Per- and polyfluoroalkyl substances (PFAS) comprise a wide group of persistent chemicals, whose ubiquitous occurrence in the environment, particularly due to their extensive use for fire suppression in aqueous film forming foams (AFFFs), has raised global attention. We evaluated the impacts of PFAS at three firefighting training sites and one industrial site in Finland, to highlight key elements to be considered in the retrospective risk assessment of these chemicals. The site assessments covered the occurrence and distribution of 23 PFAS in multiple environmental matrices, i.e., soil, sediment, surface water, groundwater, and biota, and the subsequent risks to human health and the environment owing to the migration of and exposure to the selected compounds. Our study showed that the extensive use of nowadays restricted or substituted PFAS, particularly PFOS, are still often the predominant compounds detected at AFFF-impacted sites and will continue to cause long-term risks to the environment. The most significant environmental or health risks at these sites are likely to concern aquatic ecosystems, fish consumption or groundwater usage due to the off-site migration of PFAS. Here, even a single fire extinguishing event can be a considerable contributor. We also illustrate that conventional procedures based on simple mass-balance, and exposure models, with a focus on PFOS and other site-specifically relevant PFAS may provide sufficient means to assess the risks. Moreover, we address that despite the exceedance of the very stringent regulatory threshold values issued recently for PFAS, the actual site-specific risks to human health and the environment may remain reasonably low.

A wide range of pharmaceutical residues is known to occur in the environment. While they are released into surface waters mainly through centralized wastewater treatment plants (WWTPs), their primary emission sources are located upstream in the sewer network. Information on emissions from different types of primary emission sources is scarce. However, such information could help direct emission reduction measures more efficiently. In this study, we analysed the concentrations of selected active pharmaceutical ingredients (APIs) in wastewater samples taken from altogether ten sites, covering primary emission sources (hospitals and households), and conventional WWTPs. The concentrations in WWTP effluents were used to identify APIs causing risk in recipient waterbodies. Furthermore, the API loads from households and hospitals were compared to those reaching the WWTP in mixed influents. Our results confirm previously published observations of several pharmaceuticals exceeding their predicted no-effect concentrations in effluent wastewaters. Moreover, the concentrations of most of the analysed APIs are comparatively high in hospital wastewaters, resulting in elevated risk quotients. While the total API loads are relatively low from primary emission sources, owing to the low wastewater volume generated at those sites, per capita emissions were shown to be several times higher at hospital sites than at household sites for APIs such as metronidazole, trimethoprim, and ofloxacin. These findings indicate, that directing emission reduction measures to hospitals could be an effective way to decrease the loads of several risk-posing APIs into the environment, especially where hospital contribution to overall wastewater flow to WWTPs is high.

Sewage sludge monitoring data on many harmful organic pollutants is scarce. In this study, 23 contaminants of environmental concern were identified, including: Per- and polyfluoroalkyl substances (PFAS), pharmaceuticals and personal care products, hormones, and flame retardants. First, concentration data in sludge from the Nordic countries, was compiled. Several data gaps on concentration data were found, particularly in personal care products and flame retardants groups. There were also large differences in data availability between the countries. Second, removal efficiency of the selected pollutants was reviewed. Three different treatment methods were considered: anaerobic digestion, composting, and pyrolysis. Pyrolysis emerged generally as the most efficient removal method, whereas there were large differences in the reported removal efficiencies in anaerobic digestion and composting. Overall, the most recalcitrant pollutants in sludge in this study were PFAS, certain antibiotics, and estrogens. Several factors behind the variation were identified, such as diversity in plant design, operational and seasonal parameters, and challenges in sampling and analysing the sludge matrix. Coherent study designs are needed to compare removal efficiencies more transparently. Legislative requirements are usually the main drivers for carrying out monitoring, andurrent EU legislation regulating hazardous substances in sewage sludge is outdated. There is great variation in national regulations between the Nordic countries. The lack of regulatory requirements hinders informed/science-based long-term decision-making to protect the environment. Sludge utilization is a complex question requiring consideration from regulative, technological, and societal perspectives. Monitoring contaminants is vital in both assessing risks of sludge-based fertilizers and contaminant removal efficiencies in sludge treatment.

POCIS passive samplers were deployed at differently polluted marine sites in the cities of Helsinki and Tallinn and in an open part of the Gulf of Finland. The aim was to determine baseline concentration levels for pharmaceuticals in water monitored with passive sampling techniques, which could also be applied to regulatory monitoring. That baseline concentration data method could then be applied to other sites in the Tallinn and Helsinki area to assess whether the pharmaceutical concentration is elevated or at the baseline level. Altogether, 150 pharmaceuticals were analysed from passive and grab water samples, and 30 substances were discovered. The number of pharmaceuticals detected in passive samplers (27) was higher than in grab samples (20). However, the study revealed the presence of several pharmaceuticals even from expected background sites, such as the open sea site in Gulf of Finland, implying their ubiquitous presence in the study area. The passive sampling results have been converted to TWAC with sampling rate, which is characteristic of the sampler type and studied compound. We assessed the suitability and differences of sampling rates collected from the literature, calculated from LogK _OW values and estimated from field deployment results. The selection of sampling rate is essential, as it can cause 86 to 99% differences in determined TWACs. The TWAC was compared with PNEC was calculated to evaluate the potential environmental risk. There are still open questions regarding how to reconcile the passive sampling results with regulatory monitoring obligations based on grab water sampling and existing limit concentrations.