Fate of Antibiotics in Soil

Abstract

An extensive amount of antibiotics is being used worldwide to enhance the health status, growth rate, milk, and meat production in dairy farms. In many aspects, the use of these veterinary antibiotics is crucial for the animals. But point of concern is that, animals don’t have enough ability to utilize these applied antibiotics, and it depends on the animal species and chemical composition of veterinary antibiotics. About 90% is obtained from the natural compounds like bacteria, fungi, and semisynthetic modifications and taken as “natural products,” and some are totally synthetic. Approximately 10–90% of the applied antibiotics are released in the form of urine and feces. The animal waste is used as fertilizer and exposed to the soil. Antibiotics present in manure are organic in nature and have the capability to bind with soil particles. These are many features that are affecting the fate of antibiotics in soil like the absorption and fixation rate of different antibiotics on the soil particles surfaces mainly depends on the soil pH, physico-chemical characteristics, climatic conditions, soil type, composition and quality of organic matter, soil texture, CEC, and iron oxide content and many other environmental factors. There are several procedures that are involved, including chemical nature, transport, leaching and runoff, sorption, plant uptake, and biodegradation that determines the fate of antibiotics in soil. The chemical nature determines the persistence of the antibiotic in soil and as a result of biodegradation or transformation different metabolites are produced that have different chemical composition and less risk will be associated with these metabolites than the actual antibiotic. Surface transport of antibiotics via runoff was attributed to delayed infiltration of water into the soil because of surface sealing through manure and particle bound transport. Surface runoff of antibiotics from animal waste spread the chemicals to the general water environment. Different plant organ and tissues have the ability to uptake and store the antibiotics, mostly in roots, cotyledons, and cotyledon petioles parts. Phytoremediation is potential of plants against the different antibiotics. In general, plants are used for the phytoremediation of toxic materials from soil in the past. But nowadays, phytoremediation (phytostabilization, phytotoextraction, phytovolatilization, and phytoaccumulation) emerging as a new technique was considered to be effective in elimination of antibiotic from planted soil. All these features help to determine the fate of antibiotic in soil.