Oxygenated polycyclic aromatic hydrocarbons and azaarenes in urban soils: A comparison of a tropical city (Bangkok) with two temperate cities (Bratislava and Gothenburg)

Environmental conditions in the tropics favor the formation of polar polycyclic aromatic compound (polar PACs, such as oxygenated PAHs [OPAHs] and azaarenes [AZAs]), but little is known about these hazardous compounds in tropical soils. The objectives of this work were to determine (i) the level of contamination of soils (0–5 and 5–10 cm layers) from the tropical metropolis of Bangkok (Thailand) with OPAHs and AZAs and (ii) the influence of urban emission sources and soil properties on the distribution of PACs. We hypothesized that the higher solar insolation and microbial activity in the tropics than in the temperate zone will lead to enhanced secondary formation of OPAHs. Hence, OPAH to related parent-PAH ratios will be higher in the tropical soils of Bangkok than in temperate soils of Bratislava and Gothenburg. The concentrations of ∑15OPAHs (range: 12–269 ng g−1) and ∑4AZAs (0.1–31 ng g−1) measured in soils of Bangkok were lower than those in several cities of the industrialized temperate zone. The ∑15OPAHs (r = 0.86, p < 0.01) and ∑4AZAs (r = 0.67, p < 0.01) correlated significantly with those of ∑20PAHs highlighting similar sources and related fate. The octanol–water partition coefficient did not explain the transport to the subsoil, indicating soil mixing as the reason for the polar PAC load of the lower soil layer. Data on PAC concentrations in soils of Bratislava and Gothenburg were taken from published literature. The individual OPAH to parent-PAH ratios in soils of Bangkok were mostly higher than those of Bratislava and Gothenburg (e.g. 9-fluorenone/fluorene concentration ratio was 12.2 ± 6.7, 5.6 ± 2.4, and 0.7 ± 02 in Bangkok, Bratislava and Gothenburg soils, respectively) supporting the view that tropical environmental conditions and higher microbial activity likely lead to higher OPAH to parent-PAH ratios in tropical than in temperate soils.

Tissue-specific metabolism of benzo[a]pyrene in rainbow trout (Oncorhynchus mykiss): a comparison between the liver and immune organs.

Polycyclic aromatic hydrocarbons (PAHs) are immunotoxicants in fish. In mammals, phase I metabolites are believed to be critically involved in the immunotoxicity of PAHs. This mechanism has been suggested for fish as well. The present study investigates the capacity of immune organs (head kidney, spleen) of rainbow trout, Oncorhynchus mykiss, to metabolize the prototypic PAH, benzo[a]pyrene (BaP). To this end, we analyzed 1) the induction of enzymatic capacity measured as 7-ethoxyresorufin-O-deethylase (EROD) activity in immune organs compared with liver, 2) the organ profiles of BaP metabolites generated in vivo, and 3) rates of microsomal BaP metabolite production in vitro. All measurements were done for control fish and for fish treated with an intraperitoneal injection of 15 mg BaP/kg body weight. In exposed trout, the liver, head kidney, and spleen contained similar levels of BaP, whereas EROD induction differed significantly between the organs, with liver showing the highest induction factor (132.8×), followed by head kidney (38.4×) and spleen (1.4×). Likewise, rates of microsomal metabolite formation experienced the highest induction in the liver of BaP-exposed trout, followed by the head kidney and spleen. Microsomes from control fish displayed tissue-specific differences in metabolite production. In contrast, in BaP-exposed trout, microsomes of all organs produced the potentially immunotoxic BaP-7,8-dihydrodiol as the main metabolite. The findings from this study show that PAHs, like BaP, are distributed into immune organs of fish and provide the first evidence that immune organs possess inducible PAH metabolism leading to in situ production of potentially immunotoxic PAH metabolites.

Linking Ah receptor mediated effects of sediments and impacts on fish to key pollutants in the Yangtze Three Gorges Reservoir, China – A comprehensive perspective

The Three Gorges Reservoir (TGR), created in consequence of the Yangtze River's impoundment by the Three Gorges Dam, faces numerous anthropogenic impacts that challenge its unique ecosystem. Organic pollutants, particularly aryl hydrocarbon receptor (AhR) agonists, have been widely detected in the Yangtze River, but only little research was yet done on AhR-mediated activities. Hence, in order to assess effects of organic pollution, with particular focus on AhR-mediated activities, several sites in the TGR area were examined applying the "triad approach". It combines chemical analysis, in vitro, in vivo and in situ investigations to a holistic assessment. Sediments and the benthic fish species Pelteobagrus vachellii were sampled in 2011/2012, respectively, to identify relevant endpoints. Sediment was tested in vitro with the ethoxyresorufin-O-deethylase (EROD) induction assay, and in vivo with the Fish Embryo Toxicity Test and Sediment Contact Assay with Danio rerio. Activities of phase I (EROD) and phase II (glutathione-S-transferase) biotransformation enzymes, pollutant metabolites and histopathological alterations were studied in situ in P. vachellii. EROD induction was tested in vitro and in situ to evaluate possible relationships. Two sites, near Chongqing and Kaixian city, were identified as regional hot-spots and further investigated in 2013. The sediments induced in the in vitro/in vivo bioassays AhR-mediated activities and embryotoxic/teratogenic effects - particularly on the cardiovascular system. These endpoints could be significantly correlated to each other and respective chemical data. However, particle-bound pollutants showed only low bioavailability. The in situ investigations suggested a rather poor condition of P. vachellii, with histopathological alterations in liver and excretory kidney. Fish from Chongqing city exhibited significant hepatic EROD induction and obvious parasitic infestations. The polycyclic aromatic hydrocarbon (PAH) metabolite 1-hydroxypyrene was detected in bile of fish from all sites. All endpoints in combination with the chemical data suggest a pivotal role of PAHs in the observed ecotoxicological impacts.

Approaching atrial septal defects in pulmonary hypertension

Atrial septal defects (ASDs) are one of the most frequent congenital cardiac malformations, accounting for about 8-10% of all congenital heart defects. The prevalence of pulmonary arterial hypertension (PAH) in adults with an ASD is 8-10%. Different clinical PAH scenarios can be encountered. At one end of the spectrum are adults with no or only mild pulmonary vascular disease and a large shunt. These are patients who can safely undergo shunt closure. In the elderly, mild residual pulmonary hypertension after shunt closure is the rule. At the other end of the spectrum are adults with severe, irreversible pulmonary vascular disease, shunt reversal and chronic cyanosis, that is, Eisenmenger syndrome. These are patients who need to be managed medically. The challenge is to properly classify ASD patients with PAH falling in between the two ends of the spectrum as the ones with advanced, but reversible pulmonary vascular disease amenable to repair, versus the ones with progressive pulmonary vascular disease not responding to shunt closure. There are concerns that adults with progressive pulmonary vascular disease have worse outcomes after shunt closure than patients not undergoing shunt closure. Due to the correlation of pulmonary vascular changes and pulmonary hemodynamics, cardiac catheterization is used in the decision-making process. It is important to consider the hemodynamic data in the context of the clinical picture, the defect anatomy and further noninvasive tests when evaluating the option of shunt closure in these patients.

Long-term data from the Swiss pulmonary hypertension registry.

BACKGROUND Registries are important for real-life epidemiology on different pulmonary hypertension (PH) groups. OBJECTIVE To provide long-term data of the Swiss PH registry of 1998-2012. METHODS PH patients have been classified into 5 groups and registered upon written informed consent at 5 university and 8 associated hospitals since 1998. New York Heart Association (NYHA) class, 6-min walk distance, hemodynamics and therapy were registered at baseline. Patients were regularly followed, and therapy and events (death, transplantation, endarterectomy or loss to follow-up) registered. The data were stratified according to the time of diagnosis into prevalent before 2000 and incident during 2000-2004, 2005-2008 and 2009-2012. RESULTS From 996 (53% female) PH patients, 549 had pulmonary arterial hypertension (PAH), 36 PH due to left heart disease, 127 due to lung disease, 249 to chronic thromboembolic PH (CTEPH) and 35 to miscellaneous PH. Age and BMI significantly increased over time, whereas hemodynamic severity decreased. Overall, event-free survival was 84, 72, 64 and 58% for the years 1-4 and similar for time periods since 2000, but better during the more recent periods for PAH and CTEPH. Of all PAH cases, 89% had target medical therapy and 43% combination therapy. Of CTEPH patients, 14 and 2% underwent pulmonary endarterectomy or transplantation, respectively; 87% were treated with PAH target therapy. CONCLUSION Since 2000, the incident Swiss PH patients registered were older, hemodynamically better and mostly treated with PAH target therapies. Survival has been better for PAH and CTEPH diagnosed since 2008 compared with earlier diagnosis or other classifications.

Lipids and polycyclic aromatic hydrocarbons in bottom sediments from the Atlantic sector of the Southern Ocean

Distribution and composition of lipids and contents of alkanes and polycyclic aromatic hydrocarbons(PAHs) in bottom sediments of the Scotia and Weddell seas are discussed. Comparatively low concentrations of organic carbon (average 0.35%) and lipids (average 0.024%) result from rapid decomposition of organic matter in upper layers of the water column. Composition of alkanes indicates that lipids are of autochthonous origin, and stable concentrations of PAHs (average 25.8 ppb, sigma 15.3 ppb) indicate that they represent the background level for bottom sediments. Higher concentrations of PAHs in sediments near the King George Island (252.1 ppb) and different distributions of individual polyarenes are produced there by the heating systems of the Polish Antarctic Station.

Concentrations of organic compounds in suspended matter from surface waters and surface layer bottom sediments of the Obskay Guba (Ob River estuary) and the Kara Sea

Data are presented on concentrations of aliphatic and polycyclic aromatic hydrocarbons (AHC and PAH) in interstitial waters and bottom sediments of the Kara Sea compared to distribution of particulate matter and organic carbon. It was found that AHC concentrations within the water mass (aver. 16 µg/l) are mainly formed by natural processes. Distribution of AHC represents variability of hydrological and sedimentation processes in different regions of the sea. The widest ranges of the concentrations occurred in the Obskaya Guba - Kara Sea section: in water (10-310 µg/l for AHC and 0.4-7.2 ng/l for PAH) and in the surface layer of the bottom sediments (8-42 µg/l for AHC and 9-94 ng/g for PAH). Differentiation of hydrocarbons (HC) in different media follows regularities typical for marginal filters; therefore no oil and pyrogenic compounds are supplied to the open sea. In sediments contents of HC depend on variations in redox conditions in sediments and on their composition.

Organic compounds in snow, ice, and sub-ice waters from the mouth of the Severnaya Dvina River and the Kandalaksha Gulf (White Sea)

The paper reports data on concentrations of organic compounds (organic carbon, lipids; aliphatic hydrocarbons, and polycyclic aromatic hydrocarbons) in snow, ice, and sub-ice waters from the mouth of the Severnaya Dvina River in March 2005-2007 and the Kandalaksha Gulf (Chupa Bay) in March 2004. It was established that organic compounds are accumulated in snow and the upper ice layer near Archangelsk city. Distribution of molecular markers indicates that pollutions were mainly caused by local fallouts. In the Chupa Bay organic compounds are concentrated in the lower ice layer; it is typical for Arctic snow-ice cover. High contents of organic compounds in the snow-ice cover of the White Sea are caused by pollution of air and water during the winter season.

Distribution of polycyclic aromatic hydrocarbons in eolian and eolian-deluvial sediments from the North Iceland

This work considers results of a study of Holocene cover sediments in Iceland. They are largely composed of wind-transported palagonitized hyaloclastite particles and coeval horizons of acid and basic tephras. It is established that polyciclic aromatic hydrocarbons (PAH) are released from basaltic glass in natural environments only in case of intense physicochemical alteration and destruction of its structure. This process does not influence PAH composition and their quantitative proportions. No new PAH formed during several thousands of years in Holocene section. Hydrocarbons are transferred from fixed state in basaltic glass into free state in palagonites practically without any changes. PAH were mainly redeposited by winds, derived together with palagonite from weathered hyaloclastites, and precipitated from atmosphere with tephra during eruptions.

Biochar and compost effects on mobility of Cu and other soil parameters and plant growth

A pot experiment was conducted to determine the effects of three biochars and compost on plant growth and the immobilisation of Cu in a contaminated soil obtained from a former wood preservation site in the Gironde County Saint Médard d'Eyrans, France (N 44° 43.353, W 0° 30.938). To assess Cu mobility, amended soils were analysed using CaCl**2 leaching tests pre- and post-incubation, and post-growth. Amended and unamended soils were planted with sunflower, and the resulting plant material was assessed for yield (mass and height) and Cu concentration. All amendments significantly reduced leachable Cu compared to the unamended soil, however, the greatest reductions in leachable Cu were associated with the higher biochar application rate. The greatest improvements in plant yields were obtained with the higher application rate of biochar in combination with compost. pH, DOC, EH were measured in soils to help explain the leaching and plant growth trends. Soil pore water was collected during plant growth and analysed for metal concentration, pH and EH. Prior to treatment, background analyses were carried out on the soil and individual amendments (including PAH + metal concentrations measured by gas chromatography mass spectrometry and ICP-AES respectively).

Hydrocarbons in particulate matter and bottom sediments from the north Caspian Sea shelf

Data are presented on content and composition of hydrocarbons (HC) (aliphatic AHC and polyaromatic PAH) in filtered particulate matter and in the surface layer of bottom sediments from the northern shelf of the Caspian Sea and related to data on their contents in the Volga River estuary. Because of transformation and precipitation of anthropogenic and natural compounds, HC composition in particulate matter and bottom sediments undergoes transformations caused by mixing of fresh and saline waters (in bottom sediments, within concentration ranges 70.4-4557.9 µg/g for AHC and 3.8-4800 ng/g for PAH). It was found that the greatest concentrating of HC proceeds in the region of the avalanche sedimentation, and their contents are independent of grain-size types of bottom sediments. Anthropogenic HC (oil and pyrogenous) do not get over the marginal filter of the Volga River and do not pass to the open part of the sea.

Organic geochemistry of water and bottom sediments during a seasonal flood in 2006 in the North Dvina River estuary

Heavy contaminant load released into the Northern Dvina River during flooding increased the concentrations of aliphatic (AHC) and polcyclic aromatic (PAH) hydrocarbons in water and bottom sediments. The composition of hydrocarbons was different from that of the summer low flow season. The concentrations of dissolved and particulate AHC ranged from 12 to 106 and from 192 to 599 µg/l, respectively, and bottom sediments contained from 26.2 to 329 µg/g AHC and 4 to 1785 ng/g PAH. As the transformation of AHC occurred at low spring temperatures, the alkane composition was shown to be dominated by terrigenous compounds, whereas more stable PAH showed elevated contents of petrogenic and pyrogenic compounds. It was also shown that the Northern Dvina-Dvina Bay geochemical barrier prevents contaminant input into the White Sea, i.e., acts as a marginal filter.

Geochemistry of pockmark sediments from the inner Oslofjord

Pockmarks are geological features that are found on the bottom of lakes and oceans all over the globe. Some are active, seeping oil or methane, while others are inactive. Active pockmarks are well studied since they harbor specialized microbial communities that proliferate on the seeping compounds. Such communities are not found in inactive pockmarks. Interestingly, inactive pockmarks are known to have different macrofaunal communities compared to the surrounding sediments. It is undetermined what the microbial composition of inactive pockmarks is and if it shows a similar pattern as the macrofauna. The Norwegian Oslo Fjord contains many inactive pockmarks and they are well suited to study the influence of these geological features on the microbial community in the sediment. Here we present a detailed analysis of the microbial communities found in three inactive pockmarks and two control samples at two core depth intervals. The communities were analyzed using high-throughput amplicon sequencing of the 16S rRNA V3 region. Microbial communities of surface pockmark sediments were indistinguishable from communities found in the surrounding seabed. In contrast, pockmark communities at 40 cm sediment depth had a significantly different community structure from normal sediments at the same depth. Statistical analysis of chemical variables indicated significant differences in the concentrations of total carbon and non-particulate organic carbon between 40 cm pockmark and reference sample sediments. We discuss these results in comparison with the taxonomic classification of the OTUs identified in our samples. Our results indicate that microbial surface sediment communities are affect by the water column, while the 40 cm communities are affect by local conditions within the sediment.

Geochemistry of tetrapyrrole, tetraterpenoid, and perylene pigments in sediments from the Gulf of California

Results and discussion cover pigment analyses of 36 sediment samples recovered by Deep Sea Drilling Project Leg 64, and six samples from the Leg 64 site-survey cruise in the Guaymas Basin (Scripps Institution of Oceanography, Leg 3). Pigments investigated were tetrapyrroles, tetraterpenoids, and the PAH compound perylene. Traces of mixed nickel and copper ETIO-porphyrins were ubiquitous in all sediment samples, except for the very surface (i.e., <2 m sub-bottom), and their presence is taken as an indication of minor influxes of previously oxidized allochthonous (terrestrial) organic matter. Phorbides and chlorins isolated from Site 479 sediment samples (i.e., the oxygen-minimum locale, northeast of the Guaymas Basin) well represent the reductive diagenesis ("Treibs Scheme"; see Baker and Palmer, 1978; Treibs, 1936) of chlorophyll derivatives. Three forms of pheophytin-a, plus a variety of phorbides, were found to give rise to freebase porphyrins, nickel phylloerythrin, and nickel porphyrins, with increasing depth of burial (increasing temperature). Sediments from Sites 481, 10G, and 18G yielded chlorophyll derivatives characteristic of early oxidative alterations. Included among these pigments are allomerized pheophytin-a, purpurin-18, and chlorin-p6. The high thermal gradient imposed upon the late Quaternary sediments of Site 477 greatly accelerated chlorophyll diagenesis in the adjacent overlying sediments, that is, the production of large quantities of free-base desoxophylloerythroetioporphyrin (DPEP) occurred in a section (477-7-5) presently only 49.8 meters sub-bottom. Present depth and age of these sediments are such that only chlorins and phorbides would be expected. Carotenoid (i.e., tetraterpenoids) concentrations were found to decrease rapidly with increasing sub-bottom depth. Less deeply buried sediments (e.g., 0-30 m) yielded mixtures of carotenes and oxygen-substituted carotenoids. Oxygencontaining (oxy-, oxo-, epoxy-) carotenoids were found to be lost preferentially with increased depth of burial. Early carotenoid diagenesis is suggested as involving interacting reductions and dehydrations whereby dehydro-, didehydro-, and retro-carotenes are generated. Destruction of carotenoids as pigments may involve oxidative cleavage of the isoprenoid chain through epoxy intermediates, akin to changes in the senescent cells of plants. Perylene was found to be a common component of the extractable organic matter from all sediments investigated. The generation of alkyl perylenes was found to parallel increases in the existing thermal regime at all sites. Igneous sills and sill complexes within the sediment profile of Site 481 altered (i.e., scrambled) the otherwise straightforward thermally induced alkylation of perylene. The degree of perylene alkylation is proposed as an indicator of geothermal stress for non-contemporaneous marine sediments.

Hydrocarbons in bottom sediments during a seasonal flood 2005 in the Dvina River estuary

The results of studying hydrocarbons during the flood in May 2005 are discussed. The concentration of aliphatic and polycyclic aromatic hydrocarbons are shown to match their concentrations in water areas with steady input of pollutants. Weathered oil and pyrogenic compounds dominated in their composition. The geochemical barrier the Northern Dvina River-Dvina Gulf is shown to become a filter during floods and prevents pollutants from penetrating into the White Sea.