Particulate Polycyclic Aromatic Hydrocarbons Concentrations Research Articles

Temporal trend and long‐range transport of particulate polycyclic aromatic hydrocarbons at Gosan in northeast Asia between 2001 and 2004

The temporal trend of the particulate polycyclic aromatic hydrocarbon (PAH) level was observed at Gosan, a background site in Korea, for 4 years between November 2001 and January 2004. The total average concentration of ambient particulate PAH compounds was 3.65 ± 4.74 ng m−3, which was mainly affected by a rather small number of very high PAH level samples. The PAH level at Gosan was 1 or 2 orders higher than those at other remote sites and 1 or 2 orders lower than those in urban areas in northeast Asia. The particulate PAH concentrations were high during cold periods mainly because of the seasonal variation of fossil fuel usage amount in northeast Asia. When the PAH levels were high, the ratio of BeP‐to‐BaP was also high, which is an indicator of particle residence time in the air. On the basis of the backward trajectory and upper wind direction analyses, it was observed that when air parcels were from China, the PAH levels were high. Also, the compositions of PAH compound ratios were similar to those in Beijing in winter. These indicate influence of emissions from China, especially from coal combustion and long‐range transport. The relationship between the concentrations of PAHs and non‐sea‐salt‐(nss)‐SO42− was generally good when the PAH levels were high. However, the periods of peaks were different, implying different emission patterns.

Characterization of atmospheric particulates, particle-bound transition metals and polycyclic aromatic hydrocarbons of urban air in the centre of Athens (Greece)

The concentrations of trace metals and polycyclic aromatic hydrocarbons (PAHs) adsorbed to total suspended particulate (TSP) and finer fractions of airborne particulate matter (PM) were determined from a site in the centre of Athens (Greece), which is characterized by heavy local traffic and is densely populated, during the winter and summer periods in 2003–2004. Also, we collected and analyzed samples of diesel and gasoline exhaust particles from local vehicles (buses, taxis and private cars) and from chimney exhaust of residential central heating appliances. A seasonal effect was observed for the size distribution of aerosol mass, with a shift to larger fine fractions in winter. The most commonly detected trace metals in the TSP and PM fractions were Fe, Pb, Zn, Cu, Cr, V, Ni and Cd and their concentrations were similar to levels observed in heavily polluted urban areas from local traffic and other anthropogenic emissions. Analysis of 16 PAHs bound to PM showed that they are mostly traffic related. In general, the fine particulate PAHs concentrations were higher than coarse particles. The most common PAHs in PM 10.2 and PM 2.1 were pyrene, phenanthrene, acenapthylene and fluoranthene, which are associated with diesel and gasoline exhaust particles. The results of this study underlined the importance of local emission sources, especially vehicular traffic, central heating and other local anthropogenic emissions. Compared with other big cities, Athens has much higher levels of airborne particles, especially of the finer fractions PM 10 and PM 2.5, correlated with traffic-related air pollution.

Particulate polycyclic aromatic hydrocarbons and n-alkanes in recycled paper processing operations

The aliphatic and polycyclic aromatic fractions of dust collected in the vicinity of recycled paper processing operations were analyzed using gas chromatography/mass spectrometry. Total measured dust concentration (up to 8.73+/-2.02 mg/m3) fluctuated substantially in the different steps of paper manufacture. This was attributed to the type of the operation such as, the release of fibers and particles during paper cutting and the use of reactive chemicals and excessive water under high temperature and pressure during the bleaching and the water rinsing/drying step. Particulate polycyclic aromatic hydrocarbons (PAHs) (from fluorene to benzo[ghi]perylene with mean concentrations from 3.8+/-0.5 to 41.4+/-0.4 ng/m3) and the unresolved mixture of branched, cyclic and unsaturated hydrocarbons (UCM) were measured in all samples while, n-alkanes from n-C20 to n-C27, were only observed in cutting and packaging areas (from 180.6+/-18.9 to 4297.9+/-794.9 ng/m3). The profile of occupational PAHs in bleaching and treatment of contaminated recycled raw paper was comparable to that observed for anthropogenic activities. The values of molecular diagnostic ratios indicated the contribution of oil residues and emissions from worklifts and other equipment used for pulp and paper handling. Total benzo[a]pyrene-equivalent (BaP) concentrations of particulate PAHs (varied from 323 up to 1104 pg/m3), provided evidence that workers were exposed to high quantities of PAHs as compared with exposures to urban air and other indoor settings, posing long-term threat to their health.

Size Distributions and Dry Deposition Fluxes of Particulate Polycyclic Aromatic Hydrocarbons (PAHs) at Several Sites in Korea in 1999

The atmospheric size distributions of particulate polycyclic aromatic hydrocarbons (PAHs) and their deposition fluxes were measured at four sites in August and at three sites in November 1999, in Korea. The total ambient particulate PAHs concentrations at each site ranged between 6.7 and 128.7 ng m−3. In November, the total PAHs concentrations at Inchon (IC) were the highest, followed by Yangsuri (YS) and Seoul (SE). This trend is contrary to the expectation that the total PAHs concentrations at IC and SE be higher than that at YS because IC and SE are highly industrialized large cities and YS is rural area. The size distributions of individual PAHs in IC and SE show trimodal in Dp ≤ 9 µm while the particulate PAHs in YS were distributed evenly to fine- and coarse-size particles. These results suggest that YS has local sources in addition to transport of PAHs emitted from urban sources. The measured dry deposition fluxes of total PAHs ranged from 6.9 to 12.6 µg m−2 day−1 in August, and from 5.9 to 8.5 µg ...

Source seasonality of polycyclic aromatic hydrocarbons (PAHs) in a subtropical city, Guangzhou, South China

Mega-cities are large sources of air pollution on a regional base. Differences in energy structures, geographical settings and regional climate features lead to a large variety of air pollution sources from place to place. To understand the seasonality of air pollution sources is critical to precise emission inventories and a sound protection of human health. Based on a year-round dataset, the sources of PAHs in the air of Guangzhou were drawn by principal factor analysis (PCA) in combination with diagnostic ratios, and the seasonality of these sources were analyzed by PCA/MLR (multiple linear regressions) and discussed. The average total gaseous and particulate PAHs concentrations were 313 and 23.7 ng m − 3 , respectively, with a higher concentration of vapor PAHs in summer and particulate PAHs in winter. In addition to vehicle exhaust, which contributed 69% of the particulate PAHs, coal combustion was still an important source and contributed 31% of the particulate PAHs. Relatively constant contribution from coal combustion was found through the year, implying that coal combustion in power plants was not a seasonally dependent source. Evaporation from contaminated ground may be an important source of light PAHs in summer, providing an average contribution of 68% to the total PAHs in this study. By comparing the PAH concentrations and meteorological parameters, we found that higher concentrations of particulate PAHs in winter resulted from enhanced vehicle exhaust under low temperature and accumulation of pollutants under decreased boundary layer, slower wind speed, and long-term dryness conditions. It is suggested that the typical subtropical monsoon climate in South China, cool and dry in winter, hot and humid in summer, may play a key role in controlling the source seasonality (by enhancing vehicle exhaust in winter, ground evaporation in summer), and hence the ambient concentrations of PAHs in the air.

Polycyclic Aromatic Hydrocarbons in the Atmosphere of the Eastern Mediterranean

Atmospheric processes governing the fate of the polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of the Eastern Mediterranean were studied for a two-year period (2000-2001). Atmospheric samples were collected off-shore over the Eastern Mediterranean Sea as well as at a background station in Northeastern Crete, Greece. PAH total concentration varied from 4.1 to 57.2 ng m(-3), with >90% in the gas phase. Gas-to-particle distribution of PAHs was correlated (R2 0.75-0.98, p < 0.001) with their subcooled vapor pressure. Seasonal changes in the total concentration of PAHs were not observed, while the origin of air mass was the dominant factor determining their atmospheric concentration levels. Air masses, originating from central and eastern Europe, were associated with the highest PAH concentrations. Gas-to-particle distribution of sigmaPAHs correlated well (R2 0.75-0.98, p < 0.001) with their subcooled vapor pressure. Tropospheric ozone concentration correlated with the vapor-phase PAH concentration (p < 0.001) but less (p < 0.01) with the particulate PAH concentration. Distribution of volatile PAHs over the Eastern Mediterranean basin was uniform. Conversely, particulate PAH concentrations were higher at sampling sites located close to urban centers. Calculated relative removal rates of PAHs associated with particles were significantly higher than those of volatile members.

Trace analysis of polycyclic aromatic hydrocarbons in suspended particulate matter by accelerated solvent extraction followed by gas chromatography–mass spectrometry

An analytical procedure based on extraction by accelerated solvent extraction (ASE) followed by gas chromatography-mass spectrometry (GC/MS) analysis has been developed for the determination of particulate polycyclic aromatic hydrocarbons (PAHs) from large-volume water samples (20 L). The effect of temperature and number of cycles on the efficiency of ASE was investigated: the best results were obtained by using a temperature of 100 degrees C and one static cycle. A mixture of hexane/acetone 1:1 (v/v) was used as extraction solvent. Mean total method recovery under optimized conditions was 85%. The developed methodology was applied to the analysis of suspended particulate matter from Lake Maggiore waters (north of Italy). Mean PAH concentrations in suspended particulate matter from Lake Maggiore ranged from 0.2 ng L(-1) for anthracene to 18.7 ng L(-1) for naphthalene.

Polycyclic aromatic hydrocarbons (PAHs) in the atmospheres of two French alpine valleys: sources and temporal patterns

Abstract. Alpine valleys represent some of the most important crossroads for international heavy-duty traffic in Europe, but the full impact of this traffic on air quality is not known due to a lack of data concerning these complex systems. As part of the program "Pollution des Vallées Alpines" (POVA), we performed two sampling surveys of polycyclic aromatic hydrocarbons (PAHs) in two sensitive valleys: the Chamonix and Maurienne Valleys, between France and Italy. Sampling campaigns were performed during the summer of 2000 and the winter of 2001, with both periods taking place during the closure of the "Tunnel du Mont-Blanc". The first objective of this paper is to describe the relations between PAH concentrations, external parameters (sampling site localization, meteorological parameters, sources), and aerosol characteristics, including its carbonaceous fraction (OC and EC). The second objective is to study the capacity of PAH profiles to accurately distinguish the different emission sources. Temporal evolution of the relative concentration of an individual PAH (CHR) and the PAH groups BghiP+COR and BbF+BkF is studied in order to differentiate wood combustion, gasoline, and diesel emissions, respectively. The results show that the total particulate PAH concentrations were higher in the Chamonix valley during both seasons, despite the cessation of international traffic. Seasonal cycles, with higher concentrations in winter, are also stronger in this valley. During winter, particulate PAH concentration can reach very high levels (up to 155 ng.m-3) in this valley during cold anticyclonic periods. The examination of sources shows the impact during summer of heavy-duty traffic in the Maurienne valley and of gasoline vehicles in the Chamonix valley. During winter, Chamonix is characterized by the strong influence of wood combustion in residential fireplaces, even if the temporal evolution of specific PAH ratios are difficult to interpret. Information on sources given by PAH profiles can only be considered in qualitative terms.

Vehicle traffic as a source of particulate polycyclic aromatic hydrocarbon exposure in the Mexico City metropolitan area.

Surface properties of aerosols in the Mexico City metropolitan area have been measured in a variety of exposure scenarios related to vehicle emissions in 2002, using continuous, real-time instruments. The objective of these experiments is to describe ambient and occupational particulate polycyclic aromatic hydrocarbon (PAH) concentrations associated with vehicular traffic and facilities using diesel vehicles. Median total particulate PAH concentrations along Mexico City's roadways range from 60 to 910 ng m(-3), averaged over a minimum of 1 h. These levels are approximately 5 times higher than concentrations measured in the United States and among the highest measured ambient values reported in the literature. The ratio of particulate PAH concentration to aerosol active surface area is much higher along roadways and in other areas of fresh vehicle emissions, compared to ratios measured at sites influenced more by aged emissions or noncombustion sources. For particles freshly emitted by vehicles, PAH and elemental carbon (EC) concentrations are correlated because they both originate during the combustion process. Comparison of PAH versus EC and active surface area concentrations at different locations suggests that surface PAH concentrations may diminish with particle aging. These results indicate that exposure to vehicle-related PAH emissions on Mexico City's roadways may present an important public health risk.

POLYCYCLIC AROMATIC HYDROCARBONS OF DIESEL AND GASOLINE EXHAUST AND DNA ADDUCT DETECTION IN CALF THYMUS DNA AND LYMPHOCYTE DNA OF WORKERS EXPOSED TO DIESEL EXHAUST

Particles present in urban air pollution are mainly derived from diesel- and gasoline-fueled vehicles. Exhaust emission is able to cause several health effects in humans including mutagenicity and carcinogenicity. Polycyclic aromatic hydrocarbons (PAHs) were measured in diesel and gasoline particulate extracts and DNA binding to CT DNA (±S9 and ±XO) was investigated. A large difference in content of 14 PAHs in diesel and gasoline extracts was observed, showing higher concentration of 14 PAHs, 6 carcinogenic PAHs, benzo[a]pyrene (B[a]P) in diesel than in gasoline extracts. Selected PAH standards of B[a]P, benzo[c]fluoranthene (B[c]F), and 3-nitrobenzanthrone (NBA) were used in 32P-postlabeling/polyacrylamide gel electrophoresis (PAGE) technique to identify CT DNA adducts formed by diesel particulate extracts. CT DNA adduct formation was higher for diesel extracts in comparison with gasoline extracts; however, no clear origin of DNA adducts derived from B[c]F-, 3-NBA-, B[a]P was detected. 32P-postlabeling/PAGE was a useful assay for analyzing and identifying PAH-DNA adducts. Occupational exposure to particulate and volatile PAH concentrations were evaluated using personal air samples and lymphocyte DNA adducts as markers of exposure. Overall air PAH concentrations were low in all eight workplaces, consisting of 97% of vapor phase compounds. DNA adducts analyzed by 32P-postlabeling assay were compared between the butanol and nuclease P1 enrichment procedures. Only in winter samples of exposed workers, butanol extraction revealed significantly higher adduct levels in comparison with those of control persons. No differences in adduct levels between exposed and control persons in summer were detected by using either butanol extraction or nuclease P1 treatment. Total concentrations of particulate and volatile PAHs measured in eight workplaces in winter showed a significant correlation with total DNA adducts analyzed in workers' lymphocytes (r = 0.852N = 8, p = .007).

Polycyclic aromatic hydrocarbons in indoor and outdoor environments and factors affecting their concentrations.

A highly sensitive analytical method for the simultaneous determination of 39 gaseous and particulate polycyclic aromatic hydrocarbons (PAHs) was used to determine the PAH composition of indoor and outdoor air in Shimizu, Japan. In both indoor and outdoor air, gaseous PAH concentrations were higher in summer than in winter, whereas particulate PAH concentrations were higher in winter than in summer. Correlation analysis indicated that indoor PAH compositions, especially the gaseous PAH composition, differed significantly from outdoor PAH compositions. Gaseous PAH concentrations indoors were significantly affected by insect repellents and heating sources. Particulate PAH concentrations indoors were significantly affected by cigarette smoking, the age and type (wood) of the house, and outdoor PAH concentrations. Inhalation risk associated with carcinogenic PAHs was estimated by using toxic equivalency factors based on the potency of benzo[a]pyrene (BaP). The carcinogenicity of the indoor PAH mixture was dominated by naphthalene followed by BaP and dibenz[a,h]anthracene.

Spatial distributions and profiles of atmospheric polycyclic aromatic hydrocarbons in two industrial cities in Japan.

The spatial distribution and concentration profiles of 39 vapor and particulate polycyclic aromatic hydrocarbons (PAHs) have been investigated in two Japanese industrial cities (Fuji and Shimizu; a summer and winter season in each). The concentrations of particulate PAHs in winter tended to be higher than those in the summer, but for vapor PAHs, this was not the case. Significant correlations (p < 0.01) were found between most of the PAH concentrations monitored in winter, suggesting the presence of common emission sources. To identify PAH spatial distributions and emission sources in the area, we created contour maps for PAHs monitored; this indicates that the distinctive local distributions correspond to the emission sources. PAH profiles based on benzo[e]pyrene (BeP) concentration, especially for certain relatively heavy molecular weight PAHs, showed differential behaviors among divided areas related to potential regional emission sources such as paper-making plants, power plants, and traffic. We conclude that the origins of atmospheric PAHs in the surveyed areas were dominated by not only traffic but also by stationary emission sources such as paper-making plants and power plants and that local distributions were dependent on the local wind direction.

Study of human exposure to particulate PAHs using personal air samplers.

Three common sources of environmental exposure to particulate polycyclic aromatic hydrocarbons (PAHs) in Taiwan were chosen for this study. They are smoke of incense burning, exhausts of motor vehicles, and fumes of charcoal burning. The campus environment without any specific PAH sources (nonpoint sources) was chosen as the control. The particulate PAH concentrations in the air samples containing smoke of incense burning were only slightly higher than those in the control. However, the total concentration of particulate PAHs in the air samples with exhausts of motor vehicles and fumes of charcoal burning was about 7.5 times and 22 times higher than those observed in the control, respectively. The mean inhalation amounts of particulate PAHs per unit time are very high both in samples with exhausts of motor vehicles (13.9 ng/min) and fumes of charcoal burning (38.1 ng/min). The exposure dose of 22 PAHs per day ranged from 3.18 to 18.0 microg/day under four exposure conditions. Moreover, the personal inhalation BaP(eq) levels are in the range of 0.4 to 1.55 microg/day.

Polycyclic Aromatic Hydrocarbon Concentration and Acute Toxicity of Airborne Particulate Matter: Using Microtox as a Toxicity Screening Tool

The present study evaluated six solvent vehicles and assessed acute toxicity of airborne particles in a Microtox system. Acetone, acetonitrile, dimethyl sulfoxide (DMSO), ethanol, ethylene glycol, and methanol were chosen as carrier solvents and examined for their suitability in the Microtox bioassay at initial concentrations of 5.0, 2.5, 1.0, 0.25, and 0.08% (v/v) respectively. Air samples were collected using a high-volume sampler on the roof of a four-story building and at a traffic intersection in Tainan in southern Taiwan during 2000. Results show that DMSO, at solvent levels of not more than 2.5% (v/v), is a better and more suitable solvent vehicle for assessing the acute toxicity of airborne particles in Microtox. In addition, concentrations of airborne particulate polycyclic aromatic hydrocarbons (PAHs) varied seasonally, and generally decreased with increasing temperature (winter > fall > spring > summer). However, particulate PAH concentrations measured on the roof were much lower than those measured at the traffic intersection, by factors of about 1/43 to 1/10. Concentrations of airborne particulate PAHs showed good correlation with EC 50 values for particle-associated soluble organic fraction.

Temporal and spatial variations of the particle size distribution of PAHs and their dry deposition fluxes in Korea

The atmospheric particle size distributions between 0.1 and 100 μm in diameter and their dry deposition fluxes of polycyclic aromatic hydrocarbons (PAHs) were measured at four sites in the mid-part of Korea to characterize the spatial distribution, the PAHs levels and dry deposition. Samples were collected at Inchon, Seoul, Yangsuri, and Yangpyoung between 21 and 25 February, and between 12 and 16 May 2000. Ambient size distributions were measured with a cascade impactor and a coarse particles rotary impactor. Dry deposition fluxes of particles were measured with dry deposition plates. The total particulate PAHs concentrations are between 22.9 and 410 ng m −3 , with an average of 139 ng m −3 . The total particulate PAHs dry deposition fluxes were between 10 and 24 μg m −2 day −1 in winter, and between 4.1 and 8.2 μg m −2 day −1 in spring. Both the ambient concentrations and dry deposition fluxes of PAHs in winter are higher than spring mainly due to higher fuel consumption. The ambient concentrations of PAHs in Inchon were the highest followed by Yangpyoung, Yangsuri, and Seoul. The PAHs concentrations and fluxes of Yangsuri and Yangpyoung, rural areas in Korea, are higher than the rural areas in USA. It suggests a serious PAHs pollution level of rural areas in Korea. Based on the PAHs individual compounds’ levels and size distributions, it was suggested that Yangpyoung and Yangsuri have local PAHs sources in addition to transport from urban areas.

Analysis of particulate polycyclic aromatic hydrocarbons by on-line coupled supercritical fluid extraction–liquid chromatography–gas chromatography–mass spectrometry

An on-line supercritical fluid extraction–liquid chromatography–gas chromatography–mass spectrometry (SFE–LC–GC–MS) method was developed for the analysis of the particulate polycyclic aromatic hydrocarbons (PAHs). The limits of detection of the system for the quantification standards were in the range of 0.25–0.57 ng, while the limits of determinations for filter samples varied from 0.02 to 0.04 ng m −3 (24 h sampling). The linearity was excellent from 5 to 300 ng ( R 2>0.967). The analysis could be carried out in a closed system without tedious manual sample pretreatment and with no risk of errors by contamination or loss of the analytes. The results of the SFE–LC–GC–MS method were comparable with those for Soxhlet and shake-flask extractions with GC–MS. The new method was applied to the analysis of PAHs collected by high-volume filter in the Helsinki area to study the seasonal trend of the concentrations. The individual PAH concentrations varied from 0.015 to more than 1 ng m −3, while total PAH concentrations varied from 0.81 to 5.68 ng m −3. The concentrations were generally higher in winter than in summer. The mass percentage of the total PAHs in total suspended particulates ranged from 2.85×10 −3% in July to 15.0×10 −3% in December. Increased emissions in winter, meteorological conditions, and more serious artefacts during the sampling in summer season may explain the concentration profiles.

Simultaneous Liquid Chromatographic Determination of 39 Polycyclic Aromatic Hydrocarbons in Indoor and Outdoor Air and Application to a Survey on Indoor Air Pollution in Fuji, Japan

An analytical method was established for the simultaneous determination of 39 polycyclic aromatic hydrocarbons (PAHs) in air. The method was applied to a survey of gaseous and particulate PAHs in household indoor air. The survey was performed in 21 houses in the summer of 1999 and in 20 houses in the winter of 1999-2000 in Fuji, Japan. Thirty-eight PAHs were determined in indoor and outdoor air in the summer, and 39 PAHs were determined in indoor and outdoor air in the winter. The concentrations of gaseous PAHs in indoor air tended to be higher than those in outdoor air in the summer and winter. The concentrations of particulate PAHs in indoor air were the same as or lower than those in outdoor air in the summer and winter. PAH profiles, correlations between PAH concentrations, and multiple regression analysis were used to determine the factors affecting the indoor PAH concentrations. These results showed that gaseous PAHs in indoor air were primarily from indoor emission sources, especially during the summer, and that indoor particulate PAH concentrations were significantly influenced by outdoor air pollution.

多環芳香族炭化水素および変異原性から見た屋根流出雨水水質の流出特性

The water quality of roof runoff was investigated. The runoff characteristics of mutagenicity and polycyclic aromatic hydrocarbons (PAHs) with two to five rings were elucidated. The following results were obtained: (1) The runoff of roof deposits depended on their state and rain conditions. (2) The changes in concentration of particulate PAHs corresponded with those of suspended solids, whereas the concentrations of the soluble PAHs decreased with time because of the decrease in the rainwater concentration and the amount of detentions. (3) When the molecular weight of PAH was higher, the ratio of soluble PAH to total PAH became smaller because of the lower water solubility. (4) The partition to particulate phase was observed to be ten- to a thousand-times larger than that in the equilibrium state. (5) The major components of the particulate PAHs were four- to five-ring PAHs, while those of soluble PAHs were two- to three-ring PAHs. (6) The PAHs concentrations and mutagenicities showed a tendency to change similarly in most cases. This suggested that one of the main causes for mutagenicities was a combined effect of PAHs and their derivatives.

Particulate PAHs observed in the surrounding of a municipal incinerator

An intensive sampling campaign was undertaken in the surroundings of a municipal waste incinerator located in a French great urban centre in order to evaluate the impact of particles emissions on the ambient air and to estimate the exposure levels to toxic or carcinogenic compounds for a population living in the neighbourhood of this incinerator. To minimise the effect of industrial and road activities, sampling was performed during the 2 days of a weekend and on Monday morning. Different operating modes of the incinerator were investigated: (i) normal incinerator functioning and (ii) maintenance activity of the combustion chamber corresponding to the stop and cooling furnace periods. Particulate polycyclic aromatic hydrocarbons (PAHs) and total particulate carbon concentrations were determined in three sites situated, respectively, close to the incinerator, 2 km downwind and 1 km upwind of the plant. In normal operating mode similar concentrations were observed in the three sites. During the furnace stop an increase of total PAH concentrations was observed in the sampling site close to the incinerator. The concentration was 3 times higher than those measured in the other two sampling sites. But this increase was limited in time and in space since this phenomenon is only observed in the vicinity of the incinerator. The study of PAH profiles indicated that Pyrene and Retene showed the highest enhancement of their relative concentrations. The influence of incinerator functioning parameters on the PAHs concentrations is discussed. The furnace temperature and the mode of exhaust fumes seem to be deciding parameters to explain the increase of PAH level in the incinerator site. However, the incinerator emissions remained a minor part of the atmospheric pollution in the urban area.

Particle-size distribution of PAH in the air of a remote Norway Spruce forest in Northern Bavaria

The aim of the present study was to elucidate thedistribution of particulate polycyclic aromatichydrocarbons (PAH) in the air of a remote Norwayspruce (Picea abies (L.) karst.) stand.The study encompassed a total of twenty differentcongeners. Particles in ambient air were alternativelycollected by two different Berner cascade impactors atthe field site in Northern Bavaria over a 14-weeksperiod from the end of April through to the end ofJuly 1994 and subsequently analyzed for their PAHcontent. The concentrations of total suspendedparticulate matter (TSP) ranged from 9–31 μg m-3,suggesting that the field site is an area with a lowlevel of airborne particles. There was a negativerelationship of total particle concentrations with theamount of canopy precipitation due to particle washout at precipitation events. The distribution of theparticle masses on the different size fractions witha maximum in the 1-μm range is typical for remoteareas and indicates a medium-range transport. Theaerosol-bound PAH load decreased from spring sampleswith 2–4 ng m-3 to values <1 ng m-3 in the summersamples. Concurrently, the proportion of low molecularweight congeners in the total PAH load declined.Frequently, the highest PAH concentrations (referringto the air) were found in the 0.1–3 μm sizeseparates (accumulation mode). The results suggestthat apart from PAH input to the soil with litter, dryand wet deposition of aerosol particles is animportant pathway of PAH contamination of acid forestsoils in the Fichtelgebirge mountain range.