Gauging the pharmaceutical burden on Sydney’s environment: a preventative response

Abstract Metabolized and/or unmetabolized fractions of pharmaceuticals upon excretion or being washed from the skin can undergo complex chemical reactions. Entering the sewerage system some may also react with other synthetic chemicals to form unfathomable brews. Unfortunately most sewerage treatment plants fail to remove a sizeable proportion of these compounds. Their impact when released to the environment as a component of treated effluent remains a matter for conjecture although some insight has, for example, derived from work done on the effects of antibiotics on insects at entry points (dung) to pasture and groundwater. There is the possibility too that effects are occurring toward the limits of detection of suspect compounds notably endocrine disruption. To draw attention to the seriousness of the local problem in a situation where no data exists, a gross estimate of the annual drug load has been made for Sydney’s environment using statistics collected under the Australian Government’s Prescribed Benefits and Repatriation Benefits Scheme. This amounts to 17 tonnes but allowing for hospitals and clinics as well as OTC and illicit drugs, the overall figure is probably closer to 30 tonnes per annum. A two-prong impact reduction strategy is proposed comprising suggestions for curbing the discharge of existing medications and most importantly, a longer term fix utilising both natural product pharmaceuticals and vaccines and even gene therapy.