Tracking multiple modes of endocrine activity in Australia's largest inland sewage treatment plant and effluent‐ receiving environment using a panel of in vitro bioassays

Jenna Roberts, Peter A Bain, Anupama Kumar, Christopher Hepplewhite, David J Ellis, Andrew G Christy, Sara G Beavis

Estrogenicity of sewage effluents, and related ecotoxicological effects in effluent-receiving environments, has been widely reported over the last two decades. However, relatively little attention has been given to other endocrine pathways that may be similarly disrupted by a growing list of 'contaminants of concern'. Further, the Australian evidence base is limited compared to Europe and North America. During a low dilution period in summer, we investigated multiple endocrine potencies in Australia's largest inland sewage treatment plant (STP) and the Lower Molonglo/Upper Murrumbidgee effluent-receiving environment. This STP receives 900 L/s of mostly domestic wastewater from a population of 350 000, and contributes a high proportion of total flow in the lower catchment during dry periods. A panel of in vitro receptor-driven transactivation assays were used to detect (anti)estrogenic, (anti)androgenic, (anti)progestagenic, glucocorticoid and peroxisome-proliferator activity at various stages of the sewage treatment process. Total estrogenic and (anti)androgenic potency was removed after primary and/or secondary treatment, however total removal efficiency for glucocorticoid potency was poorer (53-66%), and progestagenic potency was found to increase along the treatment train. Estrogenicity was detected in surface waters and bed sediments upstream and downstream of the effluent outfall, at maximum levels ten times lower than 'low-hazard' thresholds. Glucocorticoid and progestagenic activity were found to persist to 4 km downstream of the effluent outfall, suggesting future emphasis is needed on these EDC categories in effluent-receiving systems. This article is protected by copyright. All rights reserved.