Spatial distribution, pollution characteristics, and health risks of antibiotic resistance genes in China: a review

With the extensive production and use of antibiotics for medicinal and veterinary purposes, antibiotics and genes that code for antibiotic resistance are now present in various environmental media with higher frequencies of occurrence and at higher concentrations than before. Particularly, China has led the world in the production and consumption of antibiotics, which might lead to higher pollution levels of antibiotic resistance genes and pose a threat to human health. Here, we review the sources of antibiotic resistance genes in China, and their spatial distribution and pollution levels in surface water, e.g., in lakes and rivers, atmosphere, and soil. Statistics indicate that higher levels of antibiotics and related antibiotic resistance genes were detected in eastern China compared with other regions, and that tetracycline and sulfanilamide resistance genes are the most prevalent. The absolute concentrations of antibiotic resistance genes are 10(2) - 10(5) copies per milliliter of water, 10(4)-10(8) copies per gram of soil, and 10(4)-10(6) copies per cubic meter of atmosphere. We also analyze the pollution status and fate of antibiotic resistance genes in wastewater treatment processes. Then, the biological and abiotic factors affecting the transfer and distribution of antibiotic resistance genes are elucidated. We discuss the risks of antibiotic resistance genes for ecological safety and human health.