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

Raspodjela lindana u vodi, sedimentu i ribama iz rijeke Warri (Delta Nigera, Nigerija)

This paper is the first attempt to quantify the levels and the distribution pattern of lindane in the surface water, sediment and fish (Chrysichthys furcatus and Tilapia zilli). The samples were collected from three stations (Ovwian, Ekakpamre, and Ovu) of the Warri River in the western Niger Delta of Nigeria in 2006: during the dry (January-April) and wet seasons (May-August). The analysis included a total of 96 samples made up of 24 samples each for water, sediment, and fish. The pesticide levels were analysed using high performance liquid chromatography to elucidate its distribution in various environmental compartments. Residue levels in the matrices ranged from below the detection limit (BDL) to 1.37µg L-1 in water, BDL to 12.66 µg g-1 dry weight (dw) in sediment, BDL to 16.67 µg g-1dw in Chrysichthys furcatus, and BDL to 0.15 µg g-1dw in Tilapia zilli .The observed values were above the ecological benchmarks (0.01 µg L-1) recommended by the Nigerian Environmental Protection Agency and European Union. They were also relatively higher than in previous studies on the Nigerian environment, which calls for regular monitoring of the Niger Delta water bodies.Istražene su pojava i raspodjela lindana u površinskoj vodi, sedimentu i dvije vrste riba Chrysichthys furcatus i Tilapia zilli iz rijeke Warri u zapadnom dijelu delte Nigera (Nigerija). Uzorci su skupljeni 2006. godine na tri postaje (Ovwian, Ekakpamre i Ovu) tijekom sušne (siječanj - travanj) i vlažne sezone (svibanj - kolovoz). Analizirano je ukupno 96 uzoraka: po 24 uzorka vode, sedimenta i riba. Razine pesticida odre|ene su primjenom tekućinske kromatografije visoke djelotvornosti (HPLC) te je utvr|ivana njihova raspodjela u različitim dijelovima okoliša. Koncentracije rezidua u uzorcima vode bile su u rasponu: ispod granice detekcije (BDL) do 1,37 µg L-1, u sedimentu: BDL do 12,66 µg g-1 suhe tvari, u ribama Chrysichthys furcatus: BDL do 16,67 µg g-1 suhe tvari te Tilapia zilli: BDL do 0,15 µg g-1 suhe tvari. Određene vrijednosti bile su ispod graničnih vrijednosti (0,01 µg L-1) propisanih od Nigerijske uprave za zaštitu okoliša i Europske unije. Kako su dobivene vrijednosti bile relativno više u odnosu na podatke iz ranijih istraživanja okoliša u Nigeriji, istaknuta je potreba trajnog monitoringa vodotoka u delti Nigera

Human health risks associated with residual pesticide levels in edible tissues of slaughtered cattle in Benin City, Southern Nigeria

Pesticide residues in meat is of growing concern due to possible adverse effects on humans. Pesticide levels were assessed in five edible cattle parts: muscle, liver, kidney and tongue tissues to determine human health risk associated with consumption of these tissues. Health risk estimates were analysed using estimated daily intake (EDI), hazard quotient (HQ) and hazard index (HI) for two (2) age/weight categories: 1–11years/30 kg for children while 70 kg was used for adult. Risks were categorized for non-carcinogenic and carcinogenic health effects and measured at the average, maximum, 50th and 95th percentiles of the measured exposure concentrations (MEC). Total pesticide residues ranged from 2.38 to 3.86 μg/kg (muscle), 3.58 to 6.3 μg/kg (liver), 1.87 to 4.59 μg/kg (kidney) and 2.54 to 4.35 μg/kg (tongue). Residual pesticide concentrations in the tissues were in the order: Liver > Tongue > Muscle > Kidney. The concentrations of all the assessed pesticides observed in the tissues were however lower than the recommended maximum residual limits (MRLs). Human health risk estimations for the children showed EDI values for heptachlor epoxide, aldrin and dieldrin exceeding threshold values. Non-cancer risk posed to children on consumption of contaminated cattle parts showed HQ values for heptachlor epoxide, aldrin, dieldrin and HI values for organochlorines exceeding 1, indicating the possibility of non-carcinogenic health risks to consumers especially children from consumption of cattle meat from the selected abattoirs

Estimation of human health risk from exposure to Polycyclic Aromatic Hydrocarbons (PAHS) through dietary intake of fish and shellfish from Coal beach, Bonny River, Southern Nigeria

Dietary intake is one of the major human exposure pathways to PAHs. Consequently, the objective of the study was to estimate possible human health risk from consumption associated with PAHs concentrations in fish (Mullet fish-Mugil cephalus) and shellfish (Tiger prawn-Penaeus monodon and crab-Uca tangeri) samples, from Coal Beach, a landing site for fish catch along Bonny River, Southern Nigeria. Fish samples were observed to record the highest total mean PAH concentration of 0.126 mg/kg with total carcinogenic PAHs accounting for 47.3% of the total PAHs The highest average concentration of 0.060, 0.033 and 0.021 mg/kg was observed for benzo(a)anthracene in fish, prawn and crab respectively. Consumption of fish contributed to the highest intake of PAHs with carcinogenic PAHs accounting for 47% of the total estimated dietary intake. The estimated daily intake of PAHs in all the species analysed were however observed to be lower than the reference dose (RfD) indicating low risk through  consumption. However, further risk assessment using individual carcinogenic potencies, revealed that individual carcinogenic potencies for benzo(a)anthracene and benzo(a)pyrene in fish and shellfish exceeded the guideline screening value for human consumption indicating a high potential for carcinogenic risk. Keywords: PAHs, Fish, Shellfish, Health ris

Human health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in smoked fish species from markets in Southern Nigeria

Polycyclic Aromatic Hydrocarbons (PAHs) levels in four commonly consumed smoked fish species from markets in Southern Nigeria were assessed to evaluate possible human health risks associated with consumption. Varying levels of PAH congeners were observed in the fish tissues with the highest total concentration of PAHs in Scomber scombrus. High concentrations of benzo(a)pyrene was observed in Clarias gariepinus and Ethmalosa fimbriata with values above the guideline value of 0.05 mg/kg. The Dietary Daily Intake (DDI) value for total PAHs (âPAHs) was highest for S. scombrus while the DDI value for the total carcinogenic PAHs (âCPAHs) was highest for E. fimbriata. Carcinogenic human health risk assessment using carcinogenic toxic equivalents (TEQ), indicated that consumption of E. fimbriata has a higher potential to cause carcinogenic risks. TEQ values for all the fish species were however, below the estimated screening value (SV) of 3.556 mg/kg, while the estimated cumulative excess cancer risk (ECR) for E. fimbriata and C. gariepinus and PAH4 index for all the assessed fish species exceeded threshold values indicating potential carcinogenic risk from consumption. Keywords: PAH, Smoked fish, Human health risk, Risk indice

Diazinon Mediated Biochemical Changes in the African Toad (Bufo regularis)

The sublethal toxicity of diazinon to the adult African toad, Bufo regularis was assessed using an integration of biomarkers. Changes in acetylcholinesterase (AChE), corticosterone and total protein levels were assessed in the serum, brain, liver, lungs and gastrointestinal tract (GIT) and the results supported by bioaccumulation data. The biomarkers were chosen as indicators of key physiological functions: AChE for neurotoxicity, corticosterone and total protein levels as indicators of oxidative stress. Toads were exposed to 0.01, 0.02, 0.03 and 0.04 g/L for 28 days. Brain AChE activity reduced by 96% in the highest concentration (0.04 g/L) compared to the control brain. Similarly, AChE activities in serum, liver, lungs and GIT tissues (88%, 88%, 87, 87% umg-1 protein respectively) were also inhibited in the toads. Corticosterone and total protein levels in the tissues decreased compared to the control. The accumulation results obtained showed accumulation in the tissues (liver>serum>brain> lung>GIT), with a direct relationship between tissue concentration and changes in the biochemical indices. The alterations in all the indices were significantly concentration dependent. The biomarkers described in this study could be useful complementary indices in the risk assessment of diazinon pesticide

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

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

Biochar-facilitated batch co-digestion of food waste and cattle rumen content: An assessment of process stability, kinetic studies, and pathogen fate

Anaerobic digestion is an established sustainable route for managing the organic fraction of municipal solid waste. The commonly adopted mono digestion of organic waste is often beset by many challenges chief of which is process instability. This study assessed the role of biochar in process stability and pathogen fate for batch co-digestion of food waste (FW) and cattle rumen content (CRC). Biochar had different functional groups, a large surface area (627.50 m2/g), and a pore volume (0.32 cm3/g). Biochar amendments helped stabilize the pH and reduce the accumulation of volatile fatty acids (VFAs) and total ammonia nitrogen (TAN). Biochar amendment using 5 g biochar also facilitated biogas production at low pH conditions (3.72 – 4.45), yielding a cumulative biogas yield of 706.11 ml/gVS with a biomethane composition of 64.3%. Pathogen counts revealed significant log reductions in the range 3.0–3.2 for E. coli, Bacillus, and Salmonella within the first 7 days of digestion, corresponding to 99.9% removal, indicating the safety of the resulting digestate for agricultural use. The modified Gompertz model adequately represented the kinetics of the anaerobic digestion process. The study has provided insights into biochar-facilitated digestion of CRC and FW for enhanced process stability