Fuzzy logic modeling of bioaccumulation pattern of metals in coastal biota of Ondo State,Nigeria

The accumulation patterns of ten metals in tissues of plant, Eichornia crassipes, and fishes, Hydrocynus forskahlii and Oreochromis mossambicus, were modeled with simple fuzzy classification (SFC) to assess toxic effects of anthropogenic activities on the coastal biota. The plant sample was separated into root, stem, and leaves and the fishes into bones, internal tissues, and muscles. They were analyzed for As, Cd, Cr, Cu, Ni, Pb, V, Fe, Mn, and Zn after wet oxidation of their dried samples. The results were converted into membership functions of five accumulation classes and aggregated with SFC. The classification results showed that there was no metal accumulation in the plant parts while the fishes were classified into low accumulation category. The internal tissues of the fishes had higher metal accumulation than the other parts. Generally, Fe and Mn had highest concentrations in the biota but are natural to the area and may not constitute significant risk. Cr had the highest transfer and accumulation from the coastal water into the aquatic lives and may be indicative of risk prone system being a toxic metal. Metal contaminations in the zone had not significantly accumulated in the biota making them less prone to risk associated with metal accumulation.     

Electrochemical reduction of carbon dioxide into valuable chemicals: a review

Environmental Chemistry Letters - Global warming is partly caused by massive emissions of carbon dioxide (CO2), a greenhouse gas, in the atmosphere by industrial and other human activities....     

Accumulation of some metals in Morinda lucida from Nigeria

Transfer coefficients of the four metals As, Cd, Hg, and Pb were determined in the leaves and barks of Morinda lucida collected in Nigeria, with the view to quantify relative differences in the bioavailability of the metals to these parts of the plant. Samples were acid digested and the levels of the metals in the digestates were determined using an atomic absorption spectrophotometer. Certain properties of the soils, i.e., pH, clay fraction, electrical conductivity, cation exchange capacity, and organic matter, were also determined. The latter influence the bioavailability of the metals. All parameters correlated with the concentrations of the metals in soils. Transfer coefficient values recorded for Cd and Pb in various tissues of M. lucida Benth were within the expected ranges, while those of As and Hg showed elevated topsoil concentrations of metals. The order of bioavailability of the metals and their bioaccumulation in the tissues of M. lucida Benth was Hg > Cd > As > Pb. Stem barks of the plant showed the least bioaccumulation of all four metals and hence are most suitable for therapeutic purposes. Vegetative parts of M. lucida Benth used for therapeutic purposes should be sourced at sites that will give low transfer coefficient in order to reduce human exposure to toxicity associated with ingestion of heavy metals.     

Particulates and carbon monoxide pollution on production floor of steel recycling plant

For this study, particulates or particulate matter (PM) and carbon monoxide (CO) levels were monitored at different sections on the production floor of a scrap metal recycling factory. A Met‐One GT331 dust monitor and A Toxi‐Rae gas monitor were used to measure PM and CO concentrations, respectively. The 24‐hr averaging period concentrations of particulate matter having diameters of 2.5 microns or less in diameter (PM_2.5), particulate matter having diameters of 10 microns or less in diameter (PM₁₀), and total suspended particulates (TSP) within the plant ranged between 8.3 and 50.4 μg/m³, 12.0 and 151.3 μg/m³, and 30.0 and 285.0 μg/m³, respectively, while the maximum 8‐hr concentration of CO within the plant was 20.5 parts per million (ppm). The United States’ Environmental Protection Agency (US EPA) limits for PM_2.5, PM₁₀, and CO were exceeded only in the area around the furnace. Nigeria's Federal Ministry of Environment (FMENV), the World Health Organization (WHO), and the World Bank statutory limit for TSP were also exceeded in the area around the furnace. Toxicity potentials (TP) of the investigated pollutants were greater than 1.0 around the furnace, indicating that work spaces in proximity to the furnace could expose workers to adverse health conditions.     

The influence of sex of the approached child on the personal space of the approaching child

Personal space was studied in 2nd Grade children in terms of sex of the approaching child and similarity or dissimilarity of the seated pair. Eight children of the same sex sat one on each bench at its edge. Their places were marked with cellotape. Two batches each of four boys and four girls approached them and sat on the benches. Their places on each occasion were again marked with cellotape. After cencelling ‘8’ from random number sheets, the distances between the strips of cellotape were measured.Personal space did not vary between boys and girls. This is consistent with Nigerian cultural norm which allows close personal space between males and between females. Same-sex personal space was smaller than opposite-sex personal space. This was attributed to sexual awareness and preference for their sex by the children which is also in tune with Nigerian cultural practice.     

Cytotoxicity,redox and immune status in African catfish,Clarias gariepinus (Burchell, 1822) exposed to bisphenol A (BPA) and its analogues

The objective of the study was to determine the comparative toxicities and immune dysfunction in the African catfish, Clarias gariepinus, exposed to bisphenol A (BPA) and its two analogues: bisphenol AP (BPAP) and bisphenol P (BPP). Juveniles of C. gariepinus were exposed to sublethal concentrations (70 and 140 μg/L) of BPA, BPAP and BPP for 7, 14 or 21 days after which various endpoints which are indicative of cytotoxicity, oxidative stress and haematological and innate immune parameters were determined in the liver homogenates or blood plasma. The exposure of C. gariepinus to BPA and its analogues caused significant increased activities of lactate dehydrogenase, catalase and superoxide dismutase. The exposed fish had increased levels of DNA fragmentation, lipid peroxidation, white blood cells, nitric oxide and respiratory burst, while the red blood cell counts and the percentage packed cell volume decreased significantly in the exposed fish compared to control. The toxic effects elicited by the bisphenols were both concentration- and duration-dependent. Generally, BPA exerted the most toxic effects on the fish, followed by BPAP, while BPP exerted the least toxic effects to C. gariepinus. Summarily, the findings indicated that BPA and its two analogues studied in the research are capable of causing cytotoxicity, oxidative stress and immune dysfunction in C. gariepinus.

     

Fuzzy comprehensive assessment of metal contamination of water and sediments in Ondo Estuary,Nigeria

A more reliable methodology for evaluating metal contamination of coastal water and sediments using fuzzy comprehensive assessment (FCA) is presented by this study. Ten metals (As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, V and Zn) were investigated in water and sediments from ten sampling sites and formulated into fuzzy matrix based on three contamination classifications of pristine, moderately enriched and extremely impacted categories using regulatory limits as criteria. The products of the matrices from membership function of the observed data and the weight matrices generate indices that classify the degree of metal impact on the sites. The results of the FCA show that the estuary is negatively impacted by metals in a range of 45.5–75.1% membership in the extremely impacted category with potential adverse effects on the ecosystem of the neighbouring Atlantic Ocean. The crude oil exploration activity at site 1 is the major source input of the metals beside Fe and Mn which are natural to the geological structure of the area while domestic waste discharges contribute notably to metal contamination in some sites.     

Factors affecting the adoption of best management practices in southern Ontario

This paper examines the factors that affect the adoption of best management practices (BMPs) in Southern Ontario watersheds using both qualitative and quantitative techniques. A sample of 164 farmers was analyzed and triangulated with the results from in-depth interviews. The results suggest that farm and personal characteristics affect the adoption rate of BMPs and there should be financial incentives in order to create an enabling environment that will encourage the adoption of BMPs.     

Efficient removal of antibiotics from water resources is a public health priority: a critical assessment of the efficacy of some remediation strategies for antibiotics in water

Environmental Science and Pollution Research - This review discusses the fundamental principles and mechanism of antibiotic removal from water of some commonly applied treatment techniques...     

Correction to: Efficient removal of antibiotics from water resources is a public health priority: a critical assessment of the efficacy of some remediation strategies for antibiotics in water

Environmental Science and Pollution Research -