YEAR TIME MODULATION OF n-ALKANES,PAH, NITRO-PAH AND ORGANIC ACIDS AT MONTELIBRETTI ROME,ITALY

The organic fraction of airborne particulates was investigated at Montelibretti RM, Italy, over 12 months and n-alkanes, polycyclic aromatic hydrocarbons, nitrated polycyclic aromatics and aliphatic acids were evaluated. The year time modulations were acquired from all groups of compounds, both in quantitative (cumulative concentrations) and qualitative (percent compositions) terms. Some distribution indexes and diagnostic ratio rates drawn from congener abundances provided information about the twin nature (anthropogenic and biogenic) of sources of organic particulate. Briefly, unlike past decades the appearance of the Montelibretti location was that of a site affected overall by local pollution, as a consequence of both direct anthropogenic emissions and secondary oxidized compounds. The occurrence of polycyclic aromatic hydrocarbons (PAHs) seemed to depend overall upon vehicle emission (diesel powered in particular), although a second, unknown source with year time modulation was present, apparently not associated with biomass/wood burning. By contrast, nitro-PAHs were mainly associated to oxidation of parent PAHs. In summer, PAHs were found at concentrations similar to those measured in 1993–1995, whilst in winter they were three times more abundant than previously reported.     

DETERMINATION OF ATMOSPHERIC NITRO-POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR PRECURSORS AT A HEAVY TRAFFIC ROADSIDE AND AT A RESIDENTIAL AREA IN OSAKA,JAPAN

Concentrations of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) and polycyclic aromatic hydrocarbons (PAHs) in airborne particles collected at two sites, a residential area and a roadside with high traffic density in Osaka, Japan, in summer and winter were quantified. Five nitro-PAHs, 1-nitropyrene (1-NP), 2-nitropyrene (2-NP), 2-nitrofluoranthene (2-NF), 3-nitrofluoranthene (3-NF), and 2-nitrotriphenylene (2-NTP) and five PAHs, pyrene (Py), fluoranthene (Fl), triphenylene (Tp), benzo[k]fluoranthene (B(k)F), and benzo[a]pyrene (B(a)P) were determined by high-performance liquid chromatography with chemiluminescence and fluorescence detection. At both sites, the mean concentration of 1-NP was higher in winter than in summer. On the contrary, the mean concentrations of 2-NF and 2-NP were higher in summer than in winter. Observed 2-NF/2-NP ratio in the range from 0.40 to 16 suggests that 2-NF and 2-NP were dominantly formed via OH radical initiated reaction in the atmosphere. Nitro-PAH and PAH concentrations were generally higher at a roadside area than at a residential area due to extremely higher concentration of particles at a roadside area. 1-NP/B(k)F ratio was higher at a roadside area than at a residential area, while 2-NF/B(k)F, 2-NP/B(k)F, and 2-NTP/B(k)F ratios were higher at a residential area than at a roadside area. The diurnal changes of 2-NF/B(k)F, 2-NP/B(k)F, and 2-NTP/B(k)F ratios were slightly different from those of 1-NP/B(k)F and 3-NF/B(k)F ratios. Thus, the differences in the patterns of nitro-PAHs/B(k)F ratios may be due to the disparity in formation pathways of each nitro-PAH.     

The Exposure Profiles,Correlation Factors and Comparison of PAHs and Nitro-PAHs in Urban and Non-Urban Regions in Suspended Particulate Matter in Poland

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) and their nitrated derivatives are responsible for mutagenic activation of ambient air. The aim of the study was the assessment of exposure for PAHs and nitro-PAHs in the urbanized region in Poland in comparison with the non-urbanized region and assessment of seasonal variation of PAHs and nitro-PAHs. Concentrations of 12 PAHs, 8 nitrated PAHs in total suspended particulate matter in air of urban and suburban (reference samples-mountain region) region in Poland during four seasons have been shown. The method of solvent extraction of particulate matter, fractionation organic extract and HPLC and GC/MS analysis were applied. The concentrations of PAHs and nitro-PAHs were 10–100 times lower in reference samples than concentrations of PAHs and nitro-PAHs in urban region in summer. The concentrations of PAHs and nitro-PAHs were highest in winter. The exposure profiles of PAHs and nitro-PAHs in four seasons have been shown. The correlation factor between concentrations of PAHs and nitro-PAHs was found. Important influence of ambient air temperature for PAHs and nitro-PAHs concentrations was shown. Obtained results suggest that the coal combustion in Polish households was the main source of PAHs and their nitro derivatives contaminations. Emission from transport sources is a secondary source of air pollution in urban areas.     

Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Atmospheric Particles and Soil at a Traffic Site in Hanoi,Vietnam

The concentrations of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in total suspended particulates (TSP) and soil were measured at a traffic site in Hanoi, a typical motorcycle city of Vietnam. TSP was collected using high-volume air sampler on Pallflex 2500QAT-UP membrane filters. PAHs and NPAHs were analyzed by high-performance liquid chromatography (HPLC) using fluorescence and chemiluminescence detectors, respectively. The average concentrations of total 10 PAHs and 10 NPAHs in soil varied from 3.4–43.7 ng g^?1 and from 112–780 pg g^?1 dry weight, respectively, which were much lower than those in TSP. The results showed that large part of the higher molecular weight PAHs in soil, especially benzo[ghi]perylene and benzo[b]fluoranthene came from the atmosphere. However, NPAHs profile showed a different pattern. 3-nitroperylene and 6-nitrochrysene were the most abundant NPAHs in soil, followed by 1-nitropyrene and 6-nitrobenzo[a]pyrene. The fate of NPAHs in soil varied depending on soil properties and chemical structure of NPAHs. The finding that the [NPAH]/[PAH] concentration ratios in soil were different from those in TSP could be due to bio-degradation and/or secondary formation of NPAHs in soil, depending on NPAHs properties.     

Screening of Aerosol Filter Samples for PAHs and Nitro-PAHs by Laser Desorption Ionization TOF Mass Spectrometry

Direct and selective screening of aerosol particulate matter for polycyclic aromatic hydrocarbons (PAHs) and nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) is achieved using laser desorption ionization time-of-flight (LDI TOF) mass spectrometry. Desorption and ionization of collected aerosol particulate matter was accomplished using pulsed UV radiation at 266 nm. PAHs were detected in positive ion spectra, while nitro-PAHs were selectively detected in negative ion spectra. Direct laser desorption ionization circumvents extraction procedures necessary for HPLC or gas chromatography/mass spectrometry (GC/MS) analyses, and such screening offers potential cost saving by identifying samples which contain too little PAH for GC/MS analyses to be productive. Applicability of the LDI TOF method was demonstrated by collecting aerosol particles of less than 2.5 mu m aerodynamic diameter (PM 2 . 5) on Teflon filters from inside an urban bus terminal. Sampling of small air volumes (0.32-0.98 m3) was sufficient for LDI TOF analysis. Positive ion mass spectra of all collected aerosol samples exhibited peaks attributed to a wide range of PAHs. Of primary importance, selective ionization and detection of less abundant and more toxic nitro-PAHs is demonstrated in the negative ion spectra. GC/MS analyses of duplicate filters confirmed laser desorption ionization analyses and assisted identification of specific PAH isomers.     

Time to Say Goodbye to the 16 EPA PAHs? Toward an Up-to-Date Use of PACs for Environmental Purposes

The 16 EPA PAHs have played an exceptionally large role above all in environmental and analytical sciences in the last 40 years, but now there are good reasons to question their utility in many circumstances even though their use is so established and comfortable. Here we review the reasons why the list has been so successful and why sometimes it is seen as less relevant. Three groups of polycyclic aromatic compounds (PAC) are missing: larger and highly relevant PAHs, alkylated PACs, and compounds containing heteroatoms. Attempts to improve the situation for certain matrixes are known and here: (1) an updated list of PAHs (including the 16 EPA PAHs) for the evaluation of the toxicity in the environment (40 EnvPAHs); (2) a list of 23 NSO-heterocyclic compounds and 6 heterocyclic metabolites; and (3) lists of 10 oxy-PAHs and 10 nitro-PAHs are proposed for practical use in the future. A discussion in the scientific community about these lists is invited. Although the state of knowledge has improved dramatically since the introduction of the 16 EPA PAHs in the 1970s, this summary also shows that more research is needed about the toxicity, occurrence in the environment and chemical analysis, particularly of alkylated PAHs, higher molecular weight PAHs and substituted PACs such as amino-PAHs, cyano-PAHs, etc.. We also suggest that a long overdue discussion of an update of regulatory environmental PAH analysis is initiated.     

Polycyclic Aromatic Compounds in the Atmosphere – A Review Identifying Research Needs

Most of the 16 EPA priority PAHs (or a subset of these) are targeted in the current monitoring of air and air pollution studies. However, other parent PAHs may account for up to another ≈10%, nitro-PAHs up to ≈20%, and oxy-PAHs for even more. The reactivity in the atmospheric gas and particulate phases is incompletely quantified, in particular with regard to coverage of aerosol matrix diversity and photochemical age. Therefore, the model-based characterization of exposure is still limited. Nitro- and oxy-PAHs pose a higher health risk in ambient air than parent PAHs but have not been measured as extensively so far and are usually not included in monitoring programs. Nitro-PAHs are also interesting as tracers for air pollution source identification and pathways of photochemistry. Among heterocyclic aromatic compounds in ambient air dibenzofuran and dibenzothiophene should be targeted.     

ATMOSPHERIC OCCURRENCE OF 2-NITROBENZANTHRONE ASSOCIATED WITH AIRBORNE PARTICLES IN CENTRAL TOKYO

2- and 3-Nitrobenzanthrones (NBAs) in airborne particles collected in central Tokyo on a seasonal basis from 1996 to 2001 are quantified and possible sources are investigated. The concentrations of 2- and 3-NBA are found to range from 49 to 831 fmol m^–3and 0.5 to 3.5 fmol m^–3, while the nitrated polycyclic hydrocarbons 1-nitropyrene and 2-nitrofluoranthene are found at concentrations of 100–492 fmol m^–3 and 10–97 fmol m^–3. Significant linear correlations are identified between 2-NBA and NO₂, a photochemical product, suggesting that 2-NBA is formed by atmospheric reactions of benzanthrone initiated by hydroxyl or nitrate radicals in the presence of NO₂. 2-NBA is not correlated with directly emitted compounds such as 1-nitropyrene. The concentration ratio of 2-NBA to 1-nitropyrene is 5 or greater in all samples. Nitrated polycyclic aromatic compounds formed by atmospheric reactions therefore appear to represent a substantial contribution to the mutagenicity of airborne particulate matter.     

Beyond 16 Priority Pollutant PAHs: A Review of PACs used in Environmental Forensic Chemistry

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in soils and sediments, particularly in urbanized environments in which the concentrations of 16 (or so) PAHs are regulated. Distinguishing among the numerous PAH sources is of practical and legal concern and thereby is often an objective of environmental forensic chemistry studies. Studies of prospective sources and impacted soils and sediments that rely upon the 16 U.S. EPA Priority Pollutant PAHs are disadvantaged, as these few compounds generally lack the specificity to distinguish among different PAH sources in the environment. Advances in analytical and interpretive methods over several decades have shown that different PAH sources can be more defensibly distinguished using modified EPA Method 8270 that, among other improvements, measure many other polycyclic aromatic compounds (PACs) that co-occur with the Priority Pollutant PAHs in different sources and in the environment. The PACs include variously-alkylated PAHs and polycyclic aromatic sulfur heterocyclics (PASHs) homologs and individual isomers, which are herein reviewed. Collectively, these PACs provide a higher degree of specificity among PAC sources and can be used to understand the effects of weathering on PAH assemblages. Despite their diagnostic capacity, PACs should not be relied upon at the exclusion of other compound groups (e.g., petroleum biomarkers) in most environmental forensic chemistry studies. In light of these advances, source characterization studies that rely only upon the 16 (or so) Priority Pollutant PAHs warrant considerable caution.     

Seasonal and Geographical Distribution of PAHs in Mussels,Mytilus Edulis,Collected from an Urban Harbour

Mytilus edulis were collected intertidally from 16–18 sites located around the perimeter of Halifax Harbour, of an island located at the entrance to the harbour and from the Northwest Arm. The concentrations of 31 polycyclic aromatic hydrocarbons (PAHs), lipid and moisture content were determined in pools of this filter feeder sampled over three seasons spanning two years, along with calculating individual condition indices. Contaminants were nearly undetectable in many of the summer mussels and highest in some of the spring samples. At several sites, the sum of PAHs expressed on a dry or lipid weight basis, was either equal or higher in April compared to November. Fluoranthene was the most predominant PAH followed by pyrene and phenanthrene. At most sites, parental PAHs, associated with combustion sources of contamination, were more abundant than alkylated derivatives. A larger petroleum input was noticeable in mussel extracts from sites in close proximity to potential sources.     

ALIPHATIC,POLYCYCLIC AROMATIC HYDROCARBONS AND NITRATED-POLYCYCLIC AROMATIC HYDROCARBONS IN PM 10 IN SOUTHWESTERN MEXICO CITY

A sampling campaign of airborne particles ≤ 10 μ m (PM ₁₀ ) was carried out from February to April of 2004 at the Universidad Nacional Autónoma de México in southwestern Mexico City. The average PM ₁₀ mass concentration was 51 ± 14 μ g m^?3. Extracted organic matter was determined, with a mean of 6.5 ± 1.7 μ g m^?3, which represents 12.9% of PM ₁₀ mass concentration. The standard additions method was used on real samples at four concentration levels for 13 n-alkanes, 14 PAHs and 5 nitro-PAHs. The average concentration for the sum was 99.04 ng m^{? 3} for n-alkanes, 4.9 ng m^?3 for PAHs and 710 pg m^{? 3} for nitro-PAHs. Higher concentrations of n-alkanes > C ₂₄ were found, indicating biogenic emissions as the dominant source. Coronene, benzo[ghi]perylene, benzo[b+j+k]fluoranthenes and indeno[1,2,3-cd]pyrene were the most abundant PAHs, suggesting a strong contribution from incomplete combustion of gasoline. The PAHs considered for calculating BaPE represented 52% of the total PAHs analyzed. The presence of 9-nitroanthracene indicates direct emission from diesel combustion and heterogeneous nitrating reactions on sorbed particles, while 2-nitrofluoranthene, indicates gas-phase reactions with fluoranthene, hydroxyl (OH^?) and/or nitrate (NO ₃ ^?) radicals in the presence of nitrogen oxides (NOx).     

Monitoring and Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmosphere of Alexandria City,Egypt

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in the total suspended particulate (TSP) were measured simultaneously between January 30, 2015 and February 11, 2016 at urban, suburb, and rural sites at Alexandria City, Egypt, using pesticide samplers. Samples were extracted and analyzed using chromatography–mass spectrometric (GC–MS). There was a significant difference in concentrations between the three sites, and between particle- and vapor-phases. Mean total PAH concentrations were 502.48, 322.57, and 417.23 ng m^?3 for the urban, the rural, and the suburban sites in particulate-phase and were 723.49, 402.26, and 543.15 for the same sites in vapor-phase, respectively. At the three sites, the most abundant compounds determined were Benzo[k]fluoranthene (BkF), followed by Benzo[a]pyrene (BaP) and Indeno [1,2,3-cd] pyrene (IcdP). These high molecular weight compounds are carcinogenic and known to originate mainly from vehicular emissions. The diagnostic ratios indicated PAHs in urban and suburban sites were predominantly from gasoline and diesel engines, while that in rural site was from biomass burning. Characterization of the emission sources was further substantiated by significant correlation between individual PAH species.     

THE FATE AND BEHAVIOR OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) THROUGH FEEDING AND EXCRETION OF ANNELIDS

The concentration of polycyclic aromatic hydrocarbons (PAHs) in sediment and excrements of annelids was measured by gas chromatography-mass spectrometry (GC/MS) and the movement of PAHs in the tidal flat was investigated. The PAH concentrations ranged 4.4–80.4 and 61.2–286.9 μg/kg-dry for the excrement of Arenicola basiliensis and of Marphysa sanguinea, respectively; the former contained about 10 times as much PAHs as the sediment and the latter about 100 times. The difference in the PAH concentration between the two organisms was attributed to their feeding behavior; M. sanguinea intakes much more detritus containing PAHs than A. basiliensis. Moreover, after the excrement of M. sanguinea had stood on the sediment for 2 hours, the PAH concentrations decreased to half. The reduction of the PAHs may arise from chemical changes owing to microorganisms and/or enzymes in the excrement of M. sanguinea.     

Distribution and Sources of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Sediments from the Northern Part of the Persian Gulf (Hormuzgan Province)

Sediments from the intertidal areas of Hormuzgan province in northern part of Persian Gulf (Iran) were investigated for the levels and possible sources of 15 polycyclic aromatic hydrocarbons (PAHs). Samples of sediments were collected from twelve sampling sites and analyzed for PAHs by gas chromatography–mass spectrometry (GC-MS). The results showed that the total concentrations of PAHs ranged from 765 to 1898 ng/g dry weight. Composition pattern in the sediment samples from 12 sampling sites was dominated by 4-ring PAH compounds. Molecular indices based on ratios of PAH concentrations were used to differentiate PAHs from pyrolitic, petrogenic and mixed origins. The results of study suggested that the main sources of PAHs in the sediment were mixed with pyrolitic and petrogenic inputs. According to the US sediments quality guidelines (SQGs) (ERL/ERM) sediments of the mentioned region did not show any ecotoxicological risk for benthic organisms.     

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

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

Determination of PAHs in Combustion-Related Samples and in SRM 1597, Complex Mixture of PAHs from Coal Tar

Three types of combustion sample extracts, smokeless coal, smoky coal, and wood, were analyzed for a range of polycyclic aromatic hydrocarbons (PAHs) and polycyclic aromatic sulfur heterocycles (PASH). Standard Reference Material (SRM) 1597, Complex Mixture of PAHs from Coal Tar, was also analyzed as a control sample and for the determination of a larger number of PAHs relative to those determined previously. Target analytes included many alkyl-substituted PAHs such as dimethylphenanthrenes, methylfluoranthenes, and methylpyrenes. The analytical methods included sample clean-up and the selection of specific stationary phases to accomplish unique separations of PAHs. Clean-up involved the use of normal-phase liquid chromatographic isolation of PAHs based on the number of aromatic carbons and a total PAH fraction, PAHs in the resulting fractions were separated by gas chromatography using two stationary phases with different selectivities and analyzed using mass spectrometry. These methods are discussed below and results are presented with an emphasis on the relative concentrations and distribution of PAHs in the combustion samples.     

Priority Polycyclic Aromatic Hydrocarbons (PAHs): Distribution,Possible Sources and Toxicity Equivalency in Urban Drains

Wastewater from urban areas constitutes one of the major sources of pollutants contributed to aquatic ecosystem. This study was carried out to elucidate the occurrence and possible source of US Environmental Protection Agency identified 16 priority polycyclic aromatic hydrocarbons (PAHs) in water and sediments from the urban wastewater drains in Delhi, India. A total 60 samples (water and sediment) collected during year 2011–2012, and analyzed the following USEPA methods. Water and sediment samples were extracted using liquid-liquid and ultrasonication techniques, respectively. Glass column chromatography with activated silica was used for sample extracts clean-up, followed by quantification on HPLC equipped with diode array detector at 254 nm wavelength using mixture of acetonitrule and water as mobile phase. Concentrations of total 16 PAHs (∑16PAHs) in all drain water samples ranged from 0.29–35.22 μg/L (mean ± SD, 10.83 ± 10.66 μg/L), predominated by two- and three -ring PAHs. The ∑16PAHs concentrations in all collected sediments ranged between 220–19321 μg/kg (mean±SD, 5574 ± 6820 μg/kg) dry weights. High molecular weight PAHs (≥4-ring PAHs) were dominant in sediment samples. Benzo(a)pyrene equivalent (BaPeq), a relative carcinogenic potential to the corresponding PAHs to BaP was estimated and presented. A selected number of concentration ratios of specific PAHs compounds were calculated and used to diagnose the possible sources of PAHs contamination. The diagnostic ratios reflected pyrogenic input from gasoline or diesel powered vehicular emissions as the major source of PAHs. The levels of PAHs observed in water and sediments were compared with similar studies undertaken in other regions of the world.     

Source and Toxicological Assessment of Polycyclic Aromatic Hydrocarbons in Sediments from Imo River,Southeastern Nigeria

Polycyclic aromatic hydrocarbons (PAHs) in sediments from the Imo River were analyzed to characterize their sources and assess their toxicity potential. The total PAH concentrations ranged from 409.43 to 41,198 ng/g dw with standard deviation of 4,796 ± 1,941. This wide variation reflects a localized contamination in the study area. The inadequacy in the use of traditional isomeric ratios for PAHs source characterization in sediment from tropical environments with shallow water depth of < 10 m was highlighted. A more robust principal component analysis coupled with n-alkanes unresolved complex mixture profiles approach to apportioned specific chemical signatures to samples was proposed. This approach differentiated stations that were heavily—from those that were mildly—impacted by oil and discriminated among stations that were influenced by pyrogenic sources. Effect range low (ERL) and effect range median (ERM) as well as risk quotients (RQwcs) revealed that only naphthalene, flourene, dibenzo(a,h)anthracene and low molecular weight PAHs were implicated with ERL and ERM exceeding the US National Oceanic and Atmospheric Administration's limit of concern and RQwcs > 1, as compounds of concern. The maximum toxicity equivalency value of 179.81 ng/g TEQs_carc measured for the illegal petroleum refinery site indicated that this site requires some control measure and remedial action.     

LONG TERM MONITORING OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN BLUE MUSSELS (Mytilus edulis) FROM A REMOTE SCOTTISH LOCATION

Farmed mussels have been collected on a monthly basis since 1999 from a remote site on the west coast of Scotland for polycyclic aromatic hydrocarbon (PAHs) analysis with the aim of establishing background concentrations as a benchmark against which to assess any environmental incident. Total PAH (2- to 6-ring parent and alkylated) concentrations ranged from 12.5 to 151.2 μg kg^?1 wet weight. Seasonal trends were evident with concentrations being significantly higher for samples collected between November and March compared to those collected between April and October. By taking the median of medians for each of these time periods two background concentrations are suggested for the total PAH concentrations (2- to 6-ring PAHs parent and alkylated); for April to October: 31.2 μg kg^?1 wet weight and for November to March: 62.9 μg kg^?1 wet weight. Individual PAH concentrations were mainly below the OSPAR Background Assessment Concentrations (BACs), where they are specified, and were only exceeded for the heavier 4- and 5-ring PAHs (fluoranthene, pyrene, benz[a]anthracene and benzo[a]pyrene) in samples collected between November and March. Differences were also seen in the PAH profiles with season. Mussels collected between November and March had a higher proportion of the heavier PAHs compared to mussels collected in the summer and autumn.     

Monitoring and Origin of Polycyclic Aromatic Hydrocarbons (PAHs) in Effluents from a Surface Treatment Industry

ABSTRACT

In Europe, polycyclic aromatic hydrocarbons (PAHs) are a source of concern due to their toxic effects and are considered as priority pollutants by water authorities. In this study, we reported the results of qualitative and quantitative monitoring of 16 PAHs in effluents from a surface treatment industry to determine their origin. The results indicated that PAHs were present in the discharge waters at a concentration of 500 ng L^?1 (in average for the PAH sum). However, the further we returned to the start of the industrial process, the more the PAH concentrations increased. Indeed, the highest concentrations (>20,000 ng L^?1 for the PAH sum) were found in the degreasing baths – the first step in the part treatment. The final analyses showed that the PAHs came from the oils left on the metal parts by the suppliers. The important difference in concentrations between the upstream (first baths in the production line) and the downstream (discharge water) of the effluent showed that phenomena including dilution or potentially degradation occurred but that the major part of the PAHs tended to adsorb to sludge during the settling step in the effluent treatment plant.