Inter-Comparison of Carbon Content in PM2.5 and PM10 Collected at Five Measurement Sites in Southern Italy

Chemical composition of PM10 at a rural site in the western Mediterranean and its relationship with the oxidative potential

A comprehensive chemical characterization (water-soluble ions, organic and elemental carbon, water- and methanol-soluble organic carbon, levoglucosan, and major and trace metals) of PM10 samples collected in a rural area located in the southeast of the Iberian Peninsula was performed. Additionally, the oxidative potential of the samples, used as an indicator of aerosol toxicity, was determined by the ascorbic acid (OPAA) and dithiothreitol (OPDTT) assays. The average concentration of PM10 during the study period, spanning from late winter to early spring, was 20.2 ± 10.8 μg m-3. Nitrate, carbonate and calcium (accounting for 20% of the average PM10 mass concentration) and organic matter (with a contribution of 28%) were the main chemical components of PM10. Average concentrations of traffic tracers such as elemental carbon, copper and zinc (0.31 μg m-3, 3 ng m-3, and 9 ng m-3, respectively) were low compared with those obtained at an urban site in the same region, due to the almost total absence of traffic in the surrounding of the sampling site. Regarding levoglucosan and K+, which can be considered as tracers of biomass burning, their concentrations (0.12 μg m-3 and 55 ng m-3, respectively) were in the lower range of values reported for other rural areas in Europe, suggesting a moderate contribution form this source to PM10 levels. The results of the Pearson's correlation analysis showed that volume-normalised OPAA and OPDTT levels (average values of 0.11 and 0.32 nmol min-1 m-3, respectively) were sensitive to different PM10 chemical components. Whereas OPAA was not strongly correlated with any of the species measured, good correlation coefficients of OPDTT with water-soluble organic carbon (r = 0.81) and K+ (r = 0.73) were obtained, which points to biomass burning as an important driver of the DTT activity.

Diurnal source apportionment of organic and inorganic atmospheric particulate matter at a high-altitude mountain site under summer conditions (Sierra Nevada; Spain)

High-altitude mountain areas are sentinel ecosystems for global environmental changes such as anthropogenic pollution. In this study, we report a source apportionment of particulate material with an aerodynamic diameter smaller than 10 μm (PM10) in a high-altitude site in southern Europe (Sierra Nevada Station; SNS (2500 m a.s.l.)) during summer 2021. The emission sources and atmospheric secondary processes that determine the composition of aerosol particles in Sierra Nevada National Park (Spain) are identified from the concentrations of organic carbon (OC), elemental carbon (EC), 12 major inorganic compounds, 18 trace elements and 44 organic molecular tracer compounds in PM10 filter samples collected during day- and nighttime. The multivariate analysis of the joint dataset resolved five main PM10 sources: 1) Saharan dust, 2) advection from the urbanized valley, 3) local combustion, 4) smoke from a fire-event, and 5) aerosol from regional recirculation with high contribution of particles from secondary inorganic and organic aerosol formation processes. PM sources were clearly associated with synoptic meteorological conditions, and day- and nighttime circulation patterns typical of mountainous areas. Although a local pollution source was identified, the contribution of this source to PM10, OC and EC was small. Our results evidence the strong influence of middle- and long-range transport of aerosols, mainly from anthropogenic origin, on the aerosol chemical composition at this remote site.

Characterization of size-fractionated carbonaceous particles in the small to nano-size range in Batam city, Indonesia

A cascade impactor type sampler equipped with an inertial filter was used to collect size-segregated particles down to ultrafine particles (UFPs or PM_0.1) on Batam Island in Sumatra, Indonesia, bordered by Singapore and Malaysia during a wet and the COVID-19 pandemic season in 2021. Carbonaceous species, including organic carbon (OC) and elemental carbon (EC), were analyzed by a thermal/optical carbon analyzer to determine the carbon species and their indices. The average UFP was 3.1 ± 0.9 μg/m³, which was 2-4 times lower than in other cities in Sumatra during the same season in the normal condition. The PMs mass concentration was largely affected by local emissions but long-range transportation of particles from Singapore and Malaysia was also not negligible. The air mass arrived at the sampling site passed the ocean, which introduced out clean air with a low level of PMs. The backward trajectory of the air mass and the largest fraction of OC2 and OC3 in all sizes was identified as being transported from the 2 above countries. OC is the dominant fraction in TC and the ratio of carbonaceous components indicated that origin of all particle sizes was predominantly vehicle emissions. UFPs were dominantly emitted from vehicles exhaust emission, while coarser particles (>10 μm) were influenced by the non-exhaust emissions, such as tire wear. Other particles (0.5-1.0; 1.0-2.5; and 2.5-10 μm) were slightly affected by biomass burning. The effective carbon ratio (ECR) and inhalation dose (ID) related EC indicated that finer particles or UFPs and PM_0.5-1 contributed more to human health and global warming.

Characterisation of the correlations between oxidative potential and in vitro biological effects of PM10 at three sites in the central Mediterranean

Atmospheric particulate matter (PM) is one of the major risks for global health. The exact mechanisms of toxicity are still not completely understood leading to contrasting results when different toxicity metrics are compared. In this work, PM₁₀ was collected at three sites for the determination of acellular oxidative potential (OP), intracellular oxidative stress (OSGC), cytotoxicity (MTT assay), and genotoxicity (Comet assay). The in vitro tests were done on the A549 cell line. The objective was to investigate the correlations among acellular and intracellular toxicity indicators, the variability among the sites, and how these correlations were influenced by the main sources by using PMF receptor model coupled with MLR. The OP^DTT_V, OSGC_V, and cytotoxicity were strongly influenced by combustion sources. Advection of African dust led to lower-than-average intrinsic toxicity indicators. OP^DTT_V and OSGC_V showed site-dependent correlations suggesting that acellular OP may not be fully representative of the intracellular oxidative stress at all sites and conditions. Cytotoxicity correlated with both OP^DTT_V and OSGC_V at two sites out of three and the strength of the correlation was larger with OSGC_V. Genotoxicity was correlated with cytotoxicity at all sites and correlated with both, OP^DTT_V and OSGC_V, at two sites out of three. Results suggest that several toxicity indicators are useful to gain a global picture of the potential health effects of PM.

Kidney damage induced by repeated fine particulate matter exposure: Effects of different components

BACKGROUND

Exposure to fine particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) is associated with adverse health effects. This study aimed to evaluate the toxic effects of the constituents of PM_2.5 on mouse kidneys.

METHODS

We collected PM_2.5 near an industrial complex located in southern Kaohsiung, Taiwan, that was divided into water extract and insoluble particles. Male C57BL/6 mice were divided into five groups: control, low- and high-dose insoluble particle exposure, and low- and high-dose water extract exposure. Biochemical analysis, Western blot analysis, histological examination, and immunohistochemistry were performed to evaluate the impact of PM_2.5 constituents on mice kidneys.

RESULTS

PM_2.5 was collected from January 1, 2021, to February 8, 2021, from an industrial complex in Kaohsiung, Taiwan. Metallic element analysis showed that Pb, Ni, V, and Ti were non-essential metals with enrichment factors >10. Polycyclic aromatic hydrocarbon and nitrate polycyclic aromatic hydrocarbon analyses revealed that the toxic equivalents are, in the order, benzo(a)pyrene (BaP), indeno(1,2,3-cd) pyrene (IP), dibenzo(a,h)anthracene (DBA), and benzo(b)fluoranthene (BbF), which are potential carcinogens. Both water extract and insoluble particle exposure induced inflammatory cytokine upregulation, inflammatory cell infiltration, antioxidant activity downregulation, and elevation of kidney injury molecule 1 (KIM-1) level in mouse kidneys. A dose-dependent effect of PM_2.5 water extract and insoluble particle exposure on angiotensin converter enzyme 2 downregulation in mouse kidneys was observed.

CONCLUSION

We found that water-soluble extract and insoluble particles of PM_2.5 could induce oxidative stress and inflammatory reactions, influence the regulation of renin-angiotensin system (RAS), and lead to kidney injury marker level elevation in mouse kidneys. The lowest-observed-adverse-effect level for renal toxicity in mice was 40 μg water-soluble extract/insoluble particle inhalation per week, which was approximately equal to the ambient PM_2.5 concentration of 44 μg/m³ for mice.

Inter-annual variability of source contributions to PM10, PM2.5, and oxidative potential in an urban background site in the central mediterranean

Airborne particulate matter (PM) is studied because of its effects on human health and climate change. PM long-term characterisation allows identifying trends and evaluating the outcomes of environmental protection policies. This work is aimed to study the inter-annual variability of PM_2.5 and PM₁₀ concentrations and chemical composition in an urban background site (Italy). A dataset of daily PM_2.5 and PM₁₀ was collected in the period 2016-2017, including the content of OC, EC, major water-soluble ions, main metals, and compared to a similar dataset collected in the period 2013-2014. Oxidative potential using DTT assay (dithiothreitol) was evaluated and expressed in DTT_V as 0.39 nmol/min·m³ in PM₁₀ and 0.29 in PM_2.5 nmol/min·m³. PM source apportionment was computed using the EPA PMF5.0 model and source contributions compared with those of a previous dataset collected between 2013 and 2014. Multi linear regression analysis identified which source contributed (p < 0.05) to the oxidative potential of each size fraction. Inter-annual trends were more evident on PM_2.5 with reductions of biomass burning contribution and increases in traffic contribution in the 2016-2017 period. Crustal contributions were similar for the two periods, in both size fractions. Carbonates were comparable in PM₁₀ with a slight increase in PM_2.5. Sea spray decreased in PM₁₀. The DTT_V of PM_2.5 peaked during cold periods, while, the DTT_V of the PM_10-2.5 fraction peaked in summer, suggesting that different sources, with different seasonality, influence OP in the PM_2.5 and PM_10-2.5 fractions. Analysis showed that sea spray, crustal, and carbonates sources contribute ∼13.6% to DTT_V in PM_2.5 and ∼62.4% to DTT_V in PM_10-2.5. Combustion sources (biomass burning and traffic) contribute to the majority of DTT_V (50.6%) in PM_2.5 and contribute for ∼26% to DTT_V in PM_10-2.5. Secondary nitrate contributes to DTT_V in both fine and coarse fraction; secondary sulphate contribute to DTT_V in PM_2.5 with negligible contributions to DTT_V in PM_10-2.5.

Comparison of Ambient Air Quality among Industrial and Residential Areas of a Typical South Asian city

The rapid increase in population growth due to industrialization and urbanization has resulted in air quality deterioration in Pakistan. Consequently, a considerable increase has been seen in the types of sources of air pollutants. However, the air quality of the country has deteriorated in the absence of management capabilities against air quality. Evidence from numerous governmental organizations and international bodies has specified that the environment, health, and quality of life are at high risk due to air pollution. Although the government of Pakistan established the Pakistan Clean Air Program, along with continuous monitoring stations to manage the quality of ambient air, air quality values have not yet been achieved. The present investigations were made in the city of Faisalabad in selected locations. Sampling of a 24 h average was done for selected sites. The air quality parameters such as NO2, SO2, COx, O2, noise level, and suspended particulate matter (SPM) were measured at two locations, i.e., Khurrianwala and Liaqatabad in the Faisalabad District. The measured values of air quality parameters were compared with national environmental quality standards (NEQS). Air pollutants such as SPM, SO2, and noise levels were found to be significantly higher than the 24-h standards of NEQS, which poses harmful effects on the quality of air and health, whereas the O2 concentration was found to be lower than the normal values, and NO2 and COx values were normal. The SO2, CO2, noise level, SPM, and O2 values ranged from 418–652 and 423–661 µg/m3, 3.03–3.44 and 3.08–3.51 mg/m3, 68–73 and 69–75 dB, 555–667 and 581–682 µg/m3, and 19.5–20 and 19.5–20.3 % for summer and winter season, respectively, as compared to standard values (150 µg/m3, 10 mg/m3, 65 dB, 550 µg/m3 and 21%). After the complete analysis of the selected locations, it was concluded that the ambient air quality of this area is severely degraded due to industrial as well as other commercial activities. These significant variations in air quality parameters suggest that there is a need to check the air quality regularly to take appropriate measures for reducing ambient air pollutants, especially in industrial areas as well as commercial areas.

Particle-bound organic and elemental carbons for source identification of PM < 0.1 µm from biomass combustion

Atmospheric nanoparticles (PM < 0.1 µm) are a major cause of environmental problems and also affect health risk. To control and reduce these problems, sources identification of atmospheric particulates is necessary. Combustion of bituminous coal and biomass including rubber wood, palm kernel, palm fiber, rice stubble, rice straw, maize residue, sugarcane leaves and sugarcane bagasse, which are considered as sources of air quality problems in many countries, was performed. Emissions of particle-bound chemical components including organic carbon (OC), elemental carbon (EC), water-soluble ions (NH₄⁺, Cl^-, NO₃^-, SO₄^2-), elements (Ca, K, Mg, Na) and heavy metals (Cd, Cr, Ni, Pb) were investigated. The results revealed that PM < 0.1 µm from all samples was dominated by the OC component (>50%) with minor contribution from EC (3%-12%). The higher fraction of carbonaceous components was found in the particulates with smaller sizes, and lignin content may relate to concentration of pyrolyzed organic carbon (PyOC) resulting in the differences of OC/EC values. PM emitted from burning palm fiber and rice stubble showed high values of OC/EC and also high PyOC. Non-carbonaceous components such as Cl^-, Cr, Ca, Cd, Ni, Na and Mg may be useful as source indicators, but they did not show any correlation with the size of PM.

Chemical characterisation of PM10 from ship emissions: a study on samples from hydrofoil exhaust stacks

A chemical characterization of PM10 collected at hydrofoil exhaust stacks was performed conducting two on-board measuring campaigns, with the aim of assessing the ship emission impact on PM10 collected in the coastal area of Naples (Southern Italy) and providing information about the characteristics of this important PM emission source.Samples were analysed determining the contribution of different chemical parameters to PM10's mass, which consisted of polycyclic aromatic hydrocarbons (PAHs) (0.10 ± 0.12%), total carbon (61.9% ± 20.0%, with 40.4% of organic carbon, OC, and 21.5% of elemental carbon, EC) and elemental fraction (0.44% ± 1.00%). Differences in terms of composition and chemical parameter profiles were observed between samples collected during offshore navigation (Off) and samples collected during shunting operations (SO), the latter of higher concern on a local scale. For SO samples, lower contributions of OC and EC were observed (39.7% and 19.6% respectively) compared to Off samples (41.5% and 24.2%), and an increase in terms of elements (from 0.32 to 0.51%) and PAHs (from 0.06 to 0.12%) concentrations was observed. In addition, enrichment factors (EFs) for some elements such as V, Zn, Cd, Cu, Ag and Hg as well as PAHs profile varied significantly between SO and Off. Data presented here were compared with data on chemical composition of PM10 sampled in a tunnel, in a background site and in an urban site in the city of Naples. Results indicated that shipping activities contributed significantly to the emission of V and, in some extent, Zn and Cd; in addition, PAH profiles indicated a greater contribution to urban PM10 from vehicular traffic than shipping emissions. These results can significantly contribute to the correct evaluation of the influence of shipping emission on PM10 generation in urban coastal areas and can be a useful reference for similar studies. The coastal area of Naples is an important example of the coexistence of residential, touristic and natural areas with pollutants emission sources including, among the others, shipping emissions. In this and similar contexts, it is important to distinguish the contribution of each emission source to clearly define environmental control policies.

Particulate Matter Ionic and Elemental Composition during the Winter Season: A Comparative Study among Rural, Urban and Remote Sites in Southern Italy

We present an overview of the concentrations and distributions of water-soluble ion species and elemental components in ambient particulate matter for five measurement sites in southern Italy with the aim of investigating the influence of the different site characteristics on PM levels. The sites encompass different characteristics, ranging from urban to coastal and high-altitude remote areas. PM10 and PM2.5 fractions were collected simultaneously using dual channel samplers during the winter period from November 2015 to January 2016 and analyzed for water-soluble ion species, using ion chromatography, and elemental composition, using inductively coupled plasma mass spectrometry (ICP-MS). In all sites, PM2.5 represented the higher contribution to particulate mass, usually more than two times that of the coarse fraction (PM2.5−10). At the coastal site in Capo Granitola (Western Sicily), sea salts constituted about 30% of total PM10 mass. On average, ion species accounted for 30% to 60% of total PM10 mass and 15% to 50% of PM2.5 mass. We found that secondary ion species, i.e., SO42−, NO3− and NH4+ dominated the identifiable components within both PM2.5 and PM10 fractions. The chlorine–sodium ratio was usually lower than that expected from the natural level in sea salt, evidencing aged air masses. At the monitoring site in Naples, a highly urbanized area affected by high levels of anthropogenic source emissions, an increased contribution of ammonium was found, which was imputed to the increased ammonia emissions from industrial combustion sources and road traffic. The concentrations of the investigated elements showed noteworthy differences from one site to another. The PM10 fraction was highly enriched by sources of anthropogenic origin in the samples from the most urbanized areas. In general, the enrichment factors of the elements were similar between the PM10 and PM2.5 fractions, confirming common sources for all elements.

Compositional changes of PM2.5 in NE Spain during 2009-2018: A trend analysis of the chemical composition and source apportionment

In this work, time-series analyses of the chemical composition and source contributions of PM_2.5 from an urban background station in Barcelona (BCN) and a rural background station in Montseny (MSY) in northeastern Spain from 2009 to 2018 were investigated and compared. A multisite positive matrix factorization analysis was used to compare the source contributions between the two stations, while the trends for both the chemical species and source contributions were studied using the Theil-Sen trend estimator. Between 2009 and 2018, both stations showed a statistically significant decrease in PM_2.5 concentrations, which was driven by the downward trends of levels of chemical species and anthropogenic source contributions, mainly from heavy oil combustion, mixed combustion, industry, and secondary sulfate. These source contributions showed a continuous decrease over the study period, signifying the continuing success of mitigation strategies, although the trends of heavy oil combustion and secondary sulfate have flattened since 2016. Secondary nitrate also followed a significant decreasing trend in BCN, while secondary organic aerosols (SOA) very slightly decreased in MSY. The observed decreasing trends, in combination with the absence of a trend for the organic aerosols (OA) at both stations, resulted in an increase in the relative proportion of OA in PM_2.5 by 12% in BCN and 9% in MSY, mostly from SOA, which increased by 7% in BCN and 4% in MSY. Thus, at the end of the study period, OA accounted for 40% and 50% of the annual mean PM_2.5 at BCN and MSY, respectively. This might have relevant implications for air quality policies aiming at abating PM_2.5 in the study region and for possible changes in toxicity of PM_2.5 due to marked changes in composition and source apportionment.

Analytical study on the primary and secondary organic carbon and elemental carbon in the particulate matter at the high-altitude Monte Curcio GAW station, Italy

This study provides a thorough investigation of the trends of organic carbon (OC) and elemental carbon (EC) in particulate matter (PM)₁₀ and PM_2.5 samples collected at the Monte Curcio Observatory (1780 m a.s.l.), a station of the Global Atmosphere Watch (GAW) program and Global Mercury Observation System (GMOS) network. Although the drawn attention toward these pollutants, there is still a lack of data for southern Italy, and this work is a contribution toward the filling of this gap. PM was sampled daily in 2016 and analyzed by thermo-optical transmittance method, while equivalent black carbon (eBC) concentrations in PM₁₀ were simultaneously measured using a multiangle absorption photometer. The results showed that in PM₁₀, the average values of OC and EC were 1.43 μgC/m³ and 0.12 μgC/m³, whereas in PM_2.5, these concentrations were 1.09 μgC/m³ and 0.12 μgC/m³, respectively. We detected a clear seasonal variability in OC and EC with higher concentrations during the warm period. Moreover, the analysis of the OC/EC ratio revealed that most of the carbonaceous aerosol was transported by long-range air masses, as further confirmed by the use of the concentration-weighed trajectory (CWT) model. The mass absorption cross-section at 632 nm of EC (MAC_EC) over the entire period was 9.67 ± 4.86 m²/g and 8.70 ± 3.18 m²/g in PM_2.5 and PM₁₀, respectively, and did not exhibit a clear seasonal variation. The concentrations for OC and EC were also used for the computation of the secondary organic carbon (SOC) content, whose outcomes resulted in a seasonal trend similar to those obtained for OC and EC. As regards the eBC, its weekly pattern showed a slight increase during the weekend in the warm period, consistent with the anthropic activities in the touristic area surrounding the observatory.

Oxidative Potential, Cytotoxicity, and Intracellular Oxidative Stress Generating Capacity of PM10: A Case Study in South of Italy

Long and short-term exposure to atmospheric particulate matter (PM) has detrimental effects on human health. The effective mechanisms leading to PM toxicity are still not fully understood, even if it is known that physical-chemical properties, strongly influenced by sources and atmospheric processes, are known to play an important role. In this work, PM10 samples were collected, at an urban background site in southern Italy, to determine cytotoxicity (using MTT test on A549 cells), genotoxicity (using the comet assay), and intracellular oxidative stress on A549 cells exposed for 24 h to aqueous extracts of PM10 samples. Organic carbon (OC) and elemental carbon (EC) content of PM10 and acellular determination of oxidative potential with DTT assay were performed to compare results of acellular and cellular biological assays. Cellular (OSGCV and MTTV) and acellular (OPDTTV) outcomes, normalized in volume, are well correlated (statistically significant results) with carbon content suggesting that combustion sources play an important role in determining cellular oxidative stress and cytotoxicity of PM10. Even if the number of data is limited, genotoxicity results are well correlated (Pearson r > 0.95) with OSGCV and MTTV, and a weaker, but statistically significant correlation was observed with OPDTTV. OSGCV is well correlated with the cell mortality observed with the MTTV test and a lower, but still statistically significant correlation is observed between MTTV and OPDDTV. A statistically significant correlation was found between OPDTTV and OSGCV results. When the outcomes of the cellular and acellular assay are compared normalized in mass (i.e., intrinsic values), the correlations become significantly weaker suggesting that the different sources acting on the site produces particulate matter with different toxicological potential influencing differently the biological tests studied.

Assessment of carbonaceous fractions in ambient aerosols at high altitude and lowland urban locations of Kumaon Province, Indian Himalaya

The present study investigates the characteristics of carbonaceous species like organic carbon (OC) and elemental carbon (EC) in ambient total suspended particulates (TSP) at Bhimtal (high altitude urban, 1413 m asl) and Pantnagar (lowland urban, 224 m asl) sites of Kumaon province in Uttarakhand, Indian Himalayan region during winter and summer 2017–2018. Ambient TSP samples were taken on quartz filters with high volume sampler followed by OC and EC quantification using IMPROVE_thermal optical reflectance protocol. Results showed that distinct seasonal differences in carbonaceous species levels were observed at both sites, while day- and night-time concentrations did not show notable variations. Further, total carbonaceous aerosols (TCA) at Pantnagar were approximately 3.0 and 1.3 times higher than Bhimtal for winter and summer, respectively, where estimated TCA accounted for ~ 30% to total TSP at both sites. Among quantified eight carbon fractions, OC2 and OC3 at Bhimtal while EC1 and EC2 at Pantnagar were the most abundant components. The char-EC and soot-EC concentrations showed a similar seasonal pattern where char contributed significantly as 89–90% to total EC at both sites. The observed OC/EC ratios suggested the formation of secondary organic carbon and char-EC/soot-EC ratios implied biomass burning as major sources for carbonaceous aerosols. Pearson correlation analysis indicated that char-EC showed significant higher correlations with OC and EC than soot-EC which infers different formation mechanisms of char and soot. Most of the carbonaceous parameters exhibited contrasting positive and negative correlations with the boundary layer height, temperature, and solar radiation at Bhimtal and Pantnagar, respectively.

Agrochemical treatments as a source of heavy metals and rare earth elements in agricultural soils and bioaccumulation in ground beetles

The continuous and extensive application of agrochemicals leads to the accumulation of heavy metals (HMs) and rare earth elements (REEs) in agricultural soils and their transfer in the food web with consequent relevant risks for human and ecosystem health. In this study, HM and REE concentrations were quantified in the soil of wheat crop fields conventionally managed in the agricultural areas of Sila Mountain (Southern Italy) and compared with the concentration in a field of wild herbs, used as control. Statistical analyses and principal component analysis suggested that the use of pesticides, herbicides and fertilizers contributes to the accumulation of HMs and REEs in the soil. Different accumulation patterns were recorded in treated fields as a consequence of the type and amount of agrochemical used and the crop rotation. The exposure risk associated with the transfer through the tropic levels of agroecosystem was carried out measuring the concentration of HMs and REEs in adults of Harpalus (Pseudoophonus) rufipes (De Geer, 1774) collected from each monitored site. Different accumulation patterns found in specimens from the monitored sites highlighted the ability of this generalist predator to regulate metal uptake under field conditions. The values of bioaccumulation factor (BAF) allow to defining the order of accumulation in P. rufipes which was classified as a macroconcentrator of Cd, Cu, Mg and Zn. Our results can supplement the limited information regarding the REE accumulation in soil invertebrates and may provide reference data for assessing potential environmental risks in croplands.

Pollution Characteristics of Particulate Matter (PM2.5 and PM10) and Constituent Carbonaceous Aerosols in a South Asian Future Megacity

The future megacity of Faisalabad is of prime interest when considering environmental health because of its bulky population and abundant industrial and anthropogenic sources of coarse particles (PM10) and fine airborne particulate matter (PM2.5). The current study was aimed to investigate the concentration level of PM2.5 and PM10, also the characterization of carbonaceous aerosols including organic carbon (OC), elemental carbon (EC) and total carbon (TC) in PM2.5 and PM10 samples collected from five different sectors (residential, health, commercial, industrial, and vehicular zone). The data presented here are the first of their kind in this sprawling city having industries and agricultural activities side by side. Results of the study revealed that the mass concentration of PM2.5 and PM10 is at an elevated level throughout Faisalabad, with ambient PM2.5 and PM10 points that constantly exceeded the 24-h standards of US-EPA, and National Environment Quality Standards (NEQS) which poses harmful effects on the quality of air and health. The total carbon concentration varied between 21.33 and 206.84 μg/m3, and 26.08 and 211.15 μg/m3 with an average of 119.16 ± 64.91 μg/m3 and 124.71 ± 64.38 μg/m3 for PM2.5 in summer and winter seasons, respectively. For PM10, the concentration of TC varied from 34.52 to 289.21 μg/m3 with an average of 181.50 ± 87.38 μg/m3 (for summer season) and it ranged between 44.04 and 300.02 μg/m3 with an average of 191.04 ± 87.98 μg/m3 (winter season), respectively. No significant difference between particulate concentration and weather parameters was observed. Similarly, results of air quality index (AQI) and pollution index (PI) stated that the air quality of Faisalabad ranges from poor to severely pollute. In terms of AQI, moderate pollution was recorded on sampling sites in the following order; Ittehad Welfare Dispensary > Saleemi Chowk > Kashmir Road > Pepsi Factory, while at Nazria Pakistan Square and Allied Hospital, higher AQI values were recorded. The analysis and results presented in this study can be used by policy-makers to apply rigorous strategies that decrease air pollution and the associated health effects in Faisalabad.

Modification of the EPA method 1631E for the quantification of total mercury in natural waters

To support the effectiveness of the Minamata Convention, the accurate determinations of mercury (Hg) in natural waters is an important but certainly challenging task due to the low concentrations expected in ambient samples. Mercury contamination may occur from many sources such as the unproperly-cleaning of storage bottles or the use of reagents for sample analysis with Hg traces, thus leading the analyst to easily run into errors. In our work, we propose some key modifications to the United States Environmental Protection Agency(EPA) method 1631E aimed at reducing the Hg contamination of reagents, storage containers, and minimizing the carryover effect in the instrumental line of sampling. The changes introduced have been tailored for the use of the method with cold vapor atomic fluorescence spectroscopy (CV-AFS) instrumentation and tested as part of a United Nations Environment Program (UNEP) ring test. Although the edited method was tested with natural water samples, the proposed method improvements can also apply to the Hg analysis in solid matrices that require the prior acid digestion of the samples.•A customized version of the EPA method 1631E is proposed for the analysis of aqueous samples.•New protocols for the reduction of contamination in the storage bottles and reagents used for the preparation of BrCl solution are provided.•A useful strategy for the control of the memory effect is included.

Advances in Solid-Phase Microextraction

Analysis imposes substantial challenges, especially when dealing with analytes present at trace levels in complex matrices [...]

Vehicular Emission: Estimate of Air Pollutants to Guide Local Political Choices. A Case Study

The aim of this case study was to show how, with the use of software, is it possible to carry out a preventive screening of vehicular emissions. Moreover, thanks to this preliminary analysis, some areas that are potentially polluted can be identified in advance and suitable samplings on small-scale on them would help to verify the effectiveness of policies that can be adopted for the reduction of pollution. To this end, this paper reports a case study on vehicle traffic pollution in Calabria, a region in the south of Italy. We used the methodology called Corinair (Coordination Information AIR), developed by the EEA (European Environment Agency) and uses the software Copert4 (Computer Program to calculate Emission from Road Traffic). The total emissions per area were analyzed and the emissions for particular pollutants per unit area (km²) and per citizen were considered. The obsolete vehicles determined a substantial impact on the local atmospheric pollution. It was demonstrated how it is possible to substantially reduce the pollution of an area by adopting policies that encourage, for example, through tax concessions, the replacement of old cars of private citizens.

Characterisation of atmospheric pollution near an industrial site with a biogas production and combustion plant in southern Italy

Although biogas production can have some benefits, there is a research gap on potential influence of biogas plant emissions on local air quality, thus an accurate and comprehensive evaluation of impacts of this technology is needed. This study deals with this issue by means of a characterisation of air pollution near an industrial area including a biogas production (from biomass) and combustion plant located in South Italy. The methodology consists in advanced statistical analysis on concentration of gaseous pollutants, particles concentration and size distribution in number and mass, and PM_2.5 chemical composition. High-temporal resolution measurements, supported by ancillary meteorological parameters, and source apportionment of PM_2.5 using Positive Matrix Factorization (PMF) receptor model, are performed. The integrated approach provides the emissive picture consisting in different anthropogenic sources (i.e. traffic, biomass burning, and industrial facilities) with particular focus on biogas plant emissions. Results showed that CO and nitrogen oxides were influenced by vehicular traffic and biomass combustion, however, a contribution of the plant to NO was observed. SO₂ was influenced mainly by transport from the industrial zone, but a second local contribution compatible with the emissions of the biogas plant was detected. Number particle concentrations were analysed in four size ranges: nanoparticles (D < 0.05 μm), ultrafine particles (D < 0.3 μm), accumulation (0.3 < D < 1 μm) and coarse particles (D > 1 μm). Nanoparticles and ultrafine particles were mainly influenced by vehicular traffic and biomass burning, instead, a contribution of the plant was individuated in the accumulation mode. PMF5 identified the contribution of six sources: crustal (14.7% ± 2.1% of measured PM_2.5); marine aerosol (aged) (12.9% ± 2.3%); biomass burning (32.8% ± 1.4%); secondary sulphate (19.7% ± 2.4%); primary industrial emissions (5.4% ± 2.3%); traffic and secondary nitrate (17.0% ± 3.9%). The plant is likely to contribute to both sources, the industrial and the traffic plus secondary nitrate.

Contribution of Volcanic and Fumarolic Emission to the Aerosol in Marine Atmosphere in the Central Mediterranean Sea: Results from Med-Oceanor 2017 Cruise Campaign

This work studied the contribution of the geogenic sources volcanoes and fumaroles to the aerosol in marine atmosphere in the central Mediterranean basin. For this purpose, in the framework of the Med-Oceanor measurement program, we carried out a cruise campaign in the summer of 2017 to investigate the impact to the aerosol of the most important Mediterranean volcanoes (Mount Etna, Stromboli Island, and Marsili Seamount) and solfatara areas (Phlegraean Fields complex, Volcano Islands, Ischia Island, and Panarea submarine fumarole). We collected PM10 and PM2.5 samples in 12 sites and performed chemical characterization to gather information about the concentration of major and trace elements, elemental carbon (EC), organic carbon (OC), and ionic species. The use of triangular plots and the calculation of enrichment factors confirmed the interception of volcanic plume. We integrated the outcomes from chemical characterization with the use of factor analysis and SEM/EDX analysis for the source apportionment. Anthropogenic and natural sources including shipping emissions, volcanic and fumarolic load, as well as sea spray were identified as the main factors affecting aerosol levels in the study area. Furthermore, we performed pattern recognition analysis by stepwise linear discriminant analysis to seek differences in the composition of PM10 and PM2.5 samples according to their volcanic or solfatara origin.

Correlation of Oxidative Potential with Ecotoxicological and Cytotoxicological Potential of PM10 at an Urban Background Site in Italy

Exposure to atmospheric particulate matter (PM) has detrimental effects on health, but specific mechanisms of toxicity are still not fully understood. In recent years, there has been a growing evidence that oxidative stress is an important mechanism of toxicity; however, when acellular oxidative potential (OP) data are correlated with the outcomes of in vitro (or in vivo) toxicological tests there are contrasting results. In this work, an analysis of PM10 health effect indicators was done, using the acellular Dithiotreitol (DTT) assay to retrieve OPDTT, the Microtox® test on Vibrio fischeri bacterium to assess the ecotoxicological potential, and the in vitro MTT assay on the human cell line A549 to estimate the cytotoxicological potential. The objective was to evaluate the correlation among acellular OPDTT and the results from toxicological and ecotoxicological bioassays and how these health-related indicators are correlated with atmospheric PM10 concentrations collected at an urban background site in Southern Italy. Results indicated that both bioassays showed time-dependent and dose-dependent outcomes. Some samples presented significant ecotoxic and cytotoxic response and the correlation with PM10 concentration was limited suggesting that these health endpoints depend on PM10 chemical composition and not only on exposure concentrations. OPDTT showed a statistically significant correlation with PM10 concentrations. MTT and Microtox outcomes were not correlated suggesting that the two toxicological indicators are sensitive to different physical-chemical properties of PM10. Intrinsic oxidative potential OPDTTM (DTT activity normalised with PM10 mass) was correlated with mortality observed with MTT test (normalized with PM10 mass); however, it was not correlated with Microtox outcomes.

Carbonaceous Aerosols Collected at the Observatory of Monte Curcio in the Southern Mediterranean Basin

This work provides the first continuous measurements of carbonaceous aerosol at the Global Atmosphere Watch (GAW) Monte Curcio regional station, within the southern Mediterranean basin. We specifically analyzed elemental carbon (EC) and organic carbon (OC) concentrations in particulate matter (PM) samples, collected from April to December during the two years of 2016 and 2017. The purpose of the study is to understand the behavior of both PM and carbonaceous species, in their fine and coarse size fraction, along with their seasonal variability. Based on 18 months of observations, we obtained a dataset that resulted in a vast range of variability. We found the maximum values in summer, mainly related to the enhanced formation of secondary pollutants owing to intense solar radiation, also due to the high frequency of wildfires in the surrounding areas, as well as to the reduced precipitation and aerosol-wet removal. We otherwise observed the lowest levels during fall, coinciding with well-ventilated conditions, low photochemical activity, higher precipitation amounts, and less frequency of Saharan dust episodes. We employed the HYSPLIT model to identify long-range transport from Saharan desert. We found that the Saharan dust events caused higher concentrations of PM and OC in the coarser size fraction whereas the wildfire events likely influenced the highest PM, OC, and EC concentrations we recorded for the finer fraction.

Inter-comparison of carbon content in PM10 and PM2.5 measured with two thermo-optical protocols on samples collected in a Mediterranean site

Scientific interest is focusing on different approaches for characterising organic carbon (OC), elemental carbon (EC) and equivalent black carbon (eBC), although EUSAAR2 protocol has been established and frequently used in EU for regulatory purposes. Discrepancies are observed due to thermal protocols used for OC/EC determinations and the effect of the chemical-physical properties of aerosol using optical measurements for eBC. In this work, a long-term inter-comparison of carbon measurements with two widely used protocols (EUSAAR2 and NIOSH870) was performed on PM_2.5 and PM₁₀ samples. The influence of the protocol on the evaluation of secondary organic aerosol (SOC) and on the correlation between EC and eBC was investigated. An extensive check of repeatability gave typical uncertainties of ~ 5% for TC and OC, and ~ 10% for EC for both thermal protocols. Results show that OC is statistically comparable between the two protocols but EC is significantly higher with EUSAAR2, especially during the warm season. The ratio OC/EC is lower with EUSAAR2, also showing a seasonality (lower values in the warm season) not observed with NIOSH870. Despite the differences in OC/EC ratios, the contribution of SOC to OC (~ 50%), evaluated using the EC-tracer method, did not differ significantly between the two protocols and for both size fractions. Further, SOC/OC ratios were comparable in cold and warm periods. eBC/EC ratios larger than one for both protocols were obtained, 1.62 (EUSAAR2) and 1.92 (NIOSH870), and also correlated with the ratio OC/EC for both protocols, especially in the cold season.

High Contribution of Biomass Combustion to PM2.5 in the City Centre of Naples (Italy)

A better knowledge of the local and regional sources of the atmospheric particulate matter provides policy makers with the proper awareness when acting to improve air quality, in order to protect public health. A source apportionment study of the carbonaceous aerosol in Naples (Italy) is presented here, in order to improve this understanding in a vulnerable urban area. The aim of this study is quantifying directly fossil and non-fossil contributions to carbonaceous aerosol, by means of radiocarbon measurements. This is the first time that such an approach is implemented in this area. Fine particles with diameter ≤ 2.5 µm (PM2.5) were collected daily on top of a building in the city center, from November 2016 until January 2017. The carbonaceous aerosol was separated into organic carbon (OC) and elemental carbon (EC), by a two-step thermal desorption method. Subsequent radiocarbon analysis enabled the partitioning of the major sources of carbonaceous aerosol into fossil and non-fossil ones by applying radiocarbon isotopic mass balance. The PM2.5 concentration was on average 29 ± 3 µg⁄m3 (mean ± standard error; n = 18), with a maximum of 68.6 ± 0.7 µg⁄m3 on a day when air masses back-trajectories suggest a local origin and stagnant airflow conditions in the region. The carbonaceous component accounts for roughly half of the PM2.5 mass. Fossil fuel emissions are a minor source of OC (23%), but the dominant source of EC (66%), which is directly emitted during combustion processes. However, overall only 30% of the total carbon is of fossil origin, accounting for 14% of PM2.5 mass. Surprisingly, a comparable contribution is due to primary biomass burning carbon, which accounts in total for 15% of PM2.5 mass. Traffic pollution, the main cause of fossil fuel emissions in urban areas, is a significant, but not the predominant source of carbonaceous particle concentration. These findings support the conclusion of a predominant contribution from non-fossil sources to the carbon in airborne particulate matter, which policy makers should take into account when planning mitigation strategies to improve urban air quality.

Characterization of In Situ Aerosol Optical Properties at Three Observatories in the Central Mediterranean

In this work, results of scattering and backscattering coefficients, scattering Ångström exponent (SAE), single scattering albedo (SSA), and asymmetry parameter (g) of atmospheric aerosols are presented. All these parameters were measured during the month of April 2016 in Southern Italy on three different Global Atmosphere Watch observatories in the Central Mediterranean. This is the first time, to our knowledge, that optical aerosol properties were studied at the same time, even if in a brief intensive measurement campaign, at three sites in the South of Italy. In order to obtain a characteristic value for aerosol optical properties, different kinds of particle sources (i.e., dust, marine, and anthropic) have been identified and studied. In the measurement period, one event of a long-range transport of Saharan dust from Northern Africa was observed at all observatories. During the Saharan dust transport event, a minimum value of the SAE (0.69 ± 0.34) and a relatively higher values of SSA were observed. During the dust event, g increased up to 0.69. Marine aerosol contribution and anthropic/urban aerosol intrusion were analysed. From this analysis, SAE average values were 0.70, 0.84, and 1.22, respectively, for dust, marine, and anthropic particles. On the other hand, the SSA minimum value was 0.86 for anthropic particles, and it increased for dust (0.88) and marine (0.93) aerosols. The asymmetry parameter had a limited variability for the three types of aerosol from 0.62 to 0.58, as reported also in literature.