fed contaminated feedstuffs. Further information on contaminants in food is available in the chemicals and health assessment.

Many of the emerging contaminants of concern in soils such as per- and polyfluoroalkyl substances (PFAS), phthalates and flame retardants are associated with significant health effects (Maddela et al., 2022).

Hotspots for human exposure to soil pollution are contaminated sites, certain agricultural and urban soils, and land that has previously been flooded. A German study monitored toxic pollutants in floodplain soils across the Elbe River in central Europe and assessed health risks (Rinklebe et al., 2019). The Elbe River and its tributaries are among the most highly polluted rivers in Europe due to a history of intensive industrial activity taking place over centuries. At the same time, these floodplain soils are highly fertile and often used for agriculture. Around the Central Elbe River, arsenic was found to be the primary contributor to total health risk — with chromium second, vanadium third and lead fourth. The study found that children’s health was at dramatically more risk than adults’.

High and increasing concentrations of cadmium have been found in agricultural topsoil across Europe; this mainly comes from phosphate fertilisers. Cadmium is a heavy metal; diet is the principal exposure route in non-smokers (smokers are routinely exposed to cadmium through cigarette smoke). It is linked to harmful health effects, including renal toxicity and osteoporosis (Ougier et al., 2021). The Mediterranean area, in particular, was found to be very sensitive to the accumulation of cadmium due to local soil properties which affect retention of metals in the soils (De Vries et al., 2022).

Under the HBM4EU project, human exposure to cadmium was assessed across nine European countries (HBM4EU, 2022a). The results of this study are presented in Figure 21, which shows the percentage of participants in each study in which levels above the guideline value were detected. The study identifies significant geographical variation with the highest exposure seen in France, Germany and Poland. Increased levels of cadmium were associated with people following a vegetarian diet, with 35% higher levels seen in vegetarians as opposed to non-vegetarians. The use of mineral phosphate fertiliser on agricultural land was also linked to dietary exposure to cadmium (Snoj Tratnik et al., 2022).

Figure 21. Percentage of participants (non-smoking adults, aged 20-39) with cadmium above guideline values across nine European countries, conducted between 2014 and 2020

Source: HBM4EU (2022b).

Cover image source: © Evangelija Ivanoska, Well with Nature /EEA