Nitro-PAH in ambient particulate matter in the atmosphere of Athens

Indoor air levels of polycyclic aromatic compounds (PAC) in public buildings with creosote impregnated constructions - A pilot case study using passive samplers

Creosote has been used in Sweden as a wood preservative in buildings since the 19th century. These buildings can function as workplaces, homes, and cultural buildings to which the public has access. Creosote contains polycyclic aromatic hydrocarbons (PAH) which are well known carcinogens. To understand exposure and risks in an indoor environment, it is important to determine air levels of parent PAHs as well as the more toxic nitrated and oxygenated PAH derivatives (NPAH, OPAH). This study aims to investigate indoor air levels of polycyclic aromatic compounds (PACs) e.g., PAH, NPAH, OPAH and dibenzothiophenes in buildings containing creosote sources and whether these levels pose a health risk. Four cultural buildings were studied, all located within a radius of 130 m. Two were known to have creosote sources, and two had not. Polyurethane foam passive air samplers (PUF-PAS) were used to indicate possible point sources. PUF-PAS measurements were performed for one month in each building winter and summer. Simultaneously, PAC outdoor level measurements were performed. Buildings with creosote impregnated constructions had notably higher indoor air levels of PAC (31-1200 ng m-3) compared to the two buildings without creosote sources (14-45 ng m-3). The PAH cancer potency (sum of benzo[a]pyrene equivalents (BaPeq)) was more than one order of magnitude higher in the buildings containing creosote impregnated wood compared to reference buildings. The highest value was 5.1 BaPeq ng m-3 which was significantly higher than the outdoor winter measurement (1.3 BaPeq ng m-3). Fluoranthene and phenanthrene, with significant distribution in gas phase, but also several particulate NPAHs contributed significantly to the total cancer risk. Thus, creosote containing buildings can still contaminate the indoor air with PACs despite being over a hundred years old. The PUF-PAS was shown to be a good tool providing quantitative/semiquantitative measures of PACs exposure in indoor microenvironments.

Occurrence, partition behavior, source and ecological risk assessment of nitro-PAHs in the sediment and water of Taige Canal, China

Nitrated polycyclic aromatic hydrocarbons (NPAHs) are widespread organic pollutants that possess carcinogenic and mutagenic properties, so they may pose a risk to the environment and human health. In this study, the concentrations of 15 NPAHs and 16 polycyclic aromatic hydrocarbons (PAHs) in 30 surface water samples and 26 sediment samples were measured in 2018 from the Taige Canal, one of the main rivers flowing into Taihu Lake, China. The total NPAH concentrations in water and sediment ranged from 14.7 to 235 ng/L and 22.9 to 96.5 ng/g dw, respectively. 9-nitrophenanthrene (nd-76.3 ng/L) was the dominant compound in surface water, while 2+3-nitrofluoranthene (1.73-18.1 ng/g dw) dominated in sediment. Among PAHs, concentration ranging from 1,097 to 2,981 ng/L and 1,089 to 4,489 ng/g dw in surface water and sediment, respectively. There was a strong positive correlation between the log octanol-water partition coefficient (K_ow) and log sediment-water partition coefficient due to hydrophobic interaction. The fugacity fraction value increased with the decrease of log K_ow, and chrysene was transferred from water into sediment. The residual NPAHs in surface water and sediment of the Taige Canal have partial correlation. Diesel engine and coal combustion emissions were probably the principal sources of NPAHs in surface water and sediment. The results of ecological risk assessment showed that some NPAHs in water (e.g, 1-nitropyrene and 6-nitrochrysene) and sediment (e.g., 2-nitrobiphenyl, 5-nitroacenaphthene, 9-nitrophenanthrene and 2+3-nitrofluoranthene) had moderate ecological risks, which should be of concern.

Comprehensive Multi-compartment Sampling for Quantification of Long-Term Accumulation of PAHs in Soils

Long-term accumulation in the soils of ubiquitous organic pollutants such as many polycyclic aromatic hydrocarbons (PAHs) depends on deposition from the atmosphere, revolatilization, leaching, and degradation processes such as photolysis and biodegradation. Quantifying the phase distribution and fluxes of these compounds across environmental compartments is thus crucial to understand the long-term contaminant fate. The gas-phase exchange between soil and atmosphere follows chemical fugacity gradients that can be approximated by gas-phase concentrations, yet which are difficult to measure directly. Thus, passive sampling, measured sorption isotherms, or empirical relationships to estimate sorption distribution have been combined in this study to determine aqueous (or gas) phase concentrations from measured bulk concentrations in soil solids. All these methods have their strengths and weaknesses but agree within 1 order of magnitude except for ex situ passive samplers employed in soil slurries, which estimated much lower concentrations in soil water and gas likely due to experimental artifacts. In field measurements, PAH concentrations determined in the atmosphere show a pronounced seasonality with some revolatilization during summer and gaseous deposition during winter, but overall dry deposition dominates annual mean fluxes. The characteristic patterns of PAHs in the different phases (gas phase, atmospheric passive samplers, bulk deposition, and soil solids) confirm the expected compound-specific distribution pattern and behavior. Since revolatilization fluxes in summer are only minor and wet and dry deposition is ongoing, our results clearly show that the PAH loads in topsoils will continue to increase.

Fine particle-bound PAHs derivatives at mountain background site (Mount Tai) of the North China: Concentration, source diagnosis and health risk assessment

Ten nitrated polycyclic aromatic hydrocarbons (nPAHs) and 4 oxygenated polycyclic aromatic hydrocarbons (oPAHs) in fine particulate matter (PM_2.5) samples from Mount Tai were analyzed during summer (June to August), 2015. During the observation campaign, the mean concentration of total nPAHs and oPAHs was 31.62 pg/m³ and 0.15 ng/m³, respectively. Two of the monitored compounds, namely 9-nitro-anthracene (9N-ANT) (6.86 pg/m³) and 9-fluorenone (9FO) (0.05 ng/m³) were the predominant compounds of nPAHs and oPAHs, respectively. The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization (PMF) method and the potential source contribution function (PSCF) methods. The results revealed that biomass/coal burning, gasoline vehicle emission, diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs, which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea. The incremental life cancer risk (ILCR) values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people (infant, children and adult), and the values of ILCR were 7.02 × 10^-10, 3.49 × 10^-9 and 1.41 × 10^-8 for infant, children and adults, respectively. All these values were lower than the standard of EPA (Environmental Protection Agency) (<10^-6), indicating acceptable health risk of nPAHs and oPAHs.

Organic chemical characterization of size segregated particulate matter samples collected from a thermal power plant area

Kütahya city, a thermal power plant (TPPs) affected region of Turkey, has serious air quality problems like similar industrial regions of the world due to the emissions from three closely-located coal-fired TPPs, residential coal combustion along with the contribution of several industrial stacks. The organic chemical speciation of ambient size-segregated particulate matter (PM) was investigated during two seasons at two sites with different pollution characteristics (urban and rural). The ambient PM was collected using a high volume cascade impactor, with 6 stages: PM_>10.2, PM_10.2-4.2, PM_4.2-2.1, PM_2.1-1.3, PM_1.3-0.69 and PM_<0.69. Collected PM samples were extracted with organic solvents and the organic composition (Polycyclic aromatic hydrocarbons (PAHs), n-alkanes and carboxylic acids) was determined by GC-MS. Sources of the organic species were assessed using molecular PAH diagnostic ratios, carbon preference index and wax percentages. More than 70% of the PM-bound PAHs were quantified in submicron particles. Similarly, 34-42% of n-alkanes and approximately 30% of the carboxylic acids were found on the smallest particles. The main sources of the PM-bound organic species were considered as the anthropogenic emissions such as coal and biomass combustion and also vehicular emissions rather than the biogenic sources. Considerably high cancer risk levels were obtained through inhalation of PAHs. Seasonal variations and size distributions of the carboxylic acids and levoglucosan were also evaluated. Polar organic compound concentrations were higher in the summer period at both locations probably due to the higher sunlight intensity and temperature favoring their photochemical formation.

Fast Formation of Nitro-PAHs in the Marine Atmosphere Constrained in a Regional-Scale Lagrangian Field Experiment

Polycyclic aromatic hydrocarbons (PAHs) and some of their nitrated derivatives, NPAHs, are seemingly ubiquitous in the atmospheric environment. Atmospheric lifetimes may nevertheless vary within a wide range, and be as short as a few hours. The sources and sinks of NPAH in the atmosphere are not well understood. With a Lagrangian field experiment and modeling, we studied the conversion of the semivolatile PAHs fluoranthene and pyrene into the 2-nitro derivatives 2-nitrofluoranthene and 2-nitropyrene in a cloud-free marine atmosphere on the time scale of hours to 1 day between a coastal and an island site. Chemistry and transport during several episodes was simulated by a Lagrangian box model i.e., a box model coupled to a Lagrangian particle dispersion model, FLEXPART-WRF. It is found that the chemical kinetic data do capture photochemical degradation of the 4-ring PAHs under ambient conditions on the time scale of hours to 1 day, while the production of the corresponding NPAH, which sustained 2-nitrofluoranthene/fluoranthene and 2-nitropyrene/pyrene yields of (3.7 ± 0.2) and (1.5 ± 0.1)%, respectively, is by far underestimated. Predicted levels of NPAH come close to observed ones, when kinetic data describing the reactivity of the OH-adduct were explored by means of theoretically based estimates. Predictions are also underestimated by 1-2 orders of magnitude, when NPAH/PAH yields reported from laboratory experiments conducted under high NO_x conditions are adopted for the simulations. It is concluded that NPAH sources effective under low NO_x conditions, are largely underestimated.

Emission Characteristics of Polycyclic Aromatic Hydrocarbons and Nitro-Polycyclic Aromatic Hydrocarbons from Open Burning of Rice Straw in the North of Vietnam

This research investigated the distribution and contribution of polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) bound to particulate matter (PM) emitted from open burning of rice straw (RS) into the atmosphere in the north of Vietnam. The experiments were conducted to collect PM_2.5 and total suspended particulates (TSP) prior to and during burning in the period of 2016–2018 in suburban areas of Hanoi. Nine PAHs and 18 NPAHs were determined using the HPLC-FL system. The results showed that the proportion of RS burning seasonally affects the variation of PAHs emission in atmospheric environment. The levels of nine PAHs from RS burning were 254.4 ± 87.8 µg g⁻¹ for PM_2.5 and 209.7 ± 89.5 µg g⁻¹ for TSP. We observed the fact that, although fluoranthene (Flu) was the most abundant PAH among detected PAHs both in PM_2.5 and TSP, the enrichment of Flu in TSP from burning smoke was higher than that in PM_2.5 while the contribution of benzo[a]pyrene (BaP) and indeno[1,2,3- cd]pyrene (IDP) in PM_2.5 from burning smoke were much higher than those in TSP. This research found that 1-nitropyrene (1-NP) and 6-nitrochrysene (6-NC) emit from RS burning with the same range with those from wood burning. The 2-nitrofluorene (2-NF) and 2-nitropyrene (2-NP) released from RS burning as the secondary NPAHs. This research provides a comprehensive contribution characterization of PAHs and NPAHs in PM with different size emitted from traditional local rice straw burning in the north of Vietnam. The results help to clarify the environmental behavior of toxic organic compounds from RS burning in Southeast Asia.

Spatiotemporal variation of atmospheric nitrated polycyclic aromatic hydrocarbons in semi-arid and petrochemical industrialized Lanzhou City, Northwest China

Polyurethane foam-based passive air sampler (PUF-PAS) and passive dry deposition sampler (PAS-DD) were adopted, for the first time ever in China, to investigate the atmospheric levels and spatial-temporal distributions of air burdens and dry deposition fluxes of 12 nitrated polycyclic aromatic hydrocarbons (NPAHs) during winter and summer seasons in a multiple site field campaign in a petrochemical industrialized capital city in Northwest China. The results showed that the highest air concentration and dry deposition fluxes of ∑₁₂NPAHs occurred at a heavy traffic site among 18 sampling sites in both winter and summer season. The lowest air concentration and dry deposition fluxes were observed at the background site. The mean concentrations of ∑₁₂NPAHs in the ambient air were 8.6 ± 8.1 ng m^-3 in winter and 15 ± 11 ng m^-3 in summer. The mean dry deposition fluxes of ∑₁₂NPAHs were 1.8 × 10³ ± 1.9 × 10³ ng (m² day)^-1 in winter and 1.4 × 10³ ± 1.3 × 10³ ng (m² day)^-1 in summer, respectively. The total concentration of 12 NPAHs was mainly dominated by 1-nitro-naphthalene (1N-NAP) and 2-nitro-naphthalene(2N-NAP) in air, accounting for 32% in winter and 45% in summer of ∑₁₂NPAHs. 7-Nitro-benzo [a] anthracene (7N-BaA) made the largest contribution to dry deposition fluxes of ∑₁₂NPAHs, accounting for 28% in winter and 24% in summer. The ratios of ∑₁₂NPAHs/∑₁₅pPAHs (parent polycyclic aromatic hydrocarbons) were calculated to identify potential sources of NPAHs across the city. The results revealed that the main atmospheric air concentration and dry deposition fluxes of 12 NPAHs could be attributed to the primary emissions in winter and the secondary reaction formation in summer. The sources of primary emissions could be traced back to petrochemical, steel mills, as well as aluminum industries in winter and vehicle exhaust in summer. Higher ∑₁₂NPAH/∑₁₅pPAH concentration ratios in summer indicated that the oxidation of pPAHs contributed to the secondary formation of NPAHs via atmospheric chemical reactions in this petrochemical industrialized mountain-valley city.

Characterization and Risk Assessment of Atmospheric PM2.5 and PM10 Particulate-Bound PAHs and NPAHs in Rwanda, Central-East Africa

Exposure to airborne particulates is estimated as the largest cause of premature human mortality worldwide and is of particular concern in sub-Saharan Africa where emissions are high and data are lacking. Particulate matter (PM) contains several toxic organic species including polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs (NPAHs). This study provides the first characterization and source identification for PM₁₀- and PM_2.5-bound PAHs and NPAHs in sub-Saharan Africa during a three-month period that spanned dry and wet seasons at three locations in Rwanda. The 24-h mean PM_2.5 and PM₁₀ concentrations were significantly higher in the dry than the wet season. PAH and NPAH concentrations at the urban roadside site were significantly higher than the urban background and rural site. Source identification using diagnostic ratio analysis and principal component analysis (PCA) revealed diesel and gasoline-powered vehicles at the urban location and wood burning at the rural location as the major sources of PAHs and NPAHs. Our analysis demonstrates that PM concentrations and lifetime cancer risks resulting from inhalation exposure to PM-bound PAHs and NPAHs exceed World Health Organization safe limits. This study provides clear evidence that an immediate development of emission control measures is required.

Potential sources and meteorological factors affecting PM2.5-bound polycyclic aromatic hydrocarbon levels in six main cities of northeastern Italy: an assessment of the related carcinogenic and mutagenic risks

A yearlong sampling campaign (2012-2013) was conducted in six major cities of the Veneto region to investigate the spatial-temporal trends and the factors affecting the polycyclic aromatic hydrocarbon (PAHs) variations and identify the local sources. Sixty samples per city were collected for analyses in every alternate month (April, June, August, October, December, and February): 10 samples per sampling site in 10 consecutive days of the months selected. Samples were ultrasonically extracted with acetonitrile and processed through high-performance liquid chromatography. Total Σ-PAH concentrations ranged from 0.19 to 70.4 ng m^-3 with a mean concentration of 11.5 ng m^-3. The mean benzo[a]pyrene (BaP) concentration reached 2.0 ng m^-3, which is two-times higher than the limit set by the European Union. BaP contributed for 17.4% to the total concentration of PAHs, which showed the same pattern across the region with maxima during cold months and minima in the warm period. In this study, PAHs showed an inverse relationship with temperature, solar radiation, wind speed, and ozone. According to this study, biomass burning for household heating and cooking, followed by gaseous PAHs absorption on particles due to low atmospheric temperature, were the main reasons for increasing PAHs concentration in winter. Health risk, evaluated as lifetime lung cancer risk (LCR), showed a potential carcinogenic risk from the airborne BaP_TEQ six-fold higher in the cold season than in the warm one. Diagnostic ratios and conditional probability functions were used to locate the sources, and results confirmed that local emission, overall domestic heating, and road transport exhausts were responsible for higher concentration rates of PAHs as well as of PM_2.5.

Simultaneous determination of eighteen nitro-polyaromatic hydrocarbons in PM2.5 by atmospheric pressure gas chromatography-tandem mass spectrometry

A new atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS) was developed to simultaneously separate, identify and quantify 18 nitro-polyaromatic hydrocarbons (NPAHs) in air fine particulate matter (PM_2.5). Compared with traditional negative chemical ionization (NCI) or electron impact ionization (EI)-MS/MS methods, APGC-MS/MS equipped with an atmospheric pressure chemical ionization (APCI) source provided better sensitivity and selectivity for NPAHs analysis in PM_2.5.18 NPAHs were completely separated, and satisfactory linear response (R² > 0.99), low instrumental detection limits (0.20-2.18 pg mL^-1) and method detection limits (0.001-0.015 pg m^-3) were achieved. Due to the reliable performance of the instrument, only minimal sample pretreatment is needed. It ensured the satisfactory method recovery (70%-120%) and qualified repeatability (RSD: 1.1%-17.2%), which met the requirement of trace analysis of NAPHs in the real environmental PM_2.5. Using the developed method, the actual PM_2.5 samples collected from Taiyuan, China in both summer and winter were analyzed, and 17 NPAHs but 2-nitrofluorene were detected and quantified. According to the obtained NAPH concentration results, the generation mechanism of NPAHs in PM_2.5 and the effects on NPAHs formation caused by some ambient air pollutants were preliminarily discussed: secondary photochemical reaction might be the dominant source of NPAHs in PM_2.5 collected from Taiyuan in both summer and winter; ambient air pollutants (NO₂, SO₂, CO) had more contribution on the NPAHs secondary formation of PM_2.5 in winter.

Nitro and oxy-PAHs bounded in PM2.5 and PM1.0 under different weather conditions at Mount Tai in Eastern China: Sources, long-distance transport, and cancer risk assessment

Fourteen nitro-PAHs and five oxy-PAHs associated with PM_2.5 and PM_1.0 were analyzed by GC-MS/MS at Mount Tai, China. 85% of the nitro-PAHs and 65% of oxy-PAHs were found in PM_1.0. The combined concentration of nitro-PAHs in PM_2.5 was highest in air masses associated with biomass burning (270.50pg/m³) compared with measurements from heavily polluted days (93.21pg/m³) and clean days (81.22pg/m³). A similar trend was also reflected in measurements of PM_1.0. 9-FO, 9,10-ANQ, and 1-NALD were the most abundant oxy-PAHs in both PM_2.5 and PM_1.0 at Mount Tai. The concentration of 2+3N-FLA was markedly increased compared with other species on heavily polluted days and biomass burning days, and 9N-ANT was more concentrated in measurements from days with biomass burning emissions. Secondary generation of nitro-PAHs was also more active during periods with biomass burning. The main formation pathway of nitro-PAHs during the sampling campaign was through reactions with OH radicals, but NO₃ radicals also played a significant role at night. The incremental lifetime cancer risk (ILCR) was highest during periods with biomass burning, indicating that biomass burning has a significant impact on human health. By analyzing the results of back trajectory clustering under different meteorological conditions, we determined that a large area of straw burning in the North China Plain (NCP) was the dominant source of nitro and oxy-PAHs at Mount Tai during the measurement campaign.

A Review on Reactions of Polycyclic Aromatic Hydrocarbons with the Most Abundant Atmospheric Chemical Fragments: Theoretical and Experimental Data

Aerosols are ubiquitous in the atmosphere and have strong effects on climate and public health due to the importance of reactions of polycyclic aromatic hydrocarbon (PAH) compounds in air. Over the last decade, study of the reactions of PAHs and their derivatives in the atmosphere has become a key topic to find an effective way to decrease the impact of this spontaneous reaction and so reduce air pollution. This article aims to pool the majority of research on the reactions of PAHs with atmospheric agents such as oxygen, hydrogen and ozone and compare the theoretical and experimental results. In examining theoretical research, the number of aromatic rings is very important in calculating the rate constants and determining the main pathway of the reaction. So, while there are weak theoretical data, several papers issued in this field have concurred with key experimental results. For reactants with more than six aromatic rings, small basis sets have good conformity with experimental outcomes. Due to the abundance of OH in the atmosphere, much research has been done to find the best reaction pathway and calculate the associated rate constants experimentally and theoretically. In future, the opportunity exists for new researchers to detect the main intermediates, most important pathways, rate constants and the products of reactions with more than six aromatic rings and to detect PAHs in a dense atmosphere. Product identification will help to reduce air pollution.

Nitro-PAH exposures of occupationally-exposed traffic workers and associated urinary 1-nitropyrene metabolite concentrations

The assessment of occupational exposure to diesel exhaust (DE) is important from an epidemiological perspective. Urinary biomarkers of exposure have been proposed as a novel approach for measuring exposure to DE. In this study, we measured the concentrations of two urinary metabolites of 1-nitropyrene (1NP), a nitrated polycyclic aromatic hydrocarbon that has been suggested as a molecular marker of diesel particulate matter. These two metabolites, 6-hydroxy-1-nitropyrene and 8-hydroxy-1-nitropyrene, were determined in urine samples (10mL) from a small group of workers who were occupationally-exposed to vehicle exhaust in Trujillo, Peru, before and after their workshifts. Workshift exposures to 1NP, as well as PM_2.5, 2-nitropyrene and 2-nitrofluoranthene, were also measured. Exposures to 1NP were similar in all studied workers, averaging 105±57.9pg/m³ (±standard deviation). Median urinary concentrations of the average of the pre- and post-exposure samples for 6-hydroxy-1-nitropyrene and 8-hydroxy-1-nitropyrene, were found to be 3.9 and 2.3pgmetabolite/mg creatinine, respectively in the group of occupationally-exposed subjects (n=17) studied. A direct relationship between workshift exposure to 1NP and urinary 1NP metabolites concentrations was not observed. However, the 1NP exposures and the creatinine-corrected urinary concentrations of the hydroxynitropyrene metabolites in these Peruvian traffic workers were similar to occupationally-exposed taxi drivers in Shenyang, China, and were higher than biomarker levels in office workers from Trujillo without occupational exposure to vehicle exhaust. This study provides further evidence that urinary metabolites of 1NP are associated with exposure to DE and may serve as a useful exposure biomarker.

An improved method to determine PM-bound nitro-PAHs in ambient air

Nowadays, no a standard method for the determination of particulate bound nitro-PAHs (NPAHs) has been developed. Existing methods include complex sampling and extraction procedures. Moreover, their sensitivity does not allow to analyze daily PM10 samples, affecting the temporal resolution of NPAH concentrations. In this study an analytical method for the quantification of NPAHs on half 47 mm-filter samples of daily PM10 was developed and validated. NPAHs were recovered by microwave-assisted extraction, and analyzed by using a gas chromatography-triple quadrupole mass spectrometry in MRM mode. The analytical performance for 14 NPAHs (2-nitrofluorene, 9-nitroanthracene, 9-nitrophenantrene, 3-nitrophenantrene, 2-nitroanthracene, 3-nitrofluoranthene, 1-nitropyrene, 2,7-dinitrofluorene, 7-nitrobenzo[a]anthracene, 6-nitrochrysene, 1,3-dinitropyrene, 1,8-dinitropyrene, 1,6-dinitropyrene, 6-nitrobenza[a]pyrene) was investigated. Recovery extraction percentage exceeded 95% for all target compounds in the range between 0.25 and 10 ng/mL. The repeatability, expressed as Relative Standard Deviation percentage (RSD%) of five determinations, was less than 10% for target compounds except for 2,7-dinitrofluorene, 1,3- and 1,8-dinitropyrene (RSD% < 15%). The limit of detection (LOD) ranged from 12 to 84 pg/mL for most of NPAHs, except for dinitro-pyrenes and nitro-benzo(a)anthracene for which the LOD reached 1.8 ng/mL. The method developed was applied to real samples in order to evaluate the levels of NPAHs in the urban and industrial area of Taranto (South of Italy). The analysis of PM10 samples collected at four industrial and one urban sites, highlighted that in proximity of critical emission source as the biggest European steel plant and under certain weather conditions, combustion processes were the main source of NPAHs in atmosphere.

One-year study of polycyclic aromatic compounds at an urban site in Grenoble (France): Seasonal variations, gas/particle partitioning and cancer risk estimation

21 PAHs, 27 oxy-PAHs and 32 nitro-PAHs were measured every third day over a year in both gaseous (G) and particulate PM10 (P) phases in ambient air of Grenoble (France). Mean total concentrations (G+P) of PAHs and oxy-PAHs were in the same range and about 10ngm(-3). Nitro-PAHs were 50 to 100 times less concentrated averaging 100pgm(-3). Polycyclic aromatic compound (PAC) concentrations were 5 to 7 times higher in "cold" period (October to March) than in "warm" period (April to September). Seasonal variations may be explained by higher primary emissions from residential heating, especially biomass burning in "cold" season. Meteorological conditions and influence of the geomorphology around Grenoble, with the formation of thermal inversion layers leading to the stagnation of pollutants, were additional key parameters. Maximum individual PAC concentrations were observed during two PM10 pollution events in December and February-March. Chemical processes and secondary formation of oxy- and nitro-PAH were probably enhanced by the accumulation of the pollutants during these events. PAC gas/particle partitioning depended on compound molecular weight and vapour pressure. Gas/particle partitioning of oxy- and nitro-PAHs were evaluated using a multi-phase poly-parameter linear free energy relationship model. The PAC cancer risk was assessed using toxic equivalency factors available in the literature (19 PAHs, 10 nitro-PAHs and 1 oxy-PAH). Overall, particle-bound PACs contributed about 76% of the cancer risk. While PAHs accounted for most of the total PAC cancer risk, oxy- and nitro-PAHs could account for up to 24%. The risk quantification across substance classes is limited by toxicological data availability.

Characterization of polycyclic aromatic hydrocarbons in fugitive PM10 emissions from an integrated iron and steel plant

Fugitive emissions of PM10 (particles <10μm in diameter) and associated polycyclic aromatic hydrocarbons (PAHs) were monitored in the vicinity of coking unit, sintering unit, blast furnace and steel manufacturing unit in an integrated iron and steel plant situated in India. Concentrations of PM10, PM10-bound total PAHs, benzo (a) pyrene, carcinogenic PAHs and combustion PAHs were found to be highest around the sintering unit. Concentrations of 3-ring and 4-ring PAHs were recorded to be highest in the coking unit whereas 5-and 6-ring PAHs were found to be highest in other units. The following indicatory PAHs were identified: indeno (1,2,3-cd) pyrene, dibenzo (a,h) anthracene, benzo (k) fluoranthene in blast furnace unit; indeno (1,2,3-cd) pyrene, dibenzo (a,h) anthracene, chrysene in sintering unit; Anthracene, fluoranthene, chrysene in coking unit and acenaphthene, fluoranthene, fluorene in steel making unit. Total-BaP-TEQ (Total BaP toxic equivalent quotient) and BaP-MEQ (Total BaP mutagenic equivalent quotient) concentration levels ranged from 2.4 to 231.7ng/m(3) and 1.9 to 175.8ng/m(3), respectively. BaP and DbA (dibenzo (a,h) anthracene) contribution to total-BaP-TEQ was found to be the highest.

Urinary polycyclic aromatic hydrocarbon metabolites as biomarkers of exposure to traffic-emitted pollutants

1-Nitro-pyrene has been considered a compound specific to diesel combustion emission, while 1- and 2-nitro-napthalene are mainly produced through photochemical conversion of naphthalene released to the atmosphere. Metabolites of these compounds may serve as biomarkers of exposure to traffic related pollutants. We collected urine samples from 111 healthy and non-smoking subjects within (i.e., during the Beijing Olympics) and outside (i.e., before and after the Olympics) a traffic control regime to improve Beijing's air quality. Urines were analyzed for the sum of 1&2-amino-naphthalene (metabolites of 1- and 2-nitro-naphthalene) and 1-amino-pyrene (a metabolite of 1-nitro-pyrene), using an HPLC-fluorescence method. Within the same time periods, PM2.5 mass and constituents were measured, including elemental carbon, sulfate, nitrate, PAHs, carbon monoxide, nitrogen dioxide, sulfur dioxide, ozone, and particle number concentrations. The associations between the urinary metabolites and air pollutants were analyzed using linear mixed-effects models. From the pre- to during-Olympic period, 1&2-amino-naphthalene and 1-hydroxy-pyrene decreased by 23% (p=0.066) and 16% (p=0.049), respectively, while there was no change in 1-amino-pyrene (2% increase, p=0.892). From during- to post-Olympic period, 1&2-amino-naphthalene, 1-amino-pyrene and 1-hydroxy-pyrene concentrations increased by 26% (p=0.441), 37% (p=0.355), and 3% (p=0.868), respectively. Furthermore, 1&2-amino-naphthalene and 1-hydroxy-pyrene were associated with traffic related pollutants in a similar lag pattern. 1-amino-pyrene was associated more strongly with diesel combustion products (e.g. PN and elemental carbon) and not affected by season. Time-lag analyses indicate strongest/largest associations occurred 24-72h following exposure. 1&2-amino-naphthalene and 1-hydroxy-pyrene can be used as a biomarker of exposure to general vehicle-emitted pollutants. More data are needed to confirm 1-amino-pyrene as a biomarker of exposure to diesel combustion emissions. Controlling creatinine as an independent variable in the models will provide a moderate adjusting effect on the biomarker analysis.

One-year intensive characterization on PM2.5 nearby port area of Thessaloniki, Greece

The chemical characterization of particulate matter (PM) 2.5 fraction was studied during a 1-year sampling campaign conducted at a site near Thessaloniki's port area. PM2.5 collected samples were chemically analyzed for polycyclic aromatic hydrocarbons, minerals, and trace elements (Pb, Ni, Cu, V, Mn, Cr, Zn, Mg, K, Ti, Fe, Ca, and Al); water-soluble ions (Cl(-), NO3 (-), SO4 (2-), K(+), Na(+), NH4 (+), Mg(2+), Ca(2+)); and organic and elemental carbon. The average annual PM2.5 concentration (66.0 μg/m(3)) was at the highest level compared with other studies reported for the same city but different sampling sites. The average daily sum of the measured concentration of polycyclic aromatic hydrocarbons (PAHs) was 12.76 ng/m(3); this value decreased to 6.73 ng/m(3) for the warm period and reached the value of 19.8 ng/m(3) for the cold period. The average concentration of benzo[a]pyrene during the sampling period was 0.75 ng/m(3), which is below the European Union limit value of 1.0 ng/m(3). The ionic content comprised, on average, 22.6 % of the PM2.5 mass, with sulfate and ammonium being the most abundant species (31 and 26 %, respectively, of measured ions during the whole sampling period). The annual mean concentrations of organic carbon (OC) and elemental carbon (EC) were 10.5 ± 6.3 and 2.3 ± 1.5 μg/m(3), respectively. The OC/EC ratio ranged from 1.6 to 9.9, suggesting that there is a significant influence of residential wood burning for heating as well as ship and vehicle emissions to the sampling area. Finally, the elemental composition of associated PM2.5 was dominated by Ca, Fe, and Al. Although conclusions based only on PM2.5 measurements cannot entirely estimate all harbor sources' contribution, there is evidence to support that port activities affect the city's air quality and vice versa.

Measurement of organic and elemental carbon in downtown Rome and background area: physical behavior and chemical speciation

A significant portion of the particulate matter is the total carbonaceous fraction (or total carbon, TC), composed of two main fractions, elemental carbon (EC) and organic carbon (OC), which shows a large variety of organic compounds, e.g. aliphatic, aromatic compounds, alcohols, acids, etc. In this paper, TC, EC and OC concentrations determined in a downtown Rome urban area are discussed considering the influence of meteorological conditions on the temporal-spatial aerosol distribution. Similar measurements were performed at ENEA Casaccia, an area outside Rome, which is considered as the ome background. Since 2000, TC, EC and OC measurements have been performed by means of an Ambient Carbon Particulate Monitor equipped with a NDIR detector. The EC and OC concentrations trends are compared with benzene and CO trends, which are specific indicators of autovehicular traffic, for identifying the primary EC and OC contributions and the secondary OC fraction origin. Further, a chemical investigation is reported for investigating how the main organic (i.e., n-alkanes, n-alkanoic acids, polyaromatic hydrocarbons and nitro-polyaromatic hydrocarbons) and inorganic (i.e., metals, ions) fractions vary their levels during the investigated period in relationship to new regulations and/or technological innovations.

Study of nitro-polycyclic aromatic hydrocarbons in particulate matter in Dongguan

Total suspended and size-segregated atmospheric particles were collected in four seasons at three representative points in different functional areas of Dongguan City. The detailed size distributions of six nitro-PAHs [2-nitrofluorene (2-NF), 9-nitroanthracene, 2-nitrofluoranthene (2-NFL), 3-nitrofluoranthene, 1-nitropyrene, and 2-nitropyrene (2-NP)] were determined by high-performance liquid chromatography (HPLC) with UV detection using a binary elution gradient (methanol and water). We used a toxicity assessment based on potency equivalency factors (PEFs) to estimate the inhalation risk of the particulate matter. The results showed that, aside from 2-NF and 2-NFL, the content of the other four nitro-PAHs in the microparticles (<0.4 μm) were more than 20%, a percentage significantly higher than other fractions of particulate matter. The seasonal distribution of nitro-PAHs shows that their concentrations were higher in the winter, while the PAH concentrations were higher in the summer. The study found that secondary formation (2-NFL and 2-NP) had a positive correlation with NO x and NO2, but a negative correlation with O3. The benzo[a]pyrene equivalent (BaPeq) toxicity of particulate matter in Dongguan City ranged from 0.04 to 2.63 ng m(-3), and the carcinogenic index ranged from 0.04 × 10(-6) to 2.39 × 10(-6). These values do not represent a serious threat to human health.

Occupational exposure to airborne particles and other pollutants in an aviation base

The occupational exposure to airborne particles and other pollutants in a high performance jet engine airport was investigated. Three spatial scales were considered: i) a downwind receptor site, ii) close to the airstrip, iii) personal monitoring. Particle number, surface area, mass concentrations and distributions were measured as well as inorganic and organic fractions, ionic fractions and Polycyclic Aromatic Hydrocarbons. Particle number distribution measured at a receptor site presents a mode of 80 nm and an average total concentration of 6.5 × 10(3) part. cm(-3); the chemical analysis shows that all the elements may be attributed to long-range transport from the sea. Particle number concentrations in the proximity of the airstrip show short term peaks during the working day mainly related to takeoff, landing and pre-flight operations of jet engines. Personal exposure of workers highlights a median number concentration of 2.5 × 10(4) part. cm(-3) and 1.7 × 10(4) part. cm(-3) for crew chief and hangar operator.

Can car air filters be useful as a sampling medium for air pollution monitoring purposes?

Urban air quality and real human exposure to chemical environmental stressors is an issue of high scientific and political interest. In an effort to find innovative and inexpensive means for air quality monitoring, the ability of car engine air filters (CAFs) to act as efficient samplers collecting street level air, to which people are exposed to, was tested. In particular, in the case of taxis, air filters are replaced after regular distances, the itineraries are almost exclusively urban, cruising mode is similar and, thus, knowledge of the air flow can provide with an integrated city air sample. The present pilot study focused on polycyclic aromatic hydrocarbons (PAHs), the most important category of organic pollutants associated with traffic emissions. Concentrations of ΣPAHs in CAFs ranged between 650 and 2900 μg CAF(-1), with benzo[b]fluoranthene, benzo[k]fluoranthene and indeno[123-cd]pyrene being the most abundant PAHs. Benzo[a]pyrene (BaP) ranged between 110 and 250 μg CAF(-1), accounting regularly for 5-15% of the total carcinogenic PAHs. The CAF PAH loads were used to derive road-level atmospheric PAH concentrations from a standard formula relating to the CAF air flow. Important parameters/assumptions for these estimates are the cruising speed and the exposure duration of each CAF. Based on information obtained from the garage experts, an average 'sampled air volume' of 48,750 m(3) per CAF was estimated, with uncertainty in this calculation estimated to be about a factor of 4 between the two extreme scenarios. Based on this air volume, ΣPAHs ranged between 13 and 56 ng m(-3) and BaP between 2.1 and 5.0 ng m(-3), suggesting that in-traffic BaP concentrations can be many times higher than the limit values set by the UK (0.25 ng m(-3)) and the European Union (1.0 ng m(-3)), or from active sampling stations normally cited on building roof tops or far from city centres. Notwithstanding the limitations of this approach, the very low cost, the continuous availability of very high amounts of "sample", and the "retroactivity" render it very useful and complementary to existing passive sampling techniques. This approach yields estimated air concentrations that reflect the pollutant concentrations to which taxi drivers, pedestrians, cyclists and road-related professionals are exposed.

Diurnal/nocturnal concentrations and sources of particulate-bound PAHs, OPAHs and NPAHs at traffic and suburban sites in the region of Paris (France)

Particulate concentrations of polycyclic aromatic compounds (PACs) including, 17 polycyclic aromatic hydrocarbons (PAHs), 9 oxygenated PAHs (OPAHs) and 18 nitrated PAHs (NPAHs) were determined at traffic and suburban sites located in the region of Paris. A 12 h sampling basis time resolution was applied in order to study their diurnal and nocturnal variations. Observed concentrations were about 10 times higher at the traffic site for all compounds and were higher during the night-time for both sites (except for NPAHs at the traffic site). No significant differences in PAH and OPAH profiles were observed at both sites whereas, for NPAHs, 1-nitropyrene (diesel source) was the most abundant at the traffic site and 2+3-nitrofluoranthene (secondary formed by gas-phase reaction) was predominant at the suburban site. The study of the specific ratio 2-nitrofluoranthene/1-nitropyrene (2-NFlt/1-NP) showed a local formation of NPAHs in gaseous phase at the suburban site. A detailed analysis showed that atmospheric humidity and rainfalls modified differently PAH and NPAH profiles, in comparison to OPAH. A difference of the scale variability of water solubility between, light (MW≤228 g mol(-1)) and heavy compounds (MW≥273 g mol(-1)), could explain these observations. The specific study of the relationships between PACs and other measured pollutants highlighted that particle resuspension could constitute a significant source of PM on the traffic site. Even if NPAH formation seemed clearly evident at the suburban site during periods characterised by high O(3) and NO(2) concentration levels, results showed also that the primary and/or secondary origins of OPAHs and NPAHs were strongly dependent on the sampling site and on sampling conditions. Finally, we conclude that higher time sampling resolutions would be helpful in investigating the atmospheric chemistry and behaviours of PACs in correlation with the local meteorological variations and the daily cycle of human activities.

One year intensive PM2.5 bound polycyclic aromatic hydrocarbons monitoring in the area of Tuscany, Italy. Concentrations, source understanding and implications

Polycyclic aromatic hydrocarbons (PAHs) associated to PM(2.5) particles were monitored at three sites in the region of Tuscany, Italy, during the period March 2009-March 2010. PAH concentrations ranged between 0.92 ng m(-3) and 13 ng m(-3). The spatial and seasonal differences observed at the three sites are discussed and attributed to specific PAH sources. Benzo[a]Pyrene average annual values were below the EU limit value of 1.0 ng m(-3). The results of this study suggest that emissions from commuting and work related traffic play an important role for the city of Florence, whereas for the city of Livorno, the harbor activities seem to impact the PAH burden substantially, as well. The PAH cancer risk (expressed as the "BaPE index") has shown a 6-fold decline compared to early 1990's concentrations and 2- to 3-fold decline compared to the late 1990's.

Preliminary characterization of polycyclic aromatic hydrocarbons, nitrated polycyclic aromatic hydrocarbons and polychlorinated dibenzo-p-dioxins and furans in atmospheric PM10 of an urban and a remote area of Chile

The composition of particulate organic fraction was determined in atmospheric aerosols emitted in two sites of central and southern Chile. In particular, polycyclic aromatic hydrocarbons (PAHs), nitrated-PAHs (N-PAHs) and polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs) were investigated in both the urban site of Concepcion and the remote site of Coyhaique. The sampling was carried out with an active device during March and April 2007, and organic compounds adsorbed in air particles, having an aerodynamic diameter lower than 10 microm (PM10), were characterized using gas chromatography coupled with mass spectrometric detection (GC-MS). Aerosol contents varied from 0.004 to 3.4 ng m(-3) for PAH, from 0.007 to 3.5 pg m(-3) for N-PAH, from 0.002 to 355.7 fg Nm(-3) for PCDDs and from 0.04 to 15 fg Nm(-3) for PCDFs. As expected, the lowest values were found in the remote area. In Concepcion city, despite the low number of samples, PAH levels and diagnostic ratios of some marker compounds suggested the diesel emissions, probably coming from trucks, as the major source of particulate organic pollutants associated with direct emission. Another important source of atmospheric pollution in the urban site was likely represented by the steel industry existing in this area, outlined both by the analysis of PAH and PCDD/F levels. In the samples collected in the remote air of Coyhaique (located in the southern part of Chile), the concentration of pollutants characterized by a long lifetime, as PCDD/Fs, could be related to long-range transport phenomena, instead of local sources.

Determination of anthropogenic and biogenic compounds on atmospheric aerosol collected in urban, biomass burning and forest areas in São Paulo, Brazil

This study was conducted at three sites of different characteristics in São Paulo State: São Paulo (SPA), Piracicaba (PRB) and Mata Atlântica Forest (MAT). PM(10), n-alkanes, pristane and phytane, PAHs, water-soluble ions and biomass burning tracers like levoglucosan and retene, were determined in quartz fiber filters. Samplings occurred on May 8th to August 8th, 2007 at the MAT site; on August 15th to 29th in 2007 and November 10th to 29th in 2008 at the PRB site and, March 13th to April 4th in 2007 and August 7th to 29th in 2008 at the SPA site. Aliphatic compounds emitted biogenically were less abundant at the urban sites than at the forest site, and its distribution showed the influence of tropical vascular plants. Air mass transport from biomass burning regions is likely to impact the sites with specific molecular markers. The concentrations of all species were variable and dependent of seasonal changes. In the most dry and polluted seasons, n-alkane and cation total concentrations were similar between the megacity and the biomass burning site. PAHs and inorganic ion abundances were higher at São Paulo than Piracicaba, yet, the site influenced by biomass burning seems to be the most impacted by the organic anion abundance in the atmosphere. Pristane and phytane confirm the contamination by petroleum residues at urban sites; at the MAT site, biological activity and long range transport of pollutants might influence the levels of pristane.

Temporal variation of nitro-polycyclic aromatic hydrocarbons in PM10 and PM2.5 collected in Northern Mexico City

With the aim to determine the presence of individual nitro-PAH contained in particles in the atmosphere of Mexico City, a monitoring campaign for particulate matter (PM(10) and PM(2.5)) was carried out in Northern Mexico City, from April 2006 to February 2007. The PM(10) annual median concentration was 65.2μgm(-3) associated to 7.6μgm(-3) of solvent-extractable organic matter (SEOM) corresponding to 11.4% of the PM(10) concentration and 38.6μgm(-3) with 5.9μgm(-3) SEOM corresponding to 15.2% for PM(2.5). PM concentration and SEOM varied with the season and the particle size. The quantification of nitro-polycyclic aromatic hydrocarbons (nitro-PAH) was developed through the standards addition method under two schemes: reference standard with and without matrix, the former giving the best results. The recovery percentages varied with the extraction method within the 52 to 97% range depending on each nitro-PAH. The determination of the latter was effected with and without sample purification, also termed fractioning, giving similar results. 8 nitro-PAH were quantified, and their sum ranged from 111 to 819pgm(-3) for PM(10) and from 58 to 383pgm(-3) for PM(2.5), depending on the season. The greatest concentration was for 9-Nitroanthracene in PM(10) and PM(2.5), detected during the cold-dry season, with a median (10th-90th percentiles) concentration in 235pgm(-3) (66-449pgm(-3)) for PM(10) and 73pgm(-3) (18-117pgm(-3)) for PM(2.5). The correlation among mass concentrations of the nitro-PAH and criteria pollutants was statistically significant for some nitro-PAH with PM(10), SEOM in PM(10), SEOM in PM(2.5), NO(X), NO(2) and CO, suggesting either sources, primary or secondary origin. The measured concentrations of nitro-PAH were higher than those reported in other countries, but lower than those from Chinese cities. Knowledge of nitro-PAH atmospheric concentrations can aid during the surveillance of diseases (cardiovascular and cancer risk) associated with these exposures.

Dimensional and chemical characterization of particles at a downwind receptor site of a waste-to-energy plant

In the last years numerous epidemiological studies were carried out to evaluate the effects of particulate matter on human health. In industrialized areas, anthropogenic activities highly contribute to the fine and ultrafine particle concentrations. Then, it is important to characterize the evolution of particle size distribution and chemical composition near these emission points. Waste incineration represents a favorable technique for reducing the waste volume. However, in the past, municipal waste incinerators (MWIs) had a bad reputation due to the emission of toxic combustion byproducts. Consequently, the risk perception of the people living near MWIs is very high even if in Western countries waste incineration has nowadays to be considered a relatively clean process from a technical point of view. The study here presented has an exemplary meaning for developing appropriate management and control strategies for air quality in the surrounding of MWIs and to perform exposure assessment for populations involved. Environment particles were continuously measured through a SMPS/APS system over 12 months. The monitoring site represents a downwind receptor of a typical MWI. Furthermore, elements and organic fractions were measured by means of the Instrumental Neutron Activation Analysis and using dichotomous and high volume samplers. Annual mean values of 8.6 x 10(3)+/-3.7 x 10(2)part.cm(-3) and 31.1+/-9.0 microg m(-3) were found for number and mass concentration, typical of a rural site. Most of the elements can be attributed to long-range transport from other natural and/or anthropogenic sources. Finally, the Polycyclic Aromatic Hydrocarbons present low concentrations with a mean value of 24.6 ng m(-3).

Particle-phase concentrations of polycyclic aromatic hydrocarbons in ambient air of rural residential areas in southern Germany

An important source of polycyclic aromatic hydrocarbons (PAHs) in residential areas, particularly in the winter season, is the burning process when wood is used for domestic heating. The target of this study was to investigate the particle-phase PAH composition of ambient samples in order to assess the influence of wood combustion on air quality in residential areas. PM(10) samples (particulate matter <10 mum) were collected during two winter seasons at two rural residential areas near Stuttgart in Germany. Samples were extracted using toluene in an ultrasonic bath and subsequently analysed by gas chromatography-mass spectrometry. Twenty-one PAH compounds were detected and quantified. The PAH fingerprints of different wood combustion emissions were found in significant amounts in ambient samples and high correlations between total PAHs and other wood smoke tracers were found, indicating the dominant influence of wood combustion on air quality in residential areas. Carcinogenic PAHs were detected in high concentrations and contributed 49% of the total PAHs in the ambient air. To assess the health risk, we investigated the exposure profile of individual PAHs. The findings suggest that attention should be focused on using the best combustion technology available to reduce emissions from wood-fired heating during the winter in residential areas.

Exposures to particulate air pollution and nitro-polycyclic aromatic hydrocarbons among taxi drivers in Shenyang, China

Exposures to particulate matter (PM) of both 10-2.5 microm (PM(10-2.5)) and below 2.5 microm (PM(2.5)) were measured for a cohort of taxi drivers in Shenyang, China, during August 2007. PM samples were collected inside and outside the taxi during the drivers' workshifts, and also inside the drivers' homes when they were off-shift. Ambient PM samples were also collected at a stationary location in Shenyang. Elemental carbon (EC) and organic carbon (OC) were also measured in PM collected on quartz filters inside the taxis as well as at the stationary site. Concentrations of three nitro-polycyclic aromatic hydrocarbons (NPAHs), 1-nitropyrene (1NP), 2-nitropyrene (2NP), and 2-nitrofluoranthene (2NFl), were determined in extracts of the PM samples by using a 2D-HPLC-MS/MS method. The 2NP and 2NFl concentrations did not change substantially with sampling location, but the 1NP concentrations were much higher in samples collected inside and outside the taxis as compared with sampling locations that were more removed from traffic. Concentration ratios of specific NPAHs were used to assess the atmospheric conditions in Shenyang during the sampling period. The relatively high ratios of 2NFl/1NP ( approximately 8-50) indicate an important contribution from secondary NPAH formation to ambient NPAH levels, especially for the nontaxi samples. The ratios of 2NFl/2NP (2.5-4.3) indicate that 2NFl is primarily formed via the hydroxyl-initiated reaction.

Particle-associated polycyclic aromatic hydrocarbons in the atmospheric environment of Zonguldak, Turkey

Airborne fine (PM(2.5)) and coarse (PM(2.5-10)) particulate matter was collected from January to December in 2007 in Zonguldak, Turkey using dichotomous Partisol 2025 sampler. Fourteen selected polycyclic aromatic hydrocarbons (PAHs) in particulate matter were determined simultaneously by high-performance liquid chromatography with fluorescence detection (HPLC-FL) and seasonal distributions were examined. The source identification of PAHs in airborne particulates was performed by principal component analysis (PCA) in combination with diagnostic ratios. The predominant PAHs determined in PM(2.5) were pyrene, fluoranthene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene. The total concentrations of PAHs were up to 464.0 ng m(-3) in fine and 28.0 ng m(-3) in coarse fraction in winter, whereas in summer times were up to 22.9 and 3.0 ng m(-3) respectively. Approximately 93.3% of total PAHs concentration was determined in PM(2.5) in winter and 84.0% in summer. The concentration levels of PAHs fluctuate significantly within a year with higher means and peak concentrations in the winter compared to that of summer times. Higher benzo(a)pyrene-equivalent (BaPE) concentrations of PAHs were obtained for PM(2.5) especially in winter. The results obtained from PCA in combination with diagnostic ratios revealed that coal combustion and vehicle emissions were the major pollutant sources for both PM(2.5) and PM(2.5-10) associated PAHs in studied area. Two principal components for PM(2.5) and three for PM(2.5-10) were identified and these accounted for 89.4 and 85.2% of the total variance respectively. The emissions from coal combustion were estimated to be the main source of PAHs in the ambient air particulates with contributions of 80.8% of total variance for PM(2.5) and 53.8% for PM(2.5-10).

Characterisation of solvent extractable organic constituents in atmospheric particulate matter: an overview

In spite of accounting for 10-70% of the atmospheric aerosol mass, particulate-phase organic compounds are not well characterised, and many aspects of aerosol formation and evolution are still unknown. The growing awareness of the impact of particulate aerosols on climate, and the incompletely recognised but serious effects of anthropogenic constituents on air quality and human health, have conducted to several scientific studies. These investigations have provided information about the behaviour of atmospheric particulate matter and the description of the character of its carbonaceous content. The compilation of such results is important as they append to the emergent global-wide dataset of the organic composition of atmospheric aerosols. The contribution of the major emission sources to regional particulate pollution can be diagnosed by using specific molecular markers. This overview is mainly focused on results obtained with gas chromatography coupled with mass spectrometry, since it is the analytical method of choice in elucidating the solvent-extractable organic compounds in atmospheric particulate matter. A synopsis of the selection of organic tracers and the application of geochemical parameters to the analysis of organic constituents as a tool for source apportionment is shown here. Besides the assessment of current knowledge, this paper also presents the identification of further areas of concern.

Sorptive behavior of nitro-PAHs in street runoff and their potential as indicators of diesel vehicle exhaust particles

This is the first report to reveal the particle-water distribution of nitropolycyclic aromatic hydrocarbons (NPAHs) and to discuss their potential risks and utility as indicators of diesel vehicle exhaust particles (DEP). Time-series samples of runoff were collected from a highway, and NPAHs and polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography-mass spectrometry (GC-MS) to study their dynamic behavior. The concentrations of total NPAHs ranged from 11 to 73 ng/L in particulate phase (>0.7 mcirom) and from 2.3 to 4.9 ng/L in dissolved phase (<0.7 microm). Like their PAH analogs, most (81-97%) NPAHs were associated with particulate matter. The organic carbon-normalized in situ partition coefficients (Koc') of NPAHs observed in runoff events (10(5.8-6.3) for 2-nitrofluoranthene and 10(5.8-6.2) for 1-nitropyrene [1-NP]) were more than 1 order of magnitude higher than those expected from their Kow, indicating great affinity for particulate matter such as soot. Concentrations of PAHs and NPAHs adjusted by potency equivalency factors and induction equivalency factors showed that the potential risks of NPAHs were smaller than those of PAHs by a factor of more than a hundred for the particulate phase and morethan fourforthe dissolved phase. Comparison of concentrations and compositions of NPAHs and PAHs among runoff, DEP, gasoline vehicle exhaust particles, boiler exhaust particles, and aerosols suggested that the ratio of 1-NP to total PAHs (1-NP/PAH) is a useful indicator of DEP for source apportionment of PAHs among traffic-related sources. Source-apportionment of PAHs in the runoff by 1-NP/PAH and methylphenanthrene/phenanthrene ratios suggested that most PAHs in the runoff except the second flush peak were derived from DEP but that other pyrogenic sources contributed to the particles at the second flush and thus to the overall runoff particles.

Diurnal cycle of PAHs, nitro-PAHs, and oxy-PAHs in a high oxidation capacity marine background atmosphere

To improve our understanding of the formation and fate of nitro-PAHs, which contribute to the toxicity of ambient particles, the diurnal variation of their ambient concentration was studied concurrently with the corresponding PAH, OH radical, ozone, and oxy-PAH concentration, during an intensive field campaign at an eastern Mediterranean marine background location (Finokalia, Island of Crete) in August, 2001. The gas-phase PAH and OH radical concentrations maximized at noon. Gas-phase PAH concentrations were correlated (p < 0.001) with ambient temperatures. The gas-phase OH-radical-initiated PAH reaction was identified as the major process contributing to the ambient burden of nitro-PAHs. 2-Nitrofluoranthene and 2-nitropyrene were the most abundant particle-associated nitro-PAHs. A well-defined diurnal pattern was identified for both compounds exhibiting a maximum during midday followed by a rapid decrease. 9,10-Anthracenodione and 9-fluorenone, the most abundant oxy-PAHs, did not present a diurnal variation of concentration.

Polycyclic aromatic hydrocarbons (PAHs), nitrated PAHs and oxygenated PAHs in ambient air of the Marseilles area (South of France): concentrations and sources

Ambient measurements (gas+particle phases) of 15 polycyclic aromatic hydrocarbons (PAHs), 17 nitrated PAHs (NPAHs) and 9 oxygenated PAHs (OPAHs) were carried out during July 2004 on three different sites (urban, sub-urban and rural) in the region of Marseilles (South of France). Atmospheric concentrations of these classes of polyaromatics are great of interest because of their high potential mutagenicity and carcinogenicity. OPAH concentrations were of the same order of magnitude as those of PAHs while NPAH concentrations were one to two orders lower. 9-Fluorenone and 9,10-anthraquinone were the most abundant OPAHs, accounting for about 60% and 20% of the total OPAH concentration. Respectively 1-and 2-nitronaphthalene were the most abundant NPAHs and were accounting for about 30-50% and 15-30% of the total NPAH concentration. NPAHs and OPAHs concentration levels were consistent with the characteristics of the sampling sites. Study of source specific ratios (2-nitrofluoranthene/1-nitropyrene) clearly showed those primary NPAH sources influence the urban and sub-urban sites whereas production of secondary NPAHs by gas phase reactions was prevalent at the rural site. The study of NPAH and OPAH sources suggested that gasoline engines were an important source of such compounds Whereas the dominant source of 1-nitropyrene, 2-nitrofluorene, 6-nitrochrysene and benz[a]anthracene-7,12-dione seems to be diesel vehicles. Finally, 9,10-anthraquinone presents a double origin: primary diesel emission and photochemical processes. Formation of 9,10-anthraquinone from anthracene ozonation was shown at the rural site. Further investigations will be necessary in order to discriminate when (before or during the sampling) the OPAHs are formed.

Determination of nitro-polycyclic aromatic hydrocarbons in atmospheric aerosols using HPLC fluorescence with a post-column derivatisation technique

The objective of this study was to develop an efficient and sensitive analytical protocol for the determination of nitrated polycyclic aromatic hydrocarbons (NPAHs) in aerosol samples. The separation of 16 NPAH (mono-and dinitro-PAH) was achieved by reversed-phase high-performance liquid chromatography (HPLC) followed by on-line reduction of the NPAHs to their corresponding amino polycyclic aromatic hydrocarbons (APAHs) and quantification by fluorescence detection. The main factors affecting the on-line reduction efficiency, such as the flow rate, the temperature, the position and packing of the reduction column were evaluated and optimised. The optimal conditions obtained were: packing of the reduction column with Pt-Al(2)O(3); a reduction column oven temperature of 90 degrees C; a flow rate of 0.8 mL min(-1). The resulting detection limits of the method ranged between 0.06 (2 NN) and 1.25 microg L(-1) (1.8 DNN), with an uncertainty of about 6%. The lifetime of the reduction column was identical to that of a typical analytical column. This analytical method was applied to particulate matter samples collected during December 2005 and August 2006 in Strasbourg (Alsace, eastern France). The NPAH concentrations observed for this urban site showed that the compounds are more abundant during winter (average of 534 pg m(-3)) than during summer (average of 118 pg m(-3)). 1-Nitropyrene was the predominant NPAH species, independent of season.

Detection of cocaine in the airborne particles of the Italian cities Rome and Taranto

Cocaine was first detected in the air of two Italian cities, Rome and Taranto, where it reached concentrations sometimes exceeding 100 pg/m(3), by HRGC-MS analysis of carbonaceous aerosol samples. By contrast, the drug was virtually absent in Algiers (Algeria). In Italy, atmospheric concentrations of cocaine were, on average, similar to those of other toxic pollutants like polychlorobiphenyls or nitrated polynuclear aromatic hydrocarbons, and higher than those of polychlorodibenzo-p-dioxins/polychlorodibenzofurans. The cocaine concentrations seemed to correlate with regional consumption of the drug in Rome and Taranto. By contrast, it correlated neither with nicotine or caffeine, nor with benzo[a]pyrene, the sole organic compound associated with aerosols that is quoted according to Italian legislation.

Aryl hydrocarbon receptor plays a significant role in mediating airborne particulate-induced carcinogenesis in mice

Urban particulate air pollution is associated with an increased incidence of cancers, and especially lung cancer. Organic extracts of airborne particulate matter (APM) cause cancer in mice, and PAHs adsorbed to APM are associated with particle-induced carcinogenesis. PAHs are agonists for AhR and are predominantly responsible for lung cancer through induction of highly carcinogenic metabolites. PAH metabolization requires CYP1A1 induction through activation of AhR, and therefore we hypothesized that carcinogenesis due to PAHs in APM would be reduced in AhR-/- mice. To examine this hypothesis, we performed a long-term continuous-application study of carcinogenesis in AhR-/- mice using airborne particulate extract (APE) of APM collected in Sapporo. Tumor development (squamous cell carcinoma) occurred in 8 of 17 AhR+/+ mice (47%), but no tumors were found in AhR-/-mice, and CYP1A1 was induced in AhR+/+ mice but not in AhR-/- mice. These results demonstrate that AhR plays a significant role in APE-induced carcinogenesis in AhR+/+ mice and CYP1A1 activation of carcinogenic PAHs is also of importance. Therefore, measurement of CYP1A1 induction in vitro may be useful for assessment of APM-induced carcinogenesis in humans. We also show that PAH-like compounds are major contributors to AhR-mediated carcinogenesis, whereas TCDD and related compounds make a smaller contribution.

Genotoxicity of organic extracts of urban airborne particulate matter: an assessment within a personal exposure study

Airborne particulate matter, PM(10) and PM(2.5), are associated with a range of health effects including lung cancer. Their complex organic fraction contains genotoxic and carcinogenic compounds such as polycyclic aromatic hydrocarbons (PAHs) and their derivatives. This study evaluates the genotoxicity of the PM(10) and PM(2.5) organic extracts that were sampled in the framework of a personal exposure study in three French metropolitan areas (Paris, Rouen and Strasbourg), using the comet assay, performed on HeLa S3 cells. In each city, 60-90 non-smoking volunteers composed of two groups of equal size (adults and children) carried the personal Harvard Chempass multi-pollutant sampler during 48h along two different seasons ('hot' and 'cold'). Volunteers were selected so as to live (home and work/school) in 3 different urban sectors contrasted in terms of air pollution within each city (one highly exposed to traffic emissions, one influenced by local industrial sources, and a background urban environment). Genotoxic effects are stronger for PM(2.5) extracts than for PM(10), and greater in winter than in summer. Fine particles collected by subjects living within the traffic proximity sector present the strongest genotoxic responses, especially in the Paris metropolitan area. This work confirms the genotoxic potency of particulate matter (PM(10) and PM(2.5)) organic extracts to which urban populations are exposed.

Development of analytical methods for polycyclic aromatic hydrocarbons (PAHs) in airborne particulates: a review

In the present work, the different sample collection, pretreatment and analytical methods for polycyclic aromatic hydrocarbons (PAHs) in airborne particulates is systematacially reviewed, and the applications of these pretreatment and analytical methods for PAHs are compared in detail. Some comments on the future expectation are also presented.