Micro(Nano)Plastics as Carriers of Toxic Agents and Their Impact on Human Health

Currently, globally the demand and production of plastic items are increasing exorbitantly, generating a large amount of waste, and polluting the ecosystem, a site in which degradation processes are triggered, which give rise to smaller particles such as micro(nano)plastics (MNP). Continuous human exposure to these particles generates negative alterations in the host’s health. Three routes of MNP exposure or contact have been established: inhalation, ingestion of particles, and dermal absorption. Recently, it has been pointed out that microplastics (MP) can even be found in the human placenta. This chapter aims to compile and provide information on their role as conveyor vectors of agents potentially toxic to humans, mechanisms by which they enter the human body, their bioaccumulation, and health human effects

NO2 seasonal evolution in the north subtropical free troposphere

Three years of multi-axis differential optical absorption spectroscopy (MAXDOAS) measurements (2011-2013) have been used for estimating the NO2 mixing ratio along a horizontal line of sight from the high mountain subtropical observatory of Izaña, at 2370 m a.s.l. (NDACC station, 28.3° N, 16.5° W). The method is based on horizontal path calculation from the O2-O2 collisional complex at the 477 nm absorption band which is measured simultaneously to the NO2 column density, and is applicable under low aerosol-loading conditions. The MAXDOAS technique, applied in horizontal mode in the free troposphere, minimizes the impact of the NO2 contamination resulting from the arrival of marine boundary layer (MBL) air masses from thermally forced upwelling breeze during middle hours of the day. Comparisons with in situ observations show that during most of the measuring period, the MAXDOAS is insensitive or very slightly sensitive to the upwelling breeze. Exceptions are found for pollution events during southern wind conditions. On these occasions, evidence of fast, efficient and irreversible transport from the surface to the free troposphere is found. Background NO2 volume mixing ratio (vmr), representative of the remote free troposphere, is in the range of 20-45 pptv. The observed seasonal evolution shows an annual wave where the peak is in phase with the solar radiation. Model simulations with the chemistry-climate CAM-Chem model are in good agreement with the NO2 measurements, and are used to further investigate the possible drivers of the NO2 seasonality observed at Izaña.Peer Reviewe

Recent increase in NO2 levels in the southeast of the Iberian Peninsula

12 pags., 7 figs.We report the evolution of tropospheric NO over the south-east of the Iberian Peninsula from 2005 to 2017. We have used hourly NO levels measured at air-quality stations in urban and suburban environments. Annual averages ranged between 14 and 45 μg m, with peaks above 200 μg m. A monthly variation was observed, with higher concentrations in cold months (40–60 μg m) and lower levels in the warm season (13–17 μg m). A diurnal pattern was found in urban and suburban areas. The upward trend in NO observed during the whole period contrasts with the upward trend reported in 2013–2017. The NO tropospheric column levels measured by the Ozone Monitoring Instrument over the Iberian Peninsula indicated a similar behaviour; nevertheless, the largest Spanish metropolitan areas did not show this increase. The mean sea level pressure and wind field data of ERA5 (European Centre for Medium-Range Weather Forecasts) were used to investigate the weather conditions, the NO outputs of the Copernicus Monitoring Services being used for the assessment of the NO spatial distribution. NO regional events, with concentrations in the range 140–150 μg m, and which occurred both in the winter and summer season under anticyclonic conditions, are also described. A local origin is identified in winter, whereas in summer, they are associated with a high-pressure system that blocks Mediterranean outflows towards the Atlantic Ocean. The high NO levels are attributed mainly to two factors: i) local emissions, rather than contributions from the western Mediterranean (or even North Africa), and ii) an increase in the pressure gradient between the Atlantic and the Mediterranean pressure systems, associated with a decrease in wind speed, was found during the last five years compared with the previous eight. Meteorological and chemical changes in mid-latitudes associated with global warming should also be investigated in the future.The authors wish to thank the Survey and Air Quality Control Net-work of the Environmental Department of the Regional Governmentof Andalusia (Spain) for access to its database. Thanks are due to theECMWF (European Centre for Medium-Range Weather Forecasts) forthe ERA5 meteorological fields and its free access to the Copernicus At-mosphere Service (CAMS), to NASA for the OMI measurements and tothe Goddard Earth Sciences (GES) Data and Information Services Center(DISC) for archiving and distributing the informatio

Insights into the Molecular Basis of Huanglongbing Tolerance in Persian Lime (<i>Citrus latifolia</i> Tan.) through a Transcriptomic Approach

Huanglongbing (HLB) is a vascular disease of Citrus caused by three species of the α-proteobacteria “Candidatus Liberibacter”, with “Candidatus Liberibacter asiaticus” (CLas) being the most widespread and the one causing significant economic losses in citrus-producing regions worldwide. However, Persian lime (Citrus latifolia Tanaka) has shown tolerance to the disease. To understand the molecular mechanisms of this tolerance, transcriptomic analysis of HLB was performed using asymptomatic and symptomatic leaves. RNA-Seq analysis revealed 652 differentially expressed genes (DEGs) in response to CLas infection, of which 457 were upregulated and 195 were downregulated. KEGG analysis revealed that after CLas infection, some DEGs were present in the plant–pathogen interaction and in the starch and sucrose metabolism pathways. DEGs present in the plant–pathogen interaction pathway suggests that tolerance against HLB in Persian lime could be mediated, at least partly, by the ClRSP2 and ClHSP90 genes. Previous reports documented that RSP2 and HSP90 showed low expression in susceptible citrus genotypes. Regarding the starch and sucrose metabolism pathways, some genes were identified as being related to the imbalance of starch accumulation. On the other hand, eight biotic stress-related genes were selected for further RT-qPCR analysis to validate our results. RT-qPCR results confirmed that symptomatic HLB leaves had high relative expression levels of the ClPR1, ClNFP, ClDR27, and ClSRK genes, whereas the ClHSL1, ClRPP13, ClPDR1, and ClNAC genes were expressed at lower levels than those from HLB asymptomatic leaves. Taken together, the present transcriptomic analysis contributes to the understanding of the CLas-Persian lime interaction in its natural environment and may set the basis for developing strategies for the integrated management of this important Citrus disease through the identification of blanks for genetic improvement

Recent and historical pollution legacy in high altitude Lake Marboré (Central Pyrenees): A record of mining and smelting since pre-Roman times in the Iberian Peninsula

16 pags., 7 figs., 2 tabs.We have analyzed potential harmful trace elements (PHTE; Pb, Hg, Zn, As and Cu) on sediment cores retrieved from lake Marboré (LM) (2612 m a.s.l, 42°41′N; 0° 2′E). PHTE variability allowed us to reconstruct the timing and magnitude of trace metal pollutants fluxes over the last 3000 years in the Central Pyrenees. A statistical treatment of the dataset (PCA) enabled us to discern the depositional processes of PHTE, that reach the lake via direct atmospheric deposition. Indeed, the location of LM above the atmospheric boundary layer makes this lake an exceptional site to record the long-range transport of atmospheric pollutants in the free troposphere. Air masses back-trajectories analyses enabled us to understand the transport pathways of atmospheric pollutants while lead isotopic analyses contributed to evaluate the source areas of metal pollution in SW Europe during the Late Holocene. PHTE variability, shows a clear agreement with the main exploitation phases of metal resources in Southern Europe during the Pre-Industrial Period. We observed an abrupt lead enrichment from 20 to 375 yrs CE mostly associated to silver and lead mining and smelting practices in Southern Iberia during the Roman Empire. This geochemical data suggests that regional atmospheric metal pollution during the Roman times rivalled the Industrial Period. PHTE also increased during the High and Late Middle Ages (10–15 centuries) associated to a reactivation of mining and metallurgy activities in high altitude Pyrenean mining sites during climate amelioration phases. Atmospheric mercury deposition in the Lake Marboré record mostly reflects global emissions, particularly from Almadén mines (central Spain) and slightly fluctuates during the last three millennia with a significant increase during the last five centuries. Our findings reveal a strong mining-related pollution legacy in alpine lakes and watersheds that needs to be considered in management plans for mountain ecosystems as global warming and human pressure effects may contribute to their future degradation.Financial support has been received by the Sobrarbe Geoparkhrough the project“Reconstrucción de la minería histórica en la Comarca del Sobrarbe y su impacto ambiental durante el Antropoceno”and by the Spanish Ministry of Economy and Competitiveness(MINECO) project MEDLANT (CGL2016-76215-R). This work is also supported by the FEDER funds through the INTERREG V-A Spain-France-Andorra (POCTEFA 2014-2020, REPLIM project, Ref. EFA056/15