A survey of per- and polyfluoroalkyl substances (PFAS) was conducted in Melbourne, Australia to determine background concentrations in residential, industrial, municipal wastewater treatment plants, and rural land uses. Surface water and sediment samples collected from 65 sites with different catchment land uses were analysed for thirty-three PFAS. Twenty-two out of thirty-three targeted PFAS were detected, with at least one PFAS species was detected in 98% water samples and 8% sediment samples. One site was determined to have point-source pollution from an airport (surface water Σ₃₃PFAS = 4261 ng/L) and was excluded from statistical analyses. The median Σ₃₃PFAS concentration in surface water was 63.5 ng/L and the average was 78.6 ng/L (range < DL-526 ng/L). PFAS species with the highest median concentrations were PFBA (11.3 ng/L), PFHxA (9.2 ng/L), PFOA (8.3 ng/L), PFOS (8.0 ng/L), PFPeA (7.5 ng/L), PFHpA (3.2 ng/L), and PFHxS (2.9 ng/L). The average Σ₄PFAS in sediments was 0.35 ng/g d.w. (range = <DL-6.7 ng/g) and the congeners detected were PFOS, N-MeFOSAA, N-EtFOSAA, and N-EtFOSE. Significantly higher concentrations of all PFAS were found in urban areas than rural, except for PFBA which was evenly dispersed throughout all areas. Short-chain perfluoroalkyl carboxylic acids (PFCAs), PFBA, PFPeA, PFHxA, PFHpA, and the PFSA, PFBS were evenly dispersed throughout urban and industrial areas. PFOA, PFNA, and PFDA were higher, but not significantly, in residential catchments than industrial catchments. Industrial areas had significantly higher concentrations of perfluoroalkyl sulfonic acids (PFSAs), PFPeS, PFHxS, and PFOS, and 6:2 FTS than other urbanised areas. The distribution of PFAS throughout catchment types in this study displayed similar trends to other studies including findings of PFBA in background areas. Ongoing monitoring of defined catchments is recommended to improve understanding of PFAS sources and changes in environmental profiles, and to assess the implications of its occurrence throughout the environment.

"The Gems of Water" citizens' engagement activity united the Joint Research Centre (JRC) of the European Commission with the Costa Rican based NGO Coral Conservation to screen for pesticides in local rivers using wide-screening technology. Citizens used stir bar sorptive extraction to collect and extract samples from three rivers and two wells in the south Caribbean region of Costa Rica, an area known for export-based banana agriculture. The advanced wide-screening method provided by the JRC Water Laboratory enabled the assessment of 230 agrochemicals. While the JRC supplied the technical equipment and protocols, the pesticide screening to be investigated and the monitoring scheme were co-designed with Coral Conservation group members, a local NGO. The pilot study collected new data on pesticide occurrence and their toxicity in the local tropical environment, complementing on-going studies in the region. The study found 23 pesticides, the majority of which are fungicides registered for use in banana cultivation (azoxystrobin, difenoconazole, fluopyram, thiabendazole). Cumulative pesticide concentrations ranged from 5.3 ng/L in the upper catchment of the Estrella River (E-a) to 954.9 ng/L in the lower catchment of the Sixaola River (S-c), where the highest individual compound concentration was also recorded for fungicide azoxystrobin (425.0 ng/L). At the sampling sites along the Carbon River and in the lower catchment of the Sixaola River, compounds fenamiphos, fenpropathrin and azoxystrobin were the main responsible for the elevated toxic units (Toxic Units >0.01) for crustacean daphnia magna. Beyond highlighting the link between agrochemical occurrences in surface waters and surrounding land use, the citizens' engagement aspect promotes alternative water quality monitoring methods, raising awareness and scientific literacy in local communities and underscoring the value of bottom-up approaches.

This exploratory study aims to investigate the health of sand flathead (Platycephalus bassensis) sampled from five sites in Port Phillip Bay, Australia using gas chromatography-mass spectrometry (GC-MS) metabolomics approaches. Three of the sites were the recipients of industrial, agricultural, and urban run-off and were considered urban sites, while the remaining two sites were remote from contaminant inputs, and hence classed as rural sites. Morphological parameters as well as polar and free fatty acid metabolites were used to investigate inter-site differences in fish health. Significant differences in liver somatic index (LSI) and metabolite abundance were observed between the urban and rural sites. Differences included higher LSI, an increased abundance of amino acids and energy metabolites, and reduced abundance of free fatty acids at the urban sites compared to the rural sites. These differences might be related to the additional energy requirements needed to cope with low-level contaminant exposure through energy demanding processes such as detoxification and antioxidant responses as well as differences in diet between the sites. In this study, we demonstrate that metabolomics approaches can offer a greater level of sensitivity compared to traditional parameters such as physiological parameters or biochemical markers of fish health, most of which showed no or little inter-site differences in the present study. Moreover, the metabolite responses are more informative than traditional biomarkers in terms of biological significance as disturbances in specific metabolic pathways can be identified.