Temporal and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in the Danube River in Hungary

The Danube is a significant transboundary river on a global scale, with several tributaries. The effluents from industrial operations and wastewater treatment plants have an impact on the river's aquatic ecosystem. These discharges provide a significant threat to aquatic life by deteriorating the quality of water and sediment. Hence, a total of 16 Polycyclic Aromatic Hydrocarbons (PAHs) compounds were analyzed at six locations along the river, covering a period of 12 months. The objective was to explore the temporal and spatial fluctuations of these chemicals in both water and sediment. The study revealed a significant fluctuation in the concentration of PAHs in water throughout the year, with levels ranging from 224.8 ng/L during the summer to 365.8 ng/L during the winter. Similarly, the concentration of PAHs in sediment samples varied from 316.7 ng/g in dry weight during the summer to 422.9 ng/g in dry weight during the winter. According to the Europe Drinking Water Directive, the levels of PAHs exceeded the permitted limit of 100 ng/L, resulting in a 124.8% rise in summer and a 265.8% increase in winter. The results suggest that the potential human-caused sources of PAHs were mostly derived from pyrolytic and pyrogenic processes, with pyrogenic sources being more dominant. Assessment of sediment quality standards (SQGs) showed that the levels of PAHs in sediments were below the Effect Range Low (ERL), except for acenaphthylene (Acy) and fluorene (Fl) concentrations. This suggests that there could be occasional biological consequences. The cumulative Individual Lifetime Cancer Risk (ILCR) exceeds 1/104 for both adults and children in all sites.

A century-long record of polycyclic aromatic hydrocarbon deposition in the Old Yellow River Estuary, China

Polycyclic aromatic hydrocarbons (PAHs) are potential geochemical indicators for assessing the impact of human activities and can be used to reconstruct historical human activities. This study collected a 108 cm sediment core from the 5th lobe of the Yellow River Delta for the first time and analyzed the historical distribution characteristics of PAHs in this area. The results showed that the sedimentation history of the core was from 1908 to 2014. The average value of PAHs was 28.93 ng/g. Biomass and coal combustion sources were the main sources of PAHs in the low-value areas, while oil spill sources were the main sources in the significantly higher PAHs areas in the 1960s, mid-1980s, late 1990s, and late 2010s, which was consistent with the development history of Shengli Oilfield. Compared with global estuaries, the historical industrial activity intensity in this area was weaker.

Emission profiles, source identifications, and health risk of polycyclic aromatic hydrocarbons (PAHs) in a road tunnel located in Xi'an, China

Understanding the sources and characteristics of PM2.5-bound PAHs from traffic-related pollution can provide valuable data for mitigating air contamination from traffic in local urban regions. However, little information on PAHs is available regarding the typical arterial highway-Qinling Mountains No.1 tunnel in Xi'an. We estimated the profiles, sources, and emission factors of PM2.5-bound PAHs in this tunnel. The total PAH concentrations were 22.78 ng·m-3 and 52.80 ng·m-3 at the tunnel middle and exit, which were 1.09 and 3.84 times higher than that at the tunnel entrance. Pyr, Flt, Phe, Chr, BaP, and BbF were the dominant PAH species (representing approximately 78.01% of total PAHs). The four rings PAHs were dominant (58%) among the total PAH concentrations in PM2.5. The results demonstrated that diesel and gasoline vehicles exhaust emissions contributed 56.81% and 22.60% to the PAHs, respectively, while the corresponding value for together brakes, tyre wear, and road dust was 20.59%. The emission factors of total PAHs were 29.35 μg·veh-1·km-1, and emission factors of 4 rings PAHs were significantly higher than those of the other PAHs. The sum of ILCR was estimated to be 1.41×10-4, which accorded with acceptable level of cancer risk (10-6-10-4), PAHs should not ignored as they still affect the public health of inhabitants. This study shed light on PAH profiles and traffic-related sources in the tunnel, thereby facilitating the assessment of control measures targeting PAHs in local areas.

Biomonitoring of polycyclic aromatic hydrocarbons (PAHs) by Murraya paniculata (L.) Jack in South Kolkata, West Bengal, India: spatial and temporal variations

Attempts have been made in the present study for ascertaining the concentrations of atmospheric polycyclic aromatic hydrocarbons (PAHs) using passive biosamplers in preference to conventional air sampling methods. Mechanical stirring, sonication, Soxhlet technique and microwave-assisted Soxhlet extraction (MASE) were employed to extract PAHs from an evergreen plant (Murraya paniculata) leaves (having long life-span) sampled from polluted places of South Kolkata, India, with dense population and heavy traffic. Effects of extraction methods and operational parameters (solvent and time) on the recovery levels of PAHs were also investigated. Purified extracts, acquired through adsorption chromatography, were subjected to GC-MS and HPLC-UV analyses for qualitative and quantitative assessment of PAHs. Spatio-temporal distribution of accumulated PAHs across the sampling sites was monitored over premonsoon, postmonsoon and winter supported by pollutant source characterization. The results displayed that the extraction yields of Soxhlet (272.07 ± 26.15 μg g-1) and MASE (280.17 ± 15.46 μg g-1) were the highest among the four techniques. Conditions of extraction with toluene for 6 h were found to be most favorable for PAHs. In spatio-temporal analysis, total concentrations of PAHs in the foliar samples varied from 200.98 ± 2.72 to 550.79 ± 10.11 μg g-1 dry weight, and the highest values being recorded in the samples of Exide More because of daylong inexorable traffic flow/crowding increasing the burden of ambient PAHs. Widespread changes in meteorology exerted influence on seasonal concentrations of PAHs in plant leaves, and extent of leaf contamination by PAHs was observed extreme in winter followed by postmonsoon and then, premonsoon. Foliar accretion of PAHs differed in the study sites with diverse sources of emission from motor vehicles, fossil fuel and biomass burning along with other human interferences.

Investigation of the spatial distribution of airborne polycyclic aromatic hydrocarbons using Rhytidiadelphus squarrosus in Tórshavn, Faroe Islands

Due to adverse effects of Polycyclic Aromatic Hydrocarbons (PAHs) on human health, it is important to understand how airborne PAHs, are spatially distributed within urban areas. Moss has been shown to be a suitable material for biomonitoring of airborne PAH pollution. In this study, the moss Rhytidiadelphus squarrosus was sampled throughout Tórshavn, Faroe Islands. 53 Rhytidiadelphus squarrosus samples were extracted using a matrix solid-phase dispersive extraction method and analysed for 19 parent PAHs and six groups of alkylated PAHs using gas chromatography mass-spectrometry. All PAHs were quantified in at least one Rhytidiadelphus squarrosus sample, and the sum of the EPA 16 PAHs (ƩPAH_EPA16) ranged from 0.90 to 344 µg kg^-1 dry weight. Higher concentrations were found close to the harbour and the main roads. The spatial correlation was investigated for the ƩPAH_EPA16, pyrene, fluoranthene, chrysene, benzo(e)pyrene, benzo(g,h,i)perylene, C1-phenanthrenes/C1-anthracenes, and C2-phenanthrenes/C2-anthracenes using variograms. The effective range of the spatial correlation was between 500 to 700 m of all PAHs. The evaluation of diagnostic ratios of fluoranthene to pyrene, and benzo(a)anthracene to chrysene suggest that different pollution sources affect urban areas of different types. To the best of our knowledge, this is the first time airborne PAH pollution patterns were mapped in an Arctic town, and the first time, Rhytidiadelphus squarrosus was used for tracing PAH pollution sources. Rhytidiadelphus squarrosus is suitable for biomonitoring and mapping PAH pollution within urban areas since it is widespread, and suitable for mapping PAHs.

Polycyclic aromatic hydrocarbons in the surface water and sediment along Euphrates River system: Occurrence, sources, ecological and health risk assessment

This study presented for the first time a comprehensive measurement campaign of 16 PAHs along the Euphrates River for five months, in both water and sediment samples. Our study revealed that the PAHs contamination increased along the flow direction due to the increasing non-point pollution and the return flows of agriculture. The 5-6 rings PAHs were dominant in water and sediment samples with an average of 42 % and 50 %, respectively. The diagnostic ratios of PAHs suggest that the pollution of these compounds originated mainly from petroleum product combustions. The carcinogenic PAHs formed 46 % and 55 % of the total measured compounds in water and sediment samples, respectively, which highlights potential ecological and human health risks. Based on sediment quality guidelines (SQGs), most sites exhibit an effect range between low and medium. The calculated incremental lifetime cancer risk (ILCR) for adult and children were in the 10^-2-10^-3 range, which is 3-6-fold higher than what was reported in the literature. These observations call for urgent attention from environmental authorities of countries sharing this key water source in Western Asia.

Chemometric techniques in oil spill identification: A case study in Dalian 7.16 oil spill accident of China

Chemometric methods have unique advantages regarding comprehensive consideration of multiple parameters and the classification of samples or variables. Classification of oil spill sources was carried out by using chemometric techniques, such as Repeatability Limit, hierarchical cluster analysis (HCA), Student's t-test and Principal component analysis (PCA) Biplot. In addition, this paper takes the fingerprint identification of a Dalian "7.16″ oil spill accident as an example to illustrate the effectiveness of chemometric techniques in oil identification. PCA scores plot (explaining 82.77% of variance accounted for three PCs) showed that samples belong to four clusters and result of HCA method further confirmed that. The residual oil in Jinshatan Beach and Haibei Square may be caused by the explosion of Dalian "7-16" oil pipeline accident. The use of chemometric techniques is significant in providing independent validation for classifying the types of spilled oil in the investigation of oil spill pollution. The results will be of great significance to improve the accuracy and efficiency of oil spill identification based on oil fingerprint.

The first high resolution PAH record of industrialization over the past 200 years in Liaodong Bay, northeastern China

Polycyclic aromatic hydrocarbons (PAHs) are excellent tracers for fossil fuel combustion, natural fires and petroleum contamination, and have been widely used for reconstructing past wildfires and industrial activities at a variety of time scales. Here, for the first time, we obtain a high resolution (annual to decadal scale) record of PAHs from two parallel marine sediment cores from the Liaodong Bay, Northeastern China to reconstruct the industrial activities, spanning the past ∼ 200 years from 1815 to 2014. Our data indicate that PAH variations can be divided into four episodes: I) low (probably near background) PAHs from natural fires and domestic wood combustion during the pre-industrial period from 1815 to 1890; II) slightly increased (but with large fluctuations) PAH concentrations derived from intermittent warfare during the World War (1891-1945) and increased industrial activities after 1946 (1946-1965); III) a period of stagnation and, in some cases, reduction in PAHs during the "Cultural Revolution" (1966 to 1979); and IV) a rapid and persistent rise in PAHs post 1979 linked to fast economic development, with PAH concentrations doubled from 1979 to 2014. Changes in PAH distributions demonstrate major shifts in the dominant types of fuels over time from vegetation/wood, to coal and wood, followed by coal and petroleum (including vehicle emissions) over the past 200 years. We find that PAH records also show similar trend to domestic economy and the estimated regional Anthropocene CO₂ emissions from industrial activities, suggesting sedimentary PAH fluxes could be used as an indirect and qualitative proxy to track the trend for regional anthropogenic CO₂ emissions.

Spatial and temporal trends of polycyclic aromatic hydrocarbons in sediment cores of Brunei Bay, East Malaysia

The spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in three sediment cores from Brunei Bay, Southern South China Sea was investigated. The total concentrations of 16 priority PAHs (∑PAH₁₆) and their alkyl-substituted derivatives ranged from 10.4 to 376 ng g^-1 and 30.7 to 2263 ng g^-1, respectively. PAH biomarker diagnostic ratios and principal component analysis (PCA) combined with absolute principal component score (APCS) and multiple linear regression (MLR) were performed to apportion the source contribution. The results revealed mixed inputs of fuel combustion residues and uncombusted petrogenic products. The downcore PAH profile revealed that the highest peaks could be related to past human activities using biofuel and coal during the industrialization/agriculture revolution period. The 1,7/(2,6+1,7)-dimethylphenanthrene ratio also highlighted wood combustion during forest fire outbreaks, which appeared to coincide with the past climate events.

Characteristics, influence factors, and health risk assessment of volatile organic compounds through one year of high-resolution measurement at a refinery

From January 2020 to December 2020, high-resolution data of volatile organic compound (VOC) concentrations were monitored by online instruments at a petroleum refinery. The measurement results showed that the external contaminants, meteorological conditions and photochemical reactions had a great influence on the VOC data measured in the petroleum refineries. Some significant differences were observed in the emission composition of different refineries, while propene (34.2%), propane (10.2%), n-butane (5.6%), i-pentane (5.0%) were the dominant species emitted from the refinery in this study. The correlations between compounds with similar atmospheric lifetimes were strong (R² > 0.9), which indicated that the diagnostic ratios of these compounds could be used as indicators to identify the refinery emission source. Chronic health effects of non-carcinogenic risk results showed that acrolein had the highest non-carcinogenic risk and other compound-specific health risks may be of less concern in the refining area. Halogenates and aromatics accounted for 97.4% of the total carcinogenic risk values, while 1,2-dibromoethane, chloromethane, benzene, trichloromethane, 1,2-dichloroethane contributed approximately 80% of the total carcinogenic risk assessment values. This research has recorded valuable data about the VOC emission characteristics from the perspective of the high-resolution monitoring of the petroleum refinery. The results of this work will provide a reference to accurately quantify and identify the emission of petroleum refineries and further throw some light on effective VOC abatement strategies.

Concentration, source apportionment and potential carcinogenic risks of polycyclic aromatic hydrocarbons (PAHs) in roadside soils

PAHs are organic pollutants that have carcinogenic and mutagenic impacts on human health and are a subject of great concern. The soil-bound polycyclic aromatic hydrocarbons (PAHs) in the urban areas can be very lethal to human health. The concentrations, sources, and possible cancer risks of 15 PAHs were analysed by collecting roadside soil samples in Lucknow, India. The range of ∑₁₅PAHs was found to be 478.94 ng/g to 8164.07 ng/g with a mean concentration of 3748.23 ng/g. The highest contribution (32.5%) was found to be from four-ring PAHs, followed by six-ring (24.5%) and five-ring (16.7%) PAHs. The source apportionment through diagnostic ratios ANT/(ANT + PHE) against FL-2/(FL-2+PYR) highlighted the dominance of petroleum, wood, coal, and grass combustion as sources of PAHs in the study area. Source apportionment was also done through positive matrix factorization, confirming the dominance of 'vehicular emissions' (49%), followed by 'coal and biomass combustion' (∼39%), and 'leakages, volatilization and petroleum combustion' (∼12%) as potential sources. The results from lifetime cancer risks (ILCR) varied in the range of 7.5 × 10^-4 and 1.3 × 10 × ^-2 illustrating 'high cancer risk'. The total cancer risk susceptibility of children was found to be 31% more than that of adults. The highest risk associated with toxic equivalent concentration (TEQ) was found at site S8 highlighting the impact of the presence of an international airport, and huge traffic load. The present study will prove to be useful for information related to human exposure to PAHs content in soil in the study area and as baseline study for policy makers, stakeholders, and researchers.

Seasonal variations of polycyclic aromatic hydrocarbons in coastal sediments of a marine resource hot spot: the case of pars special economic energy zone, Iran

Polycyclic aromatic hydrocarbons (PAHs) are an important group of compounds of major environmental concern, which are in the class of persistent organic pollutants. Therefore, the key purpose of this research was to analyze seasonal fluctuations and to determine the probability of polycyclic aromatic hydrocarbons in coastal sediments of the Iranian Marine Resource Center based on the evaluation of 16 US-EPA important PAH compounds. These compounds have been collected from intertidal sediments located in the marine resources of southern Iran in different seasons. These samples of the surficial sediment were collected at the PSEEZ area using a stainless steel grab sampler in four seasons, from depths between 0.5 and 30 m. Surface sediment samples were removed by spoons and carefully placed in an aluminum foil; they were taken to the laboratory on ice and held at 20° C until their study. After extraction, by using a rotary evaporator apparatus, samples were condensed. The assay was added to roughly 2 g of activated copper flasks in the refrigerator for 36 h for desulfurization. Among different seasons, the highest concentration was observed in winter, with a mean of 281.3 ng g^-1. According to ecological risk assessment (concentrations of possible effects, low effect range, degree of threshold effects, and median effect range), PAH risks in surface sediments of PSEEZ were lower than the threshold results levels (TEL), possible effects levels (PEL), low range of effects (ERL), and median range of effects (ERM), indicating that a biological effect would rarely occur. The dry weight scale of the concentration of ∑PAHs ranges from 145.7 to 348.42 ng g^-1 with a mean quantity of 260.52 ng g^-1. Therefore, according to the amount of ∑PAH concentration, the sediments in the PSEEZ area indicated moderate to heavy pollutions. In this way, the sedimentary surface ecosystems of the Persian Gulf were considered as moderately polluted compared with other ecosystems worldwide. Our study highlighted some of the research gaps in PAH contamination studies and the level of PAH contamination. Therefore, this study will provide a scientific background, planning, and policies for PAH pollution control and environmental protection in Iran and similar regions around the world.

Oil spill fingerprint of low sulfur fuel oil in South Korea

A low sulfur fuel oil (LSFO) spill accident occurred in South Korea on December 17, 2019, before the introduction of the International Maritime Organization (IMO) sulfur limit. In this study, chromatograms, percentage weathering plots (PW-plots), and diagnostic ratios (DRs) of LSFOs collected in different areas during in the early spillage were compared for oil spill fingerprint. The source oil was conformed as LSFO according to physical properties and spill oils, like the source oil, show high n-alkanes and low benzo[b]naphto[1,2-d]thiophene (BNT) distribution. In the PW-plots, spill oils exhibited a decreasing trend with the reduction of low-molecular-weight compounds, which were affected by evaporation. The relative difference in the DRs was below 14%, indicating that the source and spill oils matched, excluding the ratios consisting of evaporated compounds. These results showed that spill oils confirmed as LSFO were evaporated during the initial spillage stage, and matched to the source oil.

Distribution, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in the sediments of Daihai Lake in Inner Mongolia, China

Polycyclic aromatic hydrocarbons (PAHs) are typical toxic organic pollutants that can accumulate in sediments and may be toxic to aquatic organisms. In the present study, the contamination level, composition pattern, and sources of sixteen PAHs listed by the United States Environmental Protection Agency were investigated in surface sediments and a sediment core from Daihai Lake, which is located in a typical semiarid area of Inner Mongolia, China, and the ecological risk of these PAHs was assessed. The results show that the total concentration of PAHs in the surface sediments ranged from 204.6 to 344.5 ng/g with an average value of 287.2 ng/g and that compared with other aquatic systems, the level of PAHs in the sediments from Daihai Lake was low. However, a general upward trend was observed for the concentrations of PAHs in the sediment core, which might be related to the increase in human activities in the area. Moreover, the PAH concentrations were significantly positively correlated with the total organic carbon (TOC) content in the sediments, and it is thus inferred that TOC regulates the distribution of PAHs in Daihai Lake. Three-ring and four-ring PAHs were found to be predominant in all the sediment samples, and phenanthrene (Phe) was the most abundant compound. According to the composition of PAHs and the anthracene (Ant)/(Ant+Phe) or fluoranthene (Flt)/(Flt+pyrene (Pyr)) ratios, the PAHs in Daihai Lake mainly originated from the combustion of domestic coal, grass, and wood, and petroleum cannot be ignored as a source considering the growth of industry. Risk assessment based on a comparison of PAH concentrations and the effect range low (ERL) and effect range median (ERM) values demonstrated that acenaphthene (Ace) at 11 sites and fluorene (Flu) at 7 sites had occasional adverse biological effects.

Polycyclic aromatic hydrocarbons in the Baltic Sea - Pre-industrial and industrial developments as well as current status

We report on Baltic Sea polycyclic aromatic hydrocarbon (PAH) pressure based on the U.S. EPA PAHs in view of millennial and decadal developments utilizing data from sediment deposits and seawater. Pre-industrial PAH contents ranged from 500 to 4500 ng/g TOC. Maximum PAH contents were up to 100,000 ng/g TOC and date back to the 1960s to 1970s with maximum pollutant inputs. Contemporary sediment PAH contents with 10,000 to 35,000 ng/g TOC and seawater concentrations with about 1 to 16 ng/l show spatial variability due to different local inputs and sediment characteristics. Pre-industrial compositional change from low molecular weight to high molecular weight (HMW) PAH indicates changing sources from mostly petroleum to combustion. Application of diagnostic ratios reveals petroleum and combustion as contemporary PAH sources and that traffic emissions continuously contribute to the Baltic PAH profile. Medium to high toxicological risk to the marine community might arise from current HMW PAH contents.

Occurrence, distribution, spatio-temporal variability and source identification of n-alkanes and polycyclic aromatic hydrocarbons in water and sediment from Loskop dam, South Africa

In this study, the spatial and temporal variations in the levels of C8-C40 n-alkanes and 18 polycyclic aromatic hydrocarbons (PAHs) in water and sediment from Loskop Dam (Mpumalanga Province South Africa), were investigated between 2015 and 2017. In addition, their sources, which have not been well defined, were also studied over the period. This water body is sourced from a historically contaminated water body, the Olifants River, which flows through areas where a range of industrial and agricultural activities take place. Mass crocodile and fish mortalities have been recorded in this aquatic system, and contamination by organic pollutants were highlighted as a contributing factor. The total average n-alkane concentrations in water and sediments ranged from 0.574±00811 to 18.8±1.39 µg/L and 4760±243 to 30700±906 µg/kg, respectively. Similarly, PAHs were detected at total average concentrations of between 0.150±00494 and 49.8±6.86 µg/L in water and 61.6±5.95 to 2618±300 µg/kg. n-Alkane and PAH diagnostic ratios indicated a mixture of sources of these compounds, attributed to terrestrial, submerged and floating plant material, as well as petrogenic and pyrogenic combustion. Inlet, middle and upper segment site clustering was observed with non-metric multidimensional scaling (NMDS) and hierarchical cluster analysis (HCA), mainly driven by the prevalence of PAHs at the inlet sites and n-alkanes in the upper reaches. By using indicator compounds, the sources of contamination could be predicted. The strategy described here can be applied to any water body for continuous long-term monitoring of pollutant levels and to identify sources attributing to water pollution.

Mysterious oil spill along Brazil's northeast and southeast seaboard (2019-2020): Trying to find answers and filling data gaps

Large amounts of crude oil were found along Brazil's northeast and southeast seaboard from August 2019 to January 2020. Petroleum companies and oil tankers reported no accidents previously or during this period. The stranded oil on Brazilian beaches looks like tar; it has solid aspect and is denser than seawater. Chemical characterization of this oil showed that light hydrocarbons were still present, increasing the probability of negative effects to coastal organisms and ecosystems upon release in the water column. Diagnostic ratios, chromatogram pattern, and percentage-weathering plots proved that the oil samples share the same oil source. This work provides data for future comparison with oil samples that will likely be found stranded along the Brazilian shoreline in the years to come, helping to understand long term issues associated with the mysterious oil spill that made landfall in late 2019.

PAHs emission source analysis for air and water environments by isomer ratios - Comparison by modified Cohen's d

Possible emission sources of PAHs in air and water environments were discussed by a comparison between the data sets of emission sources and environmental fields using five isomer ratios. The similarity of a pair of the datasets of different sources or environment fields for each isomer ratio was evaluated by a newly developed modified effect size d, and the mean of those for the five isomer ratios was applied as an index of similarity. From the analysis, diesel emission and/or biomass burning residues were considered to be major emission sources for almost all the datasets of environments. The pollution loading and path to the PAHs loading of coastal sediments in Hiroshima bay area were examined and it was inferred emission sources was consistently assigned by these newly developed indicators of isomer ratios. Diesel and/or biomass burning were considered to be major sources for the west side area of the bay and the biomass burning was considered to be for the east side area. Further, it was evaluated the west side area, which confronts the Hiroshima city downtown area more directly, was more similar to diesel, and the east side area, which is a bit remoted to the urban central was more similar to the biomass burning. This newly developed method would be a promising alternative application of isomer ratio analysis.

Source apportionment and toxicity assessment of PM2.5-bound PAHs in a typical iron-steel industry city in northeast China by PMF-ILCR

This study was designed to evaluate the occurrence and variation in concentrations, sources and cancer risk of PM_2.5-bound PAHs. Airborne PM_2.5-bound PAHs were sampled during a one-year campaign (2014-2015) in Anshan city, a typical iron and steel city in northeast China. A total of 374 PM_2.5 samples were collected. A source-oriented positive matrix factorization (PMF) model and PAH diagnostic ratios were used to investigate the potential sources of PAHs in the atmospheric environment of Anshan, and the lifetime cancer risk of the population associated with PAHs through inhalation exposure was assessed by a PMF-ILCR model. Concentrations of PM_2.5 and 16 PAHs ranged from 13.55 μg/m³ to 315.96 μg/m³ and 5.08 ng/m³ to 520.02 ng/m³, respectively. These values were higher in winter. PAH content from stationary sources and biomass combustion was higher than from other sources. Through the coefficient of divergence and localized PAH diagnostic ratio methods, we concluded that PM_2.5-bound PAHs in Anshan originated mainly from the following sources: biomass combustion, vehicle emissions, fugitive dust, coking dust and natural gas emissions. Based on the source-oriented PMF model, coal combustion, fugitive dust, vehicle emissions, coking dust, and biomass combustion were the main sources contributing to PM_2.5, accounting for 26.3%, 24.6%, 21.9%, 18.0%, and 6.3% of PM_2.5, respectively. According to the PMF-ILCR model results, ILCR risks estimated for adults and children were respectively 1.19 × 10^-5 and 8.55 × 10^-6 in winter, higher than in other seasons, and higher than the threshold value (10^-6). Together, vehicle emissions (diesel exhaust and gasoline exhaust), coal combustion and coking dust, contributed to over 86% of the cancer risk associated with PM_2.5-bound PAHs exposure in Anshan.

Impact of biomass combustion on occurrence and distribution of aromatic hydrocarbons in apples

Forest fires and biomass burning are known to generate aromatic hydrocarbons via incomplete combustions, due to high moisture, insufficient temperature, and oxygen content. These emission sources are particularly concerning because generated smokes cannot be treated and aromatic hydrocarbons can deposit on plant foods.The aim of this work was to study the potential deposition and absorption of monocyclic and polycyclic aromatic hydrocarbons in plant after exposure to smokes generated by burning wood. Thus, apples, used as a representative plant food model, were intentionally exposed to wood burning emissions for lengths of time varying from 1 to 2 h. Among benzene, toluene, ethylbenzene, xylenes, toluene appeared to be the most abundant compound. Concerning PAHs, linden wood combustion led to predominant deposition of compounds with molecular weights lower than 202 g/mol with the highest levels detected for phenanthrene.Aromatic hydrocarbons from wood combustion were mainly deposited on apple epicarp, and their transfer to the mesocarp was limited. Diagnostic ratio, used for the determination of PAHs emission source, was calculated with PAHs contents deposited on apple skin. Results were consistent with values proposed in the literature for the identification of biomass combustion.

Distribution pattern and health risk assessment of polycyclic aromatic hydrocarbons in the water and sediment of Algoa Bay, South Africa

Polycyclic aromatic hydrocarbons are amongst the pollutants of major concern in the terrestrial and aquatic habitats. They are mostly characterised by carcinogenic and non-carcinogenic effects. Distribution and potential health risks of sixteen priority PAHs in the water and sediment samples collected between December 2015 and June 2016 from Algoa Bay, South Africa, were evaluated. Water and sediment samples collected were extracted with liquid-liquid and soxhlet extraction methods, respectively, and then cleaned up using glass column loaded with silica gel. Final concentrations of the target PAHs were determined by gas chromatography interfaced with flame ionization detector. Results indicated that individual PAH concentrations in surface water, bottom water and sediment samples ranged from not detected (ND) to 24.66 µg/L, ND to 22.81 µg/L and ND to 5.23 mg/kg correspondingly. Total PAHs concentrations varied as 12.78-78.94 µg/L, 1.20-90.51 µg/L and 1.17-10.47 mg/kg in the three environmental matrices in that order. The non-carcinogenic risk was generally below 1, whereas risk indices (dermal contact) were above the acceptable limit of 1 × 10^-4 in the water column, suggesting possible carcinogenic effects to humans, with adults being the most vulnerable. Similarly, highest contributions to TEQs and MEQs in the sediments were made by benzo(a)pyrene and dibenzo(a,h)anthracene, the two most toxic congeners, signifying the possibility of carcinogenicity and mutagenicity in humans. Diagnostic ratios of PAHs reflect a prevailing pyrogenic input all through. The pollution was albeit moderate, yet regular check is recommended to ensure safe and healthy environment for human and aquatic lives.

Evaluation of the diagnostic ratios of adamantanes for identifying seriously weathered spilled oils from simulated experiment and actual oil spills

The composition and physical properties of spilled oil have great changes during the seriously weathering process. It brings great difficulties to the source identification of oil spill. So the stable and trustworthy diagnostic ratios (DRs) for accurate identification of severely weathered spilled oils are very important. The explosion of Sinopec pipeline happened on November 22, 2013 at Qingdao, China. Local beaches at Jiaozhou Bay were polluted by spilled oils. We have collected original spilled oil samples from an area free from human interference near the oil leakage point after the accident. Synchronized with actual beach weathering, laboratory experiments were conducted to simulate oil weathering for 360 days by using the collected original spilled oil samples. Based on t test and the repeatability limit method, 50 diagnostic ratios (DRs) of adamantanes were screened. Four DRs, namely 1,3-dimethyladamantane/total dimethyladamantane, 1-methyladamantane/(1-methyladamantane + 1,3-dimethyladamantane), dialkyl diamantane/total diamantane, and diamantane/(diamantane + dialkyl diamantane), have maintained remarkable stability during the simulated weathering experiments and field weathering process. These stable ratios can retain the characteristics of oil source during weathering. They are very beneficial to improve the accuracy of identifying the source of severely weathered oil and can be used as an effective supplement to existing index system for source identification.

Household solid fuel burning emission characterization and activity levels in India

Emission factors (EFs) of PM_2.5, carbon fractions, major ionic (K⁺, Ca²⁺, NH₄⁺, SO₄^2-, NO₃^- and Cl^-) and elemental (Al, Cr, Cu and Fe) species from combustion of commonly used household solid fuel were determined in 10 different states in India during cooking practices. The study involved sampling during actual household cooking involving use of a variety of fuels including coal balls (CB), fuel wood (FW), dung cakes (DC), crop residues (CR), mixed fuels (MF: dung cakes + fuel woods). Species-wise highest EFs (g·kg^-1) were: 34.16 ± 10.1 for PM_2.5 (CB), 14.18 ± 5.8 for OC (CB), 2.33 ± 1.4 for EC (DC), 1.03 ± 0.2 for K⁺ (CR), 2.21 ± 0.6 NH₄⁺ (DC), 0.61 ± 0.2 for NO₃^- (CB), 0.59 ± 0.1 for SO₄^2- (CB), 0.69 ± 0.1 for Cl^- (CR) among the fuels. Higher OC EFs for CB could be attributed to higher moisture content (>13%) in coal-powder that is used to handmade coal balls. It is observed that, in general, OC3 and EC1 were the dominant thermally evolved carbon mass fractions. The study averaged MCE values were in the range 0.93-0.98, which could be attributed to higher variability in flaming and smoldering episodes during the combustion of selected fuels. Sum of ionic EFs for emissions from DC, CR and MF were found to be higher than those observed for FW and CB. The K⁺/EC and Cl^-/EC (~1) ratios could be better indicators of CR fuels to differentiate it from FW, whereas NH₄⁺/EC (~1) is suitable to indicate DC. Average annual emission estimates of PM_2.5 (2.00 ± 0.53 Tg·yr^-1), OC (0.86 ± 0.23 Tg·yr^-1) and EC (0.11 ± 0.02 Tg·yr^-1) for tested fuels are evaluated to be contributing 27, 15 and 4% of total PM_2.5, OC and EC, respectively, toward annual emission budget from different anthropogenic activities in India.

Source identification of polycyclic aromatic hydrocarbons in soil sediments: Application of different methods

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that tend to rapidly associate to particulate organic matter in sediments due to their hydrophobic characteristics, inducing toxic, carcinogens and mutagens effects to many living organisms. The monitoring and identification of the sources of PAHs in sediments is relevant especially because they are the main reservoir and secondary source of contamination of aquatic systems. To identify the sources there are different methods for data treatment that complement each other: evaluation of profiles distribution, source-specific diagnostic ratios of PAHs and principal component analysis (PCA). To demonstrate the applicability of these different methods, concentrations of PAHs from sediments of four Portuguese estuarine systems were used: Ria de Aveiro, Tagus River, Sado River and Ria Formosa, in order to identify the sources.

Chemical characterization of atmospheric particulate matter in Friuli Venezia Giulia (NE Italy) by exploratory data analysis with multisite and multivariate approach

The chemical composition of atmospheric particulate (PM10) in the Friuli Venezia Giulia (FVG) region (NE Italy) has been characterized for the first time with the help of exploratory data analysis (EDA) techniques (uni-, bi-, and multivariated, i.e., principal components analysis), molecular and elemental diagnostic ratios, and seasonal trends. Despite that the available analytical data was limited to the parameters routinely analyzed on PM10 by ARPA FVG (11 elements and 16 PAH congeners), the large number of samples and of measured chemical parameters, together with the applied techniques of data analysis, allowed us to extract useful latent information from the dataset, resulting in a greater knowledge of both regional and local features. Specifically, we succeeded in matching data patterns to the known pollution sources of some sampling stations, both industrial (two secondary fusion steelworks and one coke oven) and urban (traffic and domestic heating), and in defining the mainly urban or mainly industrial feature of some questionable sampling stations. This is of paramount importance to check for possible industrial inputs in urban stations, allowing policymakers to implement the most appropriate response.

Status, sources and contamination levels of organochlorine pesticide residues in urban and agricultural areas: a preliminary review in central-southern Italian soils

Organochlorine pesticides (OCPs) are synthetic chemicals commonly used in agricultural activities to kill pests and are persistent organic pollutants (POPs). They can be detected in different environmental media, but soil is considered an important reservoir due to its retention capacity. Many different types of OCPs exist, which can have different origins and pathways in the environment. It is therefore important to study their distribution and behaviour in the environment, starting to build a picture of the potential human health risk in different contexts. This study aimed at investigating the regional distribution, possible sources and contamination levels of 24 OCP compounds in urban and rural soils from central and southern Italy. One hundred and forty-eight topsoil samples (0-20 cm top layer) from 78 urban and 70 rural areas in 11 administrative regions were collected and analysed by gas chromatography-electron capture detector (GC-ECD). Total OCP residues in soils ranged from nd (no detected) to 1043 ng/g with a mean of 29.91 ng/g and from nd to 1914 ng/g with a mean of 60.16 ng/g in urban and rural area, respectively. Endosulfan was the prevailing OCP in urban areas, followed by DDTs, Drins, Methoxychlor, HCHs, Chlordane-related compounds and HCB. In rural areas, the order of concentrations was Drins > DDTs > Methoxychlor > Endosulfans > HCHs > Chlordanes > HCB. Diagnostic ratios and robust multivariate analyses revealed that DDT in soils could be related to historical application, whilst (illegal) use of technical DDT or dicofol may still occur in some urban areas. HCH residues could be related to both historical use and recent application, whilst there was evidence that modest (yet significant) application of commercial technical HCH may still be happening in urban areas. Drins and Chlordane compounds appeared to be mostly related to historical application, whilst Endosulfan presented a complex mix of results, indicating mainly historical origin in rural areas as well as potential recent applications on urban areas. Contamination levels were quantified by Soil Quality Index (SoQI), identifying high levels in rural areas of Campania and Apulia, possibly due to the intensive nature of some agricultural practices in those regions (e.g., vineyards and olive plantations). The results from this study (which is in progress in the remaining regions of Italy) will provide an invaluable baseline for OCP distribution in Italy and a powerful argument for follow-up studies in contaminated areas. It is also hoped that similar studies will eventually constitute enough evidence to push towards an institutional response for more adequate regulation as well as a full ratification of the Stockholm Convention.

Aliphatic and aromatic biomarkers for fingerprinting of weathered chemically dispersed oil

This study evaluated the applicability of eight types of biomarkers namely, adamantanes, diamantanes, sesquiterpanes, steranes, terpanes, TA-steranes, MA-steranes, and alkylated PAHs, to characterize chemically dispersed oil (CDO) after the 60-day weathering. The stability of diagnostic ratios of the selected biomarkers was evaluated and summarized. The results indicated that the concentrations of biomarkers with low molecular weight, such as adamantanes, diamantanes, and sesquiterpanes, in CDO were markedly affected by weathering and the associated diagnostic ratios were changed extensively. Most of the alkylated PAHs were degraded during weathering as well. These biomarkers thus were not recommended for characterizing CDO. The majority of the terpanes, steranes, TA-steranes, and MA-steranes could be used for weathered CDO fingerprinting due to the relatively stable diagnostic ratios. The findings could help to identify applicable biomarkers for fingerprinting of weathered dispersed oil.

Oil mixing behavior after an oil spill: identification conflicts of different fingerprints

Clearing up whether spilled oil is mixed or not can strengthen the accuracy of oil spill identification. In the present study, the biomarkers in spilled oil samples were detected. The weathering modes of different types of diagnostic ratio and carbon isotope values of individual n-alkanes were also analyzed. The results showed that the diagnostic ratios of steroids, terpenes and aromatics, and weathering characteristics of carbon isotope composition (δ¹³C) of individual n-alkanes supported the idea that Dalian oil spill emerged from a single oil source. Furthermore, commonly used diagnostic ratios of n-alkanes indicated that the Dalian oil spill had undergone the oil mixing process. The different identifying outcomes indicate that some kinds of n-alkane-rich substance (such as oil dispersants) were mixed in the Dalian spilled oil and interfered with the routine diagnosis ratios of n-alkanes.

Characteristics of polycyclic aromatic hydrocarbons in PM2.5 emitted from different cooking activities in China

Nineteen polycyclic aromatic hydrocarbons (PAHs) in PM_2.5 emitted from five different cooking activities were characterized, and their influencing factors were determined. The total quantified particle-bounded PAH concentrations (ΣPAHs) in the airs from the cooking activities were 4.2-36.5-fold higher than those in corresponding backgrounds. The highest ΣPAHs were seen in cafeteria frying (783 ± 499 ng/m³), followed by meat roasting (420 ± 191 ng/m³), fish roasting (210 ± 105 ng/m³), snack-street boiling (202 ± 230 ng/m³), and cafeteria boiling (150 ± 65 ng/m³). The main influencing factors on the PAH emissions were cooking methods, fat contents in raw materials, and oil consumptions. Four- to six-ringed PAHs had the highest contributions to the ΣPAHs (avg. 87.5%). Diagnostic ratios of individual PAH were similar between the two charbroiling and other three conventional Chinese cooking methods, respectively, demonstrating the dominance of cooking methods in the PAH emissions. Remarkably high benzo(b)fluoranthene/benzo(k)fluoranthene (BbF/BkF) ratio (8.31) was seen in the snack-street boiling, attributed to the coal combustion as cooking fuel. Both fluoranthene/(fluoranthene + pyrene) [FLT/(FLT + PYR)] and benzo(a)anthracene/(benzo(a)anthracene + chrysene) [BaA/(BaA + CHR)] ratios were higher for the oil-based cooking than those from the water-based ones. In addition, two ratios of indeno(1,2,3-cd)pyrene/(indeno(1,2,3-cd)pyrene + benzo(g,h,i)perylene) [IPY/(IPY + BPE)] and benzo(a)pyrene/(benzo(a)pyrene + benzo(g,h,i)perylene) [BaP/(BaP + BPE)] were higher for two charbroiling than the three conventional Chinese cooking methods. The characterization work in this study is particularly important since cooking is a potential contributor of atmospheric PAHs in urban China. Carcinogenic potencies of PAHs were assessed by comparison with the air quality guideline and health risk estimation. The BaP and BaP equivalent were higher for the oil-based than the water-based cooking activities.

Distribution of VOCs in urban and rural atmospheres of subtropical India: Temporal variation, source attribution, ratios, OFP and risk assessment

This paper reports the first study which comprises the seasonal, diurnal variability, source characterization, ozone forming potential and risk assessment of volatile organic compounds (VOCs) at three sites (two urban and one rural) in the National Capital Territory of Delhi, India. The study was performed during three seasons of the year 2013-14 and two different categories of VOCs (aromatics and halogenated) have been selected. The study used the sampling and analytical procedures of NIOSH methods. Results showed that the mean concentration of sum of VOCs (∑VOC) is significantly higher at urban sites (110.0 and 137.4μg/m³ for JN and CP, respectively) as compared to the rural site, DP (56.5μg/m³). The contribution of individual to total VOC concentrations is noticed to be very similar at all the three sites. Most of the VOCs are observed to be significantly higher in winter followed by summer and autumn. Diurnal cycles of aromatic VOCs are highly influenced by the vehicular traffic and photochemical oxidations which showed higher and lower levels during morning/evening and daytime, respectively. Diagnostic ratios of the toluene/benzene (ranged from 0.65 to 13.9) infers the vehicular traffic might be the main contributing source in the urban sites while xylene/benzene ratio (ranged from 0.7 to 2.8) confirms the VOCs are transported to rural site from the nearby urban areas. Correlation and factor analysis suggested the sources are group of different species (traffic emissions, solvent usage and industrial) rather than single gas. The analysis of reactivity in terms of Prop-Equiv concentrations and ozone forming potential indicated that m/p-xylene and toluene are the main VOC contributing to the total ozone formation in urban and rural sites, respectively. Hazard ratios and lifetime cancer risk values exceeded the permissible standards established by USEPA and WHO suggests that the people are at significant risk.

Chemical composition and speciation of particulate organic matter from modern residential small-scale wood combustion appliances

Combustion technologies of small-scale wood combustion appliances are continuously developed decrease emissions of various pollutants and increase energy conversion. One strategy to reduce emissions is the implementation of air staging technology in secondary air supply, which became an established technique for modern wood combustion appliances. On that account, emissions from a modern masonry heater fuelled with three types of common logwood (beech, birch and spruce) and a modern pellet boiler fuelled with commercial softwood pellets were investigated, which refer to representative combustion appliances in northern Europe In particular, emphasis was put on the organic constituents of PM2.5, including polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs) and phenolic species, by targeted and non-targeted mass spectrometric analysis techniques. Compared to conventional wood stoves and pellet boilers, organic emissions from the modern appliances were reduced by at least one order of magnitude, but to a different extent for single species. Hence, characteristic ratios of emission constituents and emission profiles for wood combustion identification and speciation do not hold for this type of advanced combustion technology. Additionally, an overall substantial reduction of typical wood combustion markers, such as phenolic species and anhydrous sugars, were observed. Finally, it was found that slow ignition of log woods changes the distribution of characteristic resin acids and phytosterols as well as their thermal alteration products, which are used as markers for specific wood types. Our results should be considered for wood combustion identification in positive matrix factorisation or chemical mass balance in northern Europe.

Biomonitoring, status and source risk assessment of polycyclic aromatic hydrocarbons (PAHs) using honeybees, pine tree leaves, and propolis

In this study, to identify and quantify the sources of airborne polycyclic aromatic hydrocarbons (PAHs), we gathered honeybee, pine tree leaf, and propolis samples to serve as bioindicators from five stations in the village of "Bozkoy" in the Aliaga industrial district of Izmir (Turkey) during April-May 2014. The PAH concentrations which measured by gas chromatography (GC) varied from 261.18 to 553.33 μg kg^-1 dry weight (dw) in honeybee samples, 138.57-853.67 μg kg^-1 dw in pine leaf samples, and 798.61-2905.53 μg kg^-1 dw in propolis samples. The total PAH concentrations can be ranked as follows: propolis > pine leaves > honeybees. The ring sequence pattern was 5 > 3 > 6 > 4 > 2 for honeybees, 5 > 3 > 4 > 6 > 2 for pine leaves, and 5 > 4 > 6 > 3 > 2 for propolis. The diagnostic ratios [fluoranthene/fluoranthene + pyrene], [indeno(1,2,3-c,d)pyrene/indeno(1,2,3-c,d)pyrene + benzo(g,h,i)perylene], and [benzo(a)anthracene/benzo(a)anthracene + chrysene] indicate coal and biomass combustion to be the dominant PAH source in the study area. In biomonitoring studies of airborne PAHs based on honeybees, fluoranthene is considered to be a characteristic PAH compound. Distribution maps with different numbers of PAH rings among the sampling sites show the advantages of honeybee samples as indicators due to the honeybee's provision of a broader range of information with respect to heavier pollutants that are typically not in the gas or suspended phase for long periods of time. Our correlation, factor analysis, and principal components analysis (PCA) results indicate potential sources of PAH pollution in pine leaves and honeybees from airborne emissions, but we found propolis to be contaminated by PAHs due to the replacement of herbal sources of resins with synthetic gummy substances from paving materials (e.g., asphalt and tar leaks).

Diagnostic ratios for the rapid evaluation of natural attenuation of heavy fuel oil pollution along shores

Marine oil spills are typically followed by complex clean-up and monitoring operations of the shorelines affected. In this regard, determination of the changes in the chemical composition of the spilled product is crucial for evaluation purposes. The "GC-MS fingerprint" approach requires the identification of several key parameters in order to differentiate between weathering processes. In this context, we performed a 900-day study (eight sampling campaigns) of natural attenuation on a rocky shore affected by a heavy fuel oil spill. The residues coating the rocks were studied by extraction, separation and evaluation of SARA fractions, followed by GC-MS analysis for saturates and aromatics. The results identified a group of diagnostic ratios with irregular capabilities to differentiate between volatilization, photodegradation, and biodegradation (using n-alkanes, isoprenoids and PAHs), while a second group of primarily stable ratios (using dibenzothiphenes, tricyclics and hopanes) was also obtained. Notably, this is the first time that some of these ratios have been used for marine spill monitoring purposes. The ratios were applied not only to evaluate weathering at the study site, but also to obtain a comparison with the degradation of floating oil slicks-a demonstration that weathering of the latter was quicker than that of oil on the shore rocks. Additionally, Pyrolysis-GC-MS analysis of the asphaltene fraction of residues coating the rocks revealed moderate changes in the composition of this initially recalcitrant fraction. These changes were consistent with those found in the proportion of resins and asphaltene fractions over time.

Characterisation and potential source identification of polycyclic aromatic hydrocarbons in atmospheric particles (PM10) from urban and suburban residential areas in Shiraz, Iran

Polycyclic aromatic hydrocarbons (PAHs) are a generally hazardous class of organic compounds that are identified as toxic, carcinogenic, mutagenic, and teratogenic, and are considered to be a concern for human health because of their potential for causing adverse health effects. The present study aims to determine the atmospheric concentration and potential sources of particulate-bound PAHs in urban and suburban atmospheric particulate matter (PM10) in Shiraz, Iran. Ambient air samples were collected from urban and suburban areas using a SKC sampling pump equipped with a size-selective air intake during the spring of 2015. The mean PM10 concentration at the urban station (62.73 ± 23.38 μg m^-3) was higher than that at the suburban station (60.88 ± 31.03 μg m^-3). The mean (±SD) concentrations of the 16 total PAHs in the particulate phase were 19.28 ± 7.48 ng m^-3and 17.80 ± 9.17 ng m^-3 at the urban and suburban stations, respectively. Among different types of PAHs, phenanthrene had the highest concentration in both stations. Various diagnostic ratios have been suggested, which were used in this study for identification of PAHs' sources. The results of these diagnostics showed that in Shiraz, the most dominant sources of PAHs were traffic emissions, especially vehicle emissions and petroleum automobiles emissions.

Effects of short-term weathering on the stable carbon isotope compositions of crude oils and fuel oils

A short-term simulated weathering experiment was performed on two crude oils and two heavy fuel oils under natural conditions to evaluate the effects of natural weathering processes by using gas chromatography-mass spectrometry combined with gas chromatography-isotopic ratio mass spectrometry. The results of diagnostic ratios of n-alkanes show that only odd to even predominance (OEP1, OPE2) and carbon preference index (CPI) remain stabilized during the 28 d weathering process, but they cannot effectively distinguish the four types of oils. Statistical analyses based on paired sample t-test and principal component analysis (PCA) revealed that stable carbon isotope compositions of n-alkanes in the four studied oils have no significant changes over the weathering time, and that the carbon isotope discrimination (Δδ¹³C) of n-alkanes is <3‰. We have provided evidence that the stable carbon isotope compositions of n-alkanes compared to n-alkanes diagnostic ratios significantly improve the efficiency and fidelity of the oil fingerprint identification.

Assessment of exposure to polycyclic aromatic hydrocarbons in preschool children: Levels and impact of preschool indoor air on excretion of main urinary monohydroxyl metabolites

The present work aimed to assess exposure of preschool children to polycyclic aromatic hydrocarbons (PAHs) by environmental monitoring (eighteen compounds in air) and biomonitoring (six urinary biomarkers of exposure (OH-PAHs)). The impact of preschool indoor air on excretion of urinary monohydroxyl metabolites was also evaluated. Gaseous and particulate-bound PAHs were simultaneously collected indoors and outdoors in two Portuguese preschools. PAHs and OH-PAHs were quantified by high-performance liquid chromatography with fluorescence and photodiode array detection. Total air (gaseous+total suspended particles) levels of PAHs (ΣPAHs) were higher indoors than outdoors. Gaseous phase (composed by ≥98% of 2-3 rings compounds) and particulate-bound PAHs (90-99% of 5-6 rings) accounted for 93-95% and 5-7% of ΣPAHs in indoor air, respectively. Total (including probable/possible) carcinogenic PAHs represented 26-45% of ΣPAHs; naphthalene and dibenz[a,h]anthracene were the strongest contributors. A similar distribution profile was observed between airborne PAHs and urinary OH-PAHs. Urinary 1-hydroxynaphthalene+1-hydroxyacenaphthene represented more than 78% of ΣOH-PAHs, being followed by 2-hydroxyfluorene, 1-hydroxypyrene, and 1-hydroxyphenanthrene. 3-hydroxybenzo[a]pyrene (PAH biomarker of carcinogenicity) was not detected. Results suggest that children had preschool indoor air as their major exposure source of naphthalene and acenaphthene, while no conclusion was reached regarding fluorene, phenanthrene and pyrene.

Polycyclic aromatic hydrocarbons bound to outdoor and indoor airborne particles (PM2.5) and their mutagenicity and carcinogenicity in Silesian kindergartens, Poland

Assessment of exposure to polycyclic aromatic hydrocarbons (PAHs) is important due to the widespread presence of PAHs in the environment and their toxicological relevance, especially to susceptible populations such as children and their health. The aim of this study is to compare indoor and outdoor concentrations of particulate matter with a diameter of 2.5 μm or less (PM2.5) and 15 individual PAHs, as well as contribution of the analyzed PAHs to mutagenic and carcinogenic activity. Samples were collected during spring season in two sites in southern Poland (Silesia) representing urban and rural areas. Indoor samples of PM2.5 were sampled in kindergartens. At the same time, in the vicinity of the kindergarten buildings, the collection of the outdoor PM2.5 samples was carried out. Mutagenic (MEQ) and carcinogenic (TEQ) equivalents related to BaP and the percentage share expressed as mutagenic (MP) and carcinogenic (CP) potential of each individual compound to the total mutagenic/carcinogenic potential of the PAH mixture were calculated. The obtained results show that high concentrations of PM2.5 (above 25 μg/m³) and 15 PM2.5-bound PAHs in outdoor and indoor air were similar in the two studied areas. In overall PAHs mutagenic and carcinogenic potential, the percentage share of benzo(a)pyrene (BaP) was dominant and varied from 49.0-54.5% to 62.5-70.0%, respectively. The carried out study indicates the necessity of reducing PAH emission from solid fuel combustion, which is reflected in PM2.5-bound PAHs concentrations and their diagnostic ratios. In the recent years, health effects on children resulting from their activity pattern and air quality in the public places have been a serious problem.

Application of PAH concentration profiles in lake sediments as indicators for smelting activity

The ability of lake sediment cores to store long-term anthropogenic pollution establishes them as natural archives. In this study, we focus on the influence of copper shale mining and smelting in the Mansfeld area of Germany, using the depth profiles of two sediment cores from Lake Süßer See. The sediment cores provide a detailed chronological deposition history of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the studied area. Theisen sludge, a fine-grained residue from copper shale smelting, reaches the lake via deflation by wind or through riverine input; it is assumed to be the main source of pollution. To achieve the comparability of absolute contaminant concentrations, we calculated the influx of contaminants based on the sedimentation rate. Compared to the natural background concentrations, PAHs are significantly more enriched than heavy metals. They are therefore more sensitive and selective for source apportionment. We suggest two diagnostic ratios of PAHs to distinguish between Theisen sludge and its leachate: the ratio fluoranthene to pyrene ~2 and the ratio of PAH with logKOW<5.7 to PAH with a logKOW>5.7 converging to an even lower value than 2.3 (the characteristic of Theisen sludge) to identify the particulate input in lake environments.

Sources of organic pollution in particulate matter and soil of Silesian Agglomeration (Poland): evidence from geochemical markers

The exact input of particular sources to polycyclic aromatic hydrocarbons (PAHs) concentrations in urban and industrial agglomerations is still not well recognized. The major breakthrough is possible using geochemical markers. In the air aerosol and soil samples from areas located in the direct influence of industry/traffic in Silesian Agglomeration (Poland), PAHs and other organic compounds were analyzed, including geochemical markers (biomarkers) and polar compounds from fossil fuels and biomass. Gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS) were applied to investigate the composition of particulate matter and soil extracts. The results suggest that the predominant source of PAHs is fossil fuel. The presence and distribution of steranes, pentacyclic triterpenoids (i.e., hopanes and moretanes) and alkyl PAHs point to traffic emissions and fossil fuel combustion, mainly bituminous coal for power and heat purposes, as the main source of PAHs in the region. Moreover, the presence of fossil fuel biomarker in particulate matter and soil extracts from a rural site, previously considered to be free of organic pollution, requires a cautious interpretation for PAHs results. Apart from the fossil fuel, also other sources of contamination were identified in particulate matter extracts by their markers: phenols and levoglucosan for biomass and diisopropylnaphthalenes for printing materials combustion. The absence of polar biomass combustion indicators in soil extracts might be related to their higher reactivity.

Spatial and Seasonal Variations of Polycyclic Aromatic Hydrocarbons (PAHs) in Ambient Particulate Matter (PM10, PM2.5) in Three Mega-Cities in China and Identification of Major Contributing Source Types

Beijing, is the political, economic and cultural center of China. Tianjin and Shijiazhuang, located close to Beijing are also two mega-cities with huge population. The rapid economic development in the three cities in the last decades has caused severe air pollution problems, especially airborne PAHs pollution, in both gaseous and particulate phases, which has resulted in considerable harm to the health of local residents. In this study, a total of 671 air samples were collected in the three cities and reference site, and four national air quality background sites. Concentrations and seasonal variations were discussed to describe the pollution status and identify possible sources. The results showed that concentrations of BaP, a PAH that serves as an indicator of PAH pollution, exceeded the Chinese national standard by 4-12 times. PAH concentrations varied significantly in different seasons, with similar trends in the three cities. The toxic equivalents quantity (i.e., quantity of total PAHs with an equivalent toxicity to BaP) ranged from 13.35 to 22.54 ng/m(3) during the central heating period of winter and spring. These concentrations greatly exceeded the Chinese national standards for 24-h average (2.5 ng/m(3)) and annual average (1.0 ng/m(3)) concentrations of BaP. Two ratios that are indicative of PAH source, Pyr/BaP and BaP/BghiP, revealed that high percentages of the PAH pollution were contributed by coal combustion.

PAH distributions in sediments in the oil sands monitoring area and western Lake Athabasca: Concentration, composition and diagnostic ratios

Oil sands activities north of Fort McMurray, Alberta, have intensified in recent years with a concomitant debate as to their environmental impacts. The Regional Aquatics Monitoring Program and its successor, the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring (JOSM), are the primary aquatic programs monitoring this industry. Here we examine sediment data (collected by Ekman grabs) to investigate trends and sources of polycyclic aromatic hydrocarbons (PAHs), supplementing these data with sediment core studies. Total PAH (ΣPAH) concentrations were highest at Shipyard Lake (6038 ± 2679 ng/g) in the development center and lower at Isadore's Lake (1660 ± 777 ng/g) to the north; both lakes are in the Athabasca River Valley and lie below the developments. ΣPAH concentrations were lower (622-930 ng/g) in upland lakes (Kearl, McClelland) located further away from the developments. ΣPAH concentrations increased at Shipyard Lake (2001-2014) and the Ells River mouth (1998-2014) but decreased in nearshore areas at Kearl Lake (2001-2014) and a Muskeg River (2000-2014) site. Over the longer term, ΣPAH concentrations increased in Kearl (1934-2012) and Sharkbite (1928-2010) Lakes. Further (200 km) downstream in the Athabasca River delta, ΣPAH concentrations (1029 ± 671 ng/g) increased (1999-2014) when %sands were included in the regression model; however, 50 km to the east, concentrations declined (1926-2009) in Lake Athabasca. Ten diagnostic ratios based on anthracene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, chrysene, indeno[123-cd]pyrene, dibenz[a,h]anthracene, dibenzothiophene and retene were examined to infer spatial and temporal trends in PAH sources (e.g., combustion versus petrogenic) and weathering. There was some evidence of increasing contributions of unprocessed oil sands and bitumen dust to Shipyard, Sharkbite, and Isadore's Lakes and increased combustion sources in the Athabasca River delta. Some CCME interim sediment quality guidelines were exceeded, primarily in Shipyard Lake and near presumed natural bitumen sources.

Geochemical markers and polycyclic aromatic hydrocarbons in solvent extracts from diesel engine particulate matter

Exhaust particulate from compression ignition (CI) engines running on engine and chassis dynamometers was studied. Particulate dichloromethane extracts were qualitatively and quantitatively analyzed for polycyclic aromatic hydrocarbons (PAHs) and biomarkers by gas chromatography with flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). PAH group profiles were made and the PAH group shares according to the number of rings (2 or 3; 4; 5 or more) as well as diagnostic indices were calculated. Values of geochemical ratios of selected biomarkers and alkyl aromatic hydrocarbons were compared with literature values. A geochemical interpretation was carried out using these values and biomarker and alkyl aromatic hydrocarbon distributions. It has been shown that geochemical features are unequivocally connected to the emission of fossil fuels and biofuels burned in CI engines. The effect of the exothermic combustion process is limited to low-molecular-weight compounds, which shows that the applied methodology permits source identification of PAHs coexisting in the particulate emitted.

Long-term monitoring and seasonal analysis of polycyclic aromatic hydrocarbons (PAHs) measured over a decade in the ambient air of Porto, Portugal

The present paper reports the analytical results of PAHs concentrations in ambient air obtained in the PM10 and gas-phase, from 2004 to 2014, in Porto, Portugal. As part of a monitoring programme conducted by IDAD - Institute of Environment and Development and supported by the regional municipal solid waste (MSW) management authorities, an extensive database of PAH concentrations in ambient air was collected in Porto's metropolitan area. During this period a total of 201 samples were collected in two sites classified as suburban. Analytical results showed a clear decreasing trend of total PAHs (∑PAH) and benzo[a]pyrene (BaP) levels during the period of study, especially in the first years of monitoring. The average annual concentrations of BaP were, throughout the monitoring period, lower than the target value for the annual average (1 ng m(-3)) defined in the European legislation. PAHs levels showed a strong seasonality, with higher concentrations values during the colder months. The winter/summer ratio of ∑PAH for the eleven years of study was 5, revealing the seasonal variation of PAHs in the studied area. The estimated toxic equivalency factors (TEFs) used to assess the contribution of the carcinogenic potential, confirmed a significant presence of the moderately active carcinogenic BaP and dibenz[ah]anthracene (DahA) in the samples collected in Porto. The ratio values of individual PAHs concentrations were used as diagnostic tool to identify the possible origin of PAH in the ambient air of Porto. Based on diagnostic ratios, it may be concluded that automobile traffic emissions, mainly related to diesel vehicles, were the major contribution of PAH levels in the ambient air, although some others contributions, such as coal and wood combustion, were identified.

Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment

Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis - Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas.

PAH dynamics in roadside environments: Influence on the consistency of diagnostic ratio values and ecosystem contamination assessments

Roadside contamination (of air, soils and organisms) by polycyclic aromatic hydrocarbons (PAHs) was examined in an arable field and a mature forest (central France). Measured contents accounted for minute fractions of the cumulative vehicular exhaust emissions. The fate of vehicular PAHs was affected by many factors, including: atmospheric load dispersal, deposition on soils and vegetation, incorporation into water and organic matter cycles, and accumulation in species. Given these empirical results, we evaluated the consistency of a set of well-known diagnostic ratios. This effort has revealed that: i) most diagnostic ratio values vary considerably across roadside samples, including exhaust emissions; and ii) the first few meters from the carriageway or the road verge/forest interface or remote areas where surface water accumulates actually define turning or inflection points in the ratio profiles. These variations constitute a major obstacle to delimitating the extent of roadside contamination due to PAHs, in addition to raising questions over the applicability of ratios routinely used to designate sources. New ratios, namely (Flt+BkF)/(Pyr+BbF) and (Flt+BkF+BghiP)/Σ10PAH, have been specifically developed to address this challenge. The higher consistencies exhibited among environmental compartments as well as between surface soil and exhaust emissions still yield differentiated values relative to several industrial sources.

Carcinogenic activity of polycyclic aromatic hydrocarbons bounded on particle fraction

Polycyclic aromatic hydrocarbons (PAHs) originate from a variety of natural and industrial processes. In this paper, concentrations of nine PAHs in PM10 particle fraction were measured concurrently at four different sites (rural, urban residential, urban traffic, and residential-industrial) in continental Croatia. Measurements at all of the four sites showed much higher average concentrations for all of the PAHs in the winter period. The highest winter average values were measured at the industrial site and the lowest at the rural and the urban residential site. In the summer, the highest average values were also measured in the industrial area, except for benzo(ghi)perylene and indeno(1,2,3-cd)pyrene, which showed the highest average values in the rural area. Factor analysis has been applied to PAH concentrations to identify their potential sources. Extracted factors have been interpreted on basis of previous studies and weather conditions. The diagnostic ratios calculated in this study indicated mixed sources at all of the sites. The contribution of gasoline and diesel from traffic was significant at all of the sites except for the urban industrial. In the winter, potential PAH sources also arose from wood combustion. The industrial site differed from the other sites with the highest influence of diesel sources and refinery during the summer months. The contribution of BaP in total carcinogenic activity exceeded 50 % in both seasons at all of the measured sites, which suggests that BaP could be suitable as a marker of the carcinogenic potential of a PAH mixture.

Hydrocarbon concentration and source appraisal in atmospheric particulate matter (PM₂.₅) of an urban tropical area

Polycyclic aromatic (46 PAHs) and aliphatic hydrocarbons (C12-C40) were studied in atmospheric particulate matter sampled in Rio de Janeiro Metropolitan Area (RJMA). In total, 236 samples from six different sites were collected simultaneously and weekly over 1 year (January-December 2011) allowing a robust atmospheric characterization of fine particulate matter (PM2.5). Hydrocarbon concentration was in general low compared to previous studies in the area (PAHs range 0.25-19.3 ng m(-3)), possibly due to changes in fuel composition over time. Precipitation is the main meteorological parameter that rules particulate and hydrocarbon concentration, modifying PAH typology by scavenging. Aliphatic and aromatic diagnostic ratios gave indications conflicting with combustion features. However, ratios showed differences among sites. Principal component analysis (PCA) associated to multiple linear regressions (MLR) allowed quantitative estimate of sources and effectively indicated vehicular emission as the main hydrocarbon source in the atmospheric particulate matter.

The use of diagnostic ratios, biomarkers and 3-way Kohonen neural networks to monitor the temporal evolution of oil spills

Oil spill identification relies usually on a wealth of chromatographic data which requires advanced data treatment (chemometrics). A simple approach based on Kohonen neural networks to handle three-dimensional arrays is presented. A suite of 28 diagnostic ratios was considered to monitor six oils along four months. It was found that some traditional diagnostic ratios were not stable enough. In particular, alkylated PAHs (e.g. 1-methyldibenzothiophene, 4-methylpyrene, 27bbSTER and the TA21 and TA26 triaromatic steroids) seemed less resistant to medium-weathering than biomarkers. One (or two) ratios were found to differentiate each product: 30O, 28ab (and 25nor30ab), C3-dbt/C3-phe, 27Ts, TA26 and 29Ts characterized Ashtart, Brent, Maya, Sahara, IFO and Prestige oils, respectively.

GC-MS analysis of two types of mixed oils, a comparison of composition and weathering patterns

In order to compare the effects of weathering on two types of mixed oil, simulated weathering experiments were performed. The first sample was a mixture of two fresh oils and the second sample was a mixture of one fresh oil and another oil sample that had undergone a serious weathering process. Comparative studies evaluated decay rates and changes in diagnostic ratios of some fingerprinting biomarkers. Results showed that the mixing process affected the weathering rate of some compounds in the oils and also that certain diagnostic ratios are more suitable for estimating mixing proportions. A Pr/n-C17 versus Ph/n-C18 plot can be used to identify the end-numbers of mixed oils and the (C13+C14)/(C25+C26) ratio is a useful diagnostic ratio to detect the degree of weathering. Finally, hopane, sterane, and alkylated PAH fingerprints were found to give useful insights about the sources of the mixed oils.

Emission and profile characteristic of volatile organic compounds emitted from coke production, iron smelt, heating station and power plant in Liaoning Province, China

107 kinds of C₂-C₁₂ volatile organic compound (VOC) mass concentrations and profiles for four types of coal-fired stationary sources in Liaoning Province were studied by a dilution sampling system and GC-MS analysis method, which are of significant importance with regard to VOC emissions in northeast of China. The results showed that there were some differences among these VOC source profiles. The total mass concentrations of analyzed 107 VOC species varied from 10,917 to 19,652 μg m(-3). Halogenated hydrocarbons exhibited higher mass percentages for the VOC source profiles of iron smelt (48.8%) and coke production plant (37.7%). Aromatic hydrocarbons were the most abundant in heating station plant (69.1%). Ketones, alcohols and acetates held 45.0% of total VOCs in thermal power plant. For non-methane hydrocarbons (NMHCs), which are demanded for photochemical assessment in the USA, toluene and n-hexane were the most abundant species in the iron smelt, coke production and thermal power plant, with the mass percentages of 64.8%, 52.7% and 38.6%, respectively. Trimethylbenzene, n-propylbenzene and o,m-ethyltoluene approximately accounted for 70.0% in heating station plant. NMHCs emitted from coke production, iron smelt, heating station and power plant listed above presented different chemical reactivities. The average OH loss rate of NMHCs from heating station, was 4 to 5.6 times higher than that of NMHCs from iron smelt, coke production and power plant, which implies that VOCs emitted from heating station in northeast of China should be controlled firstly to avoid photochemical ozone pollution and protect human health. There are significant variations in the ratios of benzene/toluene and m, p-xylene/ethylbenzene of these coal-fired source profiles. The representativeness of the coal-fired sources studied and the VOC samples collected should be more closely examined. The accuracy of VOC source profiles related to coal-fired processes is highly dependent on location and sampling method.