Trace Elements In Particulate Matter Research Articles

Study on the distribution, enrichment and migration characteristics of trace elements in particulate matter during solid waste combustion

Trace element emissions caused by the entrainment of particulate matter (PM) has led to serious environmental pollution. This research focuses on the distribution, enrichment and migration characteristics of trace elements in different sizes of PM during the typical solid waste combustion. The results indicate that the mass concentration of trace elements in different PM is closely related to their volatility. Volatile trace elements such as Cu, In, Ag, Pb, and Cd tend to distribute in PM1. Higher temperatures facilitate the volatilization of trace elements, promoting their migration and enrichment in finer PM. The removal effect of Si–Al-based additives on trace elements in PM1 decreases with the increase of Si/Al ratio. Among them, the removal efficiency of 5% kaolin is the best. After the addition of Si–Al-additives, Zn and In mainly migrate to PM1-10, while Cu, V, Mo, As, Se, Cr, Ba, Mn, Co, Sr, and Ti mainly migrate to PM10+. Ag, Pb, and Cd migrate to both PM1-10 and PM10+ simultaneously.

Predicting intraurban airborne PM1.0-trace elements in a port city: Land use regression by ordinary least squares and a machine learning algorithm

Airborne particulate matter (PM) has been associated with cardiovascular and respiratory morbidity and mortality, and there is some evidence that spatially varying metals found in PM may contribute to adverse health effects. We developed spatially refined models for PM trace elements using ordinary least squares land use regression (OLS-LUR) and machine leaning random forest land-use regression (RF-LUR).Two-week integrated measurements of PM1.0 (median aerodiameter < 1.0 μm) were collected at 50 sampling sites during fall (2010), winter (2011), and summer (2011) in the Halifax Regional Municipality, Nova Scotia, Canada. PM1.0 filters were analyzed for metals and trace elements using inductively coupled plasma-mass spectrometry. OLS- and RF-LUR models were developed for approximately 30 PM1.0 trace elements in each season. Model predictors included industrial, commercial, and institutional/ government/ military land use, roadways, shipping, other transportation sources, and wind rose information.RF generated more accurate models than OLS for most trace elements based on 5-fold cross validation. On average, summer models had the highest cross validation R2 (OLS-LUR = 0.40, RF-LUR = 0.46), while fall had the lowest (OLS-LUR = 0.27, RF-LUR = 0.31). Many OLS-LUR models displayed overprediction in the final exposure surface. In contrast, RF-LUR models did not exhibit overpredictions. Taking overpredictions and cross validation performances into account, OLS-LUR performed better than RF-LUR in roughly 20% of the seasonal trace element models. RF-LUR models provided more interpretable predictors in most cases. Seasonal predictors varied, likely due to differences in seasonal distribution of trace elements related to source activity, and meteorology.

Exposure to indoor-outdoor particulate matter and associated trace elements within childcare facilities

Children’s exposure to trace elements through indoor and outdoor pollutants could be a risk to their health. Here, we investigated the concentrations of particulate matter (PM), and PM trace elements existed in indoor and outdoor environments of childcare facilities. The coefficient of determination (R2) was calculated to evaluate the relation between PM10 and PM2.5 concentrations in indoor and outdoor environments, and I/O ratios for PM were investigated in hallway and indoors during summer and winter seasons. We performed the factor analysis to identify the sources of trace elements in indoor PM2.5. For all childcare facilities, PM2.5 concentrations correlated well with PM10 concentrations in both indoor and outdoor environments, and their slopes are similar. In indoor-outdoor PM concentrations, the higher I/O ratios were presented in winter season, and there were significant differences between hallway and indoors in PM concentrations: childcare C (residential) for PM10 and childcare A (residential) and B (near roadway) for PM10. The factor analysis (FA) results indicated that indoor PM2.5 concentrations were contributed by outdoor pollutant sources, and the variance (%) of trace elements existed in PM2.5 determined by factors 1, 2, and 3 showed over 85%. Thus, these sources are the most significant outdoor pollutants and are sourced from re-suspended soil dust and motor vehicle emissions. More importantly, trace elements (Zn and Ni) included in PM2.5 could not be removed by an air purifier and could lead to potential pollutants in indoors of a childcare facility.

High-resolution sampling and analysis of ambient particulate matter in the Pearl River Delta region of southern China: source apportionment and health risk implications

Abstract. Hazardous air pollutants, such as trace elements in particulate matter (PM), are known or highly suspected to cause detrimental effects on human health. To understand the sources and associated risks of PM to human health, hourly time-integrated major trace elements in size-segregated coarse (PM2.5–10) and fine (PM2.5) particulate matter were collected at the industrial city of Foshan in the Pearl River Delta region, China. Receptor modeling of the data set by positive matrix factorization (PMF) was used to identify six sources contributing to PM2.5 and PM10 concentrations at the site. Dominant sources included industrial coal combustion, secondary inorganic aerosol, motor vehicles and construction dust along with two intermittent sources (biomass combustion and marine aerosol). The biomass combustion source was found to be a significant contributor to peak PM2.5 episodes along with motor vehicles and industrial coal combustion. Conditional probability function (CPF) analysis was applied to estimate the source locations using the PMF-resolved source contribution coupled with the surface wind direction data. Health exposure risk of hazardous trace elements (Pb, As, Si, Cr, Mn and Ni) and source-specific values were estimated. The total hazard quotient (HQ) of PM2.5 was 2.09, higher than the acceptable limit (HQ = 1). The total carcinogenic risk (CR) was 3.37 × 10−3 for PM2.5, which was 3 times higher than the least stringent limit (1.0 × 10−4). Among the selected trace elements, As and Pb posed the highest non-carcinogenic and carcinogenic risks to human health, respectively. In addition, our results show that the industrial coal combustion source is the dominant non-carcinogenic and carcinogenic risk contributor, highlighting the need for stringent control of this source. This study provides new insight for policy makers to prioritize sources in air quality management and health risk reduction.

Assessment of trace elements characteristics and human health risk of exposure to ambient PM2.5 in Hangzhou, China

ABSTRACTA method for simultaneously determining the trace elements in particulate matter (PM) (PM2.5) by inductively coupled plasma mass spectrometry was established. The PM2.5-loaded filter samples were digested under the optimised conditions including a mixture of HNO3–HCl–HF with ultrasonication proceeding at 70°C for 2 h. Recoveries of 90.83–103.33% were achieved for 20 elements (Co, Sr, Ag, Cd, Sb, La, Ce, Sm, W etc.) in NIST standard reference material 1648a (urban PM). PM2.5 samples were collected at urban site in Hangzhou from August 2015 to November 2015. PM2.5 concentrations of 15% sampling days exceeded the daily limitation and the mean concentrations of PM2.5 from August to November reached the 66.4% of the limitation. PM2.5 concentrations in summer were higher than that in autumn. The concentration of Zn was highest, following with Al, Pb, Mn, Cu and As. Significant enrichment was observed in Mn, Zn, Pb, Ag, V, Ni, Cu, As, Se, Hg, Co, Cd and W, which was probably induced by vehicular exhaust, oil and residual fuel combustion and industrial emissions. The daily mass concentrations of PM2.5 and elements fluctuated significantly. Rainfall could significantly reduce the concentration of Ti, Mn, Cu, Zn, As, Se, Hg, Sr, Ag, Cd, Sb, La, Ce, Sm and Pb, and the risk levels of carcinogenic elements and non-carcinogenic elements in rain day were significantly lower (43.7–81.4%) than those in non-rain day. The risk levels of Co, Cd and As could lead to adverse health outcomes through the respiratory system, which should deserve more attention, while the risk levels of Ni and non-carcinogenic elements (Hg, Mn, Cu, Zn, Pb, V) were under average risk acceptance.

Nanominerals, fullerene aggregates, and hazardous elements in coal and coal combustion-generated aerosols: An environmental and toxicological assessment

Studies on coal-derived nanoparticles as well as nano-minerals are important in the context of the human health and the environment. The coal combustion-generated aerosols also affect human health and environmental quality aspects in any coal-fired station. In this study, the feed coals and their combustion-generated aerosols from coal-fired boilers of two tea industry facilities were investigated for the presence of nanoparticles/nano minerals, fullerene aggregates, and potentially hazardous elements (PHEs). The samples were characterized by using X-ray diffraction (XRD), Time-of-flight secondary ion mass spectroscopy (TOF-SIMS), High resolution-transmission electron microscopy/energy dispersive spectroscopy (HR-TEM/EDS) and Ultra Violet-visible spectroscopy (UV–Vis) to know their extent of environmental risks to the human health when present in coals and aerosols. The feed coals contain mainly clay minerals, whilst glass fragments, spinel, quartz, and other minerals occur in lesser quantities. The PM samples contain potentially hazardous elements (PHEs) like As, Pb, Cd and Hg. Enrichment factor of the trace elements in particulate matters (PMs) was calculated to determine their sources. The aerosol samples were also found to contain nanomaterials and ultrafine particles. The fullerene aggregates along with potentially hazardous elements were also detected in the aerosol samples. The cytotoxicity studies on the coal combustion-generated PM samples show their potential risk to the human health. This detailed investigation on the inter-relationship between the feed coals and their aerosol chemistry will be useful for understanding the extent of environmental hazards and related human health risk.

Trace elements in particulate matter from metropolitan regions of Northern China: Sources, concentrations and size distributions

Public concerns over airborne trace elements (TEs) in metropolitan areas are increasing, but long-term and multi-site observations of size-resolved aerosol TEs in China are still lacking. Here, we identify highly elevated levels of atmospheric TEs in megacities and industrial sites in a Beijing–Tianjin–Hebei urban agglomeration relative to background areas, with the annual mean values of As, Pb, Ni, Cd and Mn exceeding the acceptable limits of the World Health Organization. Despite the spatial variability in concentrations, the size distribution pattern of each trace element was quite similar across the region. Crustal elements of Al and Fe were mainly found in coarse particles (2.1–9μm), whereas the main fraction of toxic metals, such as Cu, Zn, As, Se, Cd and Pb, was found in submicron particles (<1.1μm). These toxic metals were enriched by over 100-fold relative to the Earth's crust. The size distributions of Na, Mg, K, Ca, V, Cr, Mn, Ni, Mo and Ba were bimodal, with two peaks at 0.43–0.65μm and 4.7–5.8μm. The combination of the size distribution information, principal component analysis and air mass back trajectory model offered a robust technique for distinguishing the main sources for airborne TEs, e.g., soil dust, fossil fuel combustion and industrial emissions, at different sites. In addition, higher elemental concentrations coincided with westerly flow, indicating that polluted soil and fugitive dust were major sources of TEs on the regional scale. However, the contribution of coal burning, iron industry/oil combustion and non–ferrous smelters to atmospheric metal pollution in Northern China should be given more attention. Considering that the concentrations of heavy metals associated with fine particles in the target region were significantly higher than those in other Asian sites, the implementations of strict environmental standards in China are required to reduce the amounts of these hazardous pollutants released into the atmosphere.

Trace elements in particulate matter of ambient air at petroleum filling stations

Size segregated suspended particulate matter (PM2.5 and PM10-2.5) in air at four major petroleum-filling stations in Ile-Ife, Nigeria, were monitored using double staged “Gent” stacked samplers to assess variations in mass loads and elemental concentrations of 25 elements. Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Zr, Cs, Ta, W, and Pb were determined in both fractions by external ion beam proton-induced X-ray emission technique. Enrichment factors and pollution indices were calculated and results revealed that most elements were anthropogenic in both fractions with concentrations exceeding the World Health Organization guideline standards.

Characterization and Cytotoxicity of PM

Background: The potential impact of municipal solid waste incineration (MSWI), which is an anthropogenic source of aerosol emissions, is of great public health concern. This study investigated the characterization and cytotoxic effects of ambient ultrafine particles (PM<0.2), fine particles (PM0.2–2.5) and coarse particles (PM2.5–10) collected around a municipal solid waste incineration (MSWI) plant in the Pudong district of Shanghai. Methods: Mass concentrations of trace elements in particulate matter (PM) samples were determined using ICP-MS (Inductively Coupled Plasma Mass Spectrometry). The cytotoxicity of sampled atmospheric PM was evaluated by cell viability and reactive oxygen species (ROS) levels in A549 cells. Result: The mass percentage of PM0.2–2.5 accounted for 72.91% of the total mass of PM. Crustal metals (Mg, Al, and Ti) were abundant in the coarse particles, while the anthropogenic elements (V, Ni, Cu, Zn, Cd, and Pb) were dominant in the fine particles. The enrichment factors of Zn, Cd and Pb in the fine and ultrafine particles were extremely high (>100). The cytotoxicity of the size-resolved particles was in the order of coarse particles < fine particles < ultrafine particles. Conclusions: Fine particles dominated the MSWI ambient particles. Emissions from the MSWI could bring contamination of anthropogenic elements (Zn, Cd and Pb) into ambient environment. The PM around the MSWI plant displayed an additive toxic effect, and the ultrafine and fine particles possessed higher biological toxicity than the coarse particles.

Trace elements pollution and toxicity of airborne PM10 in a coal industrial city

Trace elements in particulate matter associated with coal industries hold high risk to human health. Understanding the contents and occurrences of modes of these elements as well as their contribution to particulate toxicity is significant both environmentally and pathologically. A total of 24 PM10 samples were collected in Pingdingshan City, a coal industrial city in North China, in both winter and summer of 2008. An inductively coupled plasma mass spectrometry (ICP–MS) was used to determine the concentrations of 12 trace elements associated with coal industries (Cr, Ni, Cu, Zn, As, Mo, Cd, Sn, Sb, Tl, Pb, and Bi) in PM10 samples. The results indicated that the trace element concentrations were higher in winter than in summer; due mainly to more coal combustion during winter and to the different meteorological conditions of these two seasons. The soluble proportions of these trace elements compared with total values of intact whole samples were higher in winter than in summer, and this difference was attributed mainly to more SO2 reacting with pre–existing particles to form soluble particles in winter. Of all the analyzed elements, Ni, Tl, Sb, Mo, and Cd occurred mainly in the soluble state (>50% in the soluble fraction), Cr, Cu, Zn, and As occurred in both the soluble and insoluble state (20% to 50% in the soluble fraction), and Sn, Pb, and Bi occurred mainly in the insoluble state (<20% in the soluble fraction). A plasmid DNA assay indicated that winter samples had higher toxicity than summer samples. The correlation of PM10 toxicity (TD50 value) with the contribution of various trace elements to DNA damage (trace element concentration) was further analyzed, and the results indicated that PM10 toxicity was caused mainly by the soluble fractions of trace elements, including those of Ni, Pb, Cu, Cd, As, Zn, Cr, and Tl, which were the major toxic trace elements in Pingdingshan PM10.

Effect of H2O and SO2 on the distribution characteristics of trace elements in particulate matter at high temperature under oxy-fuel combustion

The purpose of this work is to clarify the effects of high concentrations of H2O and SO2 on the generation of particulate matter (PM) and the distribution characteristics of trace elements in PM under oxy-fuel coal combustion. The experiments were carried out in a high temperature drop tube furnace which was set as 1500°C, and the Dekati Gravimetric Impactor (DGI) sampling system was applied to collect the PM at the outlet of the furnace (sampling temperature, 135°C). The results indicate that, compared to air combustion, oxy-fuel combustion significantly decreases the amount of PM and the total mass of trace elements in PM, but enhances the concentrations of trace elements in PM, except Mn. Under oxy-fuel combustion, similar conclusions about the formation of PM and migration of trace elements can be drawn, with the decreasing oxygen concentration. There is no significant difference in the amount of PM with the SO2 addition, but the total mass of trace elements or the concentrations of trace elements in PM decreases. Steam enhances the amount of PM and the total mass of trace elements in PM to a great extent but decreases the concentrations of trace elements in PM.

Hourly Variations and Potential Sources of Airborne Trace Elements in PM10 in Four Representative Regions of Southeastern China

Aerosol pollution episodes have frequently occurred in China in recent years, and the airborne trace elements in particulate matter have been a cause for concern worldwide because of their impacts on human health. However, there is limited information on the hourly variations of airborne trace elements. This paper describes a detailed investigation conducted in March 2013 on the hourly variations and potential sources of airborne trace elements. Trace elements in particles with aerodynamic diameters less than 10 μm (PM_(10)) were monitored on-line in four representative regions with similar latitudes in southeastern China. Our results showed that the number of species of elements in PM_(10) detected at urban sites and an industrial park was greater than that at a rural site, due to the influences of human activities. The hourly variation patterns of trace elements indicated that their concentrations were stable during the day at the rural site, whereas a visible ＂double peak＂ of Pb and Cu was observed in the tourist city and a ＂single morning peak＂ of Pb and As was seen in the industrial city. These variations indicated the abundant traffic in the tourist city, and strong industrial emissions in the industrial city. However, the single morning peak and the slight double peak patterns of the trace elements were both found at the industrial park, indicating a combined source of industry and traffic. The results from the source identification also indicated that the sources of airborne elements were mainly industrial emissions at industrial sites, whereas the elements in the tourist city might primarily result from traffic. The correlations between PM_(10) concentrations and trace element concentrations were also studied. The results revealed that PM_(10) correlated better with elements originating from natural sources (e.g., K, Ca, Fe) than with those from anthropogenic sources (e.g., Pb, Zn, Cu). Our results provide a scientific basis for pollution control strategies at these sites.

Spatial and temporal distribution of PM elemental composition in 20 European areas

Background: Particulate matter (PM) composition is of increasing importance for public health. This is the first European dataset of PM trace elements from harmonized sampling and centralized analysis. Aim: To characterize the spatiotemporal distributions of 26 elements within and between areas across Europe. Methods: Within the framework of ESCAPE (European study of cohorts for air pollution effects), 20 areas were monitored. In each area, an additional 20 sites were chosen to characterize within area spatial variability. PM2.5 &amp; PM10 teflon filters were analyzed by x-ray fluorescence with about 25 elements well detected. Results: Year-round PM2.5 elemental mass gradually increased from north to south with highs in industrial areas. In contrast, coarse PM (PMc, PM10-PM2.5) elemental mass showed a more uniform level across northern/central Europe before a jump in the south. S (primarily as sulfate) is almost entirely in the PM2.5 fraction, while crustal elements (Sr, Ca, Ti, Si, Mg, Fe, Al) are mainly in the coarse fraction. Seasonal analysis comparing within-area median concentrations showed that a minority of elements have similar (R2&gt;0.75) seasonal spatial distributions across Europe (27% for PM2.5, 38% for PMc). Most areas showed wintertime increases of K (PM2.5) from wood burning and Na &amp; Cl (PMc) from road de-icing. Some had increases of Mg &amp; As-maybe coal use. Within areas, many traffic related elements (eg Cu, Fe) had elevated concentrations at street sites compared to urban and regional background sites. For regional pollutants, eg S, the levels were similar regardless of site type. The varying proportions of median levels of PM2.5 &amp; PMc across Europe by element, site type, and season reveals overlapping elemental contributions from different sources. Conclusions: Spatiotemporal distributions differed for most elements and by size fraction. Factor analysis by area would give insight into possible sources and likely provide a more health relevant exposure.

Elemental Composition of PM2.5 Particles Sampled in Industrial and Residential Areas of Taif, Saudi Arabia

This paper describes the first part of a project conducted to evaluate the trace element composition of atmospheric aerosol particles (PM2.5) and to determine their influence on air quality in Taif city, Saudi Arabia. PM2.5 particles were collected from two different sites (industrial and residential) in Taif during the summer of 2011. The industrial site was situated in the largest industrial area of Taif, and the residential site was situated in the city’s most crowded area. PM2.5 samples were collected on polycarbonate filters using a cyclonic collector. Each sample was collected over a 24 hour period and new samples were collected weekly. Average PM2.5 concentrations of 47 ± 15 and 46 ± 31 µg/m 3 were seen in the industrial and residential areas, respectively. An Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer with a Mo secondary target was used to analyze the solid samples because of the relative simplicity of the technique for filter analysis. The use of a Mo secondary target is advantageous, because it decreases the impact of continuum radiation from the X-ray tube and increases the signal to background ratio. Quantitative X-ray Analysis Software (PyMca) was used to perform quantitative analysis of the atmospheric aerosols. The analysis resulted in detected concentrations for sixteen elements; Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Pb and Black Carbon (BC). Using Principal Component Analysis (PCA) it was possible to distinguish between natural and anthropogenic sources. The measured concentrations of the potentially hazardous trace elements Cu, Cr, Mn, Ni and Pb were below the limits defined by international guidelines and national standards for ambient air quality. However, further long-term research will be required to validate the quantification of trace elements in particulate matter in Taif.

Impact of Traffic Emissions on Local Air Quality and the Potential Toxicity of Traffic-related Particulates in Beijing, China

ObjectiveAir-borne particulates from different sources could have different physicochemical properties and inflammatory potentials. This study aims to characterize the chemical compositions and the toxicity of ambient particulate matter (PM) associated with traffic emissions. MethodsThe concentrations of trace elements, organic carbon (OC), elemental carbon (EC) and polycyclic aromatic hydrocarbons (PAHs) in PM2.5 and PM10 were measured in samples collected at sites in Beijing, China. Their toxic effects on the pulmonary system of rats were investigated. Biochemical parameters (LDH, T-AOC, TP) and inflammatory cytokine(IL-6, IL-1, TNF-a) levels were measured in the lungs of rats exposed to traffic-related PM. Oxidative damage was observed. PM samples were taken from a near road site and an off road site in summer time in 2006. ResultsThe concentrations of the USEPA priority pollutant PAHs in both PM10 and PM2.5 were higher (299.658 and 348.412) at the near road site than those (237.728 and 268.472) at the off road site. The similar trend was observed for the concentrations of trace elements in PM. Compared to coarse particles (PM10), fine particles (PM2.5) have a greater adsorption capacity to enrich toxic elements than inhalable particles. Decrease in antioxidant capacity and an increase in the amount of lipid peroxidation products in rat lung tissues was observed. ConclusionThe findings of the present study suggest that the differing inflammatory responses of PM collected from the two road sites might have been mediated by the differing physicochemical characteristics.

Using Trace Elements in Particulate Matter To Identify the Sources of Semivolatile Organic Contaminants in Air at an Alpine Site

An approach using trace elements in particulate matter (PM) to identify the geographic sources of atmospherically transported semivolatile organic contaminants (SOCs) was investigated. Daily samples of PM and SOCs were collected with high-volume air samplers from 16 January to 16 February 2009 at Temple Basin, a remote alpine site in New Zealand's Southern Alps. The most commonly detected pesticides were dieldrin, trans-chlordane, endosulfan I, and chlorpyrifos. Polycyclic aromatic hydrocarbons and polychlorinated biphenyls were also detected. For each sampling day, the relative contribution of PM from regional New Zealand versus long-range Australian sources was determined using trace element profiles and a binary mixing model. The PM approach indicated that endosulfan I, indeno[1,2,3-c,d]pyrene, and benzo[g,h,i]perylene found at Temple Basin were largely of Australian origin. Local wind observations indicated that the chlorpyrifos found at Temple Basin primarily came from the Canterbury Plains in New Zealand.

Characterization of trace elements in PM2.5 aerosols in the vicinity of highways in northeast New Jersey in the U.S. east coast

To characterize the spatial and temporal variations of atmospheric concentrations of trace elements in particulate matter with diameter less than 2.5 µm (PM2.5) derived from vehicle emissions, aerosol sampling was conducted near the heavily trafficked New Jersey Turnpike (NJTPK) at East Rutherford, New Jersey in the U.S. east coast from September 2007 to September 2008. Aerosol samples were collected by Partisol–FRM Model 2000 air samplers at three sites within 150 m away from the NJTPK and analyzed by inductively coupled plasma mass spectrometry (ICP–MS). Concentrations of 13 trace elements (i.e., aluminum, cadmium, cobalt, chromium, copper, iron, lead, manganese, nickel, antimony, scandium, vanadium and zinc) varied as a function of distance away from NJTPK within 150 m. The concentrations of Al, Cd, Cr, Cu, Fe and Pb along the three sites decreased significantly away from the highway. In contrast, the concentrations of Mn, Sb, and Sc showed significantly positive correlations with distance. There were not clear concentration trends for Co, Ni, V and Zn with distance. Most trace elements showed slightly higher concentrations in spring and summer, except for Ni that was more enriched in the fall and winter. All measured trace elements showed higher concentrations on weekdays than on weekends, indicating high impact of traffic emissions on air pollution. In both summer and winter, most trace elements were enriched in daytime aerosols, and this trend was stronger in the winter. Meteorological conditions, mainly wind speed and wind direction, were found to affect the spatial and temporal concentration variations of trace elements in the ambient air at this location.

Application of x-ray analysis to the study of air particle pollution in northern Italy

In the framework of a large research programme on air quality in northern Italy managed by the Institute of General and Applied Physics (IFGA), an extensive investigation of air particle pollution was performed. Aerosol sampling campaigns were carried out in areas of different typology in the Po Valley with the aim of determining concentration and composition trends in space and time and also the main sources of pollution. High concentrations of particulate matter were generally measured; the main components were elements of crustal origin and sulphur compounds. The use of analytical techniques based on the spectroscopy of characteristic x-rays such as EDXRF and PIXE was of great advantage and particularly well suited for the fast and easy determination of major, minor and trace elements in particulate matter. © 1998 by John Wiley & Sons, Ltd.

Instrumental determination by neutron activation analysis of trace elements in particulate matter separated from riverine and marine coastal waters of the gulf of Gaeta (Central Italy)

This work presents the results obtained on suspended particulate matter (SPM) collected from the rivers Volturno and Garigliano and from the sea stretch between the mouth of the Volturno river and the Sabaudia lake (Central Tyrrhenian Sea). The elements As, Au, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, Hg, La, Lu, Mn, Rb, Sb, Sc, Se, Sm, Ta, Th, W and Yb were determined by instrumental neutron activation analysis. The results show that the element concentrations in SPM tend to be higher in surface than in bottom samples. Also, enrichment factors (EF's) were calculated with respect to Sc assumed as representative of alumino-silicates. Higher values of EF's were found for Zn, As, Se, Sb, Hg, W, and Au.