This review describes the different steps involved in the determination of arsenic in air, considering the particulate matter (PM) and the gaseous phase. The review focuses on sampling, sample ...preparation and instrumental analytical techniques for both total arsenic determination and speciation analysis. The origin, concentration and legislation concerning arsenic in ambient air are also considered. The review intends to describe the procedures for sample collection of total suspended particles (TSP) or particles with a certain diameter expressed in microns (e.g. PM10 and PM2.5), or the collection of the gaseous phase containing gaseous arsenic species. Sample digestion of the collecting media for PM is described, indicating proposed and established procedures that use acids or mixtures of acids aided with different heating procedures. The detection techniques are summarized and compared (ICP-MS, ICP-OES and ET-AAS), as well those techniques capable of direct analysis of the solid sample (PIXE, INAA and XRF). The studies about speciation in PM are also discussed, considering the initial works that employed a cold trap in combination with atomic spectroscopy detectors, or the more recent studies based on chromatography (GC or HPLC) combined with atomic or mass detectors (AFS, ICP-MS and MS). Further trends and challenges about determination of As in air are also addressed.
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•Review about arsenic in the air.•Sampling, sample treatment and analysis of arsenic in particulate matter and gaseous phase.•Total arsenic determination and arsenic speciation analysis.
Evidence on the short-term effects of ultrafine particles (with diameter<100nm, UFP) on health is still inconsistent. New particles in ambient urban air are the result of direct emissions and also ...the formation of secondary UFP from gaseous precursors. We segregated UFP into these two components and investigated their impact on daily mortality in three Spanish cities affected by different sources of air pollution.
We separated the UFP using a method based on the high correlation between black carbon (BC) and particle number concentration (N). The first component accounts for aerosol constituents emitted by vehicle exhaust (N1) and the second for the photochemical new particle formation enhancements (N2). We applied city-specific Poisson regression models, adjusting for long-term trends, temperature and population dynamics.
Mean BC levels were higher in Barcelona and Tenerife (1.8 and 1.2μg·m−3, respectively) than in Huelva (0.8μg·m−3). While mean UFP concentrations were similar in the three cities, from which N1 was 40% in Barcelona, 46% in Santa Cruz de Tenerife, and 27% in Huelva. We observed an association with N1 and daily mortality in Barcelona, by increasing approximately 1.5% between lags 0 and 2, per an interquartile increase (IQR) of 3277cm−3, but not with N2. A similar pattern was found in Santa Cruz de Tenerife, although none of the associations were significant. Conversely, in the industrial city of Huelva mortality was associated with N2 at lag 0, by increasing 3.9% per an IQR of 12,032·cm−3.
The pattern and origin of UFP determines their short-term effect on human health. BC is possibly the better parameter to evaluate the health effects of particulate vehicle exhaust emissions, although in areas influenced by domestic solid fuel combustion this should also be taken into account.
•Association between segregated components of UFP (N1 and N2) and daily mortality•BC is a better parameter to evaluate health effects of particulate vehicle exhaust emissions.•Pattern and origin of UFP determines its short-term effect on daily mortality.
In many large cities of Europe standard air quality limit values of particulate matter (PM) are exceeded. Emissions from road traffic and biomass burning are frequently reported to be the major ...causes. As a consequence of these exceedances a large number of air quality plans, most of them focusing on traffic emissions reductions, have been implemented in the last decade. In spite of this implementation, a number of cities did not record a decrease of PM levels. Thus, is the efficiency of air quality plans overestimated? Do the road traffic emissions contribute less than expected to ambient air PM levels in urban areas? Or do we need a more specific metric to evaluate the impact of the above emissions on the levels of urban aerosols? This study shows the results of the interpretation of the 2009 variability of levels of PM, Black Carbon (BC), aerosol number concentration (N) and a number of gaseous pollutants in seven selected urban areas covering road traffic, urban background, urban-industrial, and urban-shipping environments from southern, central and northern Europe. The results showed that variations of PM and N levels do not always reflect the variation of the impact of road traffic emissions on urban aerosols. However, BC levels vary proportionally with those of traffic related gaseous pollutants, such as CO, NO2 and NO. Due to this high correlation, one may suppose that monitoring the levels of these gaseous pollutants would be enough to extrapolate exposure to traffic-derived BC levels. However, the BC/CO, BC/NO2 and BC/NO ratios vary widely among the cities studied, as a function of distance to traffic emissions, vehicle fleet composition and the influence of other emission sources such as biomass burning. Thus, levels of BC should be measured at air quality monitoring sites. During morning traffic rush hours, a narrow variation in the N/BC ratio was evidenced, but a wide variation of this ratio was determined for the noon period. Although in central and northern Europe N and BC levels tend to vary simultaneously, not only during the traffic rush hours but also during the whole day, in urban background stations in southern Europe maximum N levels coinciding with minimum BC levels are recorded at midday in all seasons. These N maxima recorded in southern European urban background environments are attributed to midday nucleation episodes occurring when gaseous pollutants are diluted and maximum insolation and O3 levels occur. The occurrence of SO2 peaks may also contribute to the occurrence of midday nucleation bursts in specific industrial or shipping-influenced areas, although at several central European sites similar levels of SO2 are recorded without yielding nucleation episodes. Accordingly, it is clearly evidenced that N variability in different European urban environments is not equally influenced by the same emission sources and atmospheric processes. We conclude that N variability does not always reflect the impact of road traffic on air quality, whereas BC is a more consistent tracer of such an influence. However, N should be measured since ultrafine particles (<100 nm) may have large impacts on human health. The combination of PM10 and BC monitoring in urban areas potentially constitutes a useful approach for air quality monitoring. BC is mostly governed by vehicle exhaust emissions, while PM10 concentrations at these sites are also governed by non-exhaust particulate emissions resuspended by traffic, by midday atmospheric dilution and by other non-traffic emissions.
The influence of North African (NAF) dust events on the air quality at the regional level (12 representative monitoring stations) in Southern Europe during a long time series (2007–2014) was studied. ...PM10 levels and chemical composition were separated by Atlantic (ATL) and NAF air masses. An increase in the average PM10 concentrations was observed on sampling days with NAF dust influence (42 μg m−3) when compared to ATL air masses (29 μg m−3). Major compounds such as crustal components and secondary inorganic compounds (SIC), as well as toxic trace elements derived from industrial emissions, also showed higher concentrations of NAF events. A source contribution analysis using positive matrix factorisation (PMF) 5.0 of the PM10 chemical data, discriminating ATL and NAF air mass origins, allowed the identification of five sources: crustal, sea salt, traffic, regional, and industrial. A higher contribution (74%) of the natural sources to PM10 concentrations was confirmed under NAF episodes compared with ATL. Furthermore, there was an increase in anthropogenic sources during these events (51%), indicating the important influence of the NAF air masses on these sources. The results of this study highlight that environmental managers should take appropriate actions to reduce local emissions during NAF events to ensure good air quality.
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•Long time series of PM10 and chemical composition were studied in Southern Europe.•Pollutants were evaluated under the influence of North African dust (NAF) episodes.•PM10 concentrations increased from 29 to 42 μg m−3 during NAF episodes.•An increase of the anthropogenic sources (51%) was observed under NAF episodes.
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•Geochemical anomalies of toxic elements in PM10 related to metallurgy have been identified in an urban ambient.•Fugitive emissions from brass industries are an important source of ...metals and metalloids.•Speciation of Sb(III) and Sb(V) in PM10 can be used as a geochemical tracer to identify the influence of industry and traffic on the air quality.
The chemical composition of atmospheric particulate matter (PM) has been studied at the cities of Cordoba and Granada (South of Spain) between 2007 and 2013, considering urban background, traffic and industrial monitoring stations. The results of Principal Component Analysis (PCA) indicated that geochemical anomalies observed in the ambient air of Cordoba (mainly Cu, Zn, Pb and Cd) are closely related to the geochemical profile obtained from fugitive metallurgy emissions of brass industries. These findings have been confirmed performing an Sb speciation analysis of PM10 samples, which allowed to distinguish between Sb(III) and Sb(V). The percentage of Sb(V) in PM10 found in the traffic station of Granada was 64–69%. At Cordoba, the percentage of Sb(V) was found to be higher (73–77%) at both urban background and traffic stations, indicating a possible second source of Sb in the PM of this city. The PM10 samples from the industrial station of Cordoba showed a 85–86% of Sb(V). A similar percentage (84–88%) of Sb(V) was found for the fugitive emissions of the brass industries, confirming this industrial source of Sb. These results show that Sb speciation can be a useful geochemical tracer to identify anthropogenic sources (traffic and industrial) emissions of PM.
In summer 2009, emissions of trace gases and aerosols from several wildfires occurring in Portugal were sampled. A portable high-volume sampler was used to collect sequentially, on quartz fibre ...filters, coarse (PM
2.5–10) and fine (PM
2.5) smoke particles. Tedlar air sampling bags have been used for complementary chemical characterisation of the gaseous phase. The carbonaceous content (elemental and organic carbon, EC/OC) of particulate matter was analysed by a thermal-optical transmission technique. The levels of almost 50 elements were quantified by inductively coupled plasma-mass spectrometry. The water-soluble ions were obtained by ion chromatography. Emission factors of species that are favoured by the smouldering phase (e.g. CO) were above the values reported in the literature for biomass burning in other ecosystems. The CO emission factors were 231 ± 117 g kg
−1 biomass (dry basis) burned. Emissions of compounds that are promoted in fresh plumes and during the flaming phase, such as CO
2, were generally lower than those proposed for savannah and tropical forest fires. The CO
2 emission factors ranged from about 1000 to 1700 g kg
−1. Total hydrocarbons, PM
2.5, PM
10 and OC presented variable emissions, but in general substantially higher than values reported for wildfires in African and Amazonian biomes. The emission factors obtained in Portugal were as follows (in g kg
−1 biomass, dry basis): 6–350 for total hydrocarbons, 0.5–42 for PM
2.5, 1–60 for PM
10, and 0.2–42 for OC (in PM
10). The organic carbon-to-elemental carbon ratios measured in the present study largely exceeded those obtained by other researchers. The aerosol mass was dominated by organic matter (OC/PM
2.5 = 50 ± 18%, OC/PM
2.5–10 = 36 ± 18%). The metal elements represented, on average, 1.23 and 0.91%, while the measured water-soluble ions accounted for 2.6 and 2.1% of the PM
2.5 and PM
2.5–10 mass, respectively. Carbonates accounted for 0.15–3.1% (average = 0.83%) of PM
2.5–10. The dominant elements were B, Ti, Mn, Cu, Zn, Zr and Ba.
► Wildfires are a major contributor of trace gases and aerosol species. ►Emissions are a function of the vegetation type and combustion phase. ► Wildfire emissions in the Mediterranean area are not well-studied. ► Emission factors for CO, CO2 and hydrocarbons were determined. ► The chemical composition of smoke particles was characterised.
Trace element concentrations within PM10, gaseous pollutants (NO2 and SO2), and PM10 levels were studied during the Covid-19 lockdown at a regional level in Southern Spain (Andalusia). Pollutant ...concentrations were compared considering different mobility periods (pre-lockdown, lockdown, and relaxation) in 2020 and previous years (2013–2016). An acute decrease in NO2 levels (<50%) was observed as a consequence of traffic diminution during the confinement period. Moreover, a lower reduction in PM10 levels and a non-clear pattern for SO2 levels were observed.
During the lockdown period, PM10 elements released from traffic emissions (Sn and Sb) showed the highest concentration diminution in the study area. Regarding the primary industrial sites, there were no significant differences in V, Ni, La, and Cr concentration reduction during 2020 associated with industrial activity (stainless steel and oil refinery) in Algeciras Bay. Similarly, concentrations of Zn showed the same behaviour at Cordoba, indicating that the Zn-smelter activity was not affected by the lockdown. Nevertheless, stronger reductions of Cu, Zn, and As in Huelva during the confinement period indicated a decrease in the nearby Cu-smelter emissions. Brick factories in Bailen were also influenced by the confinement measures, as corroborated by the marked decrease in concentrations of Ni, V, Cu, and Zn during the lockdown compared to that from previous years.
This work has shown the baseline concentrations of trace elements of PM10, which is of great value to air quality managers in order to minimise pollution levels by applying the confinement of the population, affecting both traffic and industrial anthropogenic activities.
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•The effect of Covid-19 lockdown over air pollutants has been studied at Andalusia.•PM10 trace elements and NO2 levels, related to traffic, were highly reduced.•General conclusions for industrial sites cannot be drawn.
•Geochemical anomalies of toxic elements in PM10 related to mining have been studied.•High concentrations of Cu and As have been detected in rural and background stations.•As speciation explains the ...low impact of the mining area on the rural surrounding.•Pyrometallurgic activity produces fine particles which are transported long-distance.
A characterization of chemical composition and source contribution of PM10 in three representative environments of southwest Spain related to mining activities (mineral extraction, mining waste and Cu-smelting) has been performed. A study of geochemical anomalies was conducted in the samples collected at the three stations between July 2012 and October 2013. The influence of Cu-smelting processes was compared to other mining activities, where common tracers were identified. The Cu and As concentrations in the study area are higher than in other rural and urban stations of Spain, in which geochemical anomalies of As, Se, Bi, Cd, and Pb have been reported.
The results of source contribution showed similar geochemical signatures in the industrial and mining factors. However, the contribution to PM10 is different according to the type of industrial activity. These results have been confirmed performing an arsenic speciation analysis of the PM10 samples, in which the mean extraction efficiency of arsenic depended on the origin of the samples. These finding indicate that the atmospheric particulate matter emitted from Cu-smelting has a high residence time in the atmosphere. This indicates that the Cu-smelter can impact areas of high ecological interest and considered as clean air.
This study presents a description of the emission, transport, dispersion, and deposition of heavy metals contained in atmospheric aerosols emitted from a large industrial complex in southern Spain ...using the HYSPLIT model coupled with high- (MM5) and low-resolution (GDAS) meteorological simulations. The dispersion model was configured to simulate eight size fractions (<0.33, 0.66, 1.3, 2.5, 5, 14, 17, and >17 μm) of metals based on direct measurements taken at the industrial emission stacks. Twelve stacks in four plants were studied and the stacks showed considerable differences for both emission fluxes and size ranges of metals. We model the dispersion of six major metals; Cr, Co, Ni, La, Zn, and Mo, which represent 77% of the total mass of the 43 measured elements. The prediction shows that the modeled industrial emissions produce an enrichment of heavy metals by a factor of 2–5 for local receptor sites when compared to urban and rural background areas in Spain. The HYSPLIT predictions based on the meteorological fields from MM5 show reasonable consistence with the temporal evolution of concentrations of Cr, Co, and Ni observed at three sites downwind of the industrial area. The magnitude of concentrations of metals at two receptors was underestimated for both MM5 (by a factor of 2–3) and GDAS (by a factor of 4–5) meteorological runs. The model prediction shows that heavy metal pollution from industrial emissions in this area is dominated by the ultra-fine (<0.66 μm) and fine (<2.5 μm) size fractions.
► We modeled the dispersion of heavy metals originating from industrial complex. ► The model was refined by configuration of eight size fractions of metals. ► High- and low-resolution meteorological models were compared. ► Model driven by MM5 had reasonable prediction of metal pollution. ► Industrial emissions enhanced metal pollution levels by a factor of 2–5.
Wood combustion experiments were carried out in a Portuguese woodstove to determine the effects of biofuel type, ignition technique, biomass load and cleavage, as well as secondary air supply, on the ...chemical composition of particles (PM10). Two typical wood fuels in the Iberian Peninsula were tested: pine (Pinus pinaster), a softwood, and beech (Fagus sylvatica), a hardwood. PM10 samples were analysed for organic and elemental carbon (OC and EC), levoglucosan and 56 elements. Total carbon (TC) represented 54–73wt.% of the particulate mass emitted during the combustion process, regardless of wood species burned or operating condition tested. The carbonaceous component of PM10 was dominated by OC. The OC content of PM10 was higher when higher loads were fed into the combustion chamber, for both fuels. EC represented from 8 to 35wt.% of the particulate mass. OC/EC ranged from 1.1 to 6.1 (avg. 3.0±1.8) for pine combustion and from 1.1 to 3.4 (avg. 2.0±0.8) for beech combustion. The lowest OC/EC ratios for both woods were observed for ignition from the top. Levoglucosan was found in all samples, representing from 3.7 to 7.5wt.% and from 4.2 to 8.9wt.% of PM10 emitted from the combustion of pine and beech, respectively. The use of low loads of fuel generated high amounts of levoglucosan either for pine or beech. Altogether, trace elements obtained by ICP-MS and ICP-AES comprised from 0.46wt.% to 1.41wt.% and from 0.87wt.% to 2.36wt.% of the PM10 mass for pine and beech combustion, respectively. Among elements, K, Ca, Na, Mg, Fe and Al contributed to more than 75% of the total ICP-MS mass. Potassium was the major element in almost all PM10 samples.
•Chemical composition of particles from distinct operating conditions was studied.•Organic carbon contributes to more than 30% of the PM10 mass.•K, Ca, Na, Mg, Fe and Al were the dominant trace elements in smoke particles.•PM10 composition can vary greatly with operating conditions.
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