40 research outputs found

    Hazard quotient, microbial diversity, and plant composition of spent crude oil-polluted soil

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    Abstract Background The present work assesses the concentration of some heavy metal, plant species composition, and microbial diversity of spent crude oil-polluted soil from electric generator plant house, auto mechanic workshop, bakery, and auto spare part shops in four local governments areas (Egor, Ikpoba-Okha, Oredo, and Ovia North) in Edo State, Southern Nigeria. Results Hazard quotient (HQ) of heavy metals varied in all the spent crude oil-polluted soil evaluated in the study. The HQ of heavy metals from auto mechanic workshop had the highest values for Cr (2.19), Mn (0.0965), Zn (4.1108), Fe (9.32015), and Cd (0.0155). The most frequent bacterial and fungal species found in all 16 sites were Bacillus subtilis (93.75%) and Aspergillus niger (100.0%) respectively. Auto spare part shops in Oredo had a bacterial count of 1.0 × 105 CFU/g while the bacteria count around power generator plants in Egor had a bacteria count of 1.71 × 105 CFU/g. Some of the plant species identified around all the sites include Acanthospermum hispidum, Alternanthera repens, Axonopus compressus, Cyperus esculentus, Eleusine indica, Paspalum scrobiculatum, and Tridax procumbens. Conclusion Spent crude oil pollution of the soil led to high amounts of heavy metal in the soil. However, the presence of higher plants and variable diversity and richness of microorganisms found in the soil are likely contributing to the remediation of the polluted soil

    Single-tree influence of Tectona grandis Linn. f. on plant distribution and soil characteristics in a planted forest

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    Abstract Background Little is known about the single-tree influence of Tectona grandis Linn. f. on plant distribution and soil characteristics in Benin City, Nigeria. We investigated the possible single-tree effect of T. grandis on understory plants in an 8-year-old teak plantation at the Moist Forest Research Station. An area of 36.57 m by 60.96 m was marked out and divided into 15 equal-sized subplots containing 10 trees per subplot. Marked distances from the base of a randomly selected tree per subplot were made (0–0.5 m, 0.5–1.0 m and 1.0–1.5 m). Results Single-tree influence of T. grandis was observed in the soil total organic carbon, total nitrogen and soluble phosphorus, where concentrations were higher with 1.5-m radius from the tree than beyond. Moreover, the pH of the topsoil within 1.5 m from the base of the tree was lower (pH 4.4) than beyond 1.5 m from the base of the tree (pH 5.4). Species-specific single-tree effect was also observed on the understory plant distribution likely due to diverse ecophysiological interactions. Within 1.5 m from the tree, plant species abundance, especially of Sida garckeana, Reisantia indica, Momordica charantia and Tridax procumbens were negatively affected. However, the distribution of Eleusine indica around the tree was not negatively influenced. Plant abundance was generally suppressed in Cynodon dactylon, Axonopus compressus, Andropogon gayanus, Commelina diffusa and Euphorbia hirta. Generally, there were more plant species beyond the canopy fringes than within the canopy, indicating inhibitory single-tree effects. Conclusion Not all plant species in close proximity to T. grandis are affected. This is important considering that plant-plant associations affect the quality of forest soils. Generally, more plant species were recorded outside the 1.5-m demarcation than within, an increase in soil organic matter may further enhance such plant species abundance. The impact of T. grandis in forest soil quality is possibly a factor of the outcome of its association with neighbouring plant species. Diverse mechanisms at play may be responsible for the observed effects on soil chemistry. However, a reduction in the soil organic matter and variations in other environmental factors also contributed to observed single-tree effect

    Shelf Life, Fruit Quality and Safety of Banana (Musa Species) Ripened through Traditional Ripening Techniques in Nigeria

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    Many fruit vendors in Nigeria adopt unhealthy practices to induce fruit ripening and increase the availability of ripe fruits in the markets. We investigated the safety of traditional induced ripen..

    Growth and yield performances of rice ( Oryza sativa var. nerica) after exposure to biosynthesized nanoparticles

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    Abstract Background Rice (Oryza sativa L.) is a common staple food in Nigeria. However, cultivation is impaired by heavy metal contamination, particularly iron (Fe). This study aimed to investigate the impacts of biosynthesized nanoparticles (NPs) in enhancing the growth and yield components of rice sown in ferruginous soil. Viable seeds of O. sativa var. nerica were sown in ferruginous and non-ferruginous soils. After four weeks, the plants were exposed to foliar sprays of biosynthesized NPs from silver nitrate, using extracts of leaves of Carica papaya, Vernonia amygdalina, Moringa oleifera, and Azadirachta indica; and the flowers of Hibiscus sabderiffa, following standard procedure. The originally prepared stock solution was diluted to give 5, 15, and 30% concentrations of each synthesized NP. Results Results showed that soil ferrugenicity impeded the growth and yield of rice. Azadirachta-synthesized NPs was better enhanced in the ferruginous soils, which might be due to Fe interaction and activities. Moreover, there was increased antioxidant activity in the ferruginous rice compared to the non-ferruginous rice, thus it is evidence that ferrugenicity is a major source of physiological stress for the rice plant. Conclusion The study provided evidence that Ag-NPs can enhance plant yield by huge proportions in ferruginous soil, a condition (ferrugenicity) that was hitherto inimical to yield disposition of rice

    Mass Changes of the Greenland and Antarctic Ice Sheets and Shelves and Contributions to Sea-level Rise: 1992-2002

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    Changes in ice mass are estimated from elevation changes derived from 10.5 years (Greenland) and 9 years (Antarctica) of satellite radar altimetry data from the European Remote-sensing Satellites ERS-1 and -2. For the first time, the dH/dt values are adjusted for changes in surface elevation resulting from temperature-driven variations in the rate of fun compaction. The Greenland ice sheet is thinning at the margins (-42 plus or minus 2 Gta(sup -1) below the equilibrium line altitude (ELA)) and growing inland (+53 plus or minus 2 Gt a(sup -1)above the ELA) with a small overall mass gain (+11 plus or minus 3 Gt a(sup -1); -0.03 mm a(sup -1) SLE (sea level equivalent)). The ice sheet in West Antarctica (WA) is losing mass (-47 (dot) 4 GT a(sup -1) and the ice sheet in East Antarctica (EA) shows a small mass gain (+16 plus or minus 11 Gt a(sup -1) for a combined net change of -31 plus or minus 12 Gt a(sup -1) (+0.08 mm a(sup -1) SLE)). The contribution of the three ice sheets to sea level is +0.05 plus or minus 0.03 mm a(sup -1). The Antarctic ice shelves show corresponding mass changes of -95 (dot) 11 Gt a(sup -1) in WA and +142 plus or minus 10 Gt a(sup -1) in EA. Thinning at the margins of the Greenland ice sheet and growth at higher elevations is an expected response to increasing temperatures and precipitation in a warming climate. The marked thinnings in the Pine Island and Thwaites Glacier basins of WA and the Totten Glacier basin in EA are probably ice-dynamic responses to long-term climate change and perhaps past removal of their adjacent ice shelves. The ice growth in the southern Antarctic Peninsula and parts of EA may be due to increasing precipitation during the last century

    Greenland Ice Sheet Mass Balance: Distribution of Increased Mass Loss with Climate Warming; 2003-07 Versus 1992-2002

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    We derive mass changes of the Greenland ice sheet (GIS) for 2003-07 from ICESat laser altimetry and compare them with results for 1992-2002 from ERS radar and airborne laser altimetry. The GIS continued to grow inland and thin at the margins during 2003 07, but surface melting and accelerated flow significantly increased the marginal thinning compared with the 1990s. The net balance changed from a small loss of 7 plus or minus 3 Gt a 1(sup -1) in the 1990s to 171 plus or minus 4 Gt a (sup -1) for 2003-07, contributing 0.5 mm a(sup -1) to recent global sea-level rise. We divide the derived mass changes into two components: (1) from changes in melting and ice dynamics and (2) from changes in precipitation and accumulation rate. We use our firn compaction model to calculate the elevation changes driven by changes in both temperature and accumulation rate and to calculate the appropriate density to convert the accumulation-driven changes to mass changes. Increased losses from melting and ice dynamics (17-206 Gt a(sup-1) are over seven times larger than increased gains from precipitation (10 35 Gt a(sup-1) during a warming period of approximately 2 K (10 a)(sup -1) over the GIS. Above 2000m elevation, the rate of gain decreased from 44 to 28 Gt a(sup-1), while below 2000m the rate of loss increased from 51 to 198 Gt a(sup-1). Enhanced thinning below the equilibrium line on outlet glaciers indicates that increased melting has a significant impact on outlet glaciers, as well as accelerating ice flow. Increased thinning at higher elevations appears to be induced by dynamic coupling to thinning at the margins on decadal timescales

    Gastrointestinal decontamination in the acutely poisoned patient

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    ObjectiveTo define the role of gastrointestinal (GI) decontamination of the poisoned patient.Data sourcesA computer-based PubMed/MEDLINE search of the literature on GI decontamination in the poisoned patient with cross referencing of sources.Study selection and data extractionClinical, animal and in vitro studies were reviewed for clinical relevance to GI decontamination of the poisoned patient.Data synthesisThe literature suggests that previously, widely used, aggressive approaches including the use of ipecac syrup, gastric lavage, and cathartics are now rarely recommended. Whole bowel irrigation is still often recommended for slow-release drugs, metals, and patients who "pack" or "stuff" foreign bodies filled with drugs of abuse, but with little quality data to support it. Activated charcoal (AC), single or multiple doses, was also a previous mainstay of GI decontamination, but the utility of AC is now recognized to be limited and more time dependent than previously practiced. These recommendations have resulted in several treatment guidelines that are mostly based on retrospective analysis, animal studies or small case series, and rarely based on randomized clinical trials.ConclusionsThe current literature supports limited use of GI decontamination of the poisoned patient
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