Land application of treated municipal wastewater as an irrigant for turfgrass has been used extensively in golf course management. Runoff from wastewater-irrigated turf may contain organic microcontaminants derived from the wastewater itself or from routine application of turf-management chemicals (e.g. fungicides and herbicides). If this runoff enters surface waters, it may pose a hazard to aquatic life.
In several years of field work, we have examined the in vivo and in vitro effects and occurrence of wastewater-derived and turf grass management organic contaminants in tidally-influenced stormwater detention ponds impacted by sewage-derived irrigation water and located on a coastal golf course community at Kiawah Island, SC. We have employed a combination of passive sampling (POCIS) and high-frequency grab sampling to chemically characterize the suite of organic microcontaminants in this unique environment. Wastewater-derived compounds commonly detected in the irrigation water and runoff include xenoestrogens (4-nonylphenol, bisphenol A), biogenic estrogens (17β-estradiol, estrone, and estriol - typically below 10 ng·L-1), and human pharmaceuticals such as carbamezapine and ibuprofen. Turf management chemicals, including herbicides (e.g. atrazine and 2,4-D), insecticides (including fipronil and several pyrethroids), and fungicides (e.g. propiconazole) were measured at part-per-trillion to part-per-billion levels in stormwater retention ponds adjacent to fairway turf. We have tested a range of biologically-relevant endpoints including In vivo estrogenic activity of stormwater and wastewater by exposing male fathead minnows (Pimephales promelus) for 14 days to treated wastewater in an effluent holding pond as well as 3 stormwater detention ponds receiving irrigation runoff from land-application of wastewater effluent. The fish are exposed on-site to pond water and wastewater using a trace-organic clean, field-deployable, flow-through environmental exposure chamber system (the Mini-Mobile Unit, developed by our collaborator Dr. Alan Kolok at the University of Nebraska, Omaha).
Additionally, to determine other biomarkers of exposure to complex mixtures containing xenoestrogens, we are performing microarray (gene expression) and proteomic analyses on liver, gonad and brain tissues from the fish. This discovery-based approach extends the endocrine-centered bioassays and allows us to identify unanticipated biological responses in the fish during exposure. To complement these assays, we are developing and applying non-targeted organic contaminant analysis strategies using high-resolution Orbitrap MS/MS detection. These experiments are designed to allow identification of novel and emerging organic contaminants in complex mixtures (such as those in the Kiawah stormwater ponds) without the necessary a priori knowledge of their occurrence typically required in targeted analytical strategies.
The overall goal of this project is to understand the link between environmental exposure to complex mixtures of environmental contaminants and adverse effects along a biological pathway or set of pathways, using combined systems biology and high-fidelity analytical chemistry approaches.