Natural and organic fertilizers as a source of environmental contamination with antimicrobial substances

Veterinary antibiotics (VAs) are widely used worldwide to treat and prevent infectious diseases, as well as to promote growth and improve the feeding efficiency of food-producing animals in livestock activities. Research indicates that animals can excrete up to 90% of VAs through their droppings. Agriculture, especially industrial animal breeding, is among the main sources of environmental pollution with antimicrobials. The intensive breeding of farm animals is excessively loading the environment with excrements. Environmental pollution is caused, among others, by the use of antibacterial substances on a large scale, excretion of unchanged forms of antibiotics with feces and urine, as well as fertilization of arable land with manure. The paper outlines problems resulting from the excretion of antibacterial substances by farm animals and the introduction of these substances in the form of natural or organic fertilizers into arable soils. It reviews the available publications on the presence of such substances in fertilizers and soil, as well as methods of their degradation and their influence on soil and the environment.