Health risks posed by using organic fertilizers

Agricultural production has been intensifying for a while and this has made for growing volumes of organic wastes; a part of them is later used as fertilizers. At present, more than 200 types of organic fertilizers are employed in agriculture; they differ in their origin, properties, and effects on the environment. Wastes from agricultural productions typically contain biocides, antibiotics included, and also, which is especially important, pathogens and opportunistic pathogenic microorganisms. Soil contamination with such wastes destroys natural biocenosis. Moreover, pathogens that remain in wastes due to absence of proper treatment can pose serious hazard for humans and animals. Safety of food products made of raw materials, growth of which relies on using organic fertilizers, is a significant component of the overall issue. This analytical review provides a classification and descriptions of organic fertilizers and data on production volumes and accumulation of animal husbandry wastes. It also describes major biological and chemical factors of health risks associated with using organic fertilizers as well as provides the results of up-to-date studies that focus on negative effects of organic fertilizers. Special attention is paid to literature data about negative impacts exerted on human health and the environment by organic fertilizers that contain antibiotics and salts of heavy metals. It is emphasized specifically that organic fertilizers can very often contain copper, zinc, cadmium, nickel, chromium, arsenic, lead and mercury compounds. Improper use of technologies for treatment of organic fertilizers is shown to result in microbial and chemical pollution in soils and water objects. Methods employed to assess effects of animal husbandry wastes on human health and the environment are described considering international and Russian practices and documents that establish regulatory requirements to safe use of organic fertilizers. The review establishes that a strategy for providing safety of agricultural production should consider risks for human health and include systemic monitoring over quality of the environment and population health.