Chemical composition and oxidative potential of atmospheric coarse particles at an industrial and urban background site in the alpine region of northern Italy

The chemical composition and oxidative potential (OP) of particulate matter (PM10) samples were investigated at an industrial (Ala) and a background (TN) site in northern Italy. Three emission sources of airborne metals were identified by Positive Matrix Factorization (PMF) analysis, i.e., the zinc coating facility located in the area, the traffic on the nearby motorway and the pesticides normally used in the extensive vineyard cultivation. PM10redox activity was measured using dithiothreitol (OPDTTV) and ascorbic acid (OPAAV) cell-free assays. Similar OPDTTVresponses were obtained at the two sites (0.60 ± 0.23 mmol min−1m−3), while higher (OPAAV) values were measured at Ala (1.4 ± 1.1 nmol min−1m−3) than at TN (0.7 ± 0.4 nmol min−1m−3). Overall, both OPDTTVand OPAAVresponses were found to be broadly correlated with several inorganic species, namely ions and soluble metals, and organic components. In particular, OPAAVresponses are mainly affected by Zn directly emitted from the zinc factory and Cu used in the vineyard cultivation. Therefore, the higher OPAAVvalues measured at Ala can be explained by the higher concentration of these metals at the industrial site

Impact Assessment of metal-rich airborne particulate on air quality and Oxidative Potential: a case study in Trentino region

The chemical composition and toxicological impact of metal rich PM10 samples was assessed in an industrial (Ala) and background (TN) sites in Trentino region. Source apportionment study using Positive Matrix Factorization assessed that the main emission sources of airborne metals at Ala are a zinc coating facility located in the area, traffic on the A-22 Brenner motorway and pesticide/fungicide spraying in the surrounding vineyard district. PM10 toxicological impact was quantified by measuring the oxidative potential OP using two a- cellular assays, i.e., dithiothreitol (DTT) and ascorbic acid (AA) assays [1]. The responses of the DTT assay (volume-normalized OPVDTT) are similar at both size (mean values ~ 0.60±0.23 nmol min-1m-3) while OPVAA values show significantly higher values at Ala (1.4±1.1 nmol AA min-1m-3) than at TN (0.7±0.4 nmol AA min-1m-3). This is consistent with the different sensitivity of the two assays towards the same redox-active species present in ambient PM, as elucidated by linear correlation analysis of OPV with the concentration of tracer pollutants and highlighted by Heat Maps representation. At the industry site OPVDTT is correlated only with potassium and rubidium (R ~ 0.8), while OPVAA almost exclusively with Cu (R= 0.88). Otherwise, at TN both OPVDTT and OPVAA are both correlated with several species (R ≥ 0.7), such as WSTC, SO42-, NH4+, K, Mn, Cu and Zn. In addition, at Ala pronounced day-of-week evolution was observed for OPVAA values confirming the contribution of heavy metals from the anthropogenic sources. In conclusion, our study clearly shows that PM10 oxidative potential is strongly enhanced by few selected metals, mainly Zn and Cu, emitted by the anthropogenic activities carried out in the investigated area, even if they only weakly impacted PM10 chemical composition. Concerning the still open question of different sensitivity of the DTT and AA assays, our results may be considered an experimental proof of the highest sensitivity of AA assay towards transition metals

Impact Assessment of metal-rich airborne particulate on air quality and Oxidative Potential: a case study in Trentino region.

The chemical composition and toxicological impact of metal rich PM10 samples was assessed in an industrial (Ala) and background (TN) sites in Trentino region. Source apportionment study using Positive Matrix Factorization assessed that the main emission sources of airborne metals at Ala are a zinc coating facility located in the area, traffic on the A-22 Brenner motorway and pesticide/fungicide spraying in the surrounding vineyard district. PM10 toxicological impact was quantified by measuring the oxidative potential OP using two a-cellular assays, i.e., dithiothreitol (DTT) and ascorbic acid (AA) assays. The responses of the DTT assay (volume-normalized OPVDTT) are similar at both sites (mean values ~ 0.60±0.23 nmol min-1 m-3) while OPVAA values show significantly higher values at Ala (1.4±1.1 nmol AA min-1 m-3) than at TN (0.7±0.4 nmol AA min-1 m-3). This is consistent with the different sensitivity of the two assays towards the same redox-active species present in ambient PM, as elucidated by linear correlation analysis of OPV with the concentration of tracer pollutants and highlighted by Heat Maps representation. At the industry site OPVDTT is correlated only with potassium and rubidium (R ~ 0.8), while OPVAA almost exclusively with Cu (R= 0.88). Otherwise, at TN both OPVDTT and OPVAA are both correlated with several species (R ≥ 0.7), such as WSTC, SO42-, NH4+, K, Mn, Cu and Zn. In addition, at Ala pronounced day-of-week evolution was observed for OPAAV values confirming the contribution of heavy metals from the anthropogenic sources. In conclusion, our study clearly show that PM10 oxidative potential is strongly enhanced by few selected metals, mainly Zn and Cu, emitted by the anthropogenic activities carried out in the investigated area, even if they only weakly impacted PM10 chemical composition. Concerning the still open question of different sensitivity of the DTT and AA assays, our results may be considered an experimental proof of the highest sensitivity of AA assay towards transition metals

Estimating ozone risks using forest monitoring networks—results for science, policy, and society

International audienceKey messageFew integration steps (adding low-cost ozone measurements, link to existing conventional monitors, joint data processing) transformed the traditional forest monitoring network into a multifunctional infrastructure producing information relevant for estimating risk to vegetation and human health Context Traditionally, forest monitoring networks have been designed to assess status and trends of forest condition. We argue that they can help providing answers to a much broader range of questions for science, policy, and society. Here, we concentrate on the example of ground-level ozone pollution. Aims The aim of this study is to demonstrate the value of present forest monitoring networks as infrastructures that—with few integration steps—can provide important data and information to estimate the risk posed by ground-level ozone to vegetation and human health. Methods We measured ozone concentration by passive samplers at the local (Trentino, northern Italy) plots of the ICP Forests Level I network over the period 2007–2011. By integrating these data with those from conventional ozone monitors (mostly located in urban areas), we (i) obtained an even distribution of air quality measurements over the investigated area, (ii) estimated international exposure indicators for vegetation and human population, and (iii) obtained data allowing geostatistical modeling and mapping of ozone concentrations, exposure, and associated potential risk.Results Mean May–July ozone concentration ranged from 58 to 169 μg m−3, depending on forest site and year. Modeling and mapping (root-mean-square deviation (RMSD) = 12.31 μg m−3) provided evidence that the risk threshold for vegetation in terms of AOT40 was exceeded in large parts (90 %) of the study area, and frequently even by two times, depending on the year. With respect to population, up to 43 % of the dwellers were exposed to medium–high risk of exceedances of the information threshold. Conclusion Ozone measurements carried out at the ICP Forests Level I forest monitoring network permitted mapping ozone levels and the estimation of possible risk for vegetation and human health. Forest monitoring networks can be seen as infrastructures that can be useful to address a wide range of environmental issues and with a much broader scope than their original one