Polycyclic Aromatic Hydrocarbons and Potentially Toxic Elements in Soils of the Vicinity of the Bulgarian Antarctic Station “St. Kliment Ohridski” (Antarctic Peninsula)

The investigation conducted was dialed to quantitative and qualitative evaluation of 15 priority polycyclic aromatic hydrocarbons (PAHs) and Potentially Toxic Elements (Cu, Pb, Zn, Cd, Ni, and Cr) is soils and cryoconites on “St. Kliment Ohridski” Antarctic station territory and its vicinities. Estimation of benzo(a)pyrene (BaP)–equivalents, PAHs and different PAHs isomer pair ratios were used for identification of general toxicity, nature and origin of individual PAHs and their groups. Total concentrations of PAHs in BaP–equivalents showed, that ∑15PAH of all selected points was higher than the threshold concentration (20 μg × kg−1–Russian environmental legislation) for benzo(a)pyrene. Different PAHs isomer ratios showed the natural (petrogenic) source of PAHs at all soils examples (except Cryosol Toxic Transportic). The maximum content among potentially toxic elements was recorded for Zn (75.7 mg × kg−1 at L26), the minimum for Cd (0.201 mg × kg−1 at L1A). Average concentrations of potentially toxic elements are generally lower compared to the results of previous studies. Application of Igeo index, characterizes the majority of the studied soils as unpolluted or practically unpolluted. Data obtained indicates that there is no current critical anthropogenic load on the environmental components of the landscapes investigated.

Study of the Crude oil Properties of Oily seepages found in South Eastern Nigeria.

ASTM D-270 method was applied in obtaining well-head crude oil samples from Awoba 8T (Rivers State), Odidi 23L, and Odidi 46S (Delta State), Eremor 1L (Bayelsa State) and Oily Seepage samples from Ugwueme (Enugu State) and Anam (Anambra State). The0API gravity value of all the samples were 16.190 and 21.470 for Ugwueme seepage and Eremorcrude respectively, 22.470 for Odidi 46s crudeand 44.700, 43.840 and 34.760 for Anam seepage, Awoba 8t and Odidi 23L crudesrespectively, indicating heavy, medium and light crude oils respectively. All the well-head crudes and oily seepage samples studied in this work are onshore samples except Odidi 46s which is an offshore crude sample. The samples were subjected to liquid-liquid extraction using a mixture of n-hexane and dichloromethane (3:1). The extracted fractions were analyzed using GC-FID. The result of the analyses gave polycyclic aromatic hydrocarbons (PAHs) concentrations (mg/kg) of 7106.43 for Awoba 8T crude, 6767.41 for Odidi 23L crude, 5771.20 for Odidi 46S crude, 5191.21 for Eremor crude, 4908.04 for Ugwueme Seepage and 6983.16 for Anam seepage. The predominance of low molecular weight PAHs (LMWPs) over the high molecular weight PAHs (HMWPs) indicate that both the crude oil samples and the oily seepage samples were of Petrogenic Source. However, various ratios were obtained to identify the possible source of PAHs in the crude oil and seepage samples. Mixed sources of pyrogenic and petrogenic PAHs were also discovered with evidence of „pyrolytic‟ input which may suggest some geothermal-mediated processes.

LEVELS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) IN FISH SAMPLES FROM DIFFERENT PROCESSING METHODS

Fish is easily contaminated from water prone to water pollution. In this study, the levels of polycyclic aromatic hydrocarbons (PAHs) in fish samples processed, using three methods and marketed in Makurdi, Benue state, were determined. The samples were coded as SF (Smoked Fish), SD (Sundried) and FD (fried) fish samples. PAHs in the samples were quantified, using gas chromatography – mass spectrometer (GC-MS). The Ʃ16PAH concentrations were in the range of 0.2- 10.0 mg/kg. Both LPAHs/HPAHs and the binary diagnostic ratios of PAHs indicated pyrogenic and petrogenic sources Ʃ16PAH and their dominant PAH ring-types were separately computed for each sample. The six-membered ring PAHs in smoked fish was 32.07% (with Bezo(ghi)perylene as most dominant). High levels of six member ring PAHs (Dibenz(a,h) anthracene) were also found in Sundried fish and fried fish contain Dibenz(a,h) anthracene. Generally, the PAHs concentrations in the samples, pointed more at pyrogenic than the petrogenic source. With exception of the five and six membered rings, estimated PAH levels were within the NAFDAC permissible limits.

BIOAVAILABILITY OF SEDIMENT OIL RESIDUES FOUR YEARS FOLLOWING THE MARTINEZ SPILL

ABSTRACT Transplanted bivalves were used as sentinel organisms to assess bioavailability of San Joaquin Valley (SJV) crude oil residues in impacted sediments four years following the 1988 Shell Martinez Refinery spill in Suisun Bay, California. Sediments, bivalves exposed for three months, and control (unexposed) bivalves were analyzed by gas chromatography/mass spectrometry (GC/MS) for poly nuclear aromatic hydrocarbons (PAHs). The study documented a range of weathering stages, and a range of mixtures of SJV crude oil with another petrogenic source, pyrogenic PAHs, and diagenic alkyl PAHs in Peyton Slough intertidal sediments four years following the spill. Less-weathered SJV oil residues remaining in the estuarine sediments were more bioavailable than the intermediate or advanced weathered residues, and more bioavailable than the pyrogenic PAHs that comprise the background PAHs in the Suisun Bay sediments.