Characteristic of polycyclic aromatic hydrocarbon concentrations and source identification for fine and coarse particulates at Taichung Harbor near Taiwan Strait during 2004-2005

Fine (PM(2.5)) and coarse (PM(2.5-10)) particulate concentrations of ambient air polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously from February 2004 to January 2005 at the Taichung Harbor (TH) sampling site near Taiwan of central Taiwan. Particle-bound polycyclic aromatic hydrocarbons (PAHs) were collected on quartz filters; the collected sample was Soxhlet extracted with a dichloromethane (DCM)/n-hexane mixture (50/50, v/v) for 24 h, and then the extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). The results indicated that vehicle emissions, coal combustion, incomplete combustion and pyrolysis of fuel and oil burning were the main source of PAHs near Taiwan Strait of central Taiwan. Diagnostic ratios and principal component analysis (PCA) were also used to characterize and identify PAHs emission sources in this study.     

The PM2.5 and PM10 particles in urban areas of Taiwan

This study conducted an atmospheric aerosol sampling to measure the PM10 (particles < 10 microns in aerodynamic diameter) and PM2.5 (particles < 2.5 microns in aerodynamic diameter) mass concentrations from October 1996 to June 1997 in northern (Taipei), central (Taichung) and southern (Kaohsiung), the three largest cities of Taiwan. Seventy-eight samples were obtained to measure the mass concentrations of PM10 and PM2.5 from nine sampling sites. According to those results, the PM10 mass concentrations in Taipei, Taichung and Kaohsiung were 42.19, 60.99 and 77.10 micrograms/m3, respectively. The corresponding PM2.5 mass concentrations were 23.09, 39.97 and 48.47 micrograms/m3, respectively. The PM2.5 fraction accounted for 61-67% of the PM10 mass in central and southern Taiwan, but was lower (54-59%) in northern Taiwan. Some samples in which the PM2.5 fraction was overwhelmingly dominant could reach as high as 80-95% of the PM10 mass. In addition, the PM2.5, PM10 levels and PM2.5/PM10-2.5 (particles with aerodynamic diameters ranging from 2.5 to 10 microns) ratios in metropolitan Taiwan significantly fluctuated from site-to-site and over time. Moreover, ambient daily PM2.5 and PM10-2.5 mass concentrations did not correlate well with each other at most of the sampling sites, indicated that they originated from different kinds of sources and emitted variedly over time.     

Characterization of chemical species in PM2.5 and PM10 aerosols in suburban and rural sites of central Taiwan.

Aerosol samples for PM2.5 (particulate matter with aerodynamic diameters less than 2.5 microns), PM2.5-10 (particulate matter with aerodynamic diameters between 2.5 and 10 microns) and TSP were collected from June to September 1998 at THU (suburban) and HKIT (rural) sites in central Taiwan. The ratios of PM2.5/PM10 averaged 0.70 for the daytime and 0.63 for the nighttime at THU, respectively. At HKIT, the PM2.5/PM10 ratios averaged 0.56 for the daytime and 0.72 in the nighttime, respectively. These results indicated that the PM2.5 concentrations contribute the majority of the PM10 concentration and PM10 concentrations contribute the majority of the TSP at both sites. The averaged PM2.5 concentrations at THU are higher than those measured at HKIT during the daytime period. However, the average PM2.5-10 concentrations in THU are lower than those measured at HKIT during nighttime. The samples collected were also analyzed by atomic absorption spectrophotometry for the elemental analysis of Ca, Fe, Pb, Zn, Cu, Mn and Cr. Meanwhile ion chromatography was used to analyze for the water-soluble ions: sulphate, nitrate and chloride in the Universal samples. The concentrations of heavy metals in PM10 during daytime were all higher than nighttime at THU. However, the averaged concentrations of metal elements in PM10 during day and night period were distributed irregularly at HKIT. The results indicated that for metal elements collected at HKIT have different emission sources. The concentrations of metal elements during daytime in PM10 at THU were generally higher than HKIT. The phenomena owing to the averaged PM2.5 particle concentrations at THU (suburban) were higher than those measured at HKIT (rural) and PM2.5 occupied the major portions of PM10 for both sites during the day period. For anion species, there are no significant differences between day and night period in PM10 concentrations at both suburban and rural sites.     

Source impacts by volatile organic compounds in an industrial city of southern Taiwan

This study investigates source impacts by airborne volatile organic compounds (VOC) at two sites designated for traffic and industry, in the largest industrial area Kaohsiung, southern Taiwan. The samples were collected at the two sites simultaneously during rush and non-rush hours in summer and autumn seasons. Same pattern of VOC groups were found at both sites: most abundant aromatics (78-95%) followed by alkanes (2-16%) and alkenes (0-6%). The BTEX concentration measured at the two sites ranged from 69 to 301 ppbC. Toluene, isopentane, ethylbenzene, and benzene were found to be the most abundant species. Speciation of VOCs was characterized with several skills including principal component factor analysis and BTEX characteristic ratios. Each of the resulted principal factors at the two sites explained over 80% of the VOCs data variance, and indicated that both of the sampling sites were influenced by both traffic and industrial sources with separately different levels. The remarkable patterns of the first two factors described not only the similarity but also the discrepancy at the two sampling sites, in terms of the source impacts. The high T/B ratios (7.56-14.25) observed at the industrial site implied the important impact from mobile emissions. The indicators, m,p-xylene/benzene and o-xylene/benzene, also confirmed the potential source of motor vehicles at both of the sampling sites. Air age assessment showed that more than half of the total observations located in the domain of fresh air. Low X/E ratios implied somewhat aged air mass transported to the sampling sites. The industrial site might not only encounter emissions from the industry sources, but also under unavoidable impact from the traffic sources.     

Metallic elements study on fine and coarse particulates during daytime and nighttime periods at a traffic sampling site

Fine (PM2.5) and coarse (PM(2.5-10)) particulates were collected simultaneously by using a versatile air pollutant system at a traffic sampling site during daytime and nighttime sampling periods during August 2003 to March 2004. A flame atomic absorption spectrophotometer coupled with hollow cathode lamps were used for chemical analysis. Enrichment factor and principal component analysis were used to compare chemical components and to find the possible emission sources at this traffic sampling site. The variation of metallic element concentrations on fine and coarse particulates during daytime and nighttime was also discussed in this study. Soil dust, traffic exhaust, marine salt and anthropogenic activities were the major pollutant sources at the traffic sampling site in central Taiwan.     

Spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Xiamen, China

An intensive sampling program was conducted from October 2008 to September 2009 at the five different environmental sites in Xiamen, Fujian Province, to study the spatial and temporal characteristics of Polycyclic Aromatic Hydrocarbons (PAHs) in the gaseous and particulate phase, respectively. The PAHs concentrations at different sites were quite distinct during four seasons. The average concentrations of PAHs in winter were about 8.4 times higher than those in spring, and the concentrations of background were 0.56 times lower than those of industrial area. In addition, the higher temperature in summer affected the particle/gas partitioning of PAHs and led to the higher concentrations of gaseous PAHs. Diagnostic ratios of PAHs, which were employed to indicate the primary sources of PAHs in Xiamen, showed that the traffic vehicle exhaust was the largest contributor and the primary source for PAHs in Xiamen, especially in urban area; while the stationary combustion processes, such as petrochemical factories and power plants, were mainly responsible for PAHs sources in the industrial areas. The health risk of PAHs in the particulate phase was higher than those of the gaseous phase at the five sampling sites. The average toxic equivalent (BaP_eq) of the benzo[a]pyrene values for PAHs were 0.14, 0.32, 1.38 and 3.59 ng m^− 3 in spring, summer, autumn and winter, respectively. Furthermore, the results of average BaP_eq in all four seasons indicated that the health risks of particulate PAHs were higher than those of the gaseous PAHs at different sampling sites.     

Distributions of polycyclic aromatic hydrocarbons in surface waters, sediments and soils of Hangzhou City, China

Ten polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured in 17 surface water samples and 11 sediments of four water bodies, and 3 soils near the water-body bank in Hangzhou, China in December 2002. It was observed that the sum of PAHs concentrations ranged from 0.989 to 9.663 microg/L in surface waters, from 132.7 to 7343 ng/g dry weight in sediments, and from 59.71 to 615.8 ng/g dry weight in soils. The composition pattern of PAHs by ring size in water, sediment and soil were surveyed. Three-ring PAHs were dominated in surface waters and soils, meanwhile sediments were mostly dominated by four-ring PAHs. Furthermore, PAHs apparent distribution coefficients (K(d)) and solid f(oc)-normalized K(d) (e.g. K(oc)= K(d) / f(oc)) were calculated. The relationship between logK(oc) and logK(ow) of PAHs for field data on sediments and predicted values were compared. The sources of PAHs in different water bodies were evaluated by comparison of K (oc) values in sediments of the river downstream with that in soils. Hangzhou section of the Great Canal was heavily polluted by PAHs released from industrial wastewater in the past and now PAHs in sediment may serve as sources of PAHs in surface water. PAHs in Qiantang River were contributed from soil runoff. Municipal road runoff was mostly contributed to West Lake PAHs.     

PAH content, toxicity and genotoxicity of coastal marine sediments from the Rovinj area, Northern Adriatic, Croatia

Surface marine sediments collected from 8 sampling sites within the Rovinj coastal area, Northern Adriatic, Croatia, were used for determining priority pollutant polycyclic aromatic hydrocarbons (PAHs) and toxic/genotoxic potential of sediment organic extracts. Total PAH concentrations ranged from 32 microg/kg (protected area) to 13.2 mg/kg dry weight (harbor) and showed clear differences between pristine, urban industrial and harbor areas. PAHs distribution revealed their pyrogenic origin with some biogenic influence in harbor. At all sampling sites sediment extracts showed toxic potential that was consistent with the sediment type. No correlation between toxicity measured by Microtox assay and concentrations of individual or total PAHs was found. Noncytotoxic dose of sediment extracts showed no genotoxic potential in bacterial umu-test. DNA damage is positively related to total PAHs at 4 sampling sites (S-1, S-2, S-3, S-6), but the highest DNA damage was not observed at the site with the highest total sediment PAH content (S-5).     

Concentration of atmospheric particulates during a dust storm period in central Taiwan, Taichung

In this study we monitored concentrations of particles in central Taiwan using PS-1 (GPS1 PUF Sampler) and Model 310 Universal Air Sampler (UAS) from 02/23/2001 to 03/12/2001 at two sampling sites. During this period, an Asian dust storm moved across central Taiwan from 3/3 to 3/6. The total ambient air particle concentrations during the dust storm period were than compared with previous data from this region. In general, the average total suspended particulate (TSP) concentration order was during dust storm period > after dust storm period > non-dust storm period at both HKITT (traffic) and THUC (rural) sampling sites. The ratio of PM2.5/PM10 was 60% before and after the dust storm period. However, this ratio was decreased to less than 50% during the dust storm. This demonstrates that the coarse particulate concentrations (PM2.5-10) increased during the dust storm period. In contrast the increase of ambient air particles concentrations after the Taiwan Chi-Chi Earthquake were mainly due to fine particles (PM2.5). And, the increased of ambient air particles concentrations after dust storm period were mainly coarse particle (PM2.5-10) concentrations in central Taiwan.     

Polycyclic aromatic hydrocarbons associated with particles in ambient air from urban and industrial areas

This study takes into consideration an analysis of the chemical polycyclic aromatic hydrocarbon (PAH) profile and its distribution in inhalable and respirable particulate matter in urban and industrial areas in La Plata, Argentina, and Leipzig, Germany. Representative samples from three locations in La Plata (industrial, traffic influenced and control area) and two locations in Leipzig (traffic influenced and control area) were obtained in summer and winter. The sampling of particulate matter was carried out with high volume collectors using cascade impactors to separate six size fractions. PAHs were extracted with hexane through a solid-liquid equilibrium extraction and analysed by HPLC/UV/fluorescence detection. The results showed a PAH seasonal behaviour in both regions, with lower contents in summer and higher ones in winter. Highest concentrations of total PAHs were found in the industrial area in La Plata. The size distribution of particles demonstrates the greater relevance of smaller particles. More than 50% of PAHs were associated with particles of less than 0.49 microm. Moreover, this particle size fraction was associated with traffic, whereas other sources of combustion were related also to particles between 0.49 and 0.95 microm. Considering the ratio of benzo(ghi)perylene (BgP)/benzo(a)pyrene (BaP) as an indicator for traffic influence, it was observed that La Plata City was more affected than Leipzig by the same proportion in summer and in winter. The BgP/InP (indeno(123-cd)pyrene) ratio was lower in winter than in summer in both places and indicates the presence of domestic combustion sources. It is important to point out the significance of using fingerprint compound ratios to identify possible sources of pollution with PAHs bound to particles.     

Characterization and distribution of polycyclic aromatic hydrocarbon contaminations in surface sediment and water from Gao-ping River, Taiwan

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples collected from 12 locations in Gao-ping River, Taiwan were analyzed. Molecular ratios and principal component analysis (PCA) were used to characterize the possible pollution sources. Concentrations of total 16 PAHs (SigmaPAHs) in water samples ranged from below method detection limits (相似文献   

Health risk assessment for traffic policemen exposed to polycyclic aromatic hydrocarbons (PAHs) in Tianjin, China

In China, traffic policemen have to stand for several hours a day at the road intersections with high vehicle flows. To assess their exposure to airborne carcinogenic polycyclic aromatic hydrocarbons (PAHs) during their working time, a preliminary study was conducted to measure the personal exposure level to PAHs. And a probabilistic incremental lifetime cancer risk (ILCR) model together with the benzo[a]pyrene (BaP) toxic equivalents (BaP(eq)) method was used to conduct health risk assessment. Personal exposure monitors (PEM) were carried by traffic policemen to collect PM10 samples during their daily work in Tianjin, China. Meanwhile, PM100 samples were collected at the roadsides and on campus of Nankai University as comparison. PAHs species were quantitatively analyzed by GC/MS. Experimental results showed that the concentrations of total PAHs, BaP and BaP(eq) were much higher at the road intersections (867.5, 26.2, 82.4 ng m(-3)), where the traffic policemen stand during their work time, than those at the roadsides (46.6, 1.5, 5.7 ng m(-3)), and on campus (19.5, 0.7, 2.4 ng m(-3)). According to the risk assessment results, the occupational risk falls within the range from 10(-6) to 10(-3). On the basis of sensitivity analysis results, further research should be directed to give better characterization of the yearly concentration distribution of PAHs and the cancer slope factor (CSF) of BaP in order to improve the accuracy of the health risk assessment.     

The relationship between volatile organic profiles and emission sources in ozone episode region-a case study in Southern Taiwan

This study investigates the relationship between volatile organic profiles in the atmosphere and emission sources in an ozone non-attainment in region Southern Taiwan. Dynamometer test of vehicles and stack sampling from industrial facilities were conducted to obtain the fingerprints of emissions from on-road mobile sources and stationary sources, respectively. In addition, field sampling of non-methane organic compounds (NMOC) concentration at monitoring stations during episode seasons were also collected by canisters. The influences of different emissions sources on airborne concentrations were estimated by back-trojectory analysis and chemical mass balance model (CMB 8.0) calculation. Field measurement data indicated that the daily average concentration of NMOC ranges between 26.4 and 69.8 ppb at different sites. The mass fraction for paraffins, oleffins and aromatics in airborne samples at these sites were 28-47%, 7-12% and 41-52%, respectively. Toluene was the dominant species among these species, followed by isopentane, n-butane and 1,2,4-trimethylbenzene. The source apportionment of airborne NMOC in the ozone non-attainment region, based on CMB simulation, is passenger cars (28-51%), motorcycles (9-24%), industrial sources (14-33%), solvent application (13-46%) and biogenic emissions (< 1-2.4%), respectively. Both field measurement and model analysis showed that the vehicle exhaust and industrial emission are the dominant contributors of NMOC in the region.     

Inhalation exposure of traffic police officers to polycyclic aromatic hydrocarbons (PAHs) during the winter in Beijing, China

This study concerns the use of personal samplers to evaluate the exposure of traffic police to polycyclic aromatic hydrocarbons (PAHs) during the winter of 2005 in Beijing. We measured the samples collected for gas and particulate phases PAHs with the same technique used for an earlier study during the summer of 2004, and evaluated exposure risk based on the calculated benzo(a)pyrene equivalent concentrations (BaP(eq)) of both summer and winter. The mean exposure concentrations of gaseous and particulate phase PAHs in the winter are 4300+/-2900 ng/m(3) and 750+/-1000 ng/m(3), respectively, significantly higher than those measured simultaneously at control sites and also considerably higher than the values measured during the summer. The exposure PAH profiles for police and the control subjects are similar with predominant naphthalene in gaseous phase and dominant fluoranthene, pyrene, anthracene and naphthalene in particulate phase. Large daily variations occur both in summer and winter, because of the changes in the weather conditions especially wind speed and relative humidity which tend to disperse and scavenge PAHs in air. In the winter, the average BaP(eq) value for traffic police is 82.1 ng/m(3), which is significantly higher than those for the control subjects and the national standard of 10 ng/m(3) for ambient air. Particulate phase PAHs contribute more than 90% of the total exposure risk in the winter. Annually, weighted-average probabilities of exceeding the national standard (10 ng/m(3)) are 69.3% and 20.6% for the police and the controls, respectively.     

Characterization of road traffic noise exposure and prevalence of hypertension in central Taiwan

Epidemiological studies have demonstrated that road traffic noise exposure is associated with hypertension in European, but the associations related to traffic sources and in other population are unclear. This study investigated the association between road traffic noise exposure and the prevalence of diagnosed hypertension among 321 male and 499 female resided near main roads in Taichung, Taiwan. Road traffic noise levels and traffic flow rates were measured simultaneously during 0900-1700 on weekdays in 2008. Multivariate logistic regressions were applied to estimate odds ratios (ORs) for hypertension by adjusting for potential confounders. Road traffic noise levels were significantly associated with traffic flow rates of motorcycles, light-duty gasoline vehicles, light-duty diesel trucks and heavy-duty diesel trucks and had the highest correlation with motorcycles. Per one unit (vehicle per hour) increase in the log-transformed traffic flow rate of motorcycles was significantly related to the increment of 7.20 ± 1.40 A-weighted decibels (dBA) in the traffic noise exposure. The high-exposure group (82.2 ± 1.7 dBA, n = 358) had the significantly higher prevalence of hypertension (adjusted OR = 2.15, 95% CI = 1.08-4.26) than the low-exposure group (77.2 ± 1.6 dBA, n = 462). There was an increasing trend (p = 0.023) between the prevalence of hypertension and residents exposed to < 77 dBA, 77-80 dBA, 80-83 dBA and ≥ 83 dBA, respectively. Such an association was pronounced after adjusting for the total traffic flow rate. The study findings suggest that road traffic noise exposure may be associated with hypertension and the dominant source of traffic noise is motorcycles in central Taiwan.     

Gradient distribution of persistent organic contaminants along northern slope of central-Himalayas, China

High mountains may serve as condenser for persistent organic pollutants (POPs) and the vegetation in remote areas has been used as a means to characterized atmospheric concentrations of air pollutants. In this study, organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in Himalayan spruce needle samples from Zhangmu-Nyalam region (central-Himalayas) were analyzed and the altitudinal gradient of these pollutants was investigated. Total HCHs and DDTs concentration in needles were in the range of 1.3-2.9 ng g(-1) dry weight and 1.7-11 ng g(-1) dry weight, which were lower than concentrations reported in spruce needles from Alps, however higher than concentrations in conifer needles from mountain areas of Alberta. Total Himalayan spruce needle PAHs was below 600 ng g(-1) and fluorene, phenanthrene and acenaphthene were abundant individual compounds measured. The ratios of alpha-HCH/gamma-HCH in pine needles were similar with the usual values for technical HCH, implying technical HCHs might be used in this region. The high ratios of o-p'-DDT/p-p'-DDT and no p-p'-DDE measured in this study led to the suspicion that a new source of o-p'-DDT and/or p-p'-DDT existed in this region. In addition, higher ratios of low molecular weight-/high molecular weight-PAHs in this region indicated that petroleum combustion, vehicle emission and low-temperature combustion might be the major contributions of PAH source. To examine the POPs distillation, the analyte concentrations were correlated with altitude. The more volatile OCPs, alpha-HCH, gamma-HCH, aldrin and alpha-endosulfan positively correlated with altitude, however, less volatile OCPs (DDT and DDD) inversely related with elevation. Almost all PAHs detected in this area showed positive correlations with altitude. It is worthy to note that heavy PAHs (Benzo[k] fluoranthene and Benzo[a]anthracene) displayed positive correlation, which implied the sources of PAHs were near the sampling sites. The distillation of POPs was strongly affected by the proximity between sampling sites and contaminant sources. If the contaminant sources are close to the mountains, it may be the dominant factor that controls the concentration gradient.     

Source apportionment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Huangpu River, Shanghai, China

We applied cluster analysis and principal component analysis (PCA) with multivariate linear regression (MLR) to apportion sources of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Huangpu River in Shanghai, China, based on the measured PAH concentrations of 32 samples collected at eight sites in four seasons in 2006. The results indicate that petrogenic and pyrogenic sources are the important sources of PAHs. Further analysis shows that the contributions of coal combustion, traffic-related pollution and spills of oil products (petrogenic) are 40%, 36% and 24% using PCA/MLR, respectively. Pyrogenic sources (coal combustion and traffic related pollution) contribute 76% of anthropogenic PAHs to sediments, which indicates that energy consumption is a predominant factor of PAH pollution in Shanghai. Rainfall, the monsoon and temperature play important roles in the distinct seasonal variation of PAH pollution, such that the contamination level of PAHs in spring is significantly higher than in the other seasons.

Brief

We apportion PAHs in surface sediments of the Huangpu River and show that coal combustion, traffic-related pollution, and petroleum spillage are the major sources.     

Polycyclic Aromatic Hydrocarbons (PAHs) in urban topsoils: Concentration and source analysis in Xuzhou,China

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants in urban environments and are considered as the priority pollutants by the US Environmental Protection Agency (EPA). In this study, surface soils (0–10 cm) samples from 41 sampling sites in Xuzhou (China) were collected and analysed for 16 EPA priority polycyclic aromatic hydrocarbons via gas chromatograph/mass spectrometry (GC-MS). Total PAHs concentrations were in the range of 526 to 8612 ng/g with a mean of 2468 ng/g. Total PAHs concentrations were compared to guideline and results showed that nearly all urban soils in our study can be classified as heavily contaminated (>1000 ng/g). Carcinogenic PAHs were detected in relatively high concentrations and contributed 40.2% of the total PAHs in the urban soils. Multivariate statistical analysis including cluster analysis and factor analysis were performed and grouped the 16 PAHs under 2 clusters, which could indicate that the PAHs had different origins. The values of PAHs isomer indicated that vehicular emission might contribute to the soil PAHs in urban topsoils. The carcinogenic potency of PAH compounds was calculated and was found to be insignificant at the present level of emissions in Xuzhou.     

Homologue and isomer distribution of dioxins observed in water samples collected from Kahokugata Lagoon and inflowing rivers, Japan

Water samples were collected at 17 sites in Kahokugata Water Basin, a closed water basin in central Japan. We determined the concentration of dioxins of the water samples. Linear relationships between toxic equivalent (TEQ) concentrations of dioxin and concentrations of suspended solid (SS) were obtained at sites in Kahokugata Lagoon and in the rivers flowing into the lagoon. Homologue composition of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) indicated that all the water samples were still strongly influenced by chlorinated herbicides, such as chloronitrofen (CNP) and pentachlorophenol (PCP) that had been widely used in rice fields. The main isomer distributions of the PCDD homologues were not significantly different among the sampling sites, while the main isomer distributions of the PCDF homologues were considerably different among the sampling sites. At a few sampling points in the downstream part of one of the rivers, high concentrations of 1,3,6,7,8-pentachloro dibenzofuran (1,3,6,7,8-PeCDF) and its related isomers (1,3,6,8-chlorine-substituted PCDFs) were traced to a dye manufacturing plant. These non-toxic isomers are usually only minor constituents in environmental water samples and are not indicators of any known dioxin sources. The dyeing discharge was found to make a contribution only in the water samples collected near the plant and the seasonal variation of the contribution might depend on the flow rate of the river.     

Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in mosses (Hypnum cupressiforme) in Hungary

The atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) was investigated in Hungary by analyzing a moss (Hypnum cupressiforme) species as a bioindicator. In the autumn of 1997, samples were collected at 29 sites distributed across Hungary. The concentrations of total PAH at these sites were in the range of 0.1567-10.45 x 10(4) microg kg(-1) with a mean value of 1.87 x 10(4) microg kg(-1). More than 99% of the total PAHs atmospheric deposition were low molecular weight PAHs (up to 3 ring compounds). The total PAH values showed no correlation with metal concentrations. However, most of the sites in this region showed a positive linear relationship between PAHs levels and traffic volume (r2 = 0.83; P < 0.001) while no relationship existed between PAH levels and population (r2 = 0.01; P > 0.1). Atmospheric deposition of PAHs at different regions in Hungary may be due to incomplete combustion of fuel. The total concentrations of PAHs were compared to the PAH levels in vegetation samples collected from different regions around the world. The highest PAHs concentrations accumulated were found in Hypnum cupressiforme than other vegetation species. A greater affinity for PAH compounds by Hypnum cupressiforme than other moss species probably caused larger amounts of accumulation. A relationship between accumulations of PAH compounds in Hypnum cupressiforme and octanol-air partition coefficients was obtained and is briefly discussed.