Effects of Barbecuing on the Levels of Polycyclic Aromatic Hydrocarbons in Fish (Pseudotolitus Elongatus and Clarias Gariepinus)

The PAHs in fish samples Pseudotolitus elongatus (Kroka fish) and Clarias gariepinus (Catfish) processed by charcoal was investigated in this study with the aim of determining the levels of the potently carcinogenic PAHs in the fish samples. 24 samples of barbecued fish products were purchased from six different barbecued spots, processed and analyzed. The PAHs in the samples were extracted using solvents by ultrasonication and were analyzed for the 16 US EPA polycyclic aromatic hydrocarbons using HPLC with a UV DAD detector. Naphthalene, Acenaphthylene, Acenaphthene, 1, 2-Benzothracene weren’t detected in the entire sampled barbecued fishes across the study locations while  Benzo(a)pyrene which is considered one of the most toxic and dangerous PAHs was detected highest in sample of Pseudotolitus elongatus gotten from Ekewan (206.69μg/kg). PAHs with maximum concentrations detected in sampled barbecued fish was Benzo(k)fluoranthene (647.58 μg/g) in Pseudotolitus elongatus from S and T Ugbowo. Total PAHs concentration range from (1797.72 μg/g – 3031.44 μg/kg). The high values recorded in this study should considered relevant in sending out warning signs on the frequent consumption of barbecued fish due to their associated health risk. Keywords: Barbecued fish, PAHs, Charcoal, Health Risk

Effects of elevated soil carbon dioxide (CO2) concentrations on spring wheat (Triticum aestivum L.) and soil chemical properties in Sutton Bonington Campus of the University of Nottingham, UK

This study examines the effects of elevated soil carbon dioxide (CO2) concentrations on spring wheat and soil chemical properties in the Sutton Bonington Campus, of the University of Nottingham, United Kingdom using Artificial Soil Gassing and Response Detection (ASGARD) facility which controls CO2 injection into the soil. Eight plots (each 2.5 x 2.5m) were laid out within the experimental area and used for the study and were treated with high CO2 concentrations (area within 75cm from the point of injection), low CO2 concentration (area farther than 75 cm from the point of CO2 injection) and no CO2 concentration (control) at CO2 injection rate of 1.0l/min from a source point 60cm below the soil for eight (8) weeks. The variability of CO2 concentrations were determined by 3D and barholing method. The wheat plant showed visible symptoms of wilting, chlorosis and poor development within 15- 21 days of gassing. Gassing at the rate of 1.0l/min resulted in reduced plant height and a 60% decrease in chlorophyll content of wheat plant exposed to high CO2 concentrations when compared with control plots. The soil pH for the control plots at the depth of 15-30 cm was 6.31 and 6.7 after injection, showing a difference of 0.39. At the depth of 45-60 cm, the pH before injection was 5.89 while post injection was 6.39, showing a difference of 0.5. The study showed that organic carbon at 45-60cm depth of soil ranged from 2.54% to 2.58% with a mean value of 3.26%, while carbonate content ranged from 0.73 to 0.77%. Furthermore, at 45-60cm depth of soil after injection, the mean value of K across all experimental plots was 64.16 mg/lK, available P content ranged from 15.4 to 16.9 mg/lP, N content ranged from 11.2 to 16.9 mg/lN, Ca ranged from 1000 to 1300 mg/lCa, Mg ranged from 158 to168 mg/lMg while at 15-30cm depth of soil, Na range from low to moderate (10.16–10.2 mg/l Na). There was no significant difference (P<0.05) or changes in mineralogical content of the soil properties studied.Keywords: controlled injection; CO2; soil chemical properties, soil dept

Pathological alterations in the liver of post-juvenile African Catfish (Clarias gariepinus) exposed to sublethal concentrations of the herbicide Glyphosate.

The use of histopathological techniques allows investigators to examine specific target organs and cells to determine how they are affected by exposure to environmental chemicals like pesticides. Moreover, it offers a means of detecting acute and chronic harmful effects of exposure in the tissues and organs of individual animals. In this study, histopathological alterations in the liver of post-juvenile African catfish Clarias gariepinus exposed to varying concentration of the commonly used herbicide glyphosate (IPA 360g/L) were used as biomarkers of effect, and alterations were both concentration and time specific. Cellular rupture, aggregation of inflammatory cells, vacuolar degeneration in the hepatocytes, focal areas of necrosis, and rupture of blood vessels that resulted in haemorrhage were characteristic of Glyphosate-exposed liver. The observed alterations in the liver of C. gariepinus further provide evidence to support the use of pathological change in fish as an indicator for monitoring the effect of exposure to low levels of toxicants, which are capable of altering the physiological profile of an organism. Keywords: Pathology, Toxicity, Liver, Health, Glyphosate, Biomarker

Exposure to atrazine altered postembryonic organs development, functions and growth performance of Clarias gariepinus catfish juveniles

Atrazine is a selective pre- and post-emergence herbicide for the control of weeds. Decades after being banned, atrazine remains the most abundant pesticide in water bodies. This study evaluated the toxic effects of atrazine on the post-embryonic development of African catfish (Clarias gariepinus). Catfish juveniles of 0.89 ± 0.06 cm and with an average weight of 0.01 ± 0.005 g were exposed to five different concentrations (0, 0.03, 0.3, 3.0 and 30 μgL-1) of atrazine in three replicates. The catfish juveniles mortality were significantly increased with increasing atrazine concentrations (p<0.05). Probit analysis showed 48 hours LC50 of atrazine at 0.68   μgL-1 with 100 % mortality at 30 μgL-1. Significant reduction (p<0.05) was observed in the specific growth rate (SGR) and the relative growth rate (RGR) with increasing concentration of Atrazine treatment. Histological assessment revealed disintegration of the nervous tissues, vacuolization of the epithelium of the anterior intestine, loss of gill cytoarchitecture and distortions of the intestine in all atrazine-treatment groups. Our results show that environmentally realistic concentrations (0.30 – 30.00 μgL-1) of atrazine in the aquatic environment may adversely affect the post-embryonic development and survival of African catfish