High Concentrations of Unidentified Extractable Organofluorine Observed in Blubber from a Greenland Killer Whale (Orcinus orca)
It is generally accepted that per- and polyfluoroalkyl substances (PFASs) occur primarily in protein-rich tissues such as blood and liver, but few studies have examined the occurrence of legacy and novel PFASs in lipid-rich tissues such as blubber. Here we report the distribution of 24 PFASs, total fluorine, and extractable organic fluorine (EOF) in eight different tissues of a killer whale (Orcinus orca) from East Greenland. The sum of target PFAS concentrations was highest in liver (352 ng/g of wet weight) and decreased in the following order: blood > kidney ≈ lung ≈ ovary > skin ≈ muscle ≈ blubber. Most of the EOF consisted of known PFASs in all tissues except blubber, which displayed the highest concentration of EOF, almost none of which was attributed to targeted PFASs. Suspect screening using high-resolution mass spectrometry revealed the presence of additional PFASs but is unlikely to explain the high concentrations of EOF in blubber. While the identity of this unknown organofluorine and its pervasiveness in marine mammals require further investigation, this work suggests that exposure of killer whales to organofluorine substances may be underestimated by determination of legacy PFASs exclusively in liver or blood.
Using Cats as Sentinels for Human Indoor Exposure to Organic Contaminants and Potential Effects on the Thyroid Hormone System
Risk assessments of contaminated sediments from the perspective of weight of evidence strategies – a Swedish case study
Several countries currently lack common recommendations specific
to Ecological Risk Assessment (ERA) of contaminated sediments
and stakeholders report inconsistencies between currently used
approaches. The objective of this study was to provide an increased
understanding of how ERAs of contaminated sediments are conducted
in comparison to established guidelines. For this, we use
Sweden as a case study and compare seven ERAs with four internationally
established strategies. Our results indicate that contaminant
concentrations receive a comparatively high weight, despite a
lack of appropriate benchmarks; toxicity measurements are uncommon,
while routine in established strategies; and the integration and
interpretation of results lack transparency. We identify three areas
that may help improve the practice of ERAs: a common approach to
benchmarks, recommendations for how to assess toxic effects, and a
common approach for integrating and interpreting results.
From a polar to a marine environment: has the changing Arctic led to a shift in aerosol light scattering properties?Download
The study of long-term trends in aerosol optical properties is an important task to understand the underlying aerosol processes influencing the change of climate. The Arctic, as the place where climate change manifests most, is an especially sensitive region of the world. Within this work, we use a unique long-term data record of key aerosol optical properties from the Zeppelin Observatory, Svalbard, to ask the question of whether the environmental changes of the last 2 decades in the Arctic are reflected in the observations. We perform a trend analysis of the measured particle light scattering and backscattering coefficients and the derived scattering Ångström exponent and hemispheric backscattering fraction. In contrast to previous studies, the effect of in-cloud scavenging and of potential sampling losses at the site are taken explicitly into account in the trend analysis. The analysis is combined with a back trajectory analysis and satellite-derived sea ice data to support the interpretation of the observed trends. We find that the optical properties of aerosol particles have undergone clear and significant changes in the past 2 decades. The scattering Ångström exponent exhibits statistically significant decreasing of between −4.9 % yr−1 and −6.5 % yr−1 (using wavelengths of λ=450 and 550 nm), while the particle light scattering coefficient exhibits statistically significant increasing trends of between 2.6 % yr−1 and 2.9 % yr−1 (at a wavelength of λ=550 nm). The magnitudes of the trends vary depending on the season. These trends indicate a shift to an aerosol dominated more by coarse-mode particles, most likely the result of increases in the relative amount of sea spray aerosol. We show that changes in air mass circulation patterns, specifically an increase in air masses from the south-west, are responsible for the shift in aerosol optical properties, while the decrease of Arctic sea ice in the last 2 decades only had a marginal influence on the observed trends.
Atmospheric new particle formation characteristics in the Arctic as measured at Mount Zeppelin, Svalbard, from 2016 to 2018
We conducted continuous measurements of nanoparticles down to 3 nm size in the Arctic at Mount Zeppelin, Ny Ålesund, Svalbard, from October 2016 to December 2018, providing a size distribution of nanoparticles (3–60 nm). A significant number of nanoparticles as small as 3 nm were often observed during new particle formation (NPF), particularly in summer, suggesting that these were likely produced near the site rather than being transported from other regions after growth. The average NPF frequency per year was 23 %, having the highest percentage in August (63 %). The average formation rate (J) and growth rate (GR) for 3–7 nm particles were 0.04 cm−3 s−1 and 2.07 nm h−1, respectively. Although NPF frequency in the Arctic was comparable to that in continental areas, the J and GR were much lower. The number of nanoparticles increased more frequently when air mass originated over the south and southwest ocean regions; this pattern overlapped with regions having strong chlorophyll a concentration and dimethyl sulfide (DMS) production capacity (southwest ocean) and was also associated with increased NH3 and H2SO4 concentration, suggesting that marine biogenic sources were responsible for gaseous precursors to NPF. Our results show that previously developed NPF occurrence criteria (low loss rate and high cluster growth rate favor NPF) are also applicable to NPF in the Arctic.