Detection of pharmaceuticals and phytochemicals together with their metabolites in hospital effluents in Japan, and their contribution to sewage treatment plant influents

Abstract

The occurrence of 41 pharmaceuticals and phytochemicals (PPs) including their metabolites was surveyed in hospital effluent in an urban area of Japan. A detailed survey of sewage treatment plant (STP) influent and effluent, and river water was also conducted. Finally, mass balances with mass fluxes of the target PPs through the water flow were evaluated and the degree of contribution of hospital effluent to the environmental discharge was estimated.The results indicate that 38 compounds were detectable in hospital effluent over a wide concentration range from ng/L to μg/L, with a maximum of 92μg/L. The contributions of PPs in the hospital effluent to STP influent varied widely from <0.1% to 14.8%. Although almost all of the remaining components could be removed below 1.0ng/L at STPs by the addition of ozone treatment, a number of PPs still remained above 10ng/L in STP effluent.These findings suggest the importance of applying highly developed treatments to hospital effluents and at STPs in the future to reduce the environmental risks posed by PPs. To our knowledge, this is the first demonstration of the presence of two conjugated metabolites of acetaminophen, acetaminophen glucuronide and acetaminophen sulfate, as well as of loxoprofen and loxoprofen alcohol, in hospital effluent, STP, and river waters.