Publications

Per- and polyfluoroalkyl substances (PFASs) represent a class of more than 4000 compounds. Their large number and structural diversity pose a considerable challenge to analytical chemists. Measurement of total fluorine in environmental samples and consumer products is therefore critical for rapidly screening for PFASs and for assessing the fraction of unexplained fluorine(i.e., fluorine mass balance). Here we compare three emerging analytical techniques for total fluorine determination: combustion ion chromatography (CIC), particle-induced γ-ray emission spectroscopy (PIGE), and instrumental neutron activation analysis (INAA). Application of each method to a certified reference material (CRM), spiked filters, and representative food packaging samples revealed good accuracy and precision. INAA and PIGE had the advantage of being nondestructive, while CIC displayed the lowest detection limits. Inconsistencies between the methods arose due to the high aluminum content in the CRM, which precluded its analysis by INAA, and sample heterogeneity (i.e., coating on the surface of the material), which resulted in higher values from the surface measurement technique PIGE compared to the values from the bulk volume techniques INAA and CIC. Comparing CIC-based extractable organic fluorine to target PFAS measurements of food packaging samples by liquid chromatography–tandem mass spectrometry revealed large amounts of unidentified organic fluorine not captured by compound-specific analysis.

Regulatory authorities rely on hazard and risk assessments performed under REACH for identifying chemicals of concern and to take action. Therefore, these assessments must be systematic and transparent. This study investigates how registrants evaluate and report data evaluations under REACH and the procedures established by the European Chemicals Agency (ECHA) to support these data evaluations. Data on the endpoint repeated dose toxicity were retrieved from the REACH registration database for 60 substances. An analysis of these data shows that the system for registrants to evaluate data and report these evaluations is neither systematic nor transparent. First, the current framework focuses on reliability, but overlooks the equally important aspect of relevance, as well as how reliability and relevance are combined for determining the adequacy of individual studies. Reliability and relevance aspects are also confused in the ECHA guidance for read-across. Second, justifications for reliability evaluations were mainly based on studies complying with GLP and test guidelines, following the Klimisch method. This may result in GLP and guideline studies being considered reliable by default and discounting non-GLP and non-test guideline data. Third, the reported rationales for reliability were frequently vague, confusing and lacking information necessary for transparency. Fourth, insufficient documentation of a study was sometimes used as a reason for judging data unreliable. Poor reporting merely affects the possibility to evaluate reliability and should be distinguished from methodological deficiencies. Consequently, ECHA is urged to improve the procedures and guidance for registrants to evaluate data under REACH to achieve systematic and transparent risk assessments.

Traffic related non-exhaust particulate sources and road dust are an increasingly important source for PM10 air pollution as exhaust sources are decreasing due to regulations. In the Nordic countries, the road dust problem is enhanced by use of studded tyres, causing increased road wear and winter road maintenance including gritting. Efforts to reduce road dust emissions requires knowledge on temporal and spatial road dust load dynamics. The city of Stockholm, Sweden, has therefore financed seasonal (October to May) road dust sampling to be able to optimize their winter and spring time street operation measures for reduced road dust emissions. This work describes the outcome of six seasons (2011/2012 – 2016/2017) of road dust sampling in five central streets using the VTI wet dust sampler (WDS).The results show that road dust load, expressed as DL180 (dust load smaller than 180 μm) has a seasonal variation with the highest loads (up to 200 g/m2) in late winter and early spring and a minimum (down to about 15 g/m2) in early autumn and late spring. The dust load varies between streets and is depending on pavement surface properties. On a smaller scale the dust load has a high variability across streets due to differences in rates of suspension from different parts of the road surface, with low amounts in wheel tracks and higher in-between and outside the tracks. Between 2–30% of the DL180 is smaller than 10 μm and could directly contribute to PM10 emissions. In general, higher road surface texture leads to higher dust loads, but the condition of the pavement (e.g. cracks, aggregate loss) might also have an effect. A new, wear resistant pavement accumulated markedly higher road dust amounts than a several years old pavement. This paper closes with a discussion on the complex relation between road dust load and PM10 concentrations and a discussion on the challenges and comparability of road dust sampling techniques and measures.

Light-absorbing organic aerosols, known as brown carbon (BrC), counteract the overall cooling effect of aerosols on Earth’s climate. The spatial and temporal dynamics of their light-absorbing properties are poorly constrained and unaccounted for in climate models, because of limited ambient observations. We combine carbon isotope forensics (δ13C) with measurements of light absorption in a conceptual aging model to constrain the loss of light absorptivity (i.e., bleaching) of water-soluble BrC (WS-BrC) aerosols in one of the world’s largest BrC emission regions—South Asia. On this regional scale, we find that atmospheric photochemical oxidation reduces the light absorption of WS-BrC by ~84% during transport over 6000 km in the Indo-Gangetic Plain, with an ambient first-order bleaching rate of 0.20 ± 0.05 day−1 during over-ocean transit across Bay of Bengal to an Indian Ocean receptor site. This study facilitates dynamic parameterization of WS-BrC absorption properties, thereby constraining BrC climate impact over South Asia.

The goal of identifying hazardous chemicals registered under the Registration, Evaluation, Authorization and restriction of CHemicals (REACH) Regulation and taking appropriate risk management measures relies on robust data registrations. However, the current procedures for European chemical manufacturers and importers to evaluate data under REACH neither support systematic evaluations of data nor transparently communicate these assessments. The aim of this study was to explore how using a data evaluation method with predefined criteria for reliability and establishing principles for assigning reliability categories could contribute to more structured and transparent evaluations under REACH. In total, 20 peer-reviewed studies for 15 substances registered under REACH were selected for an in-depth evaluation of reliability with the SciRAP tool. The results show that using a method for study evaluation, with clear criteria for assessing reliability and assigning studies to reliability categories, contributes to more structured and transparent reliability evaluations. Consequently, it is recommended to implement a method for evaluating data under REACH with predefined criteria and fields for documenting and justifying the assessments to increase consistency of data evaluations and transparency.