Isoken T. Aighewi

The Kinetic Signature of Toxicity of Four Heavy Metals and Their Mixtures on MCF7 Breast Cancer Cell Line

This study evaluated the kinetic signature of toxicity of four heavy metals known to cause severe health and environmental issues—cadmium (Cd), mercury (Hg) lead (Pb) arsenic (As)—and the mixture of all four metals (Mix) on MCF7 cancer cells, in the presence and absence of the antioxidant glutathione (GSH). The study was carried out using real time cell electronic sensing (RT-CES). RT-CES monitors in real time the electrical impedance changes at the electrode/culture medium interface due to the number of adhered cells, which is used as an index of cell viability. Cells were seeded for 24 h before exposure to the metals and their mixtures. The results showed that in the presence and absence of cellular glutathione, arsenic was the most cytotoxic of all five treatments, inducing cell death after 5 h of exposure. Lead was the least cytotoxic in both scenarios. In the presence of cellular GSH, the cytotoxic trend was As > Cd > MIX > Hg > Pb, while in the absence of GSH, the cytotoxic trend was As > Hg > MIX > Cd > Pb. The findings from this study indicate the significance of glutathione-mediated toxicity of the metals examined—particularly for mercury—and may be clinically relevant for disorders such as autism spectrum disorder where decreased glutathione-based detoxification capacity is associated with increased mercury intoxication.

Land Use–Land Cover Changes in the Lower Eastern Shore Watersheds and Coastal Bays of Maryland: 1986–2006

Abstract Changes in land use influence surface-water quality and thus present a potential threat to coastal ecosystem health. Land use–land cover changes (LULCC) in the lower Eastern Shore watersheds of Maryland have been rapid in the last decade, with increase in real estate development an obvious indicator. The objective of this study was to evaluate the extent of historical LULCC in the lower Eastern Shore watershed and coastal bays of Maryland from 1986 to 2006. Land use–land cover data were derived by supervised classification of Landsat TM 5 satellite imagery acquired in 1986, 1996, and 2006 using the Anderson level-1 classification system in Environment for Visualizing Images (ENVI 4.5), while LULCCs were detected in an Arc-GIS 9.2 environment. The results showed that while urban and forest lands increased by 121.8% and 8.5%, respectively, in the lower Eastern Shore from 1986 to 2006, croplands and wetlands decreased by 19.6% and 21.3%, respectively. Area covered by surface water increased by 10%, submerging mostly wetlands of 150 km2 in 17 of the 23 subwatersheds studied. The loss of these coastal wetlands is attributable in part to the changing climate and the resultant sea-level rise and in part to the activities of the invasive rodent Nutria (Myocastor coypus), reported to be a major menace in Marylands Eastern Shore. The declining wetlands have serious ecological health implications for the Chesapeake Bay and its watersheds for several species and thus require urgent attention. More intensive and frequent monitoring of this delicate estuarine ecosystem is suggested.

Land Use–Land Cover Changes and Sewage Loading in the Lower Eastern Shore Watersheds and Coastal Bays of Maryland: Implications for Surface Water Quality

ABSTRACT Aighewi, I.T.; Nosakhare, O.K., and Ishaque, A.B., 2013. Land use–land cover changes and sewage loading in the lower Eastern Shore watersheds and coastal bays of Maryland: Implications for surface water quality. Changes in land use and cover influence surface water quality and thus are a potential threat to water systems and coastal ecosystem health. The objectives of this study were to evaluate the influence of historical land use–land cover (LULC) changes and point-source sewage discharge on surface water quality of some lower Eastern Shore watersheds of Maryland. LANDSAT data for 1986–2006 was acquired and classified using Anderson level-1 classification system in ENVI 4.5, whereas LULC changes were detected in Arc-GIS 9.2 environment. Historical water monitoring and climatic data were obtained from Maryland Department of Environment–Chesapeake Bay Program, and National Oceanic and Atmospheric Administration, respectively. Nutrient loading data from wastewater treatment plants were obtained from Maryland Department of Environment and data analyzed using regression analysis and principal component analysis (PCA). The result shows that total phosphorous levels in the surface waters decreased significantly (p < 0.05) during the 20-year study period. However, using PCA, we determined that the declining P trend was attributable to the decreasing agricultural land use rather than the sewage discharge from wastewater treatment plants. The increase in urban land use and the resultant runoff to the water bodies may explain the declining trends in dissolved oxygen levels observed during the period, with serious implications for eutrophication. An empirical model developed for P in surface waters (r2  =  0.90) showed that the combination of point and nonpoint sources and land use/cover change factors are good predictors. The incorporation of quantitative LULC data component as well as point-source nutrient loading into existing models is highly recommended for a more holistic assessment of land-use influence on water systems in general.

Quality assessment and public health status of harvested rainwater in a peri-urban community in Edo State of Nigeria

The harvested rainwater is an alternative water source in communities where there is limited or scarcity of water distribution system. However, contamination of roof-harvested rainwater is of immense concern to the general public health. Therefore, this study was initiated to assess the levels of physicochemical quality and heavy metal concentrations in the harvested rainwater from Oluku communities in Benin City, Edo State, Nigeria. The roof-harvested rainwater samples were collected from 20 independent different residential households in Oluku communities, between April 2015 and September 2015. Physicochemical analyses were carried out using standard analytical methods, and heavy metal concentrations were determined using atomic absorption spectrophotometry. The evaluation of the rainwater harvesting shows that 60% (12/20) of the roofs were made of corrugated iron sheets; aluminum sheets, 20% (4/20); asbestos, 10% (2/20); and open space was 10% (2/20). Also, the storage systems used for the storage of harvested rainwater were as follows: PVC tanks, 20% (4/20); drums, 30% (6/20); buckets, 25% (5/20); and wells, 25% (5/20). The physicochemical indicators investigated (temperature, nitrate, chlorine content, electrical conductivity, phosphate, total dissolved solids, and sulfate) were within World Health Organization (WHO) guidelines. However, some pH levels of the roof-harvested rainwater were acidic and below the WHO standard. Furthermore, a high value of turbidity was observed in some locations and exceeded the WHO guidelines. Though some heavy metal indicators (Zn, Na, K, and Ca) in this study were within the WHO guidelines, some locations revealed heavy metal (Cu, Fe, and Cd) concentrations slightly above the WHO guidelines. There is need for proper rainwater harvesting system and continuous monitoring of harvested rainwater for potable uses.

Comparative non-metric and morphometric analyses of rats at residential halls of the University of Benin campus, Nigeria

BACKGROUND In mammals and across rat species, the variation in conformation is markedly observed in the head and the variation in the shape of the head is mostly determined by the shape of the skull. Hence comparative topographic analysis and morphometry is a veritable tool in precise categorization of peri-domestic rats and species identification. METHODS Killed rodents around residential dwellings of students on campus were collected and measurements taken of external morphology. Thirty-one external head and corporal parameters; and 40 cranial measurements respectively were obtained. Topographic features and specific anatomical landmarks measured were matched using congruent anatomical landmarks and compared to referenced standard measurements. RESULTS External morphometry suggests that all retrieved samples were more closely related to the species Rattus rattus. However, craniodental analysis of captured rats reveals variations from the mean of typical R. rattus. In comparison with Mastomys natalensis, the mean averages of the rat species were perceptibly different for only two of the parameters viz palatine fissure length (PL) (p=0.039) and distance between interparietal bone (DP) (p=0.06). In contrast, the mean of whole length of skull (WL), length of diastema (PI), length of nasal bone (NL), length of frontal bone (LF) and occipital width (OH) were significantly different from that of R. rattus with p values of 0.047, 0.036, 0.048, 0.032 and 0.034 respectively. CONCLUSION This study focuses on peridomestic rats identification within the University campus based on morphometry, providing unique landmarks for differentiation between Mastomys, Mus, Rattus and other rat species with emphasis on the need for more comprehensive investigation, categorization and morphometric profiling of rat population in Nigeria. Metric data generated for rat profiling in Nigeria is pivotal for a more comprehensive strategy for prevention of Lassa fever.

Assessment of the Physicochemical and Heavy Metal Qualities of Rooftop Harvested Rainwater in a Rural Community

This study is conducted to assess the quality of harvested rainwater. Rooftop rainwater samples are collected between April and September 2015 from Ugbihioko village near Benin City, Nigeria. Heavy metal concentration and physicochemical quality are determined with the use of standard analytical techniques for water quality, and the results are compared to the World Health Organization (WHO) acceptable limits for drinking water. Of the different water quality parameters, the results show that temperature is within WHO drinking water standards for all locations, but pH, turbidity, sulfate, chloride, and nitrate concentrations vary considerably and do not meet the standards for all locations. Regarding the maximum acceptable concentration (MAC), electrical conductivity is well below the MAC for all cases; the heavy metals copper and iron are above the MAC for all cases; the light metals sodium and potassium are below the MAC for all cases. Lead is above the MAC for all locations, except for in one location; and selenium varied, with some sites having selenium concentrations above the MAC. The results from this study show that public health education or advising is vital for mitigating the possible risks that can be linked to the use of harvested rainwater without treatment.

The Value and Benefits of an Environmental Health Bachelor’s Degree Accredited by the National Environmental Health Science and Protection Accreditation Council for Community College Transfer Students:

The approximately 45,000 environmental health practitioners in the United States are in the front line of public health by preventing disease and injury. Environmental health practitioners enjoy good pay, good benefits, and rewarding careers. Growth of the profession is projected to be faster than average at about 15% in the next 10 years. However, few community college students, faculty, and administrators know about this career path. Students that obtain a bachelor’s degree in Environmental Health accredited by the National Environmental Health Science and Protection Accreditation Council (EHAC) have a means to assure a successful career in the field of environmental health as this degree is deemed the “industry standard” by environmental health leaders. Currently, there are 31 universities across the nation that offer EHAC-accredited Environmental Health bachelor’s degrees with courses being taught on campus and online. Students that seek transfer from a community college to an EHAC-accredited university need to have the background courses necessary to assist in a seamless transfer. Community colleges that desire their graduates to successfully transfer to EHAC-accredited programs need to offer the general education, math, and basic science courses that are the underlying requirements of an EHAC-accredited Environmental Health degree.

The Effect of L-Buthionine Sulfoximine on the Toxicities and Interactions of As, Cd, Hg and Pb and their Composite Mixture on MCF 7 Cell Line

The effect of intracellular level of GSH on the cytotoxicity and interaction of four environmentally relevant metals arsenic, cadmium, mercury and lead (As, Cd, Hg, and Pb) was investigated. LButhionine Sulfoximine (LBSO) was used to inhibit the intracellular level of GSH in MCF 7 cells. Both individual and combined cytotoxicities of the four metals on the cells were assayed by spectrofluorometric counting of the surviving cells after 24-hour exposure. Exposure of the cells to three of the studied metals: As, Cd, and Hg resulted in the production of significantly (p<0.5) higher level of cellular GSH relative to the control. However, cells exposed to Pb with or without pretreatment with LBSO exhibited about 50% decrease in cellular GSH. Individual metal toxicity was higher in GSH-depleted cells relative to GSH-rich cells; However, the effect of GSH depletion was slightly metal selective as As and Hg exhibited toxicities. Cells exposed to the composite mixture of all four metals indicated additive and antagonistic interactions in GSH depleted cells and GSH rich respectively.