Polycyclic Aromatic Hydrocarbon profile of Kpite oil spill impacted site in Rivers state, Nigeria was evaluated to determine the level of contamination of the soil. Four composite oil impacted soil samples were collected at different depths; surface (0-15cm) and subsurface (15-30cm) after a field reconnaissance. Extraction of the oil was carried out on the soil samples and the Polycyclic Aromatic Hydrocarbons were quantified using the Gas Chromatography- flame ionization detector. Results showed that Naphthalene was the most abundant in the range of 0.25 to 1.49 mg kg-1. Fluoranthene followed closely with concentrations in the range of 0.01 to 1.28 mg kg-1. PAHs like Benzo (k) fluoranthene, Benzo (e) pyrene, Dibenzo (a, h)anthracene, Indeno (1, 2, 3-cd) pyrene and Benzo (g, h, i) showed low concentrations of less than 0.01 indicating that strong weathering had occurred. The diagnostic ratios such as Phenanthrene/Anthracene (Phen/Anth), Benzo (a) anthracene Chrysene ((BaA)/Chry) and Fluoranthene/Pyrene (Flth/Py) and sum of chrysene/Phenanthrene ΣChry/ΣPhen were calculated and used to unravel the source of hydrocarbons. Results showed ratios of Flth/Py >1.0 and Phen/Anth ranges from 1.19 to 2.03 (< 10) which denote contamination sources, implying that the hydrocarbon sources are not just petrogenic but rather may due to contamination sources of combustion processes or the area was exposed to bush burning.

Inputs of polycyclic aromatic hydrocarbons (PAHs) of regulatory interest from diffuse atmospheric sources within urban areas frequently elevate local soil concentrations to levels requiring remediation despite the lack of in-situ contamination. This research sought to determine the distribution and potential health effects of aerially deposited PAHs in soil within the urban core of metropolitan Milwaukee, Wisconsin, U.S.A. as part of a soil regulatory standards reevaluation. Park areas (n = 27) identified as undisturbed for 80+ years, containing no fill material, and receiving only atmospheric deposition were selected for composite surface and 92 cm core soil sample collection (n = 295). Samples were analyzed for the 16 USEPA priority PAHs, 1- and 2- methylnapthalene and ancillary soil properties. Soil core and ancillary data confirm lack of site disturbance. PAH diagnostic ratios and homologue summations indicate that diffuse multiple point source emissions contribute equally to PAH deposition throughout the area. Benzo(a)pyrene (BaP) and dibenz(a,h)anthracene mean concentrations exceed health-based clean up levels. Risk assessment shows only a worst-case exposure scenario (BaP at the 95% upper confidence limit) increasing cancer risk (1.67 × 10⁻⁶) over current regulatory thresholds (1.0 × 10⁻⁶). Health quotients show potential health risks from fluoranthene and pyrene for daily park users and from BaP for all others. Mean soil PAH values are similar to New Orleans, but lower than Chicago, Boston, and London reflecting industrial history and site selection protocols. The soil PAH results presented here for sites selected for non-manipulated soils combined with an almost 100-year uninterrupted atmospheric exposure effectively show the maximum potential PAH values that can be found at any given undisturbed location within the Milwaukee urban core due solely to atmospheric deposition.

Hydrocarbons and their derivative compounds are recalcitrant in nature and causing adverse impacts to the environment and are classified as important pollutants. Removal of these pollutants from the atmosphere is a challenging process. Hydrophobic organic pollutants (HOPs) including crude oil, diesel, dotriacontane (C₃₂), and tetracontane (C₄₀) are subjected to the biodegradation study by using a bacterial consortium consist of Bacillus subtilis, Pseudomonas stutzeri, and Acinetobacter baumannii. The impact of pH and temperature on the biodegradation process was monitored. During the HOPs biodegradation, the impact of hydrocarbon-degrading extracellular enzymes such as alcohol dehydrogenase, alkane hydroxylase, and lipase was examined, and found average activity about 47.2, 44.3, and 51.8 μmol/mg⁻¹, respectively. Additionally, other enzymes such as catechol 1,2 dioxygenase and catechol 2,3 dioxygenase were found as 118 and 112 μmol/mg⁻¹ Enzyme as an average range in all the HOPs degradation, respectively. Also, the impact of the extracellular polymeric substance and proteins were elucidated during the biodegradation of HOPs with the average range of 116.90, 54.98 mg/L⁻¹ respectively. The impact of biosurfactants on the degradation of different types of HOPs is elucidated. Very slight changes in the pH were also noticed during the biodegradation study. Biodegradation efficiency was calculated as 90, 84, 76, and 72% for crude oil, diesel, C₃₂, and C₄₀, respectively. Changes in the major functional groups (CH, C–O–C, CO, =CH₂, CH₂, CH₃) were confirmed by FTIR analysis and intermediated metabolites were identified by GCMS analysis. The surface-active molecules along with the enzymes played a crucial role in the biodegradation process.

The hydrothermal products of the Clam hydrothermal field from the Okinawa Trough were analyzed by gas chromatography–mass spectrometry to determine abundances of hydrocarbons. The n-alkanes in the hydrothermal products conformed to a bimodal distribution and exhibited an odd-to-even predominance of high molecular weight and an even-to-odd predominance of low molecular weight n-alkanes with maxima at C₁₆ and C₁₈. The total concentration of n-alkanes in hydrothermal sediment was much higher than that in hydrothermal sulfide and altered rock. The carbon isotopic value of individual n-alkanes in hydrothermal sediment was slightly higher than that in pelagic sediment. The concentrations and individual carbon isotopic compositions of n-alkanes suggest that the n-alkanes in hydrothermal products may be mainly the result of the metabolic activity of submarine microorganisms. Additionally, the present results suggest that the abiogenic contribution to source of hydrocarbons in hydrothermal products of the Clam hydrothermal field from the Okinawa Trough should not be ignored.

A large-scale oil spill has reached over 3000 km of the NE Brazilian coast since August 2019. The cause and origin of this spill remain mysterious, and the impacts on coastal ecosystems have not been clearly understood so far. Despite the efforts to remove the oil (mainly from local communities), oil stains are still present in beaches, mangroves, and beachrocks. In this short report, we describe the occurrence of the barnacle Chthamalus bisinuatus Pilsbry, 1916 colonizing oil spill stains on intertidal surfaces of beachrocks one year after the first oil records. We quickly assessed oil stains across three different reefs located at the Conde municipality, Bahia (NE Brazil), where the species was identified and its density on oil stains calculated. The occurrence of barnacles in oil stains was restricted to zones in the wake of the reefs. Their densities varied from 0 to 238 ind./dm², with an average of 34 ± 68 ind./dm². If we account for dead individuals (empty barnacle plates), they correspond to 25.9% of the sampled population. The presence of oil possibly affected barnacle survival rates but did not seem to prevent barnacle individuals from reaching adult sizes. We also found individuals of the snail Echinolittorina lineolata (d'Orbigny, 1840) crawling on these barnacles, indicating that the barnacle assemblages on oil stains are stable enough to provide refuge for these snails. It is not clear if the presence of barnacles on oil reflects the resistance of these crustaceans to the oil toxicity or is just a result of a low substrate selectivity by the cypris larvae.

The ability of bacterial isolates viz., Enterococcus cloacae and mixed bacterial isolates, to degrade plastic was studied. The bacteria were isolated from waste effluent sites viz., industrial waste sites of Nilon’s pickle factory, Dalgaon and market waste sites of Balugaon vegetable market, Kharupetia, Assam. Plastic degradation was carried out at different time intervals within 15 and 30 days. It was observed that degradation increased with an increase in the time interval and hence effective observation was recovered after 30 days interval. Polythene bags showed maximum degradation by Enterococcus cloacae (85.25%). Plastic degradation was observed by Scanning Electron Microscope (SEM). In biodegradation of petroleum hydrocarbon, Enterococcus cloacae, Pseudomonas putidia and Ralstonia pickettii were found to degrade oil as well as they were able to grow in presence of petroleum hydrocarbons.