**Organic Fertilizers: Public Health Intricacies**

Anthony A. Adegoke, Oluyemi O. Awolusi and Thor A. Stenström

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/64195

#### **Abstract**

[16] Oliveira, E.L. Sugestão de adubação e calagem para culturas de interesse econômico

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[18] Oliveira, P.P.A.; Trivelin, P.C.O.; Oliveira, W.S.; Corsi, M. Fertilização com N e S na recuperação de pastagens de *Brachiaria brizantha* cv. Marandu em Neossoloquartzarê‐ nico. Revista Brasileira de Zootecnia. 2005;34(1806-9290):1121/1129. DOI: http://

[19] Pedreira, B.C.; Pedreira, C.G.S.; Silva, S.C. Acúmulo de forragem durante a rebrotação de capim-xaraés submetido a três estratégias de desfolhação. Revista Brasileira de Zootecnia. 2009;38(1806-9290):618/625. DOI: http://dx.doi.org/10.1590/

[20] Pedreira, B.C.; Pedreira, C.G.S. Fotossíntese foliar do capim-xaraés [*Brachiaria brizantha (A. Rich.) Stapf*. cv. Xaraés] e modelagem da assimilação potencial de dosséis sob estratégias de pastejo rotativo. . Revista Brasileira de Zootecnia. 2007;36(1806-9290):

[21] Sbrissia, A.F.; Da Silva, S.C. Compensação tamanho/densidade populacional de perfilhos em pastos de capim-marandu. Revista Brasileira de Zootecnia. 2008;37(1806-9290):35/47. DOI: http://dx.doi.org/10.1590/S1516-35982008000100005 [22] Silva, A.A.; Simioni, G.F.; Lucena, A. Efeito da adubação orgânica no crescimento do capim *Brachiaria Brizantha* cv. Marandu em Parecis/Rondônia. Enciclopédia Biosfera,

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no Estado do Paraná. IAPAR ed. Londrina:2003. 30 p.

http://dx.doi.org/10.1590/S1516-35982007000900006

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Centro Científico Conhecer. 2013;9:923/932.

http://dx.doi.org/10.1590/S0100-204X2007000600016

S1516-35982009000400005

342 Organic Fertilizers - From Basic Concepts to Applied Outcomes

Organic fertilizers are an essential source for plant nutrients and a soil conditioner in agriculture. Due to its sources and the composition of the organic inputs as well as the type, functionality and failures of the applied treatment process, the organic fertilizer may contain various amounts of infectious agents and toxic chemicals, especially the antibiotics that can be introduced to the subsequent food chain. A range of human and animal pathogens of bacterial, viral and parasitic origin have been the cause of foodborne epidemics due to unintended contamination from organic fertilizers. The use of antibiotics by humans and in animal feeds will also end up in the organic fertilizers. These antibiotics and other chemicals, depending on the sources of the organics, will enhance the likelihood of occurrence of resistant and multi-resistant strains of microorganisms in society and have been reported to cause ecotoxicological environ‐ mental effects and disruption of the ecological balance. Exposure of microorganisms to sublethal concentration of antibiotics in the organic products induces antibiotic resistance. WHO guidelines for the reuse of excreta and other organic matters identify the risk for the exposed groups to the reuse of the excreta and are applicable in the use of organic fertilizers in agriculture.

**Keywords:** organic fertilizers, food-borne illnesses, pathogens, antibiotics, ecotoxicity, WHO

#### **1. Introduction**

The potential health intricacies linked with organic fertilizers relate to their origin, their treatment and human exposure within a system perspective from origin to use, including products like crop type. Since organic fertilizers mainly are "faecal material/manure and urine

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

from different animals and/or humans, with the addition of plant materials (organic solid wastes), or in special situations waste materials 1 from food or plant processing industries", the origin of the different fractions and their amounts partly defines the risk. Usually the risk is outbalanced by a wide range of benefits that the use of organic fertilizer exerts in agricul‐ ture as nutritional fertilizers and for soil conditioning. It has been further implied as more environmental friendly than the inorganic fertilizers [1] and its effect more tender on biotic components of the ecosystem without much shift in the ecological balance [2]. This is partly reflected by organisms like earthworms which may be negatively affected by inorganic fertilizers but promoted by the use of organic fertilizers and also incorporated as decompos‐ ers in aerobic composting processes [3, 4].

As this chapter deals with the public health aspects and risks involved, we define the organic materials utilized by its sources and thus relate to the following:


Additionally, the risk may relate to some storage-specific factors like


Based on source, the risk will vary to a great extent, depending on the health of the animals/ humans that primarily defines the microbial concentration and partly occurrence of antibiotics and chemical components in the organic wastes (from domestic or animal sludge fractions) that may be conveyed to the agricultural sites and crops fertilized. Additional components may apply if organic industrial wastes are utilized. An indirect organic fertilization may occur through irrigation using wastewater effluent, where the nutrient load serves as an advantage. This is widely applied in developing countries [5]. However, this may result in additional inputs of antibiotics, toxic organic and inorganic compounds and pathogens. All these concepts are further deliberated in this chapter. The possibilities of recycling food-borne pathogens via agricultural crops to the final end consumers of the crops will additionally be discussed. Foodborne pathogens are especially important for animal faecal-based fertilizers used on fruits and vegetables farms meant to supply salads in restaurants. Other dynamics are residual antibiotics which are sometimes locked in the components of the organic fertilizers with attending public health implications to be further enumerated in this chapter.
