High concentrations of HgS, MeHg and toxic gas emissions in thermally affected waste dumps from hard coal mining in Poland.

This study aims to provide numerous environmental research approaches to understand the formation of mineral and organic mercury compounds in self-heating coal waste dumps of the Upper Silesian Coal Basin (USCB). The results are combined with environmental and health risk assessments. The mineralogy comprised accessory minerals in the fine fraction of thermally affected waste, i.e., Hg sulfides, most likely cinnabar or metacinnabar. Moreover, other metals, e.g., Pb, Zn and Cu, were found as sulfide forms. Apart from Hg, the ICP-ES/MS data confirmed the high content of Mn, Zn, Pb, Hg, Cr and Ba in these wastes. The high concentration of available Hg resulted in elevated MeHg concentrations in the dumps. There were no correlations or trends between MeHg concentrations and elemental Hg, TS, TOC, and pH. Furthermore, we did not detect microbial genes responsible for Hg methylation. The organic compounds identified in waste and emitted gases, such as organic acids, or free methyl radicals, common in such burn environments, could be responsible for the formation of MeHg. The concentration levels of gases, e.g., benzene, formaldehyde, NH3, emitted by the vents, reached or surpassed acceptable levels numerous times. The potential ecological and human health risks of these dumps were moderate to very high due to the significant influence of the high Hg concentrations.

Saccharides in atmospheric particulate and sedimentary organic matter: Status overview and future perspectives.

Saccharides are omnipresent compounds in terrestrial and marine ecosystems. Since the 2000s, their role in environmental and geochemical studies has significantly increased, but only anhydrosaccharides (mainly levoglucosan) have been reviewed. Here we present the wider knowledge about saccharides in organic matter of aerosols, bottom sediments, soils, dust, and sedimentary rocks. The main purpose here is to characterize the possible sources of saccharides, as well as sacharol formation, seasonal variability, and the possible applications in environmental and paleoenvironmental interpretations. Different saccharide sources were designated, including biomass burning, and particulate matter such as pollen, spores, lichen, and fungi, as well as polysaccharide decomposition as possible inputs of monosaccharides. The main focus was on the most common saccharides encountered in environmental samples and sedimentary rocks. These are the mono- and disaccharides glucose, fructose, sucrose, and trehalose, and sacharols arabitol and mannitol. The anhydrosaccharides levoglucosan, mannosan, and galactosan were evaluated as ancient wildfire indicators and industrialization tracers found in lacustrine sediments starting from Pleistocene to contemporary deposits. However, other anhydrosaccharides like xylosan and arabinosan were also found as products of fossil wood burning. These anhydrosaccharides have the potential to be further tracers of hemicellulose burning. Additional recommendations are proposed for future research, including environmental and paleoenvironmental topics that need to be addressed.

Polycyclic aromatic hydrocarbons in coastal sediments of Southern Terengganu, South China Sea, Malaysia: source assessment using diagnostic ratios and multivariate statistic.

Surface sediments along the Southern Terengganu coast (≤7 km from the coast) were analyzed for polycyclic aromatic hydrocarbons (PAHs). The concentrations of 16 USEPA priority polycyclic aromatic hydrocarbons (ΣPAH16) ranged from 2.59 to 155 ng g-1 and their respective alkylated ranged between 8.80 and 24.90 ng g-1. Traces of acephenanthrylene, benzo[c]phenanthrene, thiophenic PAH, and benzonaphthofuran were identified. PAH diagnostic ratios and cross-plots revealed that these sedimentary PAH compounds are derived mainly from pyrogenic sources, primarily from biomass burning and petroleum combustion residues with minor petrogenic input. The high correlations between pyrogenic PAHs to total PAHs (r >0.73, p <0.5), and the Bap/Bep ratio to total PAHs (r = 0.88, p <0.5), suggest that atmospheric deposition and urban runoff are the main deposition pathways. The concentrations of the PAHs in the southern South China Sea fall in the moderate contamination range of 100-1000 ng g-1.

Input of organic matter in Brunei Bay, East Malaysia, as indicated by sedimentary steroids and multivariate statistics.

Brunei Bay is one of the most important marine environments of East Malaysia (South China Sea), covering many productive ecosystems with activities including fisheries, tourism, and main shipping lanes for petroleum transfers. Evaluation of the sources and distributions of steroids in the surface sedimentary organic matter was carried out by gas chromatography-mass spectrometry (GC-MS). The concentrations of the total identified sterols (TIS) ranged between 0.81 and 12.69 µg g-1 dry weight, and the total sterones were between 0.11 and 5.66 µg g-1 dry weight. The coprostanol level was comparatively low (<0.10 µg g-1), and the multi-biomarker proxies indicated that the region did not exhibit significant contamination from sewage effluents. Principal component analysis (PCA) revealed the coastal environment of the study area was dominated by allochthonous (mainly terrestrial) organic matter input.

Variations in δ13C values of levoglucosan from low-temperature burning of lignite and biomass.

Levoglucosan, an anhydrosaccharide, is commonly used as an organic tracer for biomass burning, but has also been identified from coal smoke particulate matter (PM) including lignites. Here we showed that stable carbon isotope analysis specifically of levoglucosan may be one possible way to determine the relative contributions from coal combustion versus biomass burning sources. PM samples were collected from low-temperature burning/smoldering of Miocene lignites from Poland and basket willow (Salix viminalis L.) representative of biomass. The calculated levoglucosan δ13C values of xylites varied from -23.6 to -21.6‰, while for detritic coal samples they ranged from -24.2 to -23.1‰, with means of -22.7 and -23.7‰, respectively. The calculated levoglucosan δ13C value of basket willow wood was -27.1‰. Values of willow wood mixtures with xylite varied from -25.8 to -23.4‰ (with an increasing proportion of xylite), while values of mixtures of willow and detritic coal ranged from -26.9 to -24.6‰ (with an increasing proportion of detritic coal). The δ13C values for the mixtures changed proportionally to the contents of individual components with R2 = 0.88 and 0.89 for willow with xylite and detritic coal, respectively. The hopanoid distributions characteristic for low-temperature lignite/peat burning, with a predominance of 22R-α,ß-homohopane, ßß-hopanes and hopenes, as well as low or very low values of the homohopane index, were observed in smoke PM from most lignite samples and absent in the basket willow sample. Thus, the relatively high content of hopanes (with the occurrence of 22R-α,ß-homohopane, ßß-hopanes and hopenes) in atmospheric PM samples can be treated as additional tracers of lignite combustion.

Composition of organic compounds from low-temperature burning of lignite and their application as tracers in ambient air.

Levoglucosan, a product from thermal decomposition of cellulose, is widely known as an organic tracer of biomass burning, but has also been reported from coal smoke particulate matter (PM) including lignites. This study provides direct evidence that levoglucosan is generated not only during low-temperature burning/smoldering of xylite, but also from other lignite types including detritic and detroxylitic brown coals from Poland. Moreover, only trace amounts of mannosan and galactosan have been detected in PM of lignite smoke. The hopanes in lignite smoke PM comprise the thermodynamically unstable ßß-hopanes and hopenes, with values of the homohopane index 22S/(22S + 22R) ranging from 0.02 to 0.12. This is characteristic for immature organic matter, and combined with the presence of anhydrosaccharides can be used as tracers for lignite combustion in ambient air. Furthermore, almost all Miocene lignite smoke PM samples contain α-, ß-, γ-, and δ-tocopherols, and prist-1-ene. This is the first report of the occurrence of all four tocopherol isomers in the geological record (in lignite extracts) and in lignite smoke PM samples. Lower α-tocopherol is observed for the lignite burn-test samples than in the corresponding lignite extracts, probably due to partial chain degradation to prist-1-ene during combustion.

Terpenoids of the Swamp Cypress Subfamily (Taxodioideae), Cupressaceae, an Overview by GC-MS.

The resins bled from stems and in seed cones and leaves of Cryptomeria japonica, Glyptostrobus pensilis, Taxodium distichum, and T. mucronatum were characterized to provide an overview of their major natural product compositions. The total solvent extract solutions were analyzed as the free and derivatized products by gas chromatography-mass spectrometry to identify the compounds, which comprised minor mono- and sesquiterpenoids, and dominant di- and triterpenoids, plus aliphatic lipids (e.g., n-nonacosan-10-ol). Ferruginol, 7α-p-cymenylferruginol, and chamaecydin were the major characteristic markers for the Taxodioideae conifer subfamily. The mass spectrometric data can aid polar compound elucidation in environmental, geological, archeological, forensic and pharmaceutical studies.

Mulinane and Azorellane Diterpenoid Biomarkers by GC-MS from a Representative Apiaceae (Umbelliferae) Species of the Andes.

Extracts of bled resin from Azorella compacta, of the Azorelloideae family from the Andes (>4000 m), were analyzed by gas chromatography-mass spectrometry. The mass spectra of the dominant compounds of the resin and its hydrogenation products were documented. The most abundant compounds were oxygenated diterpenoids, namely mulinadien-20-oic (Δ11,13 and Δ11,14) acids, azorell-13-en-20-oic acid, 13α,14ß-dihydroxymulin-11-en-20-oic acid, and azorellanol, with a group of azorellenes and mulinadienes. The mass spectra of the novel diterpenoid hydrocarbons with the azorellane and mulinane skeletons were also presented. This study documents the molecular diversity of these diterpenoid classes, and could be of great utility for future organic geochemical, environmental, archeological, pharmaceutical, and forensic chemistry studies.

Terpenoid Compositions of Resins from Callitris Species (Cupressaceae).

The environmental fate of conifer resins and their natural product compounds as mixtures is of importance for source, alteration, and transport studies. The compound compositions of resins of the common Callitris species (Cupressaceae) based on gas chromatography-mass spectrometry have not been reported. Results show that diterpenoids were the most abundant components and callitrisic acid was present in the resin extracts of all Callitris species analyzed. Significant amounts of 4-epi-pimaric and sandaracopimaric acids, with lesser communic, ozic, and lambertianic acids, were also in the mixtures. Phenolic diterpenoids, for example, ferruginol, hinokiol, were found in trace quantities in some samples. Thus, callitrisic acid and 4-epi-pimaric acid are the characteristic diterpenoids of Callitris species that are amenable to molecular biomarker analyses in geological or environmental applications.

Environmental factors controlling the distributions of Botryococcus braunii (A, B and L) biomarkers in a subtropical freshwater wetland.

Here we report the molecular biomarker co-occurrence of three different races of Botryococcus braunii (B. braunii) in the freshwater wetland ecosystem of the Florida Everglades, USA. Thespecific biomarkers include C32-C34 botryococcenes for race B, C27-C32 n-alkadienes and n-alkatrienes for race A, and lycopadiene for race L. The n-alkadienes and n-alkatrienes were present up to 3.1 and 69.5 µg/g dry weight (dw), while lycopadiene was detected in lower amounts up to 3.0 and 1.5 µg/g dw in periphyton and floc samples, respectively. Nutrient concentrations (P and N) did not significantly correlate with the abundances of these compounds. In contrast, n-alkadienes and n-alkatrienes were present in wider diversity and higher abundance in the floc from slough (deeper water and longer hydroperiod) than ridge (shallower water and shorter hydroperiod) locations. n-Alkadienes, n-alkatrienes, and lycopadiene, showed lower δ13C values from -40.0 to -35.5‰, suggesting that the source organisms B. braunii at least partially utilize recycled CO2 (13C depleted) produced from OM respiration rather than atmospheric CO2 (13C enriched) as the major carbon sources.

The Potential of Alkyl Amides as Novel Biomarkers and Their Application to Paleocultural Deposits in China.

A series of alkyl amides was detected and identified in the sedimentary record from an archaeological site at Yuchisi, Mengcheng, Anhui, China. The alkyl amides profiles change abruptly at the depth corresponding to the transition between two prehistoric cultures, which also corresponds to an abrupt change in the fatty acid ratio C18:2/C18:0. The different patterns of variation of the longer and shorter chain alkyl amides at the depth of the cultural transition may reflect differences in their response to external environmental changes, as well as different sources. This is the first study of the stratigraphic variation of alkyl amides in sediments, and their first application to assess paleoenvironmental changes. We suggest that alkyl amides may have potential as new biomarkers in archeological and paleoenvironmental studies.

Chemical compositions and characteristics of organic compounds in propolis from Yemen.

Propolis is a gummy material made by honeybees for protecting their hives from bacteria and fungi. The main objective of this study is to determine the chemical compositions and concentrations of organic compounds in the extractable organic matter (EOM) of propolis samples collected from four different regions in Yemen. The propolis samples were extracted with a mixture of dichloromethane and methanol and analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the total extract yields ranged from 34% to 67% (mean = 55.5 ± 12.4%). The major compounds were triterpenoids (254 ± 188 mg g-1, mainly α-, ß-amyryl and dammaradienyl acetates), n-alkenes (145 ± 89 mg g-1), n-alkanes (65 ± 29 mg g-1), n-alkanoic acids (40 ± 26 mg g-1), long chain wax esters (38 ± 25 mg g-1), n-alkanols (8 ± 3 mg g-1) and methyl n-alkanoates (6 ± 4 mg g-1). The variation in the propolis chemical compositions is apparently related to the different plant sources. The compounds of these propolis samples indicate that they are potential sources of natural bio-active compounds for biological and pharmacological applications.

Occurrence and sources of natural and anthropogenic lipid tracers in surface soils from arid urban areas of Saudi Arabia.

Soil particles contain a variety of natural and anthropogenic organic components, and in urban areas can be considered as local collectors of pollutants. Surface soil samples were taken from ten urban areas in Riyadh during early winter of 2007. They were extracted with dichloromethane-methanol mixture and the extracts were analyzed by gas chromatography-mass spectrometry. The major compounds were unresolved complex mixture (UCM), plasticizers, n-alkanes, carbohydrates, n-alkanoic acids, hopanes, n-alkanols, and sterols. Vegetation detritus was the major natural source of organic compounds (24.0 ± 15.7%) in samples from areas with less human activities and included n-alkanes, n-alkanoic acids, n-alkanols, sterols and carbohydrates. Vehicular emission products and discarded plastics were the major anthropogenic sources in the soil particles (53.3 ± 21.3% and 22.7 ± 10.7%, respectively). The anthropogenic tracers were UCM, plasticizers, n-alkanes, hopanes and traces of steranes. Vegetation and human activities control the occurrence and distribution of natural and anthropogenic extractable organic matter in this arid urban area.

Organic Tracers from Asphalt in Propolis Produced by Urban Honey Bees, Apis mellifera Linn.

Propolis is a gummy material produced by honey bees to protect their hives and currently has drawn the attention of researchers due to its broad clinical use. It has been reported, based only on observations, that honey bees also collect other non-vegetation substances such as paint or asphalt/tar to make propolis. Therefore, propolis samples were collected from bee hives in Riyadh and Al-Bahah, a natural area, Saudi Arabia to determine their compositional characteristics and possible sources of the neutral organic compounds. The samples were extracted with hexane and analyzed by gas chromatography-mass spectrometry. The results showed that the major compounds were n-alkanes, n-alkenes, methyl n-alkanoates, long chain wax esters, triterpenoids and hopanes. The n-alkanes (ranging from C17 to C40) were significant with relative concentrations varying from 23.8 to 56.8% (mean = 44.9+9.4%) of the total extracts. Their odd carbon preference index (CPI) ranged from 3.6 to 7.7, with a maximum concentration at heptacosane indicating inputs from higher plant vegetation wax. The relative concentrations of the n-alkenes varied from 23.8 to 41.19% (mean = 35.6+5.1%), with CPI = 12.4-31.4, range from C25 to C35 and maximum at tritriacontane. Methyl n-alkanoates, ranged from C12 to C26 as acids, with concentrations from 3.11 to 33.2% (mean = 9.6+9.5%). Long chain wax esters and triterpenoids were minor. The main triterpenoids were α- and ß-amyrins, amyrones and amyryl acetates. The presence of hopanes in some total extracts (up to 12.5%) indicated that the bees also collected petroleum derivatives from vicinal asphalt and used that as an additional ingredient to make propolis. Therefore, caution should be taken when considering the chemical compositions of propolis as potential sources of natural products for biological and pharmacological applications. Moreover, beekeepers should be aware of the proper source of propolis in the flight range of their bee colonies.

Occurrence and distribution of monomethylalkanes in the freshwater wetland ecosystem of the Florida Everglades.

A series of mono-methylalkanes (MMAs) with carbon numbers from C10 to C23 and C29 were detected in freshwater wetlands of the Everglades. A decrease in concentration and molecular complexity was observed in the order from periphyton and floc, to surface soil and deeper soil horizons. These compounds were present in varying amounts up to 27 µg gdw(-1) in periphyton, 74 µg gdw(-1) in floc, 1.8 µg gdw(-1) in surface soil, <0.03 µg gdw(-1) in deeper soils (12-15 cm). A total of 46 MMAs, including three iso and three anteiso-alkanes, were identified. Compound specific carbon isotopes values were determined for some dominant MMAs, and suggest that they originate from microbial sources, including cyanobacteria. Potential decarboxylation from fatty acids could also potentially contribute to the MMAs detected. Early diagenetic degradation was suggested to affect the accumulation of MMAs in soils and further studies are needed to address their applications as biomarkers.

Identification and source apportionment of polycyclic aromatic hydrocarbons in ambient air particulate matter of Riyadh, Saudi Arabia.

In an effort to assess the occurrence and sources of polycyclic aromatic hydrocarbons (PAHs) in the ambient air of Riyadh, Saudi Arabia, PM10 samples were collected during December 2010. Diagnostic PAH concentration ratios were used as a tool to identify and characterize the PAH sources. The results reflect high PM10 and PAH concentrations (particulate matter (PM) = 270-1,270 µg/m(3)). The corresponding average PAH concentrations were in the range of 18 ± 8 to 1,003 ± 597 ng/m(3) and the total concentrations (total PAHs (TPAHs) of 17 compounds) varied from 1,383 to 13,470 ng/m(3) with an average of 5,871 ± 2,830 ng/m(3). The detection and quantification limits were 1-3 and 1-10 ng/ml, respectively, with a recovery range of 42-80%. The ratio of the sum of the concentrations of the nine major non-alkylated compounds to the total (CPAHs/TPAHs) was 0.87 ± 0.10, and other ratios were determined to apportion the PM sources. The PAHs found are characteristic for emissions from traffic with diesel being a predominant source.

Occurrence and sources of polar lipid tracers in sediments from the Shatt al-Arab River of Iraq and the northwestern Arabian Gulf.

Shallow surface sediment samples from the southern part of the Shatt al-Arab River estuary of Iraq and the northwestern Arabian Gulf were analyzed for polar lipid compounds including n-alkanoic acids, n-alkanols, steroids and triterpenoids. The results showed that the n-alkanoic acids, methyl n-alkanoates and n-alkanols typically ranged from C12 to C32 with total concentrations of 3.2 to 108.2 µg g(-1)dwt sample, from C12 to C30 with totals of 1.1 to 18.9 µg g(-1)dwt sample, and from C14 to C32 at 1.8 to 112.6 µg g(-1)dwt sample, respectively. Steroids and triterpenoids were detected and included stenols, stanols, stenones, stanones, tetrahymanol, tetrahymanone and extended ßß-hopanes. The total steroid concentrations ranged from 2.8 to 78.4 µg g(-1)dwt sample, whereas the triterpenoids varied from 0.05 to 7.6 µg g(-1)dwt sample. The simple regression analysis of the results and the spatial distribution patterns of the identified organic tracers indicated that the inter-compound relationships were related mainly to their major sources. Cluster analysis and principal component analysis (PCA) of data set showed that the sampling sites are similar. These sources were allochthonous (terrestrial vegetation), autochthonous (plankton residues and bacteria in the sediments) and anthropogenic (sewage and petroleum).

Enterolactone and other lignan metabolites as taxon-specific markers in modern and ancient woodrat middens.

Diversely sourced degradation products of higher plant lignans were identified in modern and ancient woodrat (Neotoma) middens. The markers indicate extensive chemical modification by intestinal microbial communities of mammals. The observed defunctionalized phenols represent a group of natural products, and their structural elements reveal information about the plant source. The phenols are derived mainly from two precursor types: (1) enterolactone and derivatives from conifer lignans, and (2) 2,3-bis(3'-hydroxybenzyl)butane and related compounds from lignans such as nordihydroguaiaretic acid common in Larrea sp. (e.g. creosote bush).

Solvent-extractable polycyclic aromatic hydrocarbons in biochar: influence of pyrolysis temperature and feedstock.

Despite the increasing agricultural use of biochar as a way of combining the utilization of biomass for energy production with the removal of CO(2) from the atmosphere, it is not known how variations in pyrolysis temperature and feedstock type affect concentration and composition of polycyclic aromatic hydrocarbons (PAHs) that inevitably form and associate with biochar. To close this knowledge gap, we quantified 11 unsubstituted three- to five-ring PAHs as well as alkylated forms of phenanthrene and anthracene in grass and wood chars produced in 100 °C increments across a temperature range (100 to 700 °C). Our results show that solvent-extractable PAH concentrations in biochars produced at heat treatment temperatures (HTTs) of 400 and 500 °C greatly exceed those observed at higher and lower temperature, supporting a low HTT solid-phase formation mechanism operable at temperatures commonly used for industrial biochar production. The maximum extractable yield of 'pyrolytic' unsubstituted PAHs for grass (22 µg g(-1) at HTT = 500 °C) greatly exceeds the value for wood (5.9 µg g(-1)). Moreover, PAH signatures (e.g., total monomethylphenanthrene to phenanthrene ratios, MP/P ~2-3) at intermediate temperatures (400 °C) resemble those of fossil oils rather than that commonly attributed to pyrolytic products. Further research is needed to characterize the PAH evolution in modern pyrolysis reactors and assess the fate of biochar-bound PAHs in soils and sediments. Various commonly applied PAH ratios and indicator compounds show promise as markers for specific feedstock materials and pyrolysis conditions of biochars in environmental systems.

Qualitative and quantitative analysis of dibenzothiophene, its methylated homologues, and benzonaphthothiophenes in crude oils, coal, and sediment extracts.

Polycyclic aromatic sulfur heterocyclics (PASHs) consist mainly of thiophene class compounds, and are the most important organosulfur compounds in crude oils and sediment extracts. Dibenzothiophene (DBT) and its methylated homologues were identified on mass chromatograms by comparison with retention indices published in the literature. Some isomers of dimethyldibenzothiophene and trimethyldibenzothiophene that were tentatively identified in previous reports have been determined here by comparison with calculated retention indices and taking the substitution pattern of the methyl groups into account. The response factors relating that of dibenzothiophene to internal standards were obtained by GC-MS analyses of mixture solutions with different concentration ratios. We concluded that DBT-d8 (octadeutero-dibenzothiophene) is the optimal internal standard for quantitative analyses of the thiophene compound class in oils, coal, and sediment extracts. Calibration experiments for each class of compounds are absolutely necessary when quantifying polycyclic aromatic hydrocarbons and other heterocyclics with a stable isotope labeled internal standard.