Federal Office for the Environment

Fluoropolymers are widely used across sectors, but their production is associated with emissions of per- and polyfluoroalkyl substances (PFASs), which are mobile, persistent, and toxic. In this work, we compiled a global inventory of fluoropolymer production plants (FPPs) and assembled PFAS concentration measurements for various media in their vicinity. We identified 52 currently operating FPPs across 11 countries and 41 cities, with 12 cities having peer-reviewed site-specific PFAS measurements specifically attributed to the FPP. At these 12 sites, at least 236 individual PFASs have been detected across multiple environmental media, including surface water, groundwater, air, dust, soils, sediments, plants, animals, and humans, with reported detections at distances of up to approximately 150 km from FPPs. Perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl ether carboxylic acids (PFECAs) were most frequently measured, often at concentrations two to three orders of magnitude higher than those measured in regions without nearby FPPs. Using high-resolution population data, we estimate that approximately 14 ± 2 million people (uncertainty reflecting ±10 km uncertainty in facility locations) live within 10 km of an FPP. These people are potentially affected by FPP associated contamination, with the largest population shares in China (≈52%), Japan (≈24%), Europe (≈13%), and the United States (≈9%). These regional proportions largely mirror differences in population density and the number of identified production facilities. This inventory reveals the large and complex global scale of PFAS contamination from fluoropolymer production, underscoring the need for expanded systematic monitoring, risk management efforts, including regulation.

Globally, food systems are at the center of an ecological, social, and health crisis. In the Global South, particularly in sub-Saharan Africa (SSA), the reorganization of food systems is crucial to achieving economic development while addressing the various crises. Raising agricultural productivity is important, within a broader development strategy, if it does not imply the destitution of millions of peasants. Agroecology, with its focus on labor-driven intensification, represents an opportunity to transform food systems and achieve sustainability. National policies play a significant role in promoting or hindering agroecological transitions (AETs). In this article we analyze the contents of agricultural policies in Senegal, to determine to what extent the official texts promote AETs. Senegal, a Western African country in the Sahel region, faces important challenges in terms of providing sufficient food for its inhabitants, within a context of worsening climate and persistent demographic growth. Agroecology could provide an opportunity to promote nation-focused agricultural development while preserving peasants. We draw on the categories of critical political economy to clarify the meaning of AETs, in terms of changes in the prevailing mode of production. Subsequently, we deploy social multi-criteria evaluation to analyze the most important agricultural policies since 2014 and assess to what extent the official policy documents are in line with AETs. The results indicate that the policies are still anchored to a narrative of agricultural modernization and are not particularly transformative. Nevertheless, we also note some improvements, particularly with respect to the gender issue, and to a lesser extent with respect to the management of soil fertility and pest control. We note how the emergence of social movements supporting AETs in Senegal may help to promote public policies that are more transformative. The results contribute to the wider debate on the role of public policies in supporting AETs.

Temperate fishes often spawn in response to environmental cues, such as temperature, thereby facilitating larval emergence concurrent with suitable biotic and abiotic conditions, such as plankton blooms. Climatic changes may alter the reproductive phenology of spring- and autumn-spawning freshwater fish populations. Such effects may depend on the sensitivity of reproductive phenology to ambient temperatures. We applied a meta-analysis approach to test whether annual temperature and year affected fish reproductive phenology. Based on preliminary tests in walleye (Sander vitreus) and Lake Constance whitefish (Coregonus arenicolus), we hypothesized that increasing temperature would promote earlier spring-spawning and later autumn-spawning. We found spawning was significantly earlier in the spring and later in the autumn. We found that migration of autumn-spawning species occurred earlier with warmer temperatures, implying that with increasing temperatures, migrating autumn-spawning species will increase residence time in tributaries. We also found that spring-spawning fishes reproduced earlier in more recent years, while we observed no significant effect in autumn-spawners. Spring- and autumn-spawning fishes displayed interannual variation in spawning dates (mean range of 34.4 and 27.0 days over 33.9 years, respectively), with spring-spawning fishes displaying a significantly broader range in spawning dates.

Reciprocal effects of adaptive radiations on the evolution of interspecific interactions, like parasitism, remain barely explored. We test whether the recent radiations of European whitefish (Coregonus spp.) across and within perialpine and subarctic lakes promote its parasite Proteocephalus fallax (Platyhelminthes: Cestoda) to undergo host repertoire expansion via opportunity and ecological fitting, or adaptive radiation by specialization. Using de novo genomic data, we examined P. fallax differentiation across lakes, within lakes across sympatric host species, and the contributions of host genetics versus host habitat use and trophic preferences. Whitefish intralake radiations prompted parasite host repertoire expansion in all lakes, whereas P. fallax differentiation remains incipient among sympatric fish hosts. Whitefish genetic differentiation per se did not explain the genetic differentiation among its parasite populations, ruling out codivergence with the host. Instead, incipient parasite differentiation was driven by whitefish phenotypic radiation in trophic preferences and habitat use in an arena of parasite opportunity and ecological fitting to utilize resources from emerging hosts. Whilst the whitefish radiation provides a substrate for the parasite to differentiate along the same water-depth ecological axis as Coregonus spp., the role of the intermediate hosts in parasite speciation may be overlooked. Parasite multiple-level ecological fitting to both fish and crustacean intermediate hosts resources may be responsible for parasite population substructure in Coregonus spp. We propose parasites’ delayed arrival was key to the initial burst of postglacial intralake whitefish diversification, followed by opportunistic tapeworm host repertoire expansion and a delayed nonadaptive radiation cascade of incipient tapeworm differentiation. At the geographical scale, dispersal, founder events, and genetic drift following colonization of spatially heterogeneous landscapes drove strong parasite differentiation. We argue that these microevolutionary processes result in the mirroring of host–parasite phylogenies through phylogenetic tracking at macroevolutionary and geographical scales.

Currently, the estimation of suspended sediment concentration (SSC) fluxes in rivers relies on river discharge and an average SSC, the latter is commonly determined through optical turbidity measurements at a single point in the river cross-section. This approach has limitations, such as the SSC data being extrapolated from a one-point measurement and indirectly determined depending on regular sampling and laboratory analysis, which is cost-intensive. Hydro-acoustic echosounders are an alternative to derive SSC across an entire profile, for accurate conversion from backscatter intensity to SSC knowledge of particle size is a requirement. In this approach, we present a method utilizing multi-frequency hydro-acoustic echosounding in addition to velocity measurements via an ADCP. Operating on various acoustic frequencies allows for the direct estimation of mean particle size from backscatter data at different frequencies over a water profile. River in-situ measurements as well as laboratory experiments have been conducted in different concentration as well as particle size distribution regimes.

Each year, rivers export more than one teragram of carbon out of Switzerland as dissolved inorganic carbon (DIC), integrating diverse atmospheric, terrestrial, and aquatic carbon sources over their catchments. However, the contributions of the different carbon sources to riverine DIC – and thus the implications of DIC dynamics for the global carbon balance and climate – remain uncertain. Building upon the 50-year dataset from the national long-term river monitoring network of Switzerland (NADUF), we attempt to predict the vertical CO2 fluxes between rivers and the atmosphere, and to quantify catchment-scale DIC production through rock weathering, leaching of soil-respired CO2, and mineralization of organic carbon during fluvial transport. Supported by the national network of groundwater monitoring sites (NAQUA) and soil sampling sites covering Switzerland, a Bayesian mixing model disentangles the sources of riverine DIC using measured data of carbon and water isotopes (14C, 13C, 2H, 18O), as well as ion concentrations. The exchanges between river DIC and atmospheric CO2 across the air–water interface are predicted with a diffusion model, validated with measurements of the CO2 flux and isotopes from in situ floating-chamber experiments. Our predictions of the DIC source contributions and the net CO2 flux from rivers help to elucidate the role of DIC in the carbon balance of alpine and perialpine river catchments, and contribute towards closing the national carbon budget of Switzerland.

Abstract Particulate filters are state-of-the-art and are used in internal combustion engines worldwide to eliminate carcinogenic nanoparticles. Health studies estimate that this prevents about one million premature deaths annually. What is less known and often neglected is their equally powerful effect on mitigating global warming. This is because these ultrafine particles form stable aerosols in the atmosphere, absorb sunlight, and heat the atmosphere due to their jet-black color. In addition, once deposited on the ground, they reduce albedo especially when deposited on ice or snow. They also thin clouds and reduce their reflectivity. In this paper, we estimate for the first time the cumulative effect of more than 300 million particulate filters currently installed globally on vehicles, showing that, while they reduce ~ 0.5 Mt of soot per year, their effect on slowing global warming is equivalent to reducing 1 Bt of CO2 per year or about one-third of the CO2 emissions of all European Union Member States combined. Despite its strong potential, this highly efficient, proven, and low-cost technology is not yet regarded as a priority in curbing global warming, even though it is possibly the easiest and quickest to implement. If used in retrofitting more diesel and petrol engines worldwide, it could triple the aforementioned effect. While modern internal combustion engines are on track to be replaced with zero-emission vehicles, it is also crucial, and we strongly suggest that, in the interim, all remaining internal fossil fuel combusting engines be fitted with particulate filters. Evidence is presented in this paper that the potential benefits of such retrofit on climate and human health will be impactful and lasting.

Over the past centuries, coregonines have been exposed to a range of stressors that have led to extinctions, extirpations, and speciation reversals. Given that some populations remain at risk and fishery managers have begun restoring coregonines where they have been extirpated, we reviewed the primary and gray literature to describe the diversity of coregonine restoration or conservation actions that have been previously used. Although stocking of hatchery-reared fish has been commonly used for supplementing existing coregonine fisheries, we considered stocking efforts only with specifically conservation or restoration goals. Likewise, conservation-driven efforts of translocation were not widespread, except in the United Kingdom for the creation of refuge populations to supplement the distribution of declining stocks. Habitat restoration efforts have occurred more broadly and have included improving spawning habitat, connectivity, or nutrient concentrations. Although harvest regulations are commonly used to regulate coregonine fisheries, we found fewer examples of the creation of protected areas or outright closures. Finally, interactions with invasive species can be a considerable stressor, yet we found relatively few examples of invasive species control undertaken for the direct benefit of coregonines. In conclusion, our review of the literature and prior Coregonid symposia revealed relatively limited direct emphasis on coregonine conservation or restoration relative to more traditional fishery approaches (e.g., supplementation of fisheries, stock assessment) or studying life history and genetics. Ideally, by providing this broad review of conservation and restoration strategies, future management efforts will benefit from learning about a greater diversity of potential actions that could be locally applied.