The occurrence of methyl, ethyl, propyl, and butyl parabens in the urban rivers and stormwaters of Sydney, Australia

Abstract

Parabens, commonly used preservatives, are emerging pollutants that are known to enter waterways through the wastewater system where they can pose a threat to aquatic organisms. Less is known about their presence and contribution to urban waterways in cities with separated stormwater and wastewater systems, such as Sydney, Australia. We measured the occurrence of methyl-(MeP), ethyl-(EtP), propyl-(PrP) and butyl-(BuP) parabens in urban river and stormwater samples across a range of land uses, using solid-phase microextraction with gas chromatography-mass spectrometry for the analysis. MeP in modified stormwater channels was more frequently detected and found at higher mean levels (6.29 μg L⁻¹) than in urban rivers (3.62 μg L⁻¹). Waterways in residential catchments had greater mean total paraben load (26.87 μg L⁻¹) when compared to parkland catchments (12.71 μg L⁻¹) and bushland catchments (2.10 μg L⁻¹). EtP had the highest peak concentrations across the study area (max = 305.55 μg L⁻¹) associated with industrial land uses and areas historically associated with poor water quality. The levels of EtP were relatively high when compared to international studies in cities with combined stormwater and wastewater systems. The results also suggest overflows from the sewer during heavy rain are likely not as significant when compared to the contribution from urban runoff. The study did not reveal the source of the EtP and further studies are recommended to identify this and the potential environmental impact.