peer reviewed

Mercury (Hg) pollution in the ocean is an issue of global concern, however bioaccumulation regimes of this ubiquitous pollutant in marine apex predators have important knowledge gaps. Our fish length and stable isotope (δ15N and δ13C) normalized data of Greenland halibut (GH) (Reinhardtius hippoglossoides) showed that Hg bioaccumulation in fillet tissue decreased by ~35–50 %, over a ten-year period from 2006 to 2015 (n = 7 individual sampling years). Hg was predominantly in the methylmercury form (>77 %). Results from a Bayesian information theoretic model showed that GH Hg concentrations decreased with time and its associated declines in Hg air emissions, estimated trophic position, and a potentially lower degree of demersal prey use as indicated by temporal trend shifts in nitrogen (δ15N) and carbon (δ13C) stable isotope values. GH trophic shifts accounted for about one third of the observed temporal reduction in Hg. Our study demonstrates the importance of simultaneously considering Hg emissions, food web dynamics and trophic shifts as important drivers of Hg bioaccumulation in a marine, deep water fish species and highlights the effectiveness of Hg regulations on ocean apex predator Hg concentrations and overall seafood safety. | publishedVersion

Areas in central Norway were heavily contaminated with fallout from the Chernobyl accident in 1986. In this study, we assess 137Cs in surface sediments and sediment cores collected in the Vefsnfjord in Nordland county. Concentrations of 137Cs in surface sediments ranged from 159 to 191 Bq kg−1 dry weight (d.w.). Sub-surface peaks of 137Cs were observed in all cores, with a maximum concentration of 432 Bq kg−1 d.w. Given that little is known about the distribution of naturally occurring radionuclides in Norwegian fjords and coastal areas, a better understanding of the total burden of radioactivity is important for the Norwegian fishing and aquaculture industries. Therefore, analyses of the natural radionuclides 40K, 226Ra, 228Ra and 210Pb were included in the study. Analyses of total sulphur (TS), total carbon (TC), total organic carbon (TOC) and grain size distribution have been performed to provide a sedimentologic context for interpreting the radionuclide results. | publishedVersion

One of the ambitions of the UN Decade of Ocean Science is stakeholder interaction to co-produce new ideas and solutions for policy action plans to ensure that environmental challenges are mitigated in a timely manner. Regulations around the release of microfibres are largely lacking, and we are at an excellent point of departure to test integrative methods of such co-production. We co-designed conceptual maps and Bayesian Belief Networks with probabilistic future scenarios within both inter- and intra-sectoral workshops with industry and scientific stakeholders to gain comparable results of policy action scenarios for curbing the challenge of microfibre pollution within this context. We found that when scientists worked on this alone, their focus was different than when working together with industry directly. Scientists focused on methods for avoiding release into the environment from a technical vantage point, whereas industry emphasized regulatory requirements needed to avoid ambiguity within the sector. | publishedVersion

Embargo until 29 December 2022. | We exposed twelve mesocosm stream channels and four instream channels to one, two, and four pulses of the insecticide lambda-cyhalothrin (0.1 μg L−1) applied at two day intervals, each pulse lasting 90 min. Unexposed controls were included. We monitored macroinvertebrate taxonomic composition in the channels and in deployed leaf packs one day before and 29 days after the first exposure. Further, we measured drift in and out of the channels and leaf litter decomposition. Lambda-cyhalothrin exposures induced significantly increased drift in both experiments especially for Gammarus pulex, Amphinemura standfussi, and Leuctra spp. Macroinvertebrate taxonomic composition increasingly changed with increasing number of lambda-cyhalothrin exposures being most pronounced in the mesocosm channels. Further, leaf decomposition significantly decreased with increasing number of exposures in the mesocosm channels. Our study showed that species with predicted highest sensitivity to lambda-cyhalothrin were primary drivers of significant changes in taxonomic composition lasting for at least one month despite continuous recolonization of exposed channels from upstream parts of the natural stream and from the water inlet in the mesocosm channels. The overall results highlight the importance of sequential exposures to insecticides for understanding the full impact of insecticides on macroinvertebrates at the community level in streams. | acceptedVersion

Endocrine-disrupting chemicals (EDCs) in diet are a health concern and their monitoring in food has been introduced in the European Union. In developing countries, EDC dietary exposure data are scarce, especially from areas perceived as pollution hotspots, including industrialized countries like India. Several persistent organic pollutants (POPs) act as EDCs and pose a pressure to human health mainly through dietary exposure. In the present study a range of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dioxins and furans were measured in several food items collected in an Indian urban (Delhi) and a rural area (Dehradun). Food basket contamination data were used to estimate dietary exposure and compare it with that of the average European population estimated from available monitoring data. All targeted contaminants were found in most food items, especially in dairies and meat products. OCPs were the main contributors. Food supplied to Delhi's markets had higher contamination than that supplied to the peri-urban market in Dehradun. Despite looser control and restrictions, Indian dietary exposure of OCPs and PBDEs were comparable with that of Europe and were lower for PCBs and dioxins. Higher meat consumption in Europe only partly explained this pattern which was driven also by the higher residues in some European food items. A substantial part of endocrine disrupting potential in the diet derives from food and animal feeds internationally traded between developed and developing countries. With increasingly globalized food systems, internationally harmonized policies on EDC in food can lead to better protection of health in both these contexts. | publishedVersion

International audience | Metabolic disorders induced by endocrine disruptors (ED) may contribute to amphibian population declines but no transgenerational studies have evaluated this hypothesis. Here we show that Xenopus tropicalis, exposed from the tadpole stage, to the ED benzo[a]pyrene (BaP, 50 ng.L−1) produced F2 progeny with delayed metamorphosis and sexual maturity. At the adult stage, F2–BaP females displayed fatty liver with inflammation, tissue disorganization and metabolomic and transcriptomic signatures typical of nonalcoholic steato-hepatitis (NASH). This phenotype, similar to that observed in F0 and F1 females, was accompanied by a pancreatic insulin secretory defect. Metabolic disrupted F2–BaP females laid eggs with metabolite contents significantly different from the control and these eggs did not produce viable progeny. This study demonstrated that an ED can induce transgenerational disruption of metabolism and population collapse in amphibians under laboratory conditions. These results show that ED benzo[a]pyrene can impact metabolism over multiple generations and support epidemiological studies implicating environmental EDs in metabolic diseases in humans.

Exposure to environmental airborne manganese (Mn) can lead to neurotoxic disorders and cognitive deficits. The degree of exposure can be assessed by personal sampling of particulate matter (PM) or through biomarkers of exposure. The aim of this work was to characterise the personal exposure to airborne Mn and other trace metals by measuring their bioaccessibility in PM filters taken from personal samplers in an environmentally exposed adult population living in the vicinity of a ferromanganese alloy plant in Santander Bay (northern Spain). Concentrations of bioaccessible and non-bioaccessible Mn and other metals associated with coarse (PM10-2.5) and fine (PM2.5) modes were quantified from 24 h personal samplers in 130 participants divided into two groups according to their Mn exposure: highly (n = 65) and moderately (n = 65) exposed. Gastric fluid and artificial lysosomal fluid (ALF) were used in the bioaccessibility tests as surrogate agents for the body fluids that can come into contact with coarse and fine particles, respectively. The mean air Mn levels in PM10-2.5 and PM2.5 were 127.2 and 126.2 ng/m3, respectively, in the highly exposed group, and 18.6 and 31.7 ng/m3 in the moderately exposed group. The bioaccessibility (%) of Mn in gastric fluid and ALF was also found to be greater in the highly exposed group. The results indicate that people living near Mn alloy plants have an increased potential health risk for Mn exposure due to higher total air Mn concentrations and bioaccessibility. | This work was funded by the Spanish Ministry of Science, Innovation and Universities through Project CTM 2017-82636-R. Bohdana Markiv also thanks the same Ministry for her PhD grant, PRE 2018-085152.

Dilution of the water chemistry caused by reduced acidification has lately received increased attention, both in Europe and North America. There has also been a declining trend in the supply of sea salts. Several studies have predicted detrimental effects on aquatic life due to dilution. A population of brook trout living in River Hunnedal in southwestern Norway was studied for 14 years (2006–2019).Despite acceptable water chemistry with respect to pH and inorganic Al, limited reproduction was found. With median conductivity, Ca and Na of 7.1– 8.6 μScm−1, and 0.17–0.19 and 0.9–1.0 mgL−1, respectively, the water at the study sites was found to be extremely dilute. We detected a significant positive effect of Na on the densities of brook trout fry, while a less distinct effect of Ca was found. However, due to the correlation between Ca and Na we cannot conclude that Ca is unimportant. For all samplings without catch of fry (n = 13), Na was 0.86 ± 0.15 mgL−1, suggesting a critical limit for Na slightly below 1 mgL−1.We suggest that the reproduction of brook trout was restricted by the highly dilute water and the subsequent scarcity of essential ions. Acidification recovery . Water chemistry . Dilution . Calcium. Sodium. Mountain streams . Brook trout | publishedVersion