Identification of emerging contaminants in greywater emitted from ships by a comprehensive LC-HRMS target and suspect screening approach

The increase in maritime traffic has led to substantial greywater discharges into the marine environment. Greywater, originating from sinks, showers, kitchen, and laundry facilities, contains a wide array of chemical contaminants influenced by on-board activities, ship size, and management practices. The lack of comprehensive regulations for greywater management, along with limited research on its chemical composition, highlights the need to characterize these waste streams. This study is one of the first to provide a comprehensive characterization of greywater samples from ships using advanced liquid chromatography coupled to high-resolution-mass-spectrometry (LC-HRMS) strategies, including wide-scope target and suspect screening. The target analysis detected 86 compounds, such as pharmaceuticals, stimulants, tobacco and food-related products, personal care products, UV filters, surfactants, perfluoroalkyl compounds, plasticizers, and flame retardants, many of which are rarely measured in routine monitoring programs. Furthermore, 11 additional compounds were tentatively identified through suspect screening. A novel scoring system further highlighted 25 priority compounds posing ecological risks to marine ecosystems, including pharmaceuticals such as tapentadol, dextrorphan, citalopram, or irbesartan. This study emphasizes the significant introduction of chemicals at μg L⁻¹ levels through greywater discharges, underscoring the urgent need for improved management practices to mitigate ecological risks to the marine ecosystem.