Cancer Risk Assessment of Airborne PAHs Based on in Vitro Mixture Potency Factors

Dreij, K.; Mattsson, Å.; Jarvis, I.W.H.; Lim, H.; Hurkmans, J.; Gustafsson, J.; Bergvall, C.; Westerholm, R.; Johansson, C.; Stenius, U.
2017 | Environ. Sci. Technol. | 51 (8805-8814)

Complex mixtures of polycyclic aromatic
hydrocarbons (PAHs) are common environmental pollutants
associated with adverse human health effects including cancer.
However, the risk of exposure to mixtures is difficult to
estimate, and risk assessment by whole mixture potency
evaluations has been suggested. To facilitate this, reliable in
vitro based testing systems are necessary. Here, we investigated
if activation of DNA damage signaling in vitro could be an
endpoint for developing whole mixture potency factors
(MPFs) for airborne PAHs. Activation of DNA damage
signaling was assessed by phosphorylation of Chk1 and H2AX
using Western blotting. To validate the in vitro approach,
potency factors were determined for seven individual PAHs
which were in very good agreement with established potency factors based on cancer data in vivo. Applying the method using
Stockholm air PAH samples indicated MPFs with orders of magnitude higher carcinogenic potency than predicted by established
in vivo-based potency factors. Applying the MPFs in cancer risk assessment suggested that 45.4 (6% of all) lung cancer cases per year
in Stockholm are due to airborne PAHs. Applying established models resulted in <1 cancer case per year, which is far from expected levels. We conclude that our in vitro based approach for establishing MPFs could be a novel method to assess whole mixture samples of airborne PAHs to improve health risk assessment.

Human exposure to legacy and emerging halogenated flame retardants via inhalation and dust ingestion in a Norwegian cohort.

Tay, J.H.; Sellström, U.; Papadopoulou, E.; Padilla-Sanchez, J.A.; Haug, L.S.; de Wit, C.A.
2017 | Environ. Sci. Technol. | 51 (8176-8184)

Human Exposure to Legacy and Emerging Halogenated Flame Retardants via Inhalation and Dust Ingestion in a Norwegian Cohort

Tay, J. H.; U. Sellström; E. Papadopoulou; J. A. Padilla-Sánchez; L. S. Haug; C. A. de Wit
2017 | Environ. Sci. Technol. | 51 (14) (8176-8184)

Estimating human exposure to perfluoroalkyl acids via solid food and drinks: Implementation and comparison of different dietary assessment methods

Papadopoulou, E.; Poothong, S.; Koekkoek, J.; Lucattini, L.; Padilla-Sánchez, J.A.; Haugen M.; Herzke, D.; , Valdersnes, S.; Maage, A.; Cousins, I.T.; Leonards, P.E.G.; Småstuen Haug, L.
2017 | Environ. Res. | 158 (269-276)

Time-resolved analysis of particle emissions from residential biomass combustion – Emissions of refractory black carbon, PAHs and organic tracers

Ingeborg E. Nielsen; Axel C. Eriksson; Robert Lindgren; Johan Martinsson; Robin Nyström; Erik Z. Nordin; Ioannis Sadiktsis; Christoffer Boman; Jacob K. Nøjgaard; Joakim Pagels
2017 | Atmos Environ | 165 (179-190)

Time-resolved particle emissions from a conventional wood stove were investigated with aerosol mass spectrometry to provide links between combustion conditions, emission factors, mixing state of refractory black carbon and implications for organic tracer methods. The addition of a new batch of fuel results in low temperature pyrolysis as the fuel heats up, resulting in strong, short-lived, variable emission peaks of organic aerosol-containing markers of anhydrous sugars, such as levoglucosan (fragment at m/z 60). Flaming combustion results in emissions dominated by refractory black carbon co-emitted with minor fractions of organic aerosol and markers of anhydrous sugars. Full cycle emissions are an external mixture of larger organic aerosol-dominated and smaller thinly coated refractory black carbon particles. A very high burn rate results in increased full cycle mass emission factors of 66, 2.7, 2.8 and 1.3 for particulate polycyclic aromatic hydrocarbons, refractory black carbon, total organic aerosol and m/z 60, respectively, compared to nominal burn rate. Polycyclic aromatic hydrocarbons are primarily associated with refractory black carbon-containing particles. We hypothesize that at very high burn rates, the central parts of the combustion zone become air starved, leading to a locally reduced combustion temperature that reduces the conversion rates from polycyclic aromatic hydrocarbons to refractory black carbon. This facilitates a strong increase of polycyclic aromatic hydrocarbons emissions. At nominal burn rates, full cycle emissions based on m/z 60 correlate well with organic aerosol, refractory black carbon and particulate matter. However, at higher burn rates, m/z 60 does not correlate with increased emissions of polycyclic aromatic hydrocarbons, refractory black carbon and organic aerosol in the flaming phase. The new knowledge can be used to advance source apportionment studies, reduce emissions of genotoxic compounds and model the climate impacts of refractory black carbon, such as absorption enhancement by lensing.

Land-use and land-cover change carbon emissions between 1901 and 2012 constrained by biomass observations

Li, W.; Ciais, P.; Peng, S.; Yue, C.; Wang, Y.; Thurner, M.; Saatchi, S. S.; Arneth, A.; Avitabile, V.; Carvalhais, N.; Harper, A. B.; Kato, E.; Koven, C.; Liu, Y. Y.; Nabel, J. E. M. S.; Pan, Y.; Pongratz, J.; Poulter, B.; Pugh, T. A. M.; Santoro, M.; Sitch, S.; Stocker, B. D.; Viovy, N.; Wiltshire, A.; Yousefpour, R.; Zaehle, S.
2017 | Biogeosci. Discuss.

The use of dynamic global vegetation models (DGVMs) to estimate CO2 emissions from land-use and land-cover change (LULCC) offers a new window to account for spatial and temporal details of emissions, and for ecosystem processes affected by LULCC. One drawback of DGVMs however is their large uncertainty. Here, we propose a new method of using satellite- and inventory-based biomass observations to constrain historical cumulative LULCC emissions (EcLUC) from an ensemble of nine DGVMs based on emerging relationships between simulated vegetation biomass and EcLUC. This method is applicable at global and regional scale. Compared to the large range of EcLUC in the original ensemble (94 to 273 Pg C) during 1901–2012, current biomass observations allow us to derive a new best estimate of 155 ± 50 (1-σ Gaussian error) Pg C. The constrained LULCC emissions are higher than prior DGVM values in tropical regions, but significantly lower in North America. Our approach of constraining cumulative LULCC emissions based on biomass observations reduces the uncertainty of the historical carbon budget, and can also be applied to evaluate the impact of land-based mitigation activities.

Inter-comparison of personal monitors for nanoparticles exposure at workplaces and in the environment

Todea, A. M.; Beckmann, S; Kaminski, H.; Bard, D.; Bau, B.; Clavaguera, S.; Dahmann, D.; Dozol, H.; Dziurowitz, N.; Elihn, K.; Fierz, M.; Lidén, G.; Meyer-Plath, A.; Monz, C.; Neumann, V.; Pelzer, J.; Simonow, B. K.; Thali, P.; Tuinman, I.; van der Vleuten, A.; Vroomen, H.; Christof Asbach, C.
2017 | Sci. Total Environ. | 605-606 (929-945)

Personal monitors based on unipolar diffusion charging (miniDiSC/DiSCmini, NanoTracer, Partector) can be used to assess the individual exposure to nanoparticles in different environments. The charge acquired by the aerosol particles is nearly proportional to the particle diameter and, by coincidence, also nearly proportional to the alveolar lung-deposited surface area (LDSA), the metric reported by all three instruments. In addition, the miniDiSC/DiSCmini and the NanoTracer report particle number concentration and mean particle size. In view of their use for personal exposure studies, the comparability of these personal monitors was assessed in two measurement campaigns. Altogether 29 different polydisperse test aerosols were generated during the two campaigns, covering a large range of particle sizes, morphologies and concentrations. The data provided by the personal monitors were compared with those obtained from reference instruments: a scanning mobility particle sizer (SMPS) for
LDSA and mean particle size and a ultrafine particle counter (UCPC) for number concentration. The results indicated that the LDSA concentrations and the mean particle sizes provided by all investigated instruments in this study were in the order of ±30% of the reference value obtained from the SMPS when the particle sizes of the test aerosols generatedwerewithin 20–400 nm and the instruments were properly calibrated. Particle size, morphology and concentration did not have a major effect within the aforementioned limits. The comparability of the number concentrations was found to be slightly worse and in the range of ±50% of the reference value obtained from the UCPC. In addition, a minor effect of the particle morphology on the number concentration measurements was observed. The presence of particles >400nm can drastically bias the measurement results of all instruments and all metrics determined.

Organic matter drives high interannual variability in methylmercury concentrations in a subarctic coastal sea

A.L. Soerensen; A.T. Schartup; A. Skrobonja; E. Björn
2017 | Environ. Pollut. | 229 (531-538)

Levels of neurotoxic methylmercury (MeHg) in phytoplankton are strongly associated to water MeHg concentrations. Because uptake by phytoplankton is the first and largest step of bioaccumulation in aquatic food webs many studies have investigated factors controlling seasonal changes in water MeHg concentrations. However organic matter (OM), widely accepted as an important driver of MeHg production and uptake by phytoplankton, is known for strong interannual variability in concentrations and composition within systems. In this study, we explore the role of OM on spatial and interannual variability of MeHg in a subarctic coastal sea, the northern Baltic Sea. Using MeHg (2014: 80±25 fM; 2015:

Early life exposure to per- and polyfluoroalkyl substances (PFASs): A critical review

Winkens, K.; Vestergren, R.; Berger, U.; Cousins, I.T.
2017 | Emerging Contaminants | 3 (55-68)

Carbon stocks and fluxes in the high latitudes: Using site-level data to evaluate Earth system models

S Chadburn; G Krinner; P Porada; A Bartsch; C Beer; L B Marchesini; J Boike; B Elberling; T Friborg; G Hugelius; M Johansson; P Kuhry; L Kutzbach; M Langer; M Lund1; F-J Parmentier; S Peng; K Van Huissteden; T Wang; S Westermann; D Zhu; E Burke
2017 | Biogeosciences | accepted

Decoupling of microbial carbon, nitrogen, and phosphorus cycling in response to extreme temperature events

Mooshammer M.; Hofhansl F.; Frank A.H.; Wanek W.; Hämmerle I.; Leitner S.; Schnecker J.; Wild B.; Watzka M.; Keiblinger K.M.; Zechmeister-Boltenstern S.; Richter A.
2017 | Sci. Adv. | 3 (e1602781)

Relationships between estimated flame retardant emissions and levels in indoor air and house dust

Liagkouridis, I.; Cequier, E.; Lazarov, B.; Palm Cousins, A.; Thomsen, C.; Stranger, M.; Cousins, I.T.
2017 | Indoor Air | 27 (3) (650-657)

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Department of Environmental Science and Analytical Chemistry (ACES)
Stockholm University
106 91 Stockholm

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