Impact of the COVID-19 lockdown to a port-city area: A two-year comparative PMF analysis of PM10 of polluting sources

The objective of this study was to evaluate the effects that the COVID-19 lockdown had in the PM10 levels and sources in a city adjacent port where the transport of bulk materials is one of the main activities. For this, the 2020 PM10 chemistry and sources will be compared to an annual baseline period of 2017-18 in the same area. A total of 337 samples were chemically analyzed (30 chemical species) and a positive matrix factorization model was used to identify major PM10 sources. A Mann-Whitney test was used to find statistically relevant differences between periods. The model identified 8 factors two of them directly related to port activities (Shipping emissions and bulk materials), one associated to road traffic, three linked secondary sources (aged sea salt, secondary nitrate, ammonium sulphate) and two natural sources including fresh sea salt and long-range transport from Saharan intrusions. Road traffic and Shipping sources show a significant reduction in the lockdown period. However, after this period, the road traffic source quickly recovered showing no differences on a yearly basis with the reference year. Only the Shipping emissions source were greatly reduced in 2020 compared to 2017-18. On the other hand, the influence of natural sources kept PM10 from reducing drastically during the lockdown year (2020).This work has been carried out within the framework of the doctoral program of the University of Alicante in collaboration with companies (UAIND-17-1A). The authors want to express their gratitude to the Alicante Port Authority for their participation in this program with the project (PUERTOALICANTE1-20Y), which together with the University provided the funding the sampling and the PhD grant

Size segregated ionic species collected in a harbour area

Water-soluble ions were analysed in size segregated aerosol samples collected in the port of Alicante (Southeastern Spain) during summer and winter using a multistage cascade impactor. Seasonal variations in the size distributions of the analysed components and the influence of bulk materials handling (loading/unloading and stockpiling) at the docks were investigated. The size distributions of SO42−, NH4+ and K+ were characterized by prominent peaks in the condensation and droplet modes, both in summer and winter, while those of Ca2+, Na+, Mg2+ and Cl− had a main peak centred at ∼4 μm. Although oxalate size distributions were similar during both seasons, the fraction of coarse-mode oxalate increased in summer most likely as a result of volatilization and repartition processes or reactions of oxalic acid with coarse alkaline particles. Nitrate size distributions were dominated by a coarse mode; however, during winter, modal peaks in the submicron size range were also observed due to favourable conditions for the formation of fine-mode NH4NO3. Harbour activities had a significant impact only on the concentrations of calcium, particularly in the coarse fraction, during both summer and winter.This work was supported by the Spanish Ministry of Science, Innovation and Universities (COSMOS Project, ref. RTI2018-098639-B-I00). The authors would also like to thank ACTRIS-Spain network (CGL2017-90884-REDT). A. Clemente thanks the Spanish Ministry of Education for a predoctoral grant (FPU18/00081)

Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations

A reliable determination of equivalent black carbon (eBC) mass concentrations derived from filter absorption photometers (FAPs) measurements depends on the appropriate quantification of the mass absorption cross-section (MAC) for converting the absorption coefficient (babs) to eBC. This study investigates the spatial–temporal variability of the MAC obtained from simultaneous elemental carbon (EC) and babs measurements performed at 22 sites. We compared different methodologies for retrieving eBC integrating different options for calculating MAC including: locally derived, median value calculated from 22 sites, and site-specific rolling MAC. The eBC concentrations that underwent correction using these methods were identified as LeBC (local MAC), MeBC (median MAC), and ReBC (Rolling MAC) respectively. Pronounced differences (up to more than 50 %) were observed between eBC as directly provided by FAPs (NeBC; Nominal instrumental MAC) and ReBC due to the differences observed between the experimental and nominal MAC values. The median MAC was 7.8 ± 3.4 m2 g-1 from 12 aethalometers at 880 nm, and 10.6 ± 4.7 m2 g-1 from 10 MAAPs at 637 nm. The experimental MAC showed significant site and seasonal dependencies, with heterogeneous patterns between summer and winter in different regions. In addition, long-term trend analysis revealed statistically significant (s.s.) decreasing trends in EC. Interestingly, we showed that the corresponding corrected eBC trends are not independent of the way eBC is calculated due to the variability of MAC. NeBC and EC decreasing trends were consistent at sites with no significant trend in experimental MAC. Conversely, where MAC showed s.s. trend, the NeBC and EC trends were not consistent while ReBC concentration followed the same pattern as EC. These results underscore the importance of accounting for MAC variations when deriving eBC measurements from FAPs and emphasize the necessity of incorporating EC observations to constrain the uncertainty associated with eBC.</p

Analysis of elemental concentrations of hourly particle matter samples collected in the surroundings of an industrial harbor (Metadata RADIATE TA Proposal 19001971-ST)

Proposal title "Analysis of elemental concentrations of hourly particle matter samples collected in the surroundings of an industrial harbor". Measurements carried out at the external beam set-up for atmospheric aerosol analysis of the INFN LABEC accelerator laboratory), from 27 till 31 January 2020. Hands-on mode. The handling, loading and unloading of bulk materials from boats are important sources of particulate matter in the vicinity of industrial harbours. The harbour in the city of Alicante is located very close to the city itself. Schools and buildings are within less than one kilometer distance to the main activities of the harbour. The harbour sources do not emit particles continuously and sometimes, due to the composition of the aerosols emitted, are difficult to differentiate from other sources such as road dust, resuspended dust, etc. If daily filters are used the estimation of the contribution of these sources is very difficult. It is for this reason a Streaker instrument was used. A Streaker allows the collection of particles with a temporal resolution of one hour during the course of one week (more than 160 hours). Furthermore, the sampler is able to collect different fractions of the particulate matter (coarse and fine) in two different subtracts (Polypropylene and Nucleopore). The quantity of sample is small and as a result very difficult to analyze using traditional chemical techniques. The PIXE technique is suitable for measuring these kinds of filters and the INFN LABEC has the set up ready for measuring them. During winter 2019, two Streaker samplers were placed in two different points inside the harbour area. One of them was located in between the docks where solid bulk materials are handled and the closest part of the harbour to the city of Alicante (where a primary school is located). The other was placed at the opposite end, close to the sea. Both sampling sites form a 180-degree angle. The campaign lasted two weeks. During the campaign, several boats docked in the harbour to load bulk materials (mainly clinker and limestone). The main objective is to determine the impact that harbour operations involving the handling of bulk material has on the concentrations and chemical composition of the particulate matter. For this reason eight filters (4 of Nucleopore and 4 of polypropylene) collected with hourly resolution with the Streaker sampler were analyzed by PIXE technique using an extracted proton beam of 2.7 MeV

Impacts on particles and ozone by transport processes recorded at urban and high-altitude monitoring stations

In order to evaluate the influence of particle transport episodes on particle number concentration temporal trends at both urban and high-altitude (Aitana peak-1558 m a.s.l.) stations, a simultaneous sampling campaign from October 2011 to September 2012 was performed. The monitoring stations are located in southeastern Spain, close to the Mediterranean coast. The annual average value of particle concentration obtained in the larger accumulation mode (size range 0.25–1 μm) at the mountain site, 55.0 ± 3.0 cm− 3, was practically half that of the value obtained at the urban station (112.0 ± 4.0 cm− 3). The largest difference between both stations was recorded during December 2011 and January 2012, when particles at the mountain station registered the lowest values. It was observed that during urban stagnant episodes, particle transport from urban sites to the mountain station could take place under specific atmospheric conditions. During these transports, the major particle transfer is produced in the 0.5–2 μm size range. The minimum difference between stations was recorded in summer, particularly in July 2012, which is most likely due to several particle transport events that affected only the mountain station. The particle concentration in the coarse mode was very similar at both monitoring sites, with the biggest difference being recorded during the summer months, 0.4 ± 0.1 cm− 3 at the urban site and 0.9 ± 0.1 cm− 3 at the Aitana peak in August 2012. Saharan dust outbreaks were the main factor responsible for these values during summer time. The regional station was affected more by these outbreaks, recording values of > 4.0 cm− 3, than the urban site. This long-range particle transport from the Sahara desert also had an effect upon O3 levels measured at the mountain station. During periods affected by Saharan dust outbreaks, ozone levels underwent a significant decrease (3–17%) with respect to its mean value.This study has been supported by the Spanish Ministry of Science and Innovation, MICINN I+D+I Program: PASSE Project, CGL2009-08036

Quantification of the impact of port activities on PM10 levels at the port-city boundary of a mediterranean city

The main objective of this work was to quantify the impact of handling of bulk materials on PM10 levels measured at the port-city border of Alicante (Spain), located on the western Mediterranean coast. To achieve that goal, 355 PM10 samples were collected at the perimeter of the harbor of Alicante from March 2017 to February 2018. A 181 sample subgroup was chemically characterized in order to perform a source apportionment study with the EPA PMF 5.0 model. Eight factors were identified, two of them directly related to the handling of bulk materials (Limestone + gypsum and Clinker), accounting jointly for 35% of the average PM10 concentration. A Road traffic factor was the second highest contributor to PM10 levels (17%) while the Shipping emissions factor accounted for only 6% of the average PM10 mass. Other factors such as Biomass burning+ secondary nitrate and Aged sea salt represented a joint contribution of 25% of the PM10 mass. Results indicate that emission abatement strategies should primarily focus on the reduction of fugitive emissions caused by the handling of bulk materials at the docks. Moreover, scenarios including reductions of more than 50% in bulk handling sources and 10% in other anthropogenic sources would help to reduce anthropogenic exceedances of the daily PM10 limit (50 μg·m−3) and to approach to WHO daily PM10 standard (20 μg m−3).This work was supported by the Spanish Ministry of Science, Innovation and Universities through the projects CGL2017-90884-REDT (ACTRIS) and RTI2018-098639-B-I00 (COSMOS) (AEI/FEDER,UE) and through an FPU Grant (FPU18/00081)