Browsing by Author "Evtyugina, Margarita"
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- Chemical speciation and oxidative potential of PM10 in different residential microenvironments: Bedroom, living room and kitchenPublication . Cipoli, Yago Alonso; Vicente, Estela D.; Evtyugina, Margarita; Figueiredo, Daniela R.; Pietrogrande, Maria C.; Lucarelli, Franco; Feliciano, Manuel; Ryšavý, Jiří; Alves, CéliaExposure to particulate matter (PM) and its chemical constituents in residential microenvironments has become a major health concern worldwide. The oxidative potential (OP) has been proposed as a metric for estimating the PM capacity to induce oxidative stress and, consequently, health effects. In the present study, PM10 was daily monitored simultaneously in the bedroom, living room and kitchen of three dwellings for one week in a small town of Portugal, to perform a detailed characterisation of its organic and inorganic constituents and the determination of the OP. Bedrooms (B) were found to be a hotspot of PM10 concentrations (B1 = 22.7 μg m-3; B2 = 19.5 μg m-3; B3 = 68.1 μg m-3). PM10-bound elements varied significantly between microenvironments in all dwellings. Lower molecular weight polycyclic aromatic hydrocarbons (PAHs) were found to be between 14 and 72 times higher than high molecular weight PAHs in bedrooms. The mean volume-normalised OP determined by the dithiothreitol and ascorbic acid assays varied within the 0.01–0.38 nmol min-1 m-3 and 0.03–0.53 nmol min-1 m-3 ranges, respectively. Quinones, oxy-aromatic, aromatic and alkyl-aromatic compounds stood out in bedrooms. Strong and significantly positive relationship between OP and black carbon, Cu and Br were observed, indicating common redox active species mainly associated with traffic emissions. Sr, Fe, Zn and Zr presented higher concentrations in dwelling 3, exhibiting excellent positive correlation with OP, indicating that the Sahara dust intrusion recorded in that house may have contributed to the formation of more redox active species thought to drive antioxidant depletion responses.
- Nighttime-daytime PM10 source apportionment and toxicity in a remoteness inland city of the Iberian PeninsulaPublication . Cipoli, Yago Alonso; Alves, Célia; Rapuano, Marco; Evtyugina, Margarita; Rienda, Ismael Casotti; Kovats, Nora; Vicente, Ana; Giardi, Fabio; Furst, Leonardo; Nunes, Teresa; Feliciano, ManuelThe distribution of daytime and nighttime sources of PM10 collected from January to March 2021 at an urban background site in the city of Braganca, Portugal, was performed using positive matrix factorisation (PMF). Additional data of PM2.5, NOx and meteorological variables were collected to support the interpretations. A solution with 5 factor profiles was found: traffic (33%), dust (24%), biomass burning (21%), secondary inorganic aerosol (SIA) (12%) and sea salt (10%). Mean daytime and nighttime PM10 concentrations were 43.1 mu g m(-3) and 46.1 mu g m(-3), respectively. Nighttime concentrations were dominated by residential biomass combustion. Vehicle traffic and dust factors showed significantly greater contributions during the day (+12% and +4%, respectively), suggesting that exhaust and non-exhaust emissions and long-range transport are important contributors to daytime PM10 levels. In contrast, there were no significant differences between day and night for SIA and sea salt. Exceedances of the daily limit to PM10 (50 mu g m(-3)) and PM2.5 (15 mu g m(-3)) were observed in 22 (33%) and 27 (40%) days of the campaign, respectively, mostly associated with biomass burning for residential heating, but also with Saharan dust outbreaks. The application of the Aliivibrio fischeri bioluminescence inhibition assay for ecotoxicity assessment allowed classifying 70% of the samples as toxic, especially those from the nocturnal period, indicating that biomass burning is one of the main sources responsible for PM10 toxicity. Both the contributions from biomass burning estimated by the PMF and multiple tracers of this source showed statistically significant correlations with the toxicity units.