Pay attention to non-wastewater emission pathways of pharmaceuticals into environments.

Pharmaceuticals have been widely detected in the aquatic environment and demonstrated to be potential risks to humans and the environment. Understanding emission pathways of pharmaceuticals is essential to the control of pharmaceutical contamination for environmental management. The present study is aimed at testing the hypothesis that non-wastewater pathway is also significant to the emission of pharmaceuticals into the environment. To this end, we compared the actual production with the amount of 12 antibiotics obtained by back calculation from sewage concentrations in Beijing, Guangzhou and Chongqing. The results showed that for over a half of investigated antibiotics, the emission through non-wastewater pathways accounted for approximately 30-80% of the total emission, varying with individual antibiotics. It was revealed that non-wastewater emission pathways could be of significance for pharmaceuticals emitted into the environment, of which disposed by household waste could be among the most important non-wastewater pathways.