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

Health risk estimations and geospatial mapping of trace metals in soil samples around automobile mechanic workshops in Benin city, Nigeria

This study was carried out to assess the distribution of trace metals in soil samples from selected automobile mechanic workshops (AMWs) in Benin City, spatially map the concentrations and estimate the health risk indices for the exposed populace. Topsoil samples were collected from twenty-one (21) AMWs in Benin City in 3 composites for three months at each station. Soil samples were analyzed for heavy metals (Pb, Cd, Fe, Cu, Ni, Cr, and Zn) using Atomic Absorption Spectrophotometer. The non-carcinogenic risks caused by exposure to the metals were insignificant, characterized by in mean values of hazard quotient (HQ) and hazard index (HI) below one (1) in adults and children. Carcinogenic risk (CR) occurred only in the children exposed to nickel through ingestion; attributable to ingestion. In adults and children, the risks associated with the uptake routes were in the order of ingestion > dermal contact > inhalation. The hazard index (HI) values of heavy metals for children and adults decreased in the order of Pb > Cr > Cd > Cu > Zn > Ni and were all lower than one (1), which indicated that the children and adults were not at non-carcinogenic risk. The contamination factors (CF) of all metals analyzed were lower than one (1), suggesting low contamination. The average CF decreased in the order of Pb (0.3715) > Zn (0.14) > Cu (0.087) > Cr (0.013) > Ni (0.01) > Fe (0.0007). Potential ecological risks of the trace metals in soils of these workshops revealed low pollution of the soils by the metals. Results indicated that the three routes of uptake in adults and children decreased in the order of ingestion > dermal > inhalation. The noncarcinogenic risks posed by metals to the children and adults were insignificant. Ingested nickel however posed potential carcinogenic risk to only the children. The toxicodynamics of heavy metals in the soil profile demonstrated in this study could be a vital information for future studies and decisions on the management of the health and environment of the study area

Interactions of trace metals with bacteria and fungi in selected agricultural soils of Egbema Kingdom, Warri North, Delta state, Nigeria

This study was aimed at investigating the relationship of trace metals with prevalence of bacteria and fungi in polluted farmland of Egbema Kingdom, Delta state. This may contribute to the knowledge on the influence of the microorganism to the arability of agricultural soil from an ecotoxicological viewpoint. Soil samples were analyzed for physico-chemical parameters and trace metals using atomic absorption spectrophotometer (Buck Scientific, 210VGP). The samples were also screened for fungi and bacteria isolates. Trace metals (Fe, Zn, Cd, Ni and Cu) determined in the agricultural soils of Egbema kingdom were below WHO limits. The fungi species with the highest number of occurrence was Aspergillus niger, while the species with the lowest occurrence were Fusarium oxsporium, Penicillium dirty white, and Penicillium sp. The order of abundance of fungi across the stations was Station 2> Station 4> Station 3> Station 1> Station 7> Station 5> Station 6> Station 9> Station 8. The bacteria species with the highest number of occurrence was Proteus sp I, while the species with the lowest occurrence was Alcaligenes sp. which occurred only once at Station 5. The order of abundance of bacteria in the soil samples across the stations was Station 4> Station 3> Stations 5 and 9> Station 2> Station 8> Station 7> Station 6. All trace metals in the agricultural soils of Egbema kingdom were below WHO limits. Fe, Zn, Cd and Ni showed no relationship with the microbial contents of the soil. Various strains of fungi and bacteria (gram positive and gram negative) were observed in the soil samples. An antagonistic relationship was observed between bacteria and fungi. Significant positive correlation occurred between the concentration of copper and bacteria counts indicating that the concentration of copper in the soil might have enhanced the abundance of bacteria in the soil, vice versa. The bacteria might be a promising tool in regulation of soil copper concentration

Principal Components and Hierarchical Cluster Analyses of Trace Metals and Total Hydrocarbons in Gills, Intestines and Muscles of Clarias gariepinus (Burchell, 1822)

The aim of the study was to comparatively analyze the interrelationships among iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and total hydrocarbons (THCs) in the gills, intestines and muscles of Clarias gariepinus collected from Osse River, Nigeria, between the periods of April, 2013 to September, 2014. The trace metals in the fish tissues were analyzed using Atomic Absorption Spectrophotometer (AAS, Philips model PU 9100), while total hydrocarbons were analyzed using High Performance Liquid Chromatograph (HPLC,Prominence Dual brand from HGE) equipped with a detector Shimadzu UV-Visible (UV-Vis Prominence SPD 20 A). The concentrations of trace metals and THCs in the tissues were subjected to principal component analysis (PCA), in conjunction with hierarchical cluster analysis (HCA), backed up by correlation analysis (CA). In the most prioritized component among the hierarchies of contaminants, characterized as principal component 1, results of communality extractions and rotated component matrices revealed the order of contaminants was Mn > Cu > Zn > Fe > Cr in the intestines, Cr > Cu > THCs > Mn > Fe in the muscle, while Pb > Cr > Fe > Mn was the order in the gills of the fish. Iron inhibited accumulation of the other trace metals in the gills, where its threshold of essentiality was maximal. Noteworthy is the fact that Mn and Cu were the most active components in the muscle and concurrently of excess concentrations in the tissue, which is the major edible part of fish, and constitutes its main body weight, hence holds its nutritional and economic values. High level of variability which occurred in the toxicant profile across the tissues of C. gariepinus is a function of uptake route, varied organ functions and specificity of tissue permeability of the compared organs. The study demonstrated variability in organ accumulation capacity and toxicant’s competitiveness irrespective of bioavailability. The study provides data useful for future ecotoxicological studies and safety of consumers of the fi

Haematological changes in Bufo maculatus treated with sublethal concentrations of Cadmium

Adult <em>Bufo maculatus</em> was exposed to sublethal cadmium concentrations of 0.25, 0.50, 1.00 and 2.00 mg/L. The toxicant from which the cadmium concentrations were prepared was cadmium chloride (CdCl2.H2O). There were three replicate tanks per treatment and three individuals per tank including control groups. The hematologic alterations based on the examination of blood indices during the 28 days of exposure showed that total erythrocyte count (TEC), hematocrit (Hct) and hemoglobin (Hb) concentration decreased (P&lt;0.05) relative to controls. The decline was concentration- dependent as concentration of cadmium increased. The decline in hemoglobin and hematocrit in the experimental organism could be due to a decrease in the synthesis or release of erythrocytes into the circulation or an increase in the rate of erythrocyte destruction inflicted by cadmium toxicity. There was significant (P&lt;0.05) elevation in total leuko- leukocyte count (TLC) with increase in the concen- cyte concentration of cadmium. The increase in total leukocyte count observed in this study could be attributed to a stimulation of the immune system in response to tissue damage caused by cadmium toxicity. The study has shown that the exposure of the <em>Bufo maculatus</em> toad to cadmium can inflict alterations in the hematologic indices, which could induce unfavorable physiological changes in the amphibian, which may lead to death. There is, therefore, the need to protect amphibians in order to sustain the biodiversity in the Nigerian Niger Delta ecological zone

Evaluating the potential health risks of heavy metal pollution in sediment and selected benthic fauna of Benin River, Southern Nigeria

Abstract The potential ecological and human health risk of heavy metal pollution in sediment and Benthic Fauna (Chrysichthys auratus and Tympanotonus fuscatus) of Benin River, Southern Nigeria, was evaluated. Three sampling sites associated with heavy anthropogenic activities along the course of the river were sampled. Heavy metals concentrations were determined in the samples using atomic absorption spectrophotometer (Model 210 VGP, Buck Scientific). In all sediment samples, only Pb exceeded the threshold/probable effect level (TEL). Very high contamination degrees (CD > 24) 181.74, 50.11, and 101.96) for stations 1, 2, and 3, respectively, were observed indicating serious anthropogenic pollution. Geoaccumulation index (i geo) showed slight pollution with Pb and Cd and severely to extremely polluted with Fe across the stations. Cd exhibited moderate individual potential risk ($$E_{\text{r}}^{i}$$ Eri ), and the other heavy metals showed low $$E_{\text{r}}^{i}$$ Eri . Potential ecological risk index (RI) showed low risk of contamination for heavy metals in sediment. Human health risk assessment for Co, Cd, Cu, Zn, Mn, Fe, and Ni in C. auratus and Co, Zn, Mn, Fe, and Ni in T. fuscatus indicated no obvious health risk from these heavy metals over a lifetime of exposure. However, hazard quotient (HQ) values for Pb in C. auratus and Cd, Cu, and Pb in T. fuscatus indicated significant health risk. The hazard index (HI) values for both C. auratus and T. fuscatus were > 1 indicating significant adverse health risk of non-carcinogenic effect. Therefore, the consumption of these contaminated fish and shellfish by the people of Koko portends risks of the health of the public. The industries operating in this community should adopt more sustainable and eco-innovative management options in order to attenuate potential ecological and human health risk of metal pollution

Effects of COVID-19 Policy on Air Quality in Lagos State, Nigeria

The decrease in air quality has been a major concern in the world for decades, and it has continued to worsen with toxic gases accumulating at exponential rates. The atmosphere has been heavily polluted as a result of anthropogenic activities, and these activities were greatly reduced during the COVID-19 pandemic when a lockdown policy was imposed. The study area, Lagos, is the state in Nigeria with the highest population count, making it most susceptible to the spread of the coronavirus and, as such, having the strictest policy regulations. This study seeks to evaluate the effects of the COVID-19 lockdown policy on air quality in Lagos State. The study adopted geographic information systems (GIS) and remote sensing techniques. Goggle Earth Engine (GEE) and Sentinel 5P (S5P) TROPOMI dataset were used to obtain results for carbon monoxide (CO), sulphur dioxide (SO2), aerosols (particulate matter), and nitrogen dioxide (NO2) through JavaScript coding for the year before the lockdown (2019), the year of the lockdown (2020), and the year after the lockdown (2021). Results from the study revealed that the year 2020 had lower concentrations of aerosols and NO2, which increased in 2021 when human and vehicular activities were back to normal. SO2 and CO concen-trations were higher in the year 2020 than in year 2019 and 2021, suggesting that the COVID-19 lockdown was loosely implemented. It is recommended that policymakers invest in green technologies such as solar systems to minimize emissions, enforce strict emission standards for industries and vehicles to limit the release of air pollutants

Bioactive profiling and therapeutic potential of mushroom (Pleurotus tuberregium) extract on Wistar albino rats (Ratus norvegicus) exposed to arsenic and chromium toxicity

Mushroom species are valued in gourmet traditions around the world for their unique taste, aroma, nutritional value and medicinal potentials. The bioactive profiling of P. tuberregium mushroom was evaluated to determine it therapeutic effect on Wistar albino rats exposed to arsenic (As) and chromium (Cr) toxicity. Proximate analysis of P. tuberregium showed high composition of carbohydrate (80.24) followed by moisture (21.16), protein (11.46), ash (3.03) and fibre (0.25) content. Phytochemical analysis revealed the presence of polyphenols (2.58), alkaloid (2.46), oxalate (4.25), flavonoid (1.68), tannin (0.38) and Saponin (trace) in trace amount. Mineral analysis yielded variable amounts of Na, Mg, K and Ca. Therapeutics assessment of P. tuberregium to Wistar albino rats exposed to As-Cr toxicity showed improved feed and water intake during the exposure duration. Haematological indices revealed significant increase in platelet (PLT), granulocytes and monocytes while lymphocyte (LY) and red cell distribution width (RDW) were low. Biochemical and redox marker of liver and kidney profiles showed decrease in alkaline phosphatase (ALP), alanine transaminase (ALT) and aspartate transaminase (AST) in the liver. Creatinine and urea in the kidney also decrease while total protein increased significantly. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione S-transferase (GST) decrease in the liver and kidney of the therapeutic group when compared with As-Cr treated rats. The presence of alkaloids and flavonoids in significant amount may have contributed in the therapeutic changes observed in all the parameters. Therefore, our findings conclude that P. tuberregium possessed remarkable effect against As-Cr induced toxicity in albino rats and may be useful in metal toxicity treatment in man and may be concluded that they are therapeutically effective. Keywords: Arsenic, Chromium, Pleurotus tuberregium, Haematological and redox marker

Impacts of acute exposure of industrial chemicals and pesticides on the survival of fish (Tilapia guineensis) and earthworms (Aporrectodea longa)

Ecotoxicological effects of industrial chemicals (Rig wash, Oil eater, Nalco, Glycol™) and pesticides (Propoxur, Deltamethrin, Atrazine, Furadan) on Tilapia guineensis (fish) and Aporrectodea longa (earthworms) were tested using the Organisation for Economic Cooperation and Development (OECD) # 203 and 207 protocols. The water and soil ratings indicate that the test chemicals were toxic to the organisms. The estimated 96 hour lethal concentration LC50 values for Rig wash, Oil eater, Nalco EC1304A/COT 505, Glycol, Propoxur, and Deltamethrin were 26.34±0.46, 6.02±0.30, 3.07±0.14, 1.31±0.01, 20.91±0 and 0.01±0 mg/l respectively. In the earthworm bioassay, the estimated 14-day LC50 values for Rigwash, Oil eater, Nalco EC1304A/COT 505, Glycol, Atrazine and Furadan were 80.05±3.5, 151.55±10.7, 172.63±14.2, 63.72±2.43, 4.97±0 and 0.29±0 mg/kg respectively. Safety factors are arbitrarily built in around the LC50 values in order to arrive at environmentally tolerable concentrations. The concentration of a chemical in the receiving environment should not exceed 10% of the L50. The organisms exposed to the test chemicals showed significant difference when compared with the levels measured in the control group. The observed sensitivity of the test organisms to the chemicals indicates that adherence to standard safety limits/measures should be maintained during use and disposal of hazardous chemicals. This would ensure that the biotic components of the Nigerian Niger Delta ecosystem are prudently protected

Accumulation patterns and risk assessment of metals and metalloid in muscle and offal of free-range chickens, cattle and goat in Benin City, Nigeria

The use of free range animals for monitoring environmental health offers opportunities to detect exposure and assess the toxicological effects of pollutants in terrestrial ecosystems. Potential human health risk of dietary intake of metals and metalloid via consumption of offal and muscle of free range chicken, cattle and goats by the urban population in Benin City was evaluated. Muscle, gizzard, liver and kidney samples were analyzed for Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, and Pb concentrations using inductively coupled plasma mass spectrometer (ICP-MS) while Hg was determined using Hg analyzer. Mean concentrations of metals (mg/kg ww) varied significantly depending upon the tissues and animal species. Human health risk estimations for children and adults showed estimated daily intake (EDI) values of tissues below oral reference dose (RfD) threshold for non essential metals Cd, As, Pb and Hg thus strongly indicating no possible health risk via consumption of animal based food. Calculated Hazard quotient (THQ) was less than 1 (< 1) for all the metals analyzed for both adult and children. However, Cd and As had the highest value of THQ suggestive of possible health risk associated with continuous consumption of Cd and As contaminated animal based foods. Hazard Index (HI) for additive effect of metals was higher in chicken liver and gizzard for children and chicken liver for adults. Thus, HI indicated that chicken liver and gizzard may contribute significantly to adult and children dietary exposure to heavy metals. Principal component analysis (PCA) showed a clear species difference in metal accumulation between chickens and the ruminants. This study provides baseline data for future studies and also valuable evidence of anthropogenic impacts necessary to initiate national and international policies for control of heavy metal and metalloid content in food items