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The Environmental Protection Agencies (EPAs) of Denmark, Sweden, Norway, Germany and the Netherlands submitted a proposal to the European Chemical Agency (ECHA) in February 2023 calling for a ban in the use of toxic industrial chemicals per- and polyfluoroalkyl substances (PFAS). These chemicals are highly toxic causing elevated cholesterol, immune suppression, reproductive failure, cancer and neuro-endocrine disruption in humans and wildlife being a significant threat to biodiversity and human health. The main reason for the submitted proposal is recent findings of significant flaws in the transition to PFAS replacements that is leading to a widespread pollution. Denmark was the first country banning PFAS, and now other EU countries support the restrictions of these carcinogenic, endocrine disruptive and immunotoxic chemicals. The proposed plan is among the most extensive received by the ECHA for 50 years. Denmark is now the first EU country to initiate the establishment of groundwater parks to try and protect its drinking water. These parks are areas free of agricultural activities and nutritious sewage sludge to secure drinking water free of xenobiotic including PFAS. The PFAS pollution also reflects the lack of comprehensive spatial and temporal environmental monitoring programs in the EU. Such monitoring programs should include key indicator species across ecosystems of livestock, fish and wildlife, to facilitate detection of early ecological warning signals and sustain public health. Simultaneously with inferring a total PFAS ban, the EU should also push for more persistent, bioaccumulative and toxic (PBT) PFAS substances to be listed on the Stockholm Convention (SC) Annex A such as PFOS (perfluorooctane sulfonic acid) that is currently listed on the SCs Annex B. The combination of these regulative restrictions combined with groundwater parks and pan-European biomonitoring programs, would pave the way forward for a cleaner environment to sustain health across the EU.

New economic developments in the Arctic, such as shipping and oil exploitation, bring along unprecedented risks of marine oil spills. Microorganisms have played a central role in degrading and reducing the impact of the spilled oil during past oil disasters. However, in the Arctic, and in particular in its pristine areas, the self-cleaning capacity and biodegradation potential of the natural microbial communities have yet to be uncovered.This review compiles and investigates the current knowledge with respect to environmental parameters and biochemical constraints that control oil biodegradation in the Arctic. Hereby, seawaters off Greenland are considered as a case study. Key factors for biodegradation include the bioavailability of hydrocarbons, the presence of hydrocarbon-degrading bacteria and the availability of nutrients. We show how these key factors may be influenced by the physical oceanographic conditions in seawaters off Greenland and other environmental parameters including low temperature, sea ice, sunlight regime, suspended sediment plumes and phytoplankton blooms that characterize the Arctic.Based on the acquired insights, a first qualitative assessment of the biodegradation potential in seawaters off Greenland is presented. In addition to the most apparent Arctic characteristics, such as low temperature and sea ice, the impact of typical Arctic features such as the oligotrophic environment, poor microbial adaptation to hydrocarbon degradation, mixing of stratified water masses, and massive phytoplankton blooms and suspended sediment plumes merit to be topics of future investigation.

Fourhorn sculpins (Myoxocephalus quadricornis) and shorthorn sculpins (Myoxocephalus scorpius) have been considered suitable local bioindicators for environmental monitoring studies in the Arctic. Because these species share many characteristics, data from the two species have previously been pooled when assessing marine metal contamination. A chemical and histological study was conducted on fourhorn and shorthorn sculpins collected around a contaminated lead-zinc mine at East Greenland to investigate whether there were any differences in the residues of metals, histopathology and parasites in liver and gills between the two sculpin species. The results demonstrated that concentrations of copper (Cu), zinc (Zn), mercury (Hg) and lead (Pb) were significantly higher in the fourhorn sculpins (p

We used PBPK (physiologically-based pharmacokinetic) modelling to investigate distribution, bioaccumulation and excretion of the seven POPs (persistent organic pollutants) CB-99, CB-153, HCB, oxychlordane, p,p'-DDE, BDE-47 and BDE-99 in 4 adult captive Greenland sledge dog (Canis familiaris) bitches fed minke whale (Balaenoptera acuterostrata) blubber for 500-635 days. The PBPK modelled POP concentrations in adipose tissue, liver, kidney and plasma were mostly within a factor 2 of actual measured tissue levels even for those at the lower concentration end. The excretion route for oxychlordane and CB-153 was modelled to be via faeces while lung alveolar excretion dominated for BDE-47, BDE-99, HCB, p,p'-DDE and CB-99. Furthermore the model suggested the retained mass of POPs after 500 and 635 days of exposure, respectively, to be relatively low despite these POPs being highly recalcitrant. The retention increased in the following order (% of total intake); p,p'-DDE (1%)

Human exposure to persistent organic pollutants (POPs) and the potential health impact in the Arctic far from the emission sources have been highlighted in numerous studies. As a supplement to human POP biomonitoring studies, a physiologically based pharmacokinetic (PBPK) model was set up to estimate the fate of POPs in Greenlandic Inuit's liver, blood, muscle and adipose tissue following long-term exposure to traditional Greenlandic diet. The PBPK model described metabolism, excretion and POP accumulation on the basis of their physicochemical properties and metabolic rates in the organisms. Basic correlations between chemically analyzed blood POP concentrations and calculated daily POP intake from food questionnaire of 118 middle age (18–35 years) Greenlandic Inuits from four cities in West Greenland (Qaanaaq: n = 40; Qeqertarsuaq: n = 36; Nuuk: n = 20; Narsaq: n = 22) taken during 2003 to 2006 were analyzed. The dietary items included were polar bear, caribou, musk oxen, several marine species such as whales, seals, bird and fish as well as imported food. The contaminant concentrations of the dietary items as well as their chemical properties, uptake, biotransformation and excretion allowed us to estimate the POP concentration in liver, blood, muscle and adipose tissue following long-term exposure to the traditional Greenlandic diet using the PBPK model. Significant correlations were found between chemically analyzed POP blood concentrations and calculated daily intake of POPs for Qeqertarsuaq, Nuuk and Narsaq Inuit but not for the northernmost settlement Qaanaaq, probably because the highest blood POP level was found in this district which might mask the interview-based POP calculations. Despite the large variation in circulating blood POP concentrations, the PBPK model predicted blood concentrations of a factor 2–3 within the actual measured values. Moreover, the PBPK model showed that estimated blood POP concentration increased significantly after consumption of meals. For individuals who had a high internal burden of POPs accumulated over years, the estimated blood levels were less influenced by recent meal intake. The model results also indicated that of the POPs accumulated in the body the concentrations were highest for CB-153 (oxychlordane: 0.6%; DDE and CB-99: 2.9%; HCB: 4.4%; CB-153: 34.5%). Furthermore, the model also estimated a significant internal body POP burden even several years after the mentioned dietetic shift and that contaminant accumulation was 2–6 folds faster than the decay after a shift to a diet low in contaminants. Using the PBPK model approach, we seek to improve the knowledge on contaminant body burden in humans of the Arctic. However, it should be noted that calculations of daily POP intake may be subject to considerable uncertainty due to imprecise information from the dietary interview. Based on these results we suggest that PBPK modeling is implemented as a tool in future human health exposure and effect assessments in Greenland. Keywords: DDE, Greenland, HCB, Humans, Oxychlordane, PBPK modeling

Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health effects, including reproductive, were conducted during 1990-2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk quotient (RQ) evaluation to more quantitatively evaluate the effect risk on reproduction (embryotoxicity and teratogenicity) based on the critical body residue (CBR) concept and using a physiologically-based pharmacokinetic (PBPK) model. We applied modelling approaches to PCBs, p,p'-DDE, dieldrin, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79-1271 ng g(-1) lw) and PCBs (range: 4128-53,923 ng g(-1) lw) reported in bears in the year 1990 were in the range to elicit possible adverse health effects on reproduction in polar bears in East Greenland (all RQs > or = 1). Similar results were found for PCBs (range: 1928-17,376 ng g(-1) lw) and PFOS (range: 104-2840 ng g(-1) ww) in the year 2000 and for dieldrin (range: 43-640 ng g(-1) lw), PCBs (range: 3491-13,243 ng g(-1) lw) and PFOS (range: 1332-6160 ng g(-1) ww) in the year 2006. The concentrations of oxychlordane, DDTs, HCB and HCHs in polar bears resulted in RQs

Sea-Nine211 has been introduced as a new biocide in antifouling paints with an immediate degradation when it is released from ship hulls. The active component of Sea-Nine211 is 4,5-dichloro-2-n-octyl-isothiazoline-3-one (DCOI). In the present study, the toxicity of DCOI and the occurrence of Pollution Induced Community Tolerance (PICT) were tested in microcosms containing eutrophic coastal water with its natural composition of phytoplankton. The experiment was performed in closed systems with a single addition of the nominal concentrations 0, 3.2, 10, 32 and 100 nM DCOI, for a period of 16 days. Pollution induced community tolerance (PICT) was observed in the phytoplankton communities exposed to the nominal concentrations 32 and 100 nM DCOI. Chemical analysis of DCOI in the coastal water utilised in the toxicity and PICT experiment was performed by GC-MS using a solid- phase extraction method. Half-life was calculated to be 2.5 days for the nominal concentrations 32 and 100 nM DCOI. The results of the present study show that nominal concentrations of 32 and 100 nM DCOI significantly increased the community tolerance already after 2 days of exposure and that the tolerance was maintained for a period of 16 days even when DCOI was degraded during this period. The causes for the persistent tolerance are discussed in relation to the degradation of DCOI and structural changes in the phytoplankton communities.

Sediments and blue mussels were collected along a transect through the Baltic Sea to the Atlantic Ocean and analysed for a number of specific halogenated organic compounds and sum parameters. Multivariance analysis indicated geographical separation of the sediment data due to high concentrations of EOCl and EPOCl in the Bay of Bothnia and Bothnian Sea, high concentrations of sPCB in the Baltic proper and low concentrations of most of the compounds in the Skagerrak. The separation in mussels was due to high concentrations of sHCH and sDDT in the Danish sounds and the Kattegat, and high concentrations of EOX, EOCl and EOBr in the Baltic Sea. In contrast to the sediments, where no correlation was found between EOCl and EOX, these parameters are well correlated in the mussels. EOCl correlates to EPOCl both in sediments and blue mussels. The share of EPOCl is remarkably similar (ca. 11% of EOCl) in sediments and mussels.

The impact of UV-B radiation on alkaline phosphatase activity (APA) was examined in water samples from a phosphorus-depleted Norwegian fjord, Hylsfjord, in July 1995. APA was regularly measured for 4–7.5 h in water samples from the fjord (Exp. 1) and from a nutrient-manipulated enclosure (Exp. 2) incubated under three different light regimes; ambient radiation (AMB), ambient radiation with enhanced artificial UV-B (+UV), 1.10 W m −2 UV-B, and ambient radiation screened for UV-B (−UV). Water samples exposed to UV-B (+UV; AMB) had significantly lower APA than water samples screened for UV-B (−UV), both in raw water samples as well as in water samples prefiltered through 1 and 0.2 μm filters. The decline could be explained by photodegradation of dissolved and cell-bound APA, with dissolved APA being more affected than APA associated with organisms. The results suggest that UV-B radiation inhibits APA in phosphorus-depleted aquatic environments and has the potential to strengthen the phosphorus limitation of microbial ecosystems.

Four indoor model ecosystems with natural plankton communities have been run. Two of the systems are exposed to artificial photosynthetic active radiation (PAR, 20 W m−2 for 16 h per day) and UV-B radiation (≈ 0.64 W m−2 for 6 h per day), while the other two are exposed to PAR only. Photosynthesis, nitrogen uptake, nutrient concentrations and contents of chlorophyll, particulate carbon, nitrogen and phosphorus are followed for six days, Photosynthesis and drlorophyli content are significantly reduced by the UV-B radition whilst uptakes of nitrate and ammonia are less affected. The contents of particulate carbon, nitrogen and phosphorus are always as high. or higher. in the UV-B-exposed communities as in the controls, while the content of chlorophyll a is reduced. Together with an increased cell number of bacterial predators, this indicates that the biomass of heterotrophs is enhanced in the UV-B-exposed communities.

The effects of tri-butyl-tin (TBT) on autotrophic pico-, nano and microplankton were assessed by a marine enclosure experiment. In accordance with the pollution-induced community tolerance (PICT) concept, an increased tolerance was found for microplankton in enclosures amended with 0.01, 0.6 and 10 nM TBT. In contrast, nanoplankton showed increased tolerance only in an enclosure amended with 10 nM TBT. Neither the entire phytoplankton community nor picoplankton showed increased tolerance. These observations are discussed in terms of the ecology of pico-, nano- and microplankton. In all enclosures amended with TBT, primary production by nanoplankton declined, and primary production by picoplankton increased: changes that are interpreted as indirect effects of TBT. A comparison of TBT levels found in polluted coastal areas and in off-shore areas indicates that phytoplankton communities might be affected by TBT. Size fractionated measurements of TBT tolerance in phytoplankton communities were proven to increase the sensitivity of the PICT concept.

A major need in ecotoxicology is the development of sensitive and robust ecotoxicological methods to detect the effects of toxic substances in complex aquatic ecosystems. In this study, we investigated how copper and atrazine affect the tolerance of microalgal communities and the succession of species. The effects of atrazine and copper on microalgal communities in large freshwater enclosures were investigated for a 20-day period. The community's tolerance of copper and atrazine was determined by short-term photosynthesis tests. Species composition was evaluated using a similarity index and multivariant analysis. In enclosures exposed to copper, tolerance gradually increased during the experiment. In the enclosures exposed to the highest copper concentration (0.24 μM), an increased tolerance of copper was found in phytoplankton communities even after 2 days, and in the enclosure exposed to the lowest copper concentration (0.016 μM), increased tolerance was found after 12 days. In accordance with the PICT (pollution-induced community tolerance) concept, the added copper was sufficient to affect the phytoplankton community, as was confirmed by changes in species composition. Communities exposed to increased copper concentrations also showed increased tolerance for zinc, indicating common tolerance mechanisms for copper and zinc. The effects of atrazine in the enclosures were small and did not induce changes in community tolerance for atrazine or diuron, although the same concentration was high enough to reduce photosynthesis activity by 20% in the short-term test and cause minor changes in species composition. Tolerance levels in phytoplankton and periphyton communities were compared. Neither copper nor atrazine induced changes in the tolerance of the periphyton communities. The short-term EC50 values for atrazine were very similar in periphyton and phytoplankton communities, but for copper, EC50 values for periphyton were about ten times higher than for phytoplankton.