Soil, food security and human health: a review

Abstract

Direct effects of soil or its constituents on human health are through its ingestion, inhalation or absorption. The soil contains many infectious organisms that may enter the human body through these pathways, but it also provides organisms on which our earliest antibiotics are based. Indirect effects of soil arise from the quantity and quality of food that humans consume. Trace elements can have both beneficial and toxic effects on humans, especially where the range for optimal intake is narrow. We focus on four trace elements (iodine, iron, selenium and zinc) whose deficiencies have substantial effects on human health. As the world's population increases issues of food security become more pressing, as does the need to sustain soil fertility and minimize its degradation. Lack of adequate food and food of poor nutritional quality lead to differing degrees of under-nutrition, which in turn causes ill health. Soil and land are finite resources and agricultural land is under severe competition from other uses. Relationships between soil and health are often difficult to extricate because of the many confounding factors present. Nevertheless, recent scientific understanding of soil processes and factors that affect human health are enabling greater insight into the effects of soil on our health. Multidisciplinary research that includes soil science, agronomy, agricultural sustainability, toxicology, epidemiology and the medical sciences will facilitate the discovery of new antibiotics, a greater understanding of how materials added to soil used for food production affect health and deciphering of the complex relationships between soil and human health.'Upon this handful of soil our survival depends. Husband it and it will grow food, our fuel, and our shelter and surround us with beauty. Abuse it and the soil will collapse and die, taking humanity with it' Vedas Sanskrit Scripture, 1500 BC.

Fortification of micronutrients for efficient agronomic production: a review

“…However, one commonality with micronutrients in different global agroecosystems is the fact that their deficiency in crops is compounded by a low crop use efficiency (i.e., low crop response per unit of micronutrient, relative to no micronutrient application), typically <10 %, compared to between 20 and 80 % for N, P, and K (Baligar et al 2001). Also, in vast regions of the globe (for instance, in several countries of Africa and Asia), it is reported that majority of the arable land is affected by multiple micronutrient deficiencies (Voortman and Bindraban 2015;Monreal et al 2015;Oliver and Gregory 2015). In these regions, the scenario is further complicated by the inadequate replenishment through fertilization of micronutrients biologically mined from the soil by plant roots, which has had negative agronomic consequences for crop productivity.…”

“…As such, a micronutrient deficiency in food crops, due to its lack in soil, could translate to micronutrient deficiency in humans (White and Broadley 2009;Martínez-Ballesta et al 2010;Joy et al 2015;Oliver and Gregory 2015). In countries where staple foods consist mainly of cereals and tubers grown in nutrient-poor soils, human micronutrient deficiency, especially of Zn, is widespread, representing a major cause of stunting and child death.…”

Selenium behavior in the soil environment and its implication for human health

“…It is necessary for the synthesis of the amino acid selenocysteine, which is involved in the formation of approximately 25-35 proteins (called selenoproteins) that are critical in mammal metabolism (Rayman, 2012;Oliver and Gregory, 2015). Examples of selenoproteins include the glutathione peroxidases (with antioxidant functions), thioredoxin reductases (oxidoreductases that act on disulfide reduction system), iodothyronine deiodinases (responsible for synthesis and metabolic regulation of thyroid hormone) methionine-R-sulfoxide reductase (a zinc-containing selenoprotein), selenophosphate synthetase 2 (synthesis of the active Se donor selenophosphate), 15-kDa selenoprotein (thioredoxin-like fold ER-resident proteins), and selenoproteins H, I, M, T, V, and W (Rayman, 2012;Labunskyy et al, 2014).…”

Unequal lands: Soil type, nutrition, and child mortality in southern Sweden, 1850-1914

“…Such impacts can be direct or indirect. Direct effects are those foremost related to various pathogens contained in the soil (Oliver and Gregory 2015), which children are particularly exposed to (Hawley 1985). Indirect effects are primarily factors such as soil fertility that affect the quantity and quality of food produced (or the kind of food that can be produced).…”

“…Indirect effects are primarily factors such as soil fertility that affect the quantity and quality of food produced (or the kind of food that can be produced). In addition, trace elements and minerals in the soils are transferred to the food cultivated in it, which in turn affect the health of humans (Abrahams 2002;Oliver and Gregory 2015). For example the availability of elements such as iron, iodine, selenium, and zinc (Oliver and Gregory 2015), which are essential to human health, is highly linked to soil quality.…”