Antibiotics enter sewage system through people not breaking down antibiotics properly or with the dumping of unused antibiotics into water systems. Another factor is the waste run off into the sewage system from pharmaceutical companies.
This concern has been raised by Professor Olya Keen, of UNC Charlotte. Keen has noted that there is a wide variety of different antibiotics found in wastewater and that these are not removed through the water treatment process. In fact, the process of treating water appears to be chemically altering the antibiotics and creating new forms.
The antibiotic that Keen has been studying most closely is doxycycline. Doxycycline is a broad-spectrum antibiotic, often sold under the brand name Vibramycin. It can be used as a defense against anthrax.
What seems to be happening with doxycycline is that the chlorine used to treat wastewater is altering the chemical composition of the antibiotic, leading to an altered structure. Keen has shown this via chemical analysis, such as the use of a spectrophotometer. The problem is that some bacteria have become resistant to this altered structure and the risk is that this fuels a new form of antibiotic resistant organism and this organism becomes prevalent in the general environment.
The issue of antibiotic resistance is of great medical and social concern. The problem is that diseases that were once readily treatable are now no longer so, leading to an increased risk for people especially within the hospital environment. This has been highlighted in a recent report by the British Royal Pharmaceutical Society: New Medicines, Better Medicines, and Better Use of Medicines.
Keen’s research was presented at a recent meeting of the American Chemical Society held in Denver, Colorado. The work has yet to be published.
