Acute and chronic effects of organophosphate pesticides (Basudin) to amphibian tadpoles (Ptychadena bibroni)

Toxicity of basudin (an organophosphate pesticide) on the larval stages of the dominant amphibian; Ptychadena bibroni of the Niger Delta ecological zone of Nigeria was assessed using acute and chronictoxicity in the laboratory. Mortality and body glycogen levels were used as ecological endpoints. The American society of testing and material (ASTM) recommended semi-static renewal bioassay wasemployed and LC50 was measured at 96 h. The amphibian larval stages were exposed to basudin concentrations of 0.1, 1.0, 10.0 and 25 ug/l. Derived 96 h LC50 values decreased with increased exposureduration. Estimated 96 h LC50 was 0.860 ug/l. Substantial mortality and incidence of abnormal avoidance response occurred more at higher concentrations. Body glycogen levels in all test concentrations were significantly different between the test and the control experiments at

EUDIOMETRIC THEORETIC-APPROACH TO MODELLING THE ASSIMILATIVE CAPACITY OF A RIVER: INCORPORATION OF BOOTSTRAPPING NEEDFUL FOR SENSITIVITY ANALYSIS

The mathematical physics underlying the adsorption and subsequent desorption of dissolved oxygen (DO) in a water body subject to effluent loading had been rarely investigated. The current state of play in this field although reflects use of different analysis, the combine use of hat matrix and bootstrapping techniques to study the phenomenon of chemical adsorption and desorption of DO at molecular level in a polluted waterbody has not been thoroughly investigated. This study seeks to use a matrix projector, H-hat (Ĥ), to cast virtual spectral rays on pollutant loadings in a water body and in the process unravel the dynamics of chemical and biological gravitation of dissolved oxygen towards constituents of effluent pollutants in water body. This approach is anchored on the ordinary least squares methodology of multivariate linear regression. The method hypothecated is studded by a mathematical physics analysis of the phenomenon. Bootstrapping was used to establish means and variances of regression parameters, and subsequently, the confidence intervals of point estimates of parameters. Tricking technique adopted facilitated the development of extreme values of the dissolved oxygen and hence the supremum and infimum of assimilative capacity of the river which fluctuates with intensity of effluent loadings and season of the year (rainy, dry, and harmattan seasons). The result of bootstrapping revealed that assimilative capacity fluctuated widely from the values detected by point estimates of regression parameters thus suggesting that tricking of regression parameters, in turn, tunes up the regression model, and hence, fine tunes the value of assimilative capacity through necessary adjustments of model parameters. The results of this study obviates the need to deploy eudiometer for laborious direct measurement of dissolved oxygen in a body of polluted water. Thus an elegant technique for crossing the stream where it is shallowest has been developed in this study. The method is considered as a great improvement on previous approaches that seem to dawdle. http://dx.doi.org/10.4314/njt.v35i1.2

Sublethal effects of industrial chemicals on fish fingerlings (Tilapia guineensis)

Tilapia guineensis commonly found in the Niger Delta ecological zone of Nigeria was exposed to sublethal concentrations (1.56, 3.13 mg/l) of neatex (industrial detergent) and norust CR 486 (corrosion inhibitor) using the Organisation for Economic Cooperation and Development (OECD) # 203 protocol. At test termination on the 28th day, the rate of bioaccumulation of surfactants in the fish gills, gut and muscle tissues were measured. The levels of surfactant in the gills, gut and muscle tissues were significantly different at levels of p < 0.05 in fish exposed to neatex and norust CR 486. Surfactant levels in the fish also increased significantly with increase in concentrations. Surfactant accumulation in the test treatments may be an indication that the observed effects on the exposed fish may have been due to the chemicals. This study demonstrates the sublethal effects of surfactant-containing industrial chemicals on T. guineensis, an economic and ecologically important sentinel

Human Health Risk Assessment of PAHs in Fish and Shellfish from Amariaria Community, Bonny River, Nigeria

The concentration of polycyclic aromatic hydrocarbons (PAHs) in Fish (Mullet fish-Mugil cephalus) and Shellfish (Tiger prawn-Penaeus Monodon and crab-Uca tangeri) samples from fishing areas in Amariaria Community, downstream of Bonny River, Southern Nigeria, were assessed to determine possible human health risk associated with consumption. Mean levels (mg/kg) of total PAHs ranged from 0.059 to 0.126 in fish, 0.015 to 0.106 in prawn and 0.057 to 0.063 in crab. A considerable predominance of the 3 and 4-rings PAHs in all the matrices was observed with benzo (a) anthracene dominating in all three species. Estimated daily intake (EDI) of PAHs through consumption of fish ranged from 0 to 0.0005 mg/kg/day, for prawn, 0 to 0.0002 mg/kg/day and for crab, 0 to 0.0002 mg/kg/day. EDI values were, however, lower than the reference dose (RfD) indicating low risk from consumption. Results of the estimated excess cancer risk (ECR) for Benzo (a) anthracene in fish, however, suggests that lifetime exposure to Benzo (a) anthracene through fish consumption would result in cancer risk

Modelling Effluent Assimilative Capacity of Ikpoba River, Benin City, Nigeria

The sheer display of reprehensible propensity on the part of public hospitals, abattoirs, breweries and city dwellers  at large to discharge untreated waste, debris, scum and, in particular, municipal and industrial effluents into Ikpoba River has morphed into a situation whereby the assimilative capacity of the river has reached a record level. The seeming quietism and clinical posture of the relevant Environmental Agency to this pathological condition is sickening and in any case seen as remiss on their part. This paper seeks to determine the assimilative capacity of the river with a view to articulating policy-proposal stream in the instance that its value is unsafe for ichthyofaunal beings and humans.  A combination of basic Streeter-Phelp equation and monograph of Fair et al. were used for the determination of the assimilative capacity and the maximum allowable biological oxygen demand (BOD) load discharged into the river from three identified point sources of wastewater and for three different seasons in Nigeria (i.e. rainy, dry and harmattan seasons). Results indicate that in all the segments studied, the Fair ratio (self-purification factor) is less than unity, indicating the predominance of deoxygenation rate over reaeration rate. Reaeration rate ranges over all real values from 0.641day-1to 0.693day-1, while deoxygenation rate ranges between 0.718 day-1 and 0.839 day-1; a condition which indicates a poor assimilative capacity potential. Moreover, a higher assimilative capacity was obtained for rainy season for all the segments studied, with sampling point 3 (Guinness-harmattan and dry season) showing an overall worse assimilative capacity and poor maximum allowable BOD of 8.1x109, 1.28x1010 and 5.60x109 kg/day respectively. In a way, the determination of the assimilative capacity of Ikpoba River is a landmark in the history of the river pollution. It beggars belief that we live down the harrowing pathological condition of the river without recognizing its wider implications.http://dx.doi.org/10.4314/njt.v34i1.1

Influence of Effluent Discharge and Runoffs into Ikpoba River on its Water Quality

Unfettered effluent discharge, in addition to seasonal runoffs, into Ikpoba River, have been blamed for the ever poor water quality noticed in the river. This study seeks to investigate the role of industrialization and/ or urbanization on the degraded water quality of the river. Chemical analyses of samples of the river water collected at predetermined sampling points were undertaken and the observations obtained were subjected to ANOVA, correlation, and eigenvalue analysis. Results obtained showed that each point source has its relative contribution to the overall degradation of the river water quality. In merit order, the eigenvalue analyses carried out suggests that phosphate, nitrate, cadmium, copper, iron, lead and turbidity are the most offensive factors showing values of 0.868, 0.933, 0.770, 0.503, 5.063, 0.717, 30mg/L respectively. Remarkably, surface runoffs from municipal drains channelled to stations 1 and 2 contribute significantly to the turbidity with 4.333 and 4.233mg/L respectively, whereupon urbanization and industrialization are seemingly the culprits

Toxicity of Neatex (industrial detergent) and Norust CR 486 (corrosion inhibitors) to earthworms (Aporrectodea longa) in naturally spiked soil

Ecological effects of indiscriminate disposal of industrial chemicals into soils of the Niger Delta environment of Nigeria were assessed using earthworms in spiked natural soil in the laboratory. Populations of indigenous epigeic adult earthworms, Aporrectodea longa, were exposed to varying concentrations of two chemicals (industrial detergent and corrosion inhibitor) in natural soil to determine the acute toxicity of the chemicals. Earthworm acute toxicity test (OECD) 207 method was employed. After two weeks of earthworm exposure to Neatex and Norust CR 486 concentrations of 62.5, 125, 250 and 500 mg/kg, percentage mortality was measured as the ecological endpoint in the earthworms. Based on OECD 2003 guidelines, the chemically spiked soil rating showed that bothchemicals were slightly toxic. The estimated LC50 concentrations showed that Norust CR 486 (corrosion inhibitor) was more toxic than Neatex (detergent) at p < 0.05, t = 8.213. Earthworm mean mortality in both chemicals increased with increasing concentrations and exposure duration. Mean mortality observed in Neatex and Norust CR 486 were significantly different from the negative control suggesting that mortality may be attributed to the effect of the chemicals. The results obtained aretherefore indications of early warning signs of future soil deteriorations occasioned by indiscriminate disposal of these chemicals in the Niger Delta environment. This calls for regular monitoring and sustainable effluent disposal management

Subtle effects of environmental stress observed in the early life stages of the Common frog, Rana temporaria

Worldwide amphibian populations are declining due to habitat loss, disease and pollution. Vulnerability to environmental contaminants such as pesticides will be dependent on the species, the sensitivity of the ontogenic life stage and hence the timing of exposure and the exposure pathway. Herein we investigated the biochemical tissue ‘fingerprint’ in spawn and early-stage tadpoles of the Common frog, Rana temporaria, using attenuated total reflection- Fourier-transform infrared (ATR-FTIR) spectroscopy with the objective of observing differences in the biochemical constituents of the respective amphibian tissues due to varying water quality in urban and agricultural ponds. Our results demonstrate that levels of stress (marked by biochemical constituents such as glycogen that are involved in compensatory metabolic mechanisms) can be observed in tadpoles present in the pond most impacted by pollution (nutrients and pesticides), but large annual variability masked any inter-site differences in the frog spawn. ATR-FTIR spectroscopy is capable of detecting differences in tadpoles that are present in selected ponds with different levels of environmental perturbation and thus serves as a rapid and cost effective tool in assessing stress-related effects of pollution in a vulnerable class of organism

Concentrations and distribution of polychlorinated biphenyls (PCBs) in aquatic environemnt of Niger Delta of Nigeria (water and sediments)

No Abstract. Discovery and Innovation Vol. 18(2) 2006: 160-16

Levels Of Polychlorinated Biphenyls Residues In Warri River, Nigeria

Sum of individual PCBs congeners in surface water and sediment samples from Warri River system, a coastal river of Niger Delta, Nigeria were measured between March and June 2003. Specific individual PCBs analysis was by HPGC series 6890. Mean concentrations of &Sigma;PCBs in surface water samples ranged from 0.35 &mu;g l-l (Tori Creek) to 1.30 &mu;g l-l (Crawford Creek). Sediment samples had higher levels ranging from 2.00 ng g-l (Tori Creek) to 7.00 ng g-l (Crawford Creek). Null hypothesis of normality was rejected at p>0.05 indicating significant difference between the matrices. Concentrations of PCB were compared with ecotoxicological benchmarks and regulatory guidelines to determine potential concern for effects on aquatic life and human health. Measured mean concentrations in surface water and sediments samples from Crawford creek station indicated concern for environmental and public health because of their exceedence of the US EPA PCB limit for drinking water (0.0005&mu;gl-l) and water quality criteria for chronic exposure (79pgl-l) through drinking water and fish ingestion. KEY WORDS: PCBs, Water, Sediment, Hazard, Warri River. Global Journal of Environmental Sciences Vol.4(1) 2005: 65-7