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.

Common air pollutants, such as nitrogen oxides (NOₓ), emitted in diesel exhaust, and ozone (O₃), have been implicated in the decline of pollinating insects. Reductionist laboratory assays, focused upon interactions between a narrow range of flowering plant and pollinator species, in combination with atmospheric chemistry models, indicate that such pollutants can chemically alter floral odors, disrupting the cues that foraging insects use to find and pollinate flowers. However, odor environments in nature are highly complex and pollination services are commonly provided by suites of insect species, each exhibiting different sensitivities to different floral odors. Therefore, the potential impacts of pollution-induced foraging disruption on both insect ecology, and the pollination services that insects provide, are currently unknown. We conducted in-situ field studies to investigate whether such pollutants could reduce pollinator foraging and as a result the pollination ecosystem service that those insects provide. Using free-air fumigation, we show that elevating diesel exhaust and O₃, individually and in combination, to levels lower than is considered safe under current air quality standards, significantly reduced counts of locally-occurring wild and managed insect pollinators by 62–70% and their flower visits by 83–90%. These reductions were driven by changes in specific pollinator groups, including bees, flies, moths and butterflies, and coincided with significant reductions (14–31%) in three different metrics of pollination and yield of a self-fertile test plant. Quantifying such effects provides new insights into the impacts of human-induced air pollution on the natural ecosystem services upon which we depend.

The increased frequency and intensity of short-term extreme warming phenomena have been associated to harsh biological and ecosystem outcomes (i.e., mass mortalities in marine organisms). Marine heatwaves (MHWs), occurring when seasonal temperature threshold is exceeded for at least 5 consecutive days, may reduce the tolerance of coastal species toward additional pressures, but interactions between such multiple stressors are virtually unexplored. The present study aimed to characterize in Mytilus galloprovincialis the influence of a simulated MHW scenario on the toxicological effects of the pharmaceutical carbamazepine (CBZ), ubiquitously detected in the marine environment and chosen as model compound for this relevant class of emerging contaminants. The bioaccumulation of CBZ and responsiveness of various biological parameters, including immune system, antioxidant status, lipid metabolism and cellular integrity, were analyzed in exposed mussels both during and after the end of the heatwave. MHW appeared to strongly modulate accumulation of CBZ, paralleled by weakened immunocompetence and onset of oxidative disturbance that finally evolved to cellular damages and lipid metabolism disorders. Elaboration of the overall results through a quantitative Weight of Evidence model, revealed the highest hazard in organisms exposed to both the stressors 10 days after the end of the heatwave, suggesting that MHWs could leave a footprint on the capability of mussels to counteract CBZ toxicity, thus affecting their vulnerability and predisposition to adverse effects toward multiple stressors.

Uranium, a radionuclide, is a predominant element utilized for speciality requirements in industrial applications, as fuels and catalyst. The radioactive properties and chemical toxicity of uranium causes a major threat to the ecosystem. The hazards associated with Uranium pollution includes the cancer in bones, liver, and lungs. The toxicological properties of Uranium are discussed in detail. Although there are many methods to eliminate those hazards, this research work is aimed to describe the application of bioremediation methods. Bioremediation methods involve elimination of the hazards of uranium, by transforming into low oxidation form using natural microbes and plants. This study deeply elucidates the methods as bioleaching, biosorption, bioreduction and phytoremediation. Bioleaching process involves bio-oxidation of tetravalent uranium when it gets in contact with acidophilic metal bacterial complex to obtain leach liquor. In biosorption, chitin/chitosan derived sorbents act as chelators and binds with uranium by electrostatic attraction. Bio reduction employs a bacterial transformation into enzymes which immobilize and reduce uranium. Phytoremediation includes phytoextraction and phytotranslocation of uranium through xylems from soil to roots and shoots of plants. The highest uranium removal and uptake reported using the different methods are listed as follows: bioleaching (100% uranium recovery), biosorption (167 g kg⁻¹ uranium uptake), bioreduction (98.9% uranium recovery), and phytoremediation (49,639 mg kg⁻¹ uranium uptake). Among all the techniques mentioned above, bioleaching has been proved to be the most efficient for uranium remediation.

Microplastics debris in the marine environment have been widely studied across the globe. Within these particles, the most abundant and prevalent type in the oceans are anthropogenic microfibers (MFs), although they have been historically overlooked mostly due to methodological constraints. MFs are currently considered omnipresent in natural environments, however, contrary to the Northern Hemisphere, data on their abundance and distribution in Southern Oceans ecosystems are still scarce, in particular for sub-Antarctic regions. Using Niskin bottles we've explored microfibers abundance and distribution in the water column (3–2450 m depth) at the Burdwood Bank (BB), a seamount located at the southern extreme of the Patagonian shelf, in the Southwestern Atlantic Ocean. The MFs detected from filtered water samples were photographed and measured using ImageJ software, to estimate length, width, and the projected surface area of each particle. Our results indicate that small pieces of fibers are widespread in the water column at the BB (mean of 17.4 ± 12.6 MFs.L⁻¹), from which, 10.6 ± 5.3 MFs.L⁻¹ were at the surface (3–10 m depth), 20 ± 9 MFs.L⁻¹ in intermediate waters (41–97 m), 24.6 ± 17.3 MFs.L⁻¹ in deeper waters (102–164 m), and 9.2 ± 5.3 MFs.L⁻¹ within the slope break of the seamount. Approximately 76.1% of the MFs were composed of Polyethylene terephthalate, and the abundance was dominated by the size fraction from 0.1 to 0.3 mm of length. Given the high relative abundance of small and aged MFs, and the oceanographic complexity of the study area, we postulate that MFs are most likely transported to the BB via the Antarctic Circumpolar Current. Our findings imply that this sub-Antarctic protected ecosystem is highly exposed to microplastic pollution, and this threat could be spreading towards the highly productive waters, north of the study area.