Government needs to study concentrations of antibiotics in rivers

In September 2014, I led a research study into Hong Kong’s river water and the findings were published in Ecotoxicology and Environmental Safety.

We discovered that the concentrations of six typical antibiotics commonly used in humans and by vets in animals (including ofloxacin, doxycycline, sulfapyridine, sulfadiazine, sulfamethoxazole, and sulfadimidine) were high and comparable to rivers on the mainland, especially doxycycline.

At some sampling sites, the concentrations of sulfamethoxazole and doxycycline in the river water were higher than in the sewage influent.

These sites were mainly in two regions, in areas of the Kam Tin River and the Shek Sheung River, which were densely populated. Doxycycline belongs to the class of antibiotics known as tetracyclines and sulfamethoxazole belongs to the class known as sulfonamides. Tetracyclines and sulfonamides are commonly used in hospitals and livestock feeding.

The consumption of aquatic products or water from those rivers which were contaminated with antibiotics can cause human allergy and toxicity problems.

Chronic exposure to tetracycline (including doxycycline in this study), for example, could lead to steatosis (an accumulation of fat in the liver) by altering genes related to lipid metabolism and transportation.