NPAHs and OPAHs in the atmosphere of two central European cities: Seasonality, urban-to-background gradients, cancer risks and gas-to-particle partitioning

Abstract

Derivatives of polycyclic aromatic hydrocarbons (PAHs) such as nitrated- and oxygenated-PAHs (NPAHs and OPAHs) could be even more toxic and harmful for the environment and humans than PAHs. We assessed the spatial and seasonal variations of NPAHs and OPAHs atmospheric levels, their cancer risks and their gas-to-particle partitioning. To this end, about 250 samples of fine particulate matter (PM 2.5 ) and 50 gaseous samples were collected in 2017 in central Europe in the cities of Brno and Ljubljana (two traffic and two urban background sites) as well as one rural site. The average particulate concentrations were ranging from below limit of quantification to 593 pg m −3 for Σ 9 NPAHs and from 1.64 to 4330 pg m −3 for Σ 11 OPAHs, with significantly higher concentrations in winter compared to summer. In winter, the particulate levels of NPAHs and OPAHs were higher at the traffic site compared to the urban background site in Brno while the opposite was found in Ljubljana. NPAHs and OPAHs particulate levels were influenced by the meteorological parameters and co-varied with several air pollutants. The significance of secondary formation on the occurrence of some NPAHs and OPAHs is indicated. In winter, 27–47% of samples collected at all sites were above the acceptable lifetime carcinogenic risk. The gas-particle partitioning of NPAHs and OPAHs was influenced by their physico-chemical properties, the season and the site-specific aerosol composition. Three NPAHs and five OPAHs had higher particulate mass fractions at the traffic site, suggesting they could be primarily emitted as particles from vehicle traffic and subsequently partitioning to the gas phase along air transport. This study underlines the importance of inclusion of the gas phase in addition to the particulate phase when assessing the atmospheric fate of polycyclic aromatic compounds and also when assessing the related health risk.

Residential Wood Combustion in Germany: A Twin-Site Study of Local Village Contributions to Particulate Pollutants and Their Potential Health Effects

“…The annual ECR value calculated from local PAH concentration increments only is 2.4 × 10–5, i.e., about 40% of the total excess cancer risk in Melpitz. These ECR values are below the reported ones for Oporto, Portugal (2.06 × 10 –4 ), in the same range as reported for Athens, Greece (4.6 × 10 –5 ), and Florence, Italy (8.8 × 10 –5 ), and above the values reported for Brno, Czech Republic, and Ljubljana, Slovenia), which ranged from 1.83 × 10 –10 to 2.94 × 10 –6 …”

“…These ECR values are below the reported ones for Oporto, Portugal (2.06 × 10 −4 ), 94 in the same range as reported for Athens, Greece (4.6 × 10 −5 ), 22 and Florence, Italy (8.8 × 10 −5 ), 94 and above the values reported for Brno, Czech Republic, and Ljubljana, Slovenia), which ranged from 1.83 × 10 −10 to 2.94 × 10 −6 . 95 During winter, the ECR value is 1.2 × 10 −4 , i.e., 12 cases per 100,000 people, which is about twice as high as for the annual value and similar to the mean reported values for winter season at other European sites like Oporto (3.10 × 10 −4 ), Florence (1.21 × 10 −4 ), 94 Dattenhausen, Germany (2.26 × 10 −4 ), 96 and Grenoble-France (1.22 × 10 −4 ). 97 The main contributors to the total BaP eq were BaP, BbF, DbahA, and BaA, contributing to the annual average of 64, 8.5, 8.2, and 5.1%, respectively.…”

Direct quantification of PAHs and nitro-PAHs in atmospheric PM by thermal desorption gas chromatography with electron ionization mass spectroscopic detection

“…Nitro-PAHs were not detected in spring samples, while the concentration of individual nitro-PAHs in the winter period was less than 0.5 ng m -3 . The dominant nitro-PAH in winter was 9nA (0.22±0.01 ng m -3 ), which is primarily emitted from diesel engines, coal or biomass burning [35]. It is interesting to note that in the same period, its non-nitrated analogue (Ant) was mostly not detected in PM2.5 (it was detected in one single spring sample), suggesting different sources of the two analytes.…”

PM-bound polycyclic aromatic compounds (PACs) in two large-scale petrochemical bases in South China: Spatial variations, sources, and risk assessment

“…Factor 4 was strongly loaded by NPAHs (19.0% −80.7%) and moderately weighted by OPAHs (5.8%−46.4%) and was assigned as secondary atmospheric reactions. Parent PAHs reaction with hydroxyl and nitrate radicals was the most important pathway for NPAHs formation in the atmosphere (Degrendele et al 2021;Wang et al 2011). Factor 5 in GDPB was mainly characterized by 2,8-DNDB (63.5%) and was identi ed as a source related to the usage of sulfurcontaining fuels, like coal and natural gas (Tang et al 2018).…”