Metals In Particulate Matter Research Articles

Insights into reactive oxygen species formation induced by water-soluble organic compounds and transition metals using spectroscopic method

Ambient particulate matter (PM) can cause adverse health effects via their ability to produce Reactive Oxygen Species (ROS). Water-Soluble Organic Compounds (WSOCs), a complex mixture of organic compounds which usually coexist with Transition Metals (TMs) in PM, have been found to contribute to ROS formation. However, the interaction between WSOCs and TMs and its effect on ROS generation are still unknown. In this study, we examined the ROS concentrations of V, Zn, Suwannee River Fulvic Acid (SRFA), Suwannee River Humic Acid (SRHA) and the mixtures of V/Zn and SRFA/SRHA by using a cell-free 2′,7′-Dichlorodihydrofluorescein (DCFH) assay. The results showed that V or Zn synergistically promoted ROS generated by SRFA, but had an antagonistic effect on ROS generated by SRHA. Fluorescence quenching experiments indicated that V and Zn were more prone to form stable complexes with aromatic humic acid-like component (C1) and fulvic acid-like component (C3) in SRFA and SRHA. Results suggested that the underlying mechanism involving the fulvic acid-like component in SRFA more tending to complex with TMs to facilitate ROS generation through π electron transfer. Our work showed that the complexing ability and complexing stability of atmospheric PM organics with metals could significantly affect ROS generation. It is recommended that the research deploying multiple analytical methods to quantify the impact of PM components on public health and environment is needed in the future.

The distribution and structural fingerprints of metals from particulate matters (PM) deposited in human lungs

This work investigated the distribution and chemical fingerprints of 24 metals in particulate matter (PM) deposited in nonoccupational human lungs. Metals in the pulmonary PM can be grouped by the mean concentration as > 5 × 103 μg/g (Al/Fe/Ca/Mg/Zn), 1–5 × 103 μg/g (Ti/Ba/Pb/Mn), 0.2–1 × 103 μg/g (Cu/Cr/As/V) and < 100 μg/g (Ni/Sn/Cd/Sb). Three parameters (LFL, LR, EFP) were defined to predict different metal leaching behaviors. The leaching factor (LFL) of metals was 10–60 for Pb/Sb/Cd/Co/Cu and decreased to 1–2 for Ni/Cr/Mg/Al/Fe. Metals showed a divergent extent of lung retention (LR), including high retention (LR>10, Al/Cd/Cr/Ba/Ni/Ti/Sn/V/Sb), moderate retention (2 <LR<10, Pb/Mn/Fe), minor retention (1 <LR <2, Cu/Co), and negligible retention (LR<1, Ca/Mg/Zn). V and Ti were found to be mainly from indoor PM sources and deserve a close attention in healthy individuals. C-, Al- and Ti-rich fine particles were the most common pulmonary particles imaged by spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM). These data establish a foundation for classification and further risk assessment of the metal species in pulmonary PM.

Automated SEM-EDS Analysis of Transition Metals and Other Metallic Compounds Emitted from Incinerating Agricultural Waste Plastic Film

Illegal open burning, which is criticized as a leading source of air pollutants among agricultural activities, currently requires constant effort and attention from countries around the world. A speciation analysis method is required to examine the harmful effects of particulate matter generated by incineration on the human body. In this study, to simulate open-air incineration, infrastructure for incineration tests complying with US EPA method 5G was built, and a large-area analysis was conducted on the particulate matter through automated SEM-EDS. For test specimens, waste mulching LDPE collected by Korea Environment Corporation Dangjin Office was used. To raise the identifiability of analyzed particles, the specimen was sampled on a plate made of Ag, which has a high atomic number, three times. Metal particulate matter showed a high reaction to C and C-O. The ratio of metal particulate matters that reacted to C and C-O was in the order of Cu (94.1%) &gt; Fe (83.3%) &gt; Al (79.7%). In this study, it was verified that waste mulching adsorbs metal chemicals originating from the soil due to its properties and deterioration, and that when it is incinerated, it emits particulate matter containing transition metals and other metals that contribute to excessive ROS production and reduction.

Precipitation of aqueous transition metals in particulate matter during the dithiothreitol (DTT) oxidative potential assay.

Transition metals in particulate matter (PM) are hypothesized to have enhanced toxicity based on their oxidative potential (OP). The acellular dithiothreitol (DTT) assay is widely used to measure the OP of PM and its chemical components. In our prior study, we showed that the DTT assay (pH 7.4, 0.1 M phosphate buffer, 37 °C) provides favorable thermodynamic conditions for precipitation of multiple metals present in PM. This study utilizes multiple techniques to characterize the precipitation of aqueous metals present at low concentrations in the DTT assay. Metal precipitation was identified using laser particle light scattering analysis, direct chemical measurement of aqueous metal removal, and microscopic imaging. Experiments were run with aqueous metals from individual metal salts and a well-characterized urban PM standard (NIST SRM-1648a, Urban Particulate Matter). Our results demonstrated rapid precipitation of metals in the DTT assay. Metal precipitation was independent of DTT but dependent on metal concentration. Metal removal in the chemically complex urban PM samples exceeded the thermodynamic predictions and removal seen in single metal salt experiments, suggesting co-precipitation and/or adsorption may have occurred. These results have broad implications for other acellular assays that study PM metals using phosphate buffer, and subsequently, the PM toxicity inferred from these assays.

Pollution Characteristics and Health Risk Assessment of Heavy Metals in PM&amp;lt;sub&amp;gt;2.5&amp;lt;/sub&amp;gt; during Winter in the Suburb of Cangzhou, China

The heavy metals in atmospheric fine particles are of great concern to human health. To understand the pollution characteristics and health risks of heavy metals in particulate matter with an aerodynamic equivalent diameter ≤2.5 μm (PM2.5) during winter in the suburb of Cangzhou, PM2.5 samples were collected with an intelligent medium-flow atmospheric particulate matter sampler from January to February 2019. The Fe, Cu, Mn, Pb and Zn contents in PM2.5 were determined via inductively coupled plasma optical emission spectrometry (ICP-OES). The sources and health risks of heavy metals in PM2.5 were analysed via the enrichment factor (EF) method and the United States Environmental Protection Agency (US EPA) health risk assessment model. The results showed that the average PM2.5 concentration in the suburb of Cangzhou reached 71.6 μg/m3, ranging from 23.7 to 169.5 μg/m3. The exceeding standard rate was 29.4% during the sampling period. The PM2.5 concentration during the nighttime was higher than that during the daytime. The heavy metal concentrations in PM2.5 decreased in the order of Fe > Mn > Zn > Cu > Pb, and the Fe, Mn, Pb and Zn concentrations decreased in the order of clean days the daytime. EF analysis revealed that Zn, Pb and Cu were significantly enriched, and Pb was highly enriched on heavy pollution days with increasing pollution degree. The enrichment level of heavy metals during the nighttime was higher than that during the daytime. Health risk assessment demonstrated that Mn posed non-carcinogenic risks to both adults and children, following the sequence of clean days . The study revealed that the pollution levels of heavy metals in PM2.5 in the suburb of Cangzhou were low, and Pb and Mn in PM2.5 posed certain health risks to the population.

The Study of Airborne Particulate Matter in Dalnegorsk Town

Mines, quarries, dumps, and tailings are the sources of air pollution. In the Dalnegorsk District (Primorsky Krai, Russia), there are 20 polymetallic deposits. This study aimed to evaluate the particle size and material composition of ambient particulate matter (PM) in Dalnegorsk town and verify the influence of mining and chemical industry facilities on the composition of PM. Ambient particulates were analyzed in samples of snow cover and washout from vegetation (conifer tree needles). According to particle size distribution data, the relative content of particles with a diameter up to 10 microns (PM10) reaches 40% in three snow samples taken in the central part of the town. Among ore minerals, pyrite and arsenopyrite predominated in the samples. In addition, sphalerite, galena, cassiterite, and iron–chromium–nickel formations of various shapes were found in the studied particles. The presence of these metals in airborne PM can negatively affect the incidence rate of PM-associated diseases and the determination of their levels are very useful for air pollution prevention strategies.

Genotoxic Activity of Particulate Matter and In Vivo Tests in Children Exposed to Air Pollution.

The aim of this paper was to investigate the relationship between micronuclei and DNA damage in children’s buccal mucosa cells and the genotoxicity and mutagenicity of the different sized fractions of particulate matter as well as the concentration of PAHs (polycyclic aromatic hydrocarbons) and metals in particulate matter. Air particulate matter was collected by high volume samplers located near the schools attended by the children on the same days of biological samplings. The mutagenic activity was assessed in different cells in in vitro tests (Ames test on bacteria and comet test on leukocytes). Our study showed weak positive correlations between (a) the mutagenicity of the PM0.5 fraction and PAHs and (b) the micronuclei test of children’s buccal cells and PAHs detected in PM0.5 and PM0.5–3 fractions. A positive correlation was also found between in vitro comet test on leukocytes and PAHs in the PM3–10 fraction. No correlation was observed for metal concentrations in each PM fraction.

Elemental Characteristics of Respirable Particulate Matter in the Urban Atmosphere of Dehradun, Uttrakhand, India

To evaluate the ambient air quality of the Dehradun city, respirable particulate matter was collected using respirable dust sampler (RDS) and analysed for the heavy metal content using atomic absorption spectroscopy (AAS). The morphology of particulates were determined using scanning electron microscope (SEM) and the elemental composition was determined through SEM- energy dispersive spectroscopy (EDS). Particulate matter mass concentration ranged from 65.00 µg m-3 to 337.33 µg m-3. Quantified heavy metals in particulate matter were Copper (Cu), Zinc (Zn), Cobalt (Co), Manganese (Mn), Iron (Fe), Nickel (Ni), Chromium (Cr), Lead (Pb) and Cadmium (Cd). The order of concentration of heavy metals were found to be in the trend of Fe&gt;Zn&gt;Cu&gt;Pb&gt;Cr&gt;Ni&gt;Mn&gt;Co&gt;Cd. Maximum concentration of PM10 was found at commercial site during summer, winter and monsoon season. Enrichment factor analysis showed substantial contribution of anthropogenic activities on PM10. Source apportionment (varimax rotated factor analysis method) showed dominance of incineration and uncontrolled burning of waste and refuses, resuspended dust with vehicular emission and crustal sources as the dominant sources in Dehradun. Plantation drive strategy have major role in ambient particulate matter mitigation measures and carbon sequestration from climate change and global problem worldwide. This study will be help to mitigate or decrease the load of air pollution by the using of various trees for sustainable human development on the marvellous earth planet.

Assessment of Pollution and Health Risks of Heavy Metals in Particulate Matter and Road Dust Along the Road Network of Dhanbad, India.

Background.The rise in particulate matter (PM) concentrations is a serious problem for the environment. Heavy metals associated with PM10, PM2.5, and road dust adversely affect human health. Different methods have been used to assess heavy metal contamination in PM10, PM2.5, and road dust and source apportionment of these heavy metals. These assessment tools utilize pollution indices and health risk assessment models.Objectives.The present study evaluates the total mass and average concentrations of heavy metals in PM10, PM2.5, and road dust along selected road networks in Dhanbad, India, analyzes the source apportionment of heavy metals, and assesses associated human health risks.Methods.A total of 112 PM samples and 21 road dust samples were collected from six stations and one background site in Dhanbad, India from December 2015 to February 2016, and were analyzed for heavy metals (iron (Fe), lead (Pb), cadmium (Cd), nickel (Ni), copper (Cu), chromium (Cr), and zinc (Zn)) using atomic absorption spectrophotometry. Source apportionment was determined using principal component analysis. A health risk assessment of heavy metal concentrations in PM10, PM2.5, and road dust was also performed.Results.The average mass concentration was found to be 229.54±118.40 μg m−3 for PM10 and 129.73 ±61.74 μg m−3 for PM2.5. The average concentration of heavy metals was found to be higher in PM2.5 than PM10. The pollution load index value of PM10 and PM2.5 road dust was found to be in the deteriorating category. Vehicles were the major source of pollution. The non-carcinogenic effects on children and adults were found to be within acceptable limits. The heavy metals present in PM and road dust posed a health risk in the order of road dust> PM10> and PM2.5. Particulate matter posed higher health risks than road dust due to particle size.Conclusions.The mass concentration analysis indicates serious PM10 and PM2.5 contamination in the study area. Vehicle traffic was the major source of heavy metals in PM10, PM2.5, and road dust. In terms of non-carcinogenic risks posed by heavy metals in the present study, children were more affected than adults. The carcinogenic risk posed by the heavy metals was negligible.Competing Interests.The authors declare no competing financial interests

In silico study of possible roles of relative humidity in chemical speciation on ambient particulate matter using PHREEQC

One of the components of ambient particulate matter (PM) that contributes to its possible toxicity are metals. Moreover, other factors in the environment, such as the presence of water as indoor humidity, can also affect the behavior of PM either physically or chemically. Chemically, the presence of water may affect the forms or species in which the metal is present. The present study aims to utilize PHREEQC, a geochemical modeling software, in the evaluation of species formation of metals in particulate matter. From all these runs, it was found that the possible roles of water in metal speciation in particulate matter are as follows: (1) in the presence of water as relative humidity (RH), metals in PM may be hydroxylated, which may facilitate further uptake of water and affect the reactivity of the PM, (2) in addition to the RH, the volume of the room may affect the species concentrations present, and (3) inferences may be made regarding the possible initial form of the metals, which may be oxides, as shown by the formation of hydroxylated metals upon exposure of metals to water vapor. These observations give a brief insight into how water may possibly interact and affect the possible toxicity of metal species in PM.

PERBANDINGAN EFEKTIVITAS JERAPAN Pb DALAM PARTIKULAT OLEH POHON TANJUNG (Mimusops elengi) DAN POHON BUNGUR (Lagerstroemia) (STUDI KASUS DI JALAN TIMOHO YOGYAKARTA)

The ability of plants to absorb metallic pollutants varies. The research has been conducted to compare the effectiveness of Tanjung (Mimusops elengi) and Bungur (Lagerstroemia) plants in absorbing Pb metal in particulate matter. The effect of location and leaf height on the effectiveness of pollutant uptake was also observed. Sampling was carried out in July 2020-September 2020 by taking leaves that were not too dark or light in color. Leaves taken at heights 3, 6, and 9 m on Timoho side Street. The particulate and leaf samples were digested and then analyzed their Pb levels using an Atomic Absorption Spectrophotometer (AAS). The results showed that the Tanjung plants with denser leaves captured more particulate deposits than the Bungur plants. This plant is also more effective at absorbing and accumulating Pb metal, which is indicated by the ratio of Pb metal in the leaves to Pb in particulates which is higher than the Bungur plant. These results were consistent for each sampling period, at each location and each crown height.

Chemical Characterization of Water-soluble Ions and Metals in Particulate Matter Generated by a Portable Two-stroke Gasoline Engine

ABSTRACT To examine the characteristics of water-soluble ions and metals on the particulate matter (PM) in the exhausts, a P2SGE (portable two-stroke gasoline engine) was fueled by unleaded gasoline #92 blended with different two-stroke engine oil brands (CPC Super Low Smoke Two-Stork Engine Oil (SLS), CPC Low Smoke Two-Stroke Engine Oil (LS), and MERCURY STAR (MS)) and operated under idling, mid-load (1.5 kW), and high-load (1.9 kW), respectively. Experimental results reveal that the PM mass concentrations in the exhausts were in the order MS (avg. 1,934 mg Nm–3) > SLS (avg. 1,543 mg Nm–3) > LS (avg. 1,167 mg Nm–3) in all test conditions. The mass concentrations and emission factors (EFs) of PM decreased as the P2SGE load increased by adding each tested lubricant. Based on fuel consumption, EFs of ΣIons were the lowest when utilizing the LS additive (avg. 89.7 mg L-fuel–1), followed by the MS and SLS (165 and 168 mg L-fuel–1, in average, respectively); whereas the lowest levels of ΣMetals were observed by using MS additive (avg. 61.3 mg L–1), followed by using the LS (avg. 83.8 mg L–1) and SLS (avg. 85.2 mg L–1). The soluble ions on the PM were mostly Na+, Ca2+, NO3–, and SO42– among eight tested species, which accounted for only 0.05–0.19% (avg. 0.1%) of PM mass. The 21 analyzed metal components represented only 0.05% of the mass of the PM, and were dominated by Na, Mg, Al, K, Ca, Fe, and Zn, which represented 98.7% by mass of ΣMetals. Our finding for portable engine emission has been rarely considered in the literature but it is unneglectable for labors who are usually exposed to the ions and metals. Further health risk assessment research is suggested to include temporarily real-life exposures with high pollutant levels.

Ambient particulate matter compositions and increased oxidative stress: Exposure-response analysis among high-level exposed population

BackgroundOxidative stress has been suggested to be one of the key drivers of health impact of particulate matter (PM). More studies on the oxidative potential of PM alone, but fewer studies have comprehensively evaluated the effects of external and internal exposure to PM compositions on oxidative stress in population. ObjectiveTo comprehensively investigate the exposure–response relationship between PM and its main compositions with oxidative stress indicators. MethodsWe conducted a cross-sectional study including 768 participants exposed to particulates. Environmental levels of fine particulate matter (PM2.5), polycyclic aromatic hydrocarbons (PAHs) and metals in PM were measured, and urinary levels of PAHs metabolites and metals were measured as internal dose, respectively. Multivariable linear regression models were used to analyze the correlations of PM exposure and urinary levels of 8-hydroxy-2́′-deoxyguanosine (8-OHdG), and 8-iso-prostaglandin-F2α (8-iso-PGF2α) and malondialdehyde (MDA). ResultsThe concentration of both PM2.5 and total PAHs was significantly correlated with increased urinary 8-OHdG, 8-iso-PGF2α and MDA levels (all p < 0.05). The levels of 4 essential metals all showed significant exposure–response increase in urinary 8-OHdG in both current and non-current smokers (all p < 0.05); ambient selenium, cobalt and zinc were found to be significantly correlated with urinary 8-iso-PGF2α (p = 0.002, 0.003, 0.01, respectively); only selenium and cobalt were significantly correlated with urinary MDA (p < 0.001, 0.01, respectively). Furthermore, we found each one-unit increase in urinary total OH-PAHs generated a 0.32 increase in urinary 8-OHdG, a 0.22 increase in urinary 8-iso-PGF2α and a 0.19 increase in urinary MDA (all p < 0.001). Furthermore, it was found that the level of 12 urinary metals all showed significant and positive correlations with three oxidative stress biomarkers in all subjects (all p < 0.001). ConclusionsOur systematic molecular epidemiological study showed that particulate matter components could induce increased oxidative stress on DNA and lipid. It may be more important to monitor and control the harmful compositions in PM rather than overall particulate mass.

HVAC filtration of particles and trace metals: Airborne measurements and the evaluation of quantitative filter forensics.

Filters installed in the heating, ventilation, and air-conditioning (HVAC) systems can serve as air-cleaning and sampling devices for indoor particles. The purpose of this article is to evaluate these dual roles. An occupied home with a central HVAC system equipped with a Minimum Efficiency Reporting Value (MERV, from ASHRAE Standard 52.2) 11 filter was monitored for six weeks. Weekly airborne gravimetric and real-time sampling was performed to measure the particle size distribution and the concentration of total suspended particles (TSP), PM10, PM2.5, PM1, and 12 trace metals. The weekly system runtimes were intentionally changed to provide a wide range of weekly filtration volumes. The quantitative filter forensics (QFF) concentrations of particulate matter (PM) and trace metals were calculated using the analysis of the dust collected on the HVAC filter, the filtration volume, and filter in-situ efficiency. The results indicated that filtration was not influential to remove PM and trace metals as the concentrations during the weeks with continuous HVAC operation were not consistently lower than those during the other weeks. This suggests the dominance of other particle and trace metal source and loss mechanisms weakens the influence of filtration in this home. The QFF evaluation results indicated that the concentration of TSP and over half of the tested trace metals (e.g., Pb, Cd, Ni, V, Sb, K, and Sr) could be estimated by QFF within a factor of two when compared to airborne sampling results. PM10, PM2.5, and PM1 concentrations were significantly underestimated by QFF potentially due to the limitations of size distribution analysis by a laser diffraction particle sizer (LDPS) for the detection of <1μm particles. Overall, while QFF was promising for TSP and some trace metals, improvement in size distribution analysis could extend the application of QFF for airborne sampling.

The effect of air pollution on immunological, antioxidative and hematological parameters, and body condition of Eurasian tree sparrows

Air pollution constitutes potential threats to wildlife and human health; therefore, it must be monitored accurately. However, little attention has been given to understanding the toxicological effects induced by air pollution and the suitability of bird species as bioindicators. The Eurasian tree sparrow (Passer montanus), a human commensal species, was used as a study model to examine toxic metal accumulation, retention of particulate matter (PM), immunological and antioxidant capacities, and hematological parameters in birds inhabiting those areas with relatively higher (Shijiazhuang city) or lower (Chengde city) levels of PM2.5 and PM10 in China. Our results showed that Shijiazhuang birds had significantly more particle retention in the lungs and toxic metal (including aluminum, arsenic, cadmium, iron, manganese, and lead) accumulation in the feathers relative to Chengde birds. They also had lower superoxide dismutase, albumin, immunoglobulin M concentrations in the lung lavage fluid, and total antioxidant capacity (T-AOC) in the lungs and hearts. Furthermore, although they had higher proportions of microcytes, hypochromia, and polychromatic erythrocytes in the peripheral blood (a symptom of anemia), both populations exhibited comparable body conditions, white cell counts, heterophil and lymphocyte ratios, and plasma T-AOC and corticosterone levels. Therefore, our results not only confirmed that Shijiazhuang birds experienced a greater burden from environmental PM and toxic metals but also identified a suite of adverse effects of environmental pollution on immunological, antioxidative, and hematological parameters in multiple tissues. These findings contribute to our understanding of the physiological health consequences induced by PM exposure in wild animals. They suggest that free-living birds inhabiting urban areas could be used as bioindicators for evaluating the adverse effects induced by environmental pollution.

Indoor air quality in rural Southwestern Uganda: particulate matter, heavy metals and carbon monoxide in kitchens using charcoal fuel in Mbarara Municipality

The use of biomass energy over open fires in sub-Saharan Africa is rampant yet it is associated with air pollution. Information on the contribution of common biomass like charcoal to indoor air pollution in Uganda is scarce; therefore, kitchen-indoor air in charcoal fueled kitchens was characterized for fine particulate matter (PM2.5), heavy metals and carbon monoxide content in Mbarara Municipality Western Uganda. PM2.5 was measured using University of California Berkeley Particle and Temperature Sensor (UCB-PATS), heavy metals were determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and carbon monoxide was measured using a portable, battery-operated, data-logging Drager Pac 7000. In the kitchens assessed, the mean 24-h concentration for PM2.5 was 0.449 mg/m3 in the wet season and 0.526 mg/m3 in the dry season; CO was 41.52 ppm, and all concentrations were higher than the World Health Organization 24-h Air Quality Guideline for PM2.5 of 0.024 mg/m3 and CO of 6.340 ppm. Heavy metals in particulate matter were in concentration ranges of 1.012–9.820 μg/m3 Fe, 0.012–0.092 μg/m3 Cr, 0.060–10.750 μg/m3 Zn, 0.048–0.300 μg/m3 Cu, 0.004–0.052 μg/m3 Pb and ND—0.004 μg/m3 Cd. All mean metal concentrations were lower than recommended exposure levels by EPA although chronic exposure is a risk to health. Kitchen ventilation and size were found to significantly influence indoor pollutant levels; charcoal fuel significantly contributed to indoor air pollution and is therefore a risk factor to human health.

Application of TXRF in monitoring trace metals in particulate matter and cloud water

Abstract. Trace metals in ambient particulate matter and cloud are considered key elements of atmospheric processes as they affect air quality, environmental ecosystems, and cloud formation. However, they are often available at trace concentrations in these media such that their analysis requires high-precision and sensitive techniques. In this study, different analytical methods were applied to quantify trace metals in particulate matter (PM) samples collected on quartz and polycarbonate filters as well as cloud water, using the Total reflection X-Ray Fluorescence (TXRF) technique. These methods considered the measurement of filter samples directly without and with chemical pretreatment. Direct measurements involved the analysis of PM samples collected on polycarbonate filters and cloud water samples after they are brought onto TXRF carrier substrates. The chemical treatment method involved the assessment of different acid digestion procedures on PM sampled on quartz filters. The solutions applied were reverse aqua regia, nitric acid, and a combination of nitric acid and hydrogen peroxide. The effect of cold-plasma treatment of samples on polycarbonate filters before TXRF measurements was also investigated. Digestion with the reverse aqua regia solution provided lower blanks and higher recovery in comparison to other tested procedures. The detection limits of the elements ranged from 0.3 to 44 ng cm−2. Ca, K, Zn, and Fe showed the highest detection limits of 44, 35, 6, and 1 ng cm−2, while As and Se had the lowest of 0.3 and 0.8 ng cm−2, respectively. The method showed higher recovery for most trace metals when applied to commercially available reference materials and field samples. TXRF measurements showed good agreement with results obtained from ion chromatography measurements for elements such as Ca and K. Cold-plasma treatment did not significantly lead to an increase in the detected concentration, and the results were element specific. Baking of the quartz filters prior to sampling showed a reduction of more than 20 % of the filter blanks for elements such as V, Sr, Mn, Zn, and Sb. The methods were applied successfully on ambient particulate matter and cloud water samples collected from the Atlas Mohammed V station in Morocco and the Cape Verde Atmospheric Observatory. The obtained concentrations were within the range reported using different techniques from similar remote and background regions elsewhere, especially for elements of anthropogenic origins such as V, Pb, and Zn with concentrations of up to 10, 19, and 28 ng m−3, respectively. Enrichment factor analysis indicated that crustal matter dominated the abundance of most of the elements, while anthropogenic activities also contributed to the abundance of elements such as Sb, Se, and Pb. The results confirm that TXRF is a useful complementary sensitive technique for trace metal analysis of particulate matter in the microgram range as well as in cloud water droplets.

Multi-Year Concentrations, Health Risk, and Source Identification, of Air Toxics in the Venice Lagoon

This work presents and discusses the results of measurements of PM10 concentrations and of its content in metals, obtained in three different sites of the Venice lagoon area where the construction of the MOSE (Modulo Sperimentale Elettromeccanico-Electromechanical Experimental Module) mobile dams was going on. Measurements were taken between 2010 and 2015 and the spatial and seasonal variability of metals and PM10 concentration were discussed. The aim of the work is to get information on the air quality in the lagoon area related to the presence of toxic metals in particulate matter produced by construction activities. Additional measurements of PAHs concentration in gas and particle phases, and the related health risk assessment, were carried out in two out of the three sites, in order to enhance the knowledge about the air quality near the construction yards. Diagnostic ratios have been calculated for the purpose of investigating the PAH sources of the area. PM10 was collected using low volume sequential aerosol samplers, with quartz filters carefully decontaminated in an atmosphere-controlled laboratory. Inorganic elements (V, Cr, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Tl, and Pb) in PM10 samples were measured by ICP-MS. Samples for PAH analyses were collected using a high-volume air sampler that allows to sample both gaseous and particulate PAH simultaneously. Gaseous PAHs were collected on pre-cleaned polyurethane foams and particulate PAHs on pre-combusted quartz fiber filters. Samples for PAHs determinations were analyzed by GC-HRMS. Results showed limited differences in metals' and PAHs' concentrations between the sites, indicating a relatively homogeneous spatial distribution of metals in PM10 and PAHs in the Venice lagoon area. Temporal trends furthermore give indication of a slight decrease in PAHs and PM10 concentration in Punta Sabbioni and in its content of Pb, Zn, and Sb. The health risk assessment showed that congeners that most contributed to the carcinogenicity of the mixture were benzo(a)pyrene e dibenzo(A,H)anthracene, mainly in the particulate phase. The study provides an important multi-years trend of chemical characterization of the Venice lagoon aerosol and about air quality in terms of toxic chemicals concentration in the atmosphere.

Lung function of primary cooks using LPG or biomass and the effect of particulate matter on airway epithelial barrier integrity

BackgroundCooks exposed to biomass fuel experience increased risk of respiratory disease and mortality. We sought to characterize lung function and environmental exposures of primary cooking women using two fuel-types in southeastern India, as well as to investigate the effect of particulate matter (PM) from kitchens on human airway epithelial (HAE) cells in vitro. MethodsWe assessed pre- and post-bronchodilator lung function on 25 primary female cooks using wood biomass or liquified petroleum gas (LPG), and quantified exposures from 34 kitchens (PM2.5, PM < 40 μm, black carbon, endotoxin, and PM metal and bacterial content). We then challenged HAE cells with PM, assessing its cytotoxicity to small-airway cells (A549) and its effect on: transepithelial conductance and macromolecule permeability (NuLi cells), and antimicrobial activity (using airway surface liquid, ASL, from primary HAE cells). ResultsLung function was impaired in cooks using both fuel-types. 60% of participants in both fuel-types had respiratory restriction (post bronchodilator FEV1/FVC>90). The remaining 40% in the LPG group had normal spirometry (post FEV1/FVC = 80–90), while only 10% of participants in the biomass group had normal spirometry, and the remaining biomass cooks (30%) had respiratory obstruction (post FEV1/FVC<80). Significant differences were found in environmental parameters, with biomass kitchens containing greater PM2.5, black carbon, zirconium, arsenic, iron, vanadium, and endotoxin concentrations. LPG kitchens tended to have more bacteria (p = 0.14), and LPG kitchen PM had greater sulphur concentrations (p = 0.02). In vitro, PM induced cytotoxicity in HAE A549 cells in a dose-dependent manner, however the effect was minimal and there were no differences between fuel-types. PM from homes of participants with a restrictive physiology increased electrical conductance of NuLi HAE cells (p = 0.06) and decreased macromolar permeability (p ≤ 0.05), while PM from homes of those with respiratory obstruction tended to increase electrical conductance (p = 0.20) and permeability (p = 0.07). PM from homes of participants with normal spirometry did not affect conductance or permeability. PM from all homes tended to inhibit antimicrobial activity of primary HAE cell airway surface liquid (p = 0.06). ConclusionsBiomass cooks had airway obstruction, and significantly greater concentrations of kitchen environmental contaminants than LPG kitchens. PM from homes of participants with respiratory restriction and obstruction altered airway cell barrier function, elucidating mechanisms potentially responsible for respiratory phenotypes observed in biomass cooks.

Trace metal variability controlled by hydrodynamic processes in a polluted inner shelf environment (Besòs prodelta, NW Mediterranean)

Trace metal pollution of coastal sediment is monitored in many countries to control its evolution and the effectiveness of preventive and corrective measures. However, temporal variability of trace metal pollution is not always due to changes in pollution management, as natural processes can induce a significant variability in the trace metal content of sediment and particulate matter, especially in strongly polluted coastal areas. To study this variability, time series of trace metals in particulate matter and bottom sediments were recorded along with hydrographic and hydrodynamic parameters in the most highly polluted zone of the Besòs River prodelta. Two benthic tripods equipped with current meters, turbidimeters and sediment traps were deployed at 20 and 30 m water depth from late-September to mid-June and sediment cores were taken four times at each site during the deployment period. Trace metal content in the trapped particulate matter and the surface sediment increased during storm events, which can resuspend and erode several cm of subsurface sediments with higher pollution levels from earlier industrial times. After the storms, significant accumulation of less polluted sediment began, and near-bottom currents redistributed it, decreasing trace metal contents in surface sediments and trapped particulate matter. Therefore, energy conditions previous to monitoring sampling must be considered in order to evaluate the evolution of trace metals in inner shelf polluted sediments.