Coastal Seawater Samples Research Articles

Study on the simultaneous determination of twelve elements in coastal seawater in Nghe An and Ha Tinh Provinces by ICP -MS method

The concentrations of 12 elements (Cr, Mn, Fe, Co, Cu, Zn, As, Se, Ag, Cd, Hg, Pb) in ten coastal seawater samples collected from Nghe An and Ha Tinh Provinces were simultaneous determined by Inductively Coupled Plasma - Mass Spectrometry method (ICP - MS), using APDC/MIBK solvent extraction to preconcentrate and separate the elements from high dissolved solid matrix of the samples. The method has low detection limits with ppt level, the relative standard deviations (% RSD) are less than 7.5%, and the recovery of elements are in the range from 63.5% to 107.7%, which meets AOAC requirements for trace analysis. The results of analysis showed that most of the elements are in the limited range of concentration according to Vietnamese regulation (QCVN 10-MT:2015/BTNMT), except cadmium in one sample and mercury in seven samples are higher.

Rapid and precise measurements of radon in water using a pulsed ionization chamber

AbstractRadon‐in‐air monitor (RAD7, Durridge Co.) has been widely used to measure 222Rn in water samples. RAD7 measures 222Rn via 218Po+ (t1/2 = 3.1 min), which is electrically attracted to a silicon alpha detector. In this study, a new method was developed for measuring 222Rn in water samples by modifying a commercially available pulsed ionization chamber (PIC, FT‐Lab Co.). The PIC detects and amplifies the electric pulses generated by microspace charges produced by 222Rn decay. Two passive PICs (volume: 2 × 400 mL) were combined and modified to form an active system (named Rn‐SNU) that continuously circulates air (~ 1 L min−1). Rn‐SNU is approximately seven to nine times more efficient than RAD7 and does not necessitate a delay of ~ 15 min to reach radioactive equilibrium between 222Rn and 218Po+. However, RAD7 is more accurate in discriminating 222Rn daughters, 218Po+ and 214Po+. In this study, 222Rn was successfully measured in coastal seawater samples using Rn‐SNU connected to a grab bottle. Our results suggest that 222Rn measurements in water samples can be conducted more efficiently and rapidly with an Rn‐SNU than with other widely used instruments and methods.

Self-assembly of silver nanoparticles on chitosan/polyvinylpyrrolidone modified micro-needle electrode for amperometric detection of nitrate in seawater

In this work, silver nanoparticles (AgNPs) were self-assembled on the micro-needle electrode (MNE) with the help of chitosan (CTS) and polyvinylpyrrolidone (PVP) and used for the amperometric (i-t) determination of nitrate (NO3–) in seawater samples. CTS/PVP was electrodeposited on the MNE surface to improve the conductivity and specific surface area of the MNE, and to provide reduction conditions needed for Ag+ reduction and strong binding affinity for combination of AgNPs which had excellent catalytic activity for NO3–. AgNPs were self-assembled uniformly on the surface of MNE with the diameter of about 150–400 nm. Thanks to the unique aciform structure of MNE, the outstanding adhesion ability of CTS/PVP, and the excellent electrocatalytic ability of AgNPs, the so-prepared AgNPs/CTS/PVP/MNE showed significantly improved performance and stability for the amperometric determination of NO3–. Under the optimal conditions, the AgNPs/CTS/PVP/MNE was found to have a wide linear range (5–2000 μM) and a low limit of detection (1.2 μM). Furthermore, the AgNPs/CTS/PVP/MNE was successfully used for the direct determination of NO3– in coastal seawater samples with satisfactory results.

Isolation of agarase-producing bacteria from seawater and examination of the enzyme activity

This study aimed to isolate agarase-producing bacteria from seawater, and then determine activity of the agarase. Eight coastal surface seawater samples were collected from Ba Ria - Vung Tau province. Twenty-one bacterial strains that are capable of liquefying agar were isolated. These isolates produced disintegration zones around their colonies on agar plates with diameters ranging from 4.0 to 7.0 cm after an incubation period of 2 days at room temperature. Five bacterial strains (M1, M5, M7, M62B, and M71) that produced large halos on plates were identified belonging to Vibrio genus with identity > 96%. The crude enzyme activities of these strains ranged from 0.15 to 0.22 U/mL in reaction with agarose as substrate. Among isolated strains, the strain M71 showed the highest agarase activity, and was used to examine the degradation of seaweed. The hydrolysis of dried Gracilaria seaweed by the crude enzyme of M71 at concentration of 5% (v/v) released 915 μM/mL reducing sugar after a 24-h incubation period at 40oC.

An Optimized Metabarcoding Method for Mimiviridae.

Mimiviridae is a group of viruses with large genomes and virions. Ecological relevance of Mimiviridae in marine environments has been increasingly recognized through the discoveries of novel isolates and metagenomic studies. To facilitate ecological profiling of Mimiviridae, we previously proposed a meta-barcoding approach based on 82 degenerate primer pairs (i.e., MEGAPRIMER) targeting the DNA polymerase gene of Mimiviridae. The method detected a larger number of operational taxonomic units (OTUs) in environmental samples than previous methods. However, it required large quantities of DNA and was laborious due to the use of individual primer pairs. Here, we examined coastal seawater samples using varying PCR conditions and purification protocols to streamline the MEGAPRIMER method. Mixing primer pairs in “cocktails” reduced the required amount of environmental DNA by 90%, while reproducing the results obtained by the original protocol. We compared the results obtained by the meta-barcoding approach with quantifications using qPCR for selected OTUs. This revealed possible amplification biases among different OTUs, but the frequency profiles for individual OTUs across multiple samples were similar to those obtained by qPCR. We anticipate that the newly developed MEGAPRIMER protocols will be useful for ecological investigation of Mimiviridae in a larger set of environmental samples.

Assessment of seawater pollution of the Al-Khafji coastal area, Arabian Gulf, Saudi Arabia.

Twenty-seven coastal seawater samples were collected to assess seawater pollution and document the possible sources at Al-Khafji coastal area, Arabian Gulf, Saudi Arabia. Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Cd, Hg, and Pb were analyzed using inductively coupled plasma mass spectrometer (ICP-MS). The results revealed the following order of concentration: Sr > Ni > V > Cu > As > Zn > Al > Fe > Cr > Mn > Pb > Co > Cd > Hg. Most metals exhibited a fluctuated pattern within the studied sites without obvious trend, except Sr and Ni, which showed a fluctuated pattern with increasing trend southwards. The studied sites were classified into polluted, slightly polluted, and non-polluted ones based on HCA analyses. The higher levels of metals in the seawater of the polluted sites may be attributed to atmospheric input and oil spills from underwater pipelines, off offshore oil wells, loading and handling operations, oil terminals, and oil tanker incidents in the Arabian Gulf in general and many other anthropogenic sources in Al-Khafji area in particular such as desalination plant, landfilling due to new constructions, industrial sewage, and the Khafji Joint Operations (KJO).

Amino acids promote black carbon aggregation and microbial colonization in coastal waters off Vietnam

The combustion of fossil fuels and biomass produces pyrogenic organic matter usually known as ‘black carbon’ (BC), which are transported across the atmosphere as particulate aerosol, eventually deposited on land and oceans. Soil studies have investigated the potential microbial colonization and remineralization of BC particles, but this process has been seldom studied in marine waters. BC provides a significant input of organic carbon to the oceans, yet its fate and role in biogeochemical cycling remains unknown. Here we explored the microbial colonization of BC particles in coastal seawater samples collected in Halong Bay (northern Vietnam). Using high-resolution mass spectrometry and microscopy methods, we observed an increasing colonization of BC particles by marine microbes in the presence of amino acids. Our results suggest that natural organic matter (NOM) present in seawater may promote the microbial colonization and eventual remineralization of BC particles. Future experiments should explore the potential microbial remineralization of BC particles to unveil the role of this massive source of carbon to marine ecosystems.

Determination of environmental H2O2 for extended periods by chemiluminescence with real-time inhibition of iron interferences

Soluble iron hinders the accurate analysis of hydrogen peroxide (H2O2) in environmental systems. We present a chemiluminescence sequential injection (SIA) system capable of the continuous analysis of H2O2 over extended periods (48 h) by the real-time addition of an iron complexing reagent (ICR; masking compounds) which inhibits >98% of the interference caused by iron species. The measurement error based on repeat analysis of a sample within 10 min was ±2.2%, and over 48 h was ±6%. The preparation and analysis of standards, the ability for discrete and continuous sampling, and the real-time addition of the ICR to minimize chemical interference were integrated within the SIA system. Evaluation of the analytical probe showed that the optimum concentration and pH of the luminol reagent for the analysis of H2O2 were 100 μM luminol and pH = 10.7, respectively; this enabled the analysis over a concentration range of 0.25–900 nM H2O2 at a detection limit of 0.14 nM. The proposed SIA system requires only small amounts of reagents (33 μL luminol and 24 μL ICR) and sample (240 μL). We used the system to measure the H2O2 concentration in a coastal seawater sample that was subject to natural photochemical reactions and the direct input of rainwater, both of which introduce soluble iron. Rainwater H2O2 increased the H2O2 concentration in the coastal seawater sample by a factor of up to 40 relative to the amounts produced by natural photochemical reactions. The H2O2 concentration in the coastal seawater sample showed high short-term variability.

Metagenomic insights into the abundance and composition of resistance genes in aquatic environments: Influence of stratification and geography

A global survey was performed with 122 aquatic metagenomic DNA datasets (92 lake water and 30 seawater) obtained from the Sequence Read Archive (SRA). Antibiotic resistance genes (ARGs) and metal resistance genes (MRGs) were derived from the dataset sequences via bioinformatic analysis. The relative abundances of ARGs and MRGs in lake samples were in the ranges ND (not detected)–1.34 × 100 and 1.22 × 10−3–1.98 × 10−1 copies per 16S rRNA, which were higher than those in seawater samples. Among ARGs, multidrug resistance genes and bacitracin resistance genes had high relative abundances in both lake and sea water samples. Multi-metal resistance genes, mercury resistance genes and copper resistance genes had the greatest relative abundance for MRGs. No significant difference was found between epilimnion and hypolimnion in abundance or the Shannon diversity index for ARGs and MRGs. Principal coordinates analysis and permutational multivariate analysis of variance (PERMANOVA) test showed that stratification and geography had significant influence on the composition of ARGs and MRGs in lakes (p < 0.05, PERMANOVA). Coastal seawater samples had significantly greater relative abundance and a higher Shannon index for both ARGs and MRGs than deep ocean and Antarctic seawater samples (p < 0.05, Kruskal-Wallis one-way ANOVA), suggesting that human activity may exert more selective pressure on ARGs and MRGs in coastal areas than those in deep ocean and Antarctic seawater.

210Po in Pacific Salmon from the West Coast of Canada and its Contribution to Dose by Ingestion.

In response to public concern in Canada regarding health impacts attributable to the Fukushima Daiichi nuclear accident, oceanic seawater samples from the north Pacific and Arctic oceans, coastal seawater samples from 16 locations along the British Columbia coastline, and seafood samples (salmon, steelhead trout, and shellfish) from British Columbia coastal waters were collected and analyzed. This paper reports radiological analysis results of Pacific salmon samples (Oncorhynchus species) obtained from summer 2013 to fall 2016. While radioactive cesium from the Fukushima disaster was not detectable in most salmon samples, naturally occurring Po was measured in almost all individual samples in varying activity concentrations, from below the detection limit of 0.2 Bq kg fresh weight up to 4.7 Bq kg fresh weight. The average Po concentration among 297 salmon samples was 0.73 Bq kg fresh weight. The average ingested radiation dose per kilogram of salmon from Po is estimated to be 0.88 μSv, and the average dose from Cs is estimated to be 0.0026 μSv. The annual dose from ingested salmon would be only a fraction of the worldwide average annual effective dose from exposure to natural background radiation (2,400 μSv y) (). The measurement results showed clearly that radiation doses to people consuming fish (such as salmon) from the Canadian west coast pose no health concern.

An efficient protocol to use feedback-controlling digital microfluidic fluorimetric sensor for detection of mercury (II) in coastal seawaters

Mercury ion is a highly toxic anthropogenic pollutants and has serious well-known effects on human. There is an ever-growing demand for convenient detection of mercury driven contaminants in environment, including coastal seawater. However, most of the reported methods are instrument-based and are not easy for portable detection. Our protocol described an efficient Digital Microfluidics method for detecting mercury in coastal seawater samples. It combined the miniaturization/automation potential of digital microfluidics and the sensitivity of fluorescence probe. To overcome a potential risk of driven failure, induced by diversity ion ingredients in seawater, a feedback control loop was included into control system. The method showed satisfied stability and selectivity in Hg sensing under high salinity condition, with the sensitivity of Hg2+ at the parts-per-billion level and total testing time of less than 20 s. With the advantages of being fast, amenable to automation and low cost, this protocol is promising for the formation of simple and rapid sensor device, especially for a routine monitoring and emergency detection of Hg/or other metals in coastal waters.

Monitoring and environmental risk assessment of benzotriazole UV stabilizers in the sewage and coastal environment of Gran Canaria (Canary Islands, Spain)

Benzotriazole UV stabilizers (BUVSs) are emerging contaminants that are widely used in personal care products, such as cosmetics and sunscreens, to absorb ultraviolet light. These compounds have been described as bioaccumulative, pseudo-persistent and toxic; therefore, it is of great importance to investigate them and determine their presence and distribution in the environment. In this research, we performed a two-year monitoring study to identify six BUVS compounds (UV-P, UV-326, UV-327, UV-328, UV-329 and UV-360) in different environmental compartments from Gran Canaria (Canary Islands, Spain): influent and effluent from five wastewater treatment plants (WWTPs) and seawater and sediment samples from three marine areas influenced by sewage outfalls discharges from WWTPs. Two methods based on on-line solid-phase extraction and microwave-assisted extraction coupled with ultra-high-performance liquid chromatography with mass spectrometry detection were applied to quantify the analytes in liquid and solid samples, respectively. The target BUVSs were measured in sewage, coastal seawater and sediment samples in concentrations in the ranges of 13.12–1933 ng L−1, 67.01–2419 ng L−1 and 4.42–2162 ng kg−1 dry weight, respectively. The studied compounds exhibited different trends of occurrence in aqueous and solid samples due to their different coefficients of hydrophobicity. The majority of the positive samples belonged to the most touristic sampling location of the island. The estimated hazard quotient, HQ, revealed no risk from the target compounds at the measured concentrations levels.

Leucothrix arctica sp. nov., isolated from Arctic seawater.

A Gram-stain-negative, non-motile, oxidase- and catalase-positive, rod-shaped bacterium was isolated from a coastal seawater sample from the Arctic Circle and designated strain IMCC9719T. On the basis of 16S rRNA gene sequence analysis, it was shown that strain IMCC9719T belonged to the genus Leucothrix and was closely related to the type strains of Leucothrix pacifica (97.6 % similarity) and Leucothrix mucor (95.1 %), while the strain shared <90.6 % sequence similarity with other bacterial species. The average nucleotide identity and genome-to-genome distance values between strain IMCC9719T and L. pacifica JCM 18388T were 71.7 and 16.9 %, respectively. The DNA G+C content of strain IMCC9719T was 43.5 mol%. Optimum growth of strain IMCC9719T was observed at 15 °C, at pH 7.5-8.5 and in the presence of 2.0-2.5 % (w/v) NaCl. The major fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c) and C16 : 0. Cells of strain IMCC9719T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified polar lipid, an unidentified aminophospholipid and two unidentified phospholipids. The major respiratory quinone was ubiquinone-8 (Q-8). Based on the taxonomic data collected in this study, strain IMCC9719T represents a novel species of the genus Leucothrix, for which the name Leucothrix arctica sp. nov. is proposed. The type strain is IMCC9719T (=KACC 18010T=NBRC 110382T).

Coupling liquid membrane and flow-injection technique as an analytical strategy for copper analysis in saline water

A tandem system based on the coupling of a bulk liquid membrane and a flow injection analysis for the separation, preconcentration and spectrophotometric determination of copper in saline water is presented. The ligand pyridine-2-acetaldehyde benzoylhydrazone has been used as a carrier in the liquid membrane as well as a spectrophotometric reagent for UV–VIS detection. Simultaneous and sequential experimental designs were used to optimise the chosen variables of each technique, respectively. The metal was separated and preconcentrated from the sample with an efficiency of 100.5 ± 0.9% and a metal preconcentration factor of 16.1. The on-line FIA determination was accomplished after metal complexation by the reagent at pH 3. A linear response was obtained in a range from 6.9 to 984.5 µg L–1 Cu(II), providing a detection limit of 1.8 µg L–1. Saline matrix and other metal ions were not cause of interferences with relative errors below 4.6% for 50 µg L−1 of Cu(II) determination. The proposed tandem system was successfully tested using a TMDA-62 certified reference material providing a relative error of + 1.9%; it was also applied to the Cu(II) determination in coastal seawater samples with low relative errors ranging from − 3.8% to 0.0% (using DPASV as reference method).

Degenerate PCR Primers to Reveal the Diversity of Giant Viruses in Coastal Waters.

“Megaviridae” is a proposed family of giant viruses infecting unicellular eukaryotes. These viruses are ubiquitous in the sea and have impact on marine microbial community structure and dynamics through their lytic infection cycle. However, their diversity and biogeography have been poorly characterized due to the scarce detection of Megaviridae sequences in metagenomes, as well as the limitation of reference sequences used to design specific primers for this viral group. Here, we propose a set of 82 degenerated primers (referred to as MEGAPRIMER), targeting DNA polymerase genes (polBs) of Megaviridae. MEGAPRIMER was designed based on 921 Megaviridae polBs from sequenced genomes and metagenomes. By applying this primer set to environmental DNA meta-barcoding of a coastal seawater sample, we report 5595 non-singleton operational taxonomic units (OTUs) of Megaviridae at 97% nucleotide sequence identity. The majority of the OTUs were found to form diverse clades, which were phylogenetically distantly related to known viruses such as Mimivirus. The Megaviridae OTUs detected in this study outnumber the giant virus OTUs identified in previous individual studies by more than an order of magnitude. Hence, MEGAPRIMER represents a useful tool to study the diversity of Megaviridae at the population level in natural environments.

Bacterial Substrate Transformation Tracked by Stable-Isotope-Guided NMR Metabolomics: Application in a Natural Aquatic Microbial Community.

The transformation of organic substrates by heterotrophic bacteria in aquatic environments constitutes one of the key processes in global material cycles. The development of procedures that would enable us to track the wide range of organic compounds transformed by aquatic bacteria would greatly improve our understanding of material cycles. In this study, we examined the applicability of nuclear magnetic resonance spectroscopy coupled with stable-isotope labeling to the investigation of metabolite transformation in a natural aquatic bacterial community. The addition of a model substrate (13C6–glucose) to a coastal seawater sample and subsequent incubation resulted in the detection of >200 peaks and the assignment of 22 metabolites from various chemical classes, including amino acids, dipeptides, organic acids, nucleosides, nucleobases, and amino alcohols, which had been identified as transformed from the 13C6–glucose. Additional experiments revealed large variability in metabolite transformation and the key compounds, showing the bacterial accumulation of glutamate over the incubation period, and that of 3-hydroxybutyrate with increasing concentrations of 13C6–glucose added. These results suggest the potential ability of our approach to track substrate transformation in aquatic bacterial communities. Further applications of this procedure may provide substantial insights into the metabolite dynamics in aquatic environments.

Planktotalea arctica sp. nov., isolated from Arctic seawater.

A Gram-staining-negative, non-motile, non-pigmented, rod-shaped bacterium was isolated from an Arctic coastal seawater sample and was designated strain IMCC9565T. Analysis of the 16S rRNA gene sequence of strain IMCC9565T revealed that the closest phylogenetic neighbours of the strain were members of the genus Planktotalea. Furthermore, the strain formed a robust clade with Planktotalea frisia SH6-1T, with which it shared 97.9 % 16S rRNA gene sequence similarity. Determination of genomic relatedness based on average nucleotide identity and genome-to-genome distance showed that strain IMCC9565T was distantly related to P. frisia, meaning the Arctic strain represents a novel species. Optimum growth of strain IMCC9565T was observed at 20 °C, pH 7.0 and in the presence of 2 % (w/v) NaCl. The major respiratory isoprenoid quinone was ubiquinone-10 (Q-10) and the major polar lipids consisted of phosphatidylglycerol, phosphatidylcholine, one unidentified aminolipid and two unidentified lipids. The principal fatty acids were C18 : 1ω7c and/or C18 : 1ω6c, C18 : 1ω7c 11-methyl and C16 : 0, and the DNA G+C content was 57.1 mol%. Based on these data, Planktotalea arctica sp. nov. is proposed to accommodate the bacterial isolate and the type strain is IMCC9565T (=KACC 18009T=NBRC 110393T).

Spatial distribution, ecological and health risk assessment of heavy metals in marine surface sediments and coastal seawaters of fringing coral reefs of the Persian Gulf, Iran

Concentrations of 13 heavy metals (Al, Fe, Mn, Zn, Cu, Cr, Co, Ni, V, As, Cd, Hg, Pb) in 360 reef surface sediments (0–5 cm) and coastal seawater samples from ten coral Islands in the Persian Gulf were analyzed to determine their spatial distribution and potential ecological risks. Different sediment quality indices were applied to assess the surface sediment quality. The mean concentrations of metals in studied sediments followed the order: Al > Fe > Ni > V > Mn > Zn > Cu > Cr > Co > As > Cd > Pb > As. Average Cd and Hg exceeded coastal background levels at most sampling sites. With the exception of As, concentrations of heavy metals decreased progressively from the west to the east of the Persian Gulf. Based on the Enrichment Factor (EF) and Potential Ecological Risk Index (RI), concentrations of V, Ni, Hg and Cd indicated moderate contamination and is of some concern. The mean values of heavy metals Toxic Units (TUs) were calculated in the following order: Hg (0.75)> Cr (0.41)> Cd (0.27)> As (0.23)> Cu (0.12)> Zn (0.05)> Pb (0.009). Furthermore, the mean contributing ratios of six heavy metals to Toxic Risk Index (TRI) values were 79% for Hg, 11.48% for Cd, 6.16% for Cr, 3.27% for Cu, 0.07% for Zn and 0.01% for Pb. Calculated values of potential ecological risk factor, revealed that the risk of the heavy metals followed the order Cd > Pb > Ni > Cr > V > Cu > Zn. The results reflected that the level of heavy metals, especially Hg and Cd, are on rise due to emerging oil exploration, industrial development, and oil refineries along the entire Gulf. Fe, Mn, Cu, Zn, V and Ni concentrations in seawater were significantly higher (p < 0.05) than the other detected dissolved heavy metals in the sampling sites. A health risk assessment using the hazard quotient index (HQ) recommended by the USEPA suggests that there is no adverse health effect through dermal exposure, and there is no carcinogenic and non-carcinogenic harm to human health.

Role of Snow Deposition of Perfluoroalkylated Substances at Coastal Livingston Island (Maritime Antarctica).

Perfluoroalkyl substances (PFAS) are ubiquitous in the environment, including remote polar regions. To evaluate the role of snow deposition as an input of PFAS to Maritime Antarctica, fresh snow deposition, surface snow, streams from melted snow, coastal seawater, and plankton samples were collected over a three-month period (December 2014-February 2015) at Livingston Island. Local sources of PFASs were significant for perfluoroalkyl sulfonates (PFSAs) and C7-14 perfluoroalkyl carboxylates (PFCAs) in snow but limited to the transited areas of the research station. The concentrations of 14 ionizable PFAS (∑PFAS) in freshly deposited snow (760-3600 pg L-1) were 1 order of magnitude higher than those in background surface snow (82-430 pg L-1). ∑PFAS ranged from 94 to 420 pg L-1 in seawater and from 3.1 to 16 ng gdw-1 in plankton. Ratios of individual PFAS concentrations in freshly deposited snow relative to surface snow (CSD/CSnow), snowmelt (CSD/CSM), and seawater (CSD/CSW) were close to 1 (from 0.44 to 1.4) for all perfluorooctanesulfonate (PFOS) isomers, suggesting that snowfall does not contribute significantly to PFOS in seawater. Conversely, these ratios for PFCAs ranged from 1 to 33 and were positively correlated with the number of carbons in the PFCA alkylated chain. These trends suggest that snow deposition, scavenging sea-salt aerosol bound PFAS, plays a role as a significant input of PFCAs to the Maritime Antarctica.

Spatial variation of PAHs and PCBs in coastal air, seawater, and sediments in a heavily industrialized region

Concurrent coastal seawater (n=22), sediment (n=22), and atmospheric samples (n=10) were collected in the Aliaga industrial region, Turkey, to explore the spatial variation, sources, and air-seawater exchange of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Seawater Σ16PAH concentrations (particle+dissolved) ranged between 5107 and 294,624pgL-1, while Σ41PCB concentrations were in the range of 880-50,829pgL-1. Levels in sediments were highly variable ranging between 35.5-49,682 and 2.7-2450μgkg-1 in dry weight for Σ16PAHs and Σ41PCBs, respectively. Atmospheric concentrations varied between 1791-274,974 and 104-20,083pgm-3 for Σ16PAHs and Σ41PCBs, respectively. Sediment organic matter (OM) content and levels of Σ16PAHs and Σ41PCBs correlated weakly (r 2=0.19-0.23, p<0.05) suggesting that the spatial variations of PAHs and PCBs were mainly affected by local sources rather than their sorption to OM. The geographical distribution of PAH and PCB concentrations in air, seawater, and sediment and factor analysis on the sediment levels pointed out that the major sources in the region are steel plants, petroleum refinery, petrochemical complex, ship breaking, loading/unloading activities at the ports, vehicular emissions, and fossil fuel combustion emissions. The direction of the air-seawater exchange was also explored by estimating seawater fugacity fractions of PAHs and PCBs. For PAHs, the number of cases implying deposition (43.0%) and volatilization (39.5%) was similar, while for PCBs, the number of cases implying volatilization (60.4%) was much higher compared to deposition (21.6%). Fugacity fractions were generally <0.36 (deposition) at the sites close to industrial and ship breaking activities where the highest seawater and sediment levels were measured, implying that atmospheric deposition is an important mechanism affecting seawater and sediment PAH and PCB levels.