Health Risks And Benefits Associated With Soil
Published on 24 April 2009 in Food, health and wellbeing
Introduction
Soil is a key natural resource that can have both positive and negative impacts on people. Its ability to supply nutrients to growing crops and pasture has a direct impact on food quality. If health benefits are to be achieved, it is important to understand any risks and opportunities and how to manage them.
The findings of our work, summarised below, have direct implications for Strategic Framework for Environment and Health (SFEH) in Scotland. Some of the findings of the work described are feeding into the EDPHiS project (Environmental Determinants of Public Health in Scotland) funded by the Scottish Government as a supporting initiative to SFEH. Scotland's soil is generally of good quality but due to its geology the soil resource in Scotland is different from other parts of the UK and Europe and presents its own opportunities and constraints. For example: - 30% (by area) of Scotland's soils are deficient in Cu, an essential trace element, compared with 5% in England and Wales (1) - The presence of potentially toxic elements or compounds in the soil may result in people being exposed to harmful substances, either in their food, or via direct contact with soil (dermal contact, inhalation of wind-blown soil particles, ingestion of soil adhered to hands or food).
Recent interest from consumers and policy advisors in "food miles" imparts greater importance to the local soil resource. This has implications for individuals and local food producers alike. See also the knowledgescotland Policy Briefing 'Supporting Sustainability By Relocalising Food And Drink Systems'. However, soil, and how individuals perceive and interact with it, also has an impact on human health and well-being. For example the perceptions of an individual's clean or polluted environment can affect their well-being and their interaction with soil e.g. in the garden is a beneficial factor in a number of health (physiological and psychological); social; ecological; and economic ways.
Key Points
A recent review (2) by researchers at the Macaulay Land Use Research Institute of international epidemiological evidence of the links between soil and negative health outcomes showed that evidence was available linking exposure to soil to specific cancers and enteric parasites. There was very limited evidence linking soil contaminants, such as heavy metals, to negative health outcomes but equally there was as little evidence contrary to this.
Another recent study looked at health impacts and benefits of urban food production in the UK, (Table 1). A number of health benefits were identified to counter the potential risks associated with perceived or actual urban pollution
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Health
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Social
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Ecological
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Economic
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Physiological
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Horticultural skills
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Open green spaces
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Food savings
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Multi-muscular exercise
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Limited noise pollution
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Lower housing density
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Food purchasing
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Fresh nutritional produce
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Communal activity
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Fresh air
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Alternative land use
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Vitamin D synthesis
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Nice view
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Allotment wildlife
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Adds to housing value
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Socialising
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Wildlife corridors
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Psychological
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Product exchange
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Low noise pollution
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Mental well-being
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Skills sharing/learning
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Scenic views
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Empowerment
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Green socialising
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Buffer zone
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Nature interaction
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Friendship
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Barrier from roads
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Relaxing/therapeutic
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Privacy
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Rural atmosphere
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Sense of community
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Rain infiltration
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Sense of security
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Reduced urban heat
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Research Undertaken
We carried out a comprehensive review of peer-reviewed international literature related to soil exposure as a risk factor for disease. Computerised database searching of a range of international databases was carried out: MEDLINE, BIDS, PubMed and Web of Science. Over 2600 references were found. The search was further refined to 394 papers that investigated soil as a risk to health. Original full texts (in English) were obtained for all studies. Studies on aggregate- or ecological-level designs, descriptive and surveillance studies, and other papers that only made inference to soil being a risk factor for disease were excluded (2).
Only the studies that quantified the level of risk to individuals from soil or soil-related activities (e.g. gardening) formed the basis of this review, although other papers within the database were used as background material. In a second study theoretical risks and self-reported benefits of producing and consuming your own food in urban allotments in the UK were elucidated using participatory approaches (as reported in Table 1).
Policy Implications
The relations linking policy, environment, exposure and health are complex and the strength of evidence linking them, and how they are affected by wider social context, is variable and sometimes contested. Soil is an important component of our environment and has a direct bearing on the quantity and quality of our food. Thus the work is also very relevant to Scotland’s food strategy, underpinning considerations for food security and heath benefits, or otherwise, of local food. How we interact with soil can have both positive or negative impacts on our health and we are working to quanitify these risks and benefits.
Author
Dr. Rupert Hough r.hough@macaulay.ac.uk
