Fate of antibiotics in soil and their uptake by edible crops

Antibiotics are bioactive substances, and their use as human and animal medicines for illness prevention, disease treatment and growth promotion has increased in recent decades. They are excreted, either unchanged or metabolized, and are discharged to the environment through animal manure, municipal wastewater or biosolids. Consequently, these chemicals reach cropland, which is advocated as a means of recycling. As these drugs are used in escalating quantities, there is growing concern over their presence, toxicity and fate in the soil, which may pose adverse effects on plant growth and productivity, as well as result in their uptake and accumulation in crops. These will contaminate the food chain and eventually affect human health. In this review, we summarize recent research and provide a detailed overview of antibiotics in soil-plant systems, including 1) the occurrence and determination of antibiotics around the world and their routes of entry to the environment, 2) the impact of wastewater irrigation and animal manure or biosolids amendment on agricultural soils, 3) the transport and persistence of antibiotics in the terrestrial environment, and 4) the bioaccumulation and translocation of antibiotics in different tissues of edible crops under laboratory and field conditions. Their impacts on the environment and potential human exposure are elucidated. Knowledge gaps and future research perspectives are discussed.