High-throughput transcriptomics of water extracts detects reductions in biological activity with water treatment processes

The presence of numerous chemical contaminants from industrial, agricultural, and pharmaceutical sources in water supplies poses a potential risk to human and ecological health. Current chemical analyses suffer from limitations including chemical coverage and high cost, and broad-coverage in vitro assays such as transcriptomics may further improve water quality monitoring by assessing a large range of possible effects. Here, we used high-throughput transcriptomics to assess the activity induced by field-derived water extracts in MCF7 breast carcinoma cells. Overall design: Wastewater, surface water, drinking water, and reclaimed water samples were collected from four sites in the United States and Australia and prepared via solid phase extraction. Samples were generally collected as pairs: surface and drinking water (as conventional water supply) and wastewater and reclaimed water (as purified recycled water). Resulting extracts were exposed to MCF7 breast carcinoma cells in an eight-point dilution series (concentration factor 0.01-50) for 6 h using three independent cultures per dose.