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The aim of this study is to assess the water quality of the Nigerian Port Authority Water way. A cross-sectional study was carried out using a composite sampling method, where three water samples were collected randomly from each station to ensure that the samples were representative of the entire station. Water samples were taken from four different locations along the waterway with new unused bottles, chosen based on the level of port activity in the area. The samples were thereafter analysed for physiochemical parameters, and heavy metal, and compared to the World Health Organization's Permissible Limits. Data analyses covered descriptive statistics, Pearson correlation coefficient analysis, Agglomerative hierarchy clustering, parallel coordinate plot and Water Quality Index computation. The results showed that most parameters were above the standards, indicating a potential risk of bioaccumulation. The water quality index for the station was found to range from 3192.635 to 5061.35 for the four stations, indicating that the waterway is of poor water quality and unsuitable for consumption, and irrigation purposes. The parallel coordinate plot identified Lead and Salinity as the main contaminant in the waterway.

The study determined the effect of changing climate on rainfall 24-hourly annual maximum series (AMS) downscaled data found to be statistically insignificant in trend for the Port Harcourt metropolis. The measured rainfall data for this study were collected for 35 years (1971-2005) from the Nigeria Meteorological Agency (NIMET). The 24-hourly (AMS) rainfall data extracted were further downscaled into shorter-duration rainfall using Indian Meteorological Department (IMD) and the Modified Chowdhury Indian Meteorological Department (MCIMD) method. The result of the slope obtained showed decreasing positive values of 0.5250 (at 0.25 hour) to 0.0249 mm/hr/year (at 24 hours) and 0.7625 (at 0.25 hour) to 0.0250 mm/hr/year (at 24 hours) for IMD and MCIMD models, respectively. The variable rate of change obtained showed 0.6 mm/year or 6.00 mm/decade at 24 hours. Relatively, the trend test for the 24-hourly monthly maximum series (MMS) also showed a p-value of 0.2289 which is greater than the alpha value at a 5% significant level with a slope value of 0.0006 to confirm the positive mild trend status of the 24-hourly AMS sample data. The trend change point date was obtained in 1988 by plotting the distribution-free cumulative (CUSUM) test, while the sequential MK (SQMK) test gave another year of change point date as 1994, further intensifying the positive trend change in the Port Harcourt metropolis. Therefore, proving the existence of mild and positive changing climatic conditions in the time series measured rainfall data for the study area.

This study focused on assessing of transient and spatial noise levels at selected Port Harcourt Metropolis junctions. Spatial noise measurement and vehicle count were conducted at Eleme and Akpajo junctions. Comparative analyses of noise level and noise pollution level using line graph/t-test and determination of decline rate of noise pollution level using regression analysis were carried out. Comparative analyses of noise levels at the two study locations using traffic count were also done. The noise pollution level was compared with National Environmental Standards and Regulations Enforcement Agency (NESREA) and World Health Organization (WHO) noise standards and a safe zone determined at study locations. Maximum and minimum noise recorded were 88.99dB(A) and 50.05dB(A) at Eleme junction, 87.51dB(A) and 49.02dB(A) at Akpajo junction. Findings showed that the noise pollution level was relatively higher than noise level with distance away from the junctions; however, there was no significant difference between noise level and noise pollution level. Maximum noise pollution level average decline rate of -0.3691dB was observed at Eleme junction in the morning, while the minimum noise pollution level average decline rate of -0.2656dB was observed at Akpajo junction, in the morning hours. External sources also contributed to noise level at the junctions. Those living or doing business within 100m and 120m of Akpajo and Eleme junctions, respectively are at risk of having noise-induced auditory, physiological and behavioral problems. There is need for continuous monitoring of noise level at study locations. Regular health assessment of people living within the study locations. Noise control regulations should be made and enforced by the Government.

This study examined the effect of changing climate for thirty-six years (1982-2017) on 24-hourly annual maximum time series (AMS) rainfall data for Benin City. The results show the existence of a trend, variation in magnitude, and change point dates. Trend analysis was performed using Mann-Kendall (MK) test and Sen’s slope estimator (SSE) applied to obtain the trend magnitude. A statistically significant trend was found for Benin City at a 5% level of significance. The MK |Z| statistic varied from 2.0710 to 2.1550 for IMD and 2.0844 to 2.0995 for MCIMD downscaling models, which were both greater than the critical Z-value of 1.96. The SSE gave the magnitude of the trend variation rate due to climate change at 24-hour duration as 1.008 mm/year (10.08 mm/decade) and 1.1376 mm/year (11.376 mm/decade) for the IMD and MCIMD models, respectively. Also, the trend change point analysis was conducted using the distribution-free cumulative sum test (CUSUM) and the sequential Mann-Kendall test (SQMK) which has rainfall pattern definite change point date for Benin City as 2005 from where continued a positive trend which intensified through the year 2015. Thus, proving the existence of increasing changing climatic condition for the study area.

This study aims to investigate the likelihood of hazard occurrence, the frequency level, the level of severity, and the consequences of work-related hazards in Offshore Installations. This study was a cross-sectional design assessment and the instrument used for this study was a well-structured questionnaire on Analysis of Work-related Accidents which was sent to e-mails of oil and gas workers. The reliability of the instrument was assessed using Cronbach's alpha. Data analyses were carried out using descriptive statistics, Risk Matrix, and Fault tree analysis. The 4 by 4 risk assessment matrix for the likelihood and consequences showed that 12 of the hazard were categorized as having high risk and Wind/Strong current was classified as extreme risk, However, 5 of the identified hazards, H5, H6, H7, H8 & H10 are risks that can be easily controlled to prevent an incident from occurring. All the offshore risks identified were either rated as high or extreme, which indicated that offshore hazards have severe consequences for the People, Environment, Asset and Reputation of the company. Therefore, high safety measures must be put in place to control these risks.

This study aimed to find out the effect of Demographic factors on work-related Injuries in the Oil and Gas Industry in the Niger Delta Region in Nigeria. The research method that was used for this study was a correlation design to test the demographic variables and how related they were to work-related injuries The instrument used for this study was a well-structured questionnaire on Analysis of Work-related Accidents which was sent to e-mails of oil and gas workers in Akwa Ibom state and the Rivers state of Nigeria for the collection of data to provide answers to the questions. The reliability of the instrument was assessed using Cronbach’s alpha which was 0.767, Different statistical test methods (Mann-Whitney, Kruskal Wallis, z-test, ANOVA and Dunn’s test) were used. The findings revealed that gender does not play any significant role in work-related injuries with p-values greater than 0.05, Education plays a role in certain types of injuries i.e. (contusion and MSDs with P-values of 0.013 and 0.015 respectively, and musculoskeletal disorders were the common types of injuries experienced by staff with a p-value of 0.05. Fractures and Amputations were experienced by workers who have spent above 16 years working offshore with p-values of 0.031, 0.035 and 0.020, 0 & 022 respectively. In Summary, certain demographic factors have effect on work-related Injuries.

The aim of this study was to examine the influence of organizational factors on safety performance in oil and gas companies in the Niger Delta region of Nigeria. This is a cross-sectional study using questionnaires administered electronically to employees working in these companies to gather data on various organizational factors, including management commitment, communication, leadership, and worker involvement. The reliability of the instrument was assessed using Cronbach’s alpha, and path analysis was used to examine the relationships between organizational factors and safety performance. The results of the study showed that positive organizational factors tend to significantly influence safety compliance and participation positively, while they influence accidents and near misses negatively. These findings suggest that organizations should focus on improving organizational factors in order to enhance safety performance in the oil and gas industry.

The purpose of this study was to investigate the level of organizational factors and safety performances among local and multinational oil and gas companies in the Niger Delta region of Nigeria. This is a cross-sectional study for which questionnaires were used as the instrument to gather data from employees in both local and multinational companies. Principal component analysis was used to understand the relationship between the organizational factors and the Oil and Gas Company types. Mann-Whitney test was used to check for significant differences in the organizational factors between the two types of companies. The mean response for management commitment for local and multinational companies were 3.34 and 3.56 respectively. For safety participation, the mean response for local and multinational companies were 3.33 and 3.62 respectively. The results of the study showed that multinational companies had a significantly higher level of organizational and safety performance factors compared to local companies. These organizational factors included management commitment to safety, safety policies/procedures, safety training, and communication. The findings of this study suggest that national culture may play a role in shaping the organizational factors and safety performance of oil and gas companies. Multinational companies, which operate in a variety of different cultural contexts, may be better equipped to adapt to different safety regulations and cultural expectations, which may contribute to their higher levels of organizational factors related to safety. Further research is needed to understand the specific ways in which national culture may influence safety performance in the oil and gas industry.

This study investigated the quantitative risk assessment of the naval ships operating within Niger-Delta, Nigeria. Descriptive and analytical research designs were adopted. Three accidents prevalent in naval ships and the associated hazards that caused these accidents were identified using the Nigerian Navy safety ledger (2010-2019). The accidents are Slip and fall accidents, Electrical accidents and Mooring operation accidents. The risk assessment was conducted by ranking of the hazards based on their risk rating using Conventional Risk Assessment (CRA) which involved multiplying the likelihood of the hazards to cause harm and the severity of the harm when it occurs. The severity and likelihood of the hazards were obtained using questionnaire and the respondents were forty-four (44) principal officers in the Eleven (11) naval ships. The results obtained were used to carry out Fault Tree Analysis (FTA) and the final outcome of the FTA revealed that the three main causes of these three accidents were poor management, lack of safety awareness and consciousness and violation of rules of safety on-board. It was then recommended, among others, that safety managers on-board naval ships should organize safety workshops for naval personnel to improve their safety awareness. Given that all the prevailing accidents, naval ships and major naval officers were not involved in this study is the major limitation of this study. It is recommended that more studies be carried out using other risk assessment tool like the Fuzzy Analytic Hierarchy Process (AHP).

The offshore oil and gas industry performs risky operations leading to high incident rates requiring the need for risk assessment which is a critical component for maintaining safety. This study, therefore, was aimed at evaluating the participation of workers in carrying out risk assessment and whether the type of company they work for influences their participation in risk assessment. A cross-sectional design was utilized in carrying out this research in the Niger Delta. 401 employees of the Multinational and National oil and gas industries who carryout underwater operations responded to the Survey questionnaire. The data collected were analyzed for descriptive statistics, and cross-tabulation using XLSTAT Ver. 17 and SPSS Ver. 22. The result showed that significant relationship exists between participation in risk assessment and gender, years of work experience, and educational status at P-values ≤0.005. In addition, the research showed that there is no significant difference between the participation in risk assessment among employees of Multinational and National oil and gas companies. It is recommended that organizations should ensure a mix of the workers groups studied when setting up Risk Assessment Teams to ensure a balanced risk assessment that when implemented will deliver on the intent of the activity.

This study aims to provide maintenance-state assessment model for forecasting of building maintenance condition. The selected institutions for the study were state funded hospitals and schools (14 functional out of 23 general hospitals and 2 out of 3 tertiary schools). In this study, considering the shortcomings of the most widely accepted condition survey protocol (CSP) 1 matrix, that is suitable for small projects and defect based, the study developed a model that is suitable for large projects and maintenance management system based for assessment of building’s condition. This model was developed analogous to CSP 1 matrix. Two types of ratings used are condition assessment and priority assessment. These two assessment criteria are then multiplied to determine the building maintenance rating score (BMRS). The study developed a 3x3 maintenance matrix model for evaluating building maintenance-state. It also found 25% of the buildings in “good condition” requiring only planned maintenance; 68.75% in “fair condition” requiring condition monitoring and 6.25% in “serious attention” condition.

This study investigated the causes of flexible pavement failure along three major roads in the Niger delta region of Nigeria. The three selected roads are Ogbia-Nembe road, East-West Road and Port Harcourt-Aba. Different types of failure such as alligator cracks, rutting, corrugations, etc., were observed on the selected road alignments. Pavement condition and traffic surveys were carried out on the selected road locations to ascertain their causes of failure. The study method involved the use of structured questionnaires which were distributed mostly to civil engineers and other construction stakeholders. A 5-point Likert scale was used to analyze the questionnaires retrieved from the respondents. The results of data analysis of the questionnaires and traffic survey showed that lack of laboratory investigation of construction materials, poor quality of the construction materials, lack of maintenance culture, poor soil condition of the road, inadequate drainage systems and overloading of road pavements are the major factors that are responsible for flexible pavement failures of the three selected roads in the Niger delta.

This study is an evaluation of the level of fire and explosion risks in petroleum handling facilities in the Niger Delta Region, Nigeria. A descriptive cross-sectional research design was employed using Stratified & Purposive sampling techniques for data collection. A Standard checklist of 17 compliance specifications of Nigerian Upstream Petroleum Regulatory Commission (NUPRC) was adopted and a walk-through survey was carried out in 118 identified facilities in 3 urban locations: Eket, Port Harcourt and Warri, respectively. Inferential and descriptive statistics were analysed using XLSTAT version 17,and the level of risk calculated as the product of the likelihood of the hazard occurring and its consequence (Severity). The level of Risk was then rated on a 5x5 Risk Assessment Matrix. The result obtained revealed that 95.37% of the 118 stations sampled rated from Medium to High Risk. This calls for a great concern and urgent need for intervention. It is therefore recommended that Facility owners should demonstrate more seriousness to safety policies; provide adequate safety measures to safeguard their facilities and engage qualified Safety officers to carry out Facility specific Fire and explosion risk assessments and manage their safety concerns.

The aim of this study is the establishment of the existence of trend and variability on a typical 24-hourly sorted thirty years (1986-2015) annual maximum series (AMS) and maximum monthly series (MMS) rainfall data for Uyo metropolis in Nigeria. Data were downscaled into shorter durations of 0.25, 0.5, …,12 hours. The statistical tool applied for the study was the Mann-Kendall (MK) test and Sen Slope estimator. The results showed that there exists increasing trend for all durations analyzed with consistency in the test statistic results. The MK statistic lZl for the AMS varied between 3.1701 and 3.2827 while that of MMS was 4.756, were greater than critical Z = 1.96. Also, the computed p-value for the AMS varied between 0.0012 and 0.0015, and were lower than the significant level of alpha, = 0.05. Thus, the null hypothesis of no trend was rejected. Similarly, the Sen Slope estimator gave an average rate of change in rainfall as 2.1288 and 2.16 mm/year for AMS and MMS time series data, respectively. The result from the Sen Slope estimator indicated that the magnitude of the trend decreased as the duration of rainfall increased such that shorter duration exhibited more trend than higher duration. The results of the MK trend and Sen Slope analysis proved that both test exhibited high degree of consistency with statistically significant positive trend and variability. These results have provided further evidence of an accelerated alarming rate in climate change increasing trend in Uyo metropolis and perhaps the environs. Therefore, planning for effective and accurate rainfall prediction for annual maximum time series data with established variability in trend will require adoption of non-stationary concept to account for the influence of changing climatic parameters in intensity-duration-frequency (IDF) modeling.

This study investigated the removal of Lead and Cadmium ions from aqueous solution using activated carbons from agricultural wastes. Activated carbons prepared by chemical activation using Phosphoric acid were characterized by Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The influence of contact time, initial concentration and adsorbent dose which governed the efficiency of the process was ascertained through batch adsorption studies. Adsorption isotherms were determined by correlating with Langmuir and Freundlich isotherms and the kinetic studies were correlated with pseudo first order and pseudo second order equations. The results showed that the amount of Lead and Cadmium adsorbed decreased as the adsorbent dose increased while the adsorption capacity increased with increased in contact time and initial concentration. Activated carbons prepared from Coconut shell and palm kernel (shell and cake) competed favorably with the commercial activated carbon in percentage removal of the metal ions as all the activated carbons had over 90 % removal within 60 minutes when 1g of adsorbent was used. The equilibrium data fitted best into Freundlich isotherms for both metal ions. The rate of adsorption could be described by pseudo second order for all the adsorbents except Coconut shell activated carbon in the adsorption of Lead while intra-particle diffusion was the limiting step for Cadmium adsorption. Therefore, the agricultural by-products can be used as effective, low-cost, and environmentally friendly adsorbents for domestic water treatment in many parts of the world.

The study assessed the concentration of heavy metals in three oil spill sites in Emohua local government area in Rivers State, Nigeria. Soil samples were collected at depth 0-30cm for surface soil samples and up to 10m for sub-surface soil samples depending on the depth of borehole. Groundwater samples were collected from drilled boreholes while the surface water samples were collected from fishponds or water bodies (rivers) close to the oil spill sites. The samples taken from the oil spill sites were analysed to determine the level of concentration of 10 Department of Petroleum Resource (DPR) specified heavy metals (Cd, Zn, Cu, Pb, Cr, Ba, Ni, Hg, As, and Co). BUCK Scientific Atomic Absorption Spectrophotometer (AAS) was used in detecting the concentration of the heavy metals. For the surface soil, Pb concentration in site A and B were significantly higher than what was obtained at site C, with a mean concentration of 219.70, 130.01 and 3.41mg/kg respectively for the three sites. The mean lead (Pb) concentration obtained in the surface soil was within DPR and United State Environmental Protection Agency (USEPA) acceptable limits. Barium also has significant concentration in both the surface soil and sub-surface soil. Kruskal Wallis test indicated significant difference in the Pb, Cd, Zn, Cu, Cr and Ba concentration in surface/topsoil among the three sites and also indicated significant difference in the concentrations of Pb, Cd, Cr, Ni, Ba and As in sub-surface soil among the sites. Little heavy metal concentration was found in both the groundwater and surface water. The study showed that even if some heavy metals were detected at the oil spill sites, they do not pose any serious health risk, as all the heavy metals in the four environmental media at the three sampling sites were below the national limit stipulated by the Department of Petroleum Resource (DPR), Nigeria.

This study was carried out to assess the human health risk associated with a crude oil spill site in Emohua Local Government Area of Rivers State, Niger Delta. The Total Content and Fraction’s approaches were adopted to assess the human health risk. Total Content approach was carried out by comparing the concentration of various contaminants in the environmental media studied with the Intervention Values prescribed while the Fractions approach was carried out using RBCA Toolkit for Chemical Releases version 2.6. The results indicate that concentration indices for Total Petroleum Hydrocarbon (TPH) and Polycyclic Aromatic Hydrocarbon (PAH) were greater than the acceptable limit of 1.0 for both the maximum and mean concentrations in soil and groundwater, indicating unacceptable risk at this site. The result from the Fraction’s approach showed that carcinogenic risks are identified for the site through the soil and grounwater exposure pathways as the Total Risk Values for soil (1.7 x10-3) and groundwater (5.6 x 10-1) are higher than the target risk of 1.0 x 10-5 while toxic effects risks are identified for all pathways in the site with Total Health Risk Index for all four pathways greater than the applicable limit of 1.0. Ingestion of groundwater for carcinogenic risk with risk value 5.6 x 10-1 and inhalation of indoor air for non-carcinogenic risk Health Risk Index of 1.0 x104 are identified as the major contributing exposure pathways at this study site. It was therefore concluded that the study site poses unacceptable risk to human health and needs immediate intervention.

The development of Intensity-Duration-Frequency (IDF) models for storm drain design and related flood mitigation structures requires rainfall amount and corresponding duration records. To achieve this purpose, three short duration downscaling methods from 24-hourly rainfall amount data were selected for improvement, namely: IMD, AIMD and MCIMD, with the CAMS method used as the experiment control. Three types of general PDF-IDF models (GEVT-1, LPT-3 and ND) were developed based on the downscaling methods yielding goodness of fit (R2) with very high correlation of 0.995–0.999 and model accuracy with mean square error (MSE) of 4.123–7.85. The PDF-IDF models predicted intensities plotted against durations for different return periods of 2, 5, 10, 25, 50 and 100 years, showed visual differences in the predictive performance of the intensities derived from the downscaling methods. Kruskal-Wallis non-parametric test of significance at 5% level carried out showed that no-significant difference exist for 15-60 minutes duration, while the difference was significant for durations between 90–300 minutes. The LPT-3 based on MCIMD yielded higher improved performance in prediction of intensities relative to the IMD. The level of improvement ranges from 35.17 to 52.26% and 25.0 to 39.89%; while that of AIMD ranges from 10.97 to 20.87% and 3.33 to 12.53% for 10 and 100 year return periods, respectively. The use of the IMD downscaling method with the LPT-3 PDF-IDF model for design purposes will be justified if modified with some percentage improvement or adjustment factor.

The design of structures for flood mitigation depends on the adequate estimation of rainfall intensity over a given catchment which is achieved by the rainfall intensity duration frequency modelling. In this study, an extensive comparative analyses were carried out on the predictive performance of three PDF – IDF model types, namely: Gumbel Extreme Value Type 1 (GEVT – 1), Log-Pearson Type 3 (LPT – 3) and Normal Distribution (ND) in 14 selected cities in Southern Nigeria. This is to rank the order of best performance. The principle of general model development was adopted in which rainfall intensities at different durations and specified return periods were used as input data set. This is not same as return period specific model that involves rainfall intensities for various durations and a given return period. The predicted rainfall intensity values with the PDF – IDF model types indicate high goodness of fit (R2) and Mean Squared Errors (MSE) ranging from: (a) R2 = 0.875 – 0.992; MSE = 33.17 – 224.6 for GEVT – 1; (b) R2 = 0.849 – 0.990; MSE = 65.34 – 405.5 for LPT – 3 and (c) R2 = 0.839 – 0.992; MSE = 29.23 – 200.2 for ND. The comparative analysis of all the 42 general models (14 locations versus 3 model types) considered showed that the order of best performance is LPT – 3 1st, GEVT - 1 2nd and ND 3rd for each return period (10, 50 and 100 years). The Kruskal Wallis test of significance indicates that no significant difference exists in the predictive performance of the three General models across the board. This may be due to the fact that the fourteen locations of the study area are bordering with the Atlantic Ocean and seems to have similar climatology. These developed General models are recommended for the computation of intensities in the fourteen locations for the design of flood control structures; and the order of preference should be LPT – 3 > GEVT – 1 > ND.

This article focuses on an overview of the processes of generating rainfall intensity-duration-frequency (IDF) models, the different types and applications. IDF model is an important tool applied in the design of either hydrologic or hydraulic design such as prediction of rainfall intensities to estimate peak runoff volumes for mitigation of flooding. IDF models evolved from stationary – parametric (empirical) and non-parametric (stochastic) models, to non-stationary models in which variables vary with time. Each category controls the ways models predict rainfall intensities, and reveals their strength and weaknesses. IDF models must therefore, be chosen in terms of the project objective, data availability, size of the study, location, output needed, and the desired simplicity. For instance, while the parametric model predicts better for shorter durations and return periods only, the non-parametric models predict better for both shorter and longer durations and return periods. For projects requiring change of input data over time and evaluation of uncertainty bounds, risk assessment, including incorporation of changes in extreme precipitation, the non-stationary model approach must be selected. Also, of importance for catchments without rainfall amount and corresponding duration records but has daily (24-hourly) record of rainfall depth, the Indian Meteorological Department (IMD) method of shorter duration disaggregation can be adopted to generate in-put data for the development of IDF curves for such a location. Therefore, each model type has limitations that may make it unsuitable for some projects. Reviewing input data and output requirements, and simplicity are all necessary to decide on which model type should be selected.

This study provides information on the health risk of As, Cd, Hg, Pb and V exposure from Nigerian foods consumption (fish, cow, goat and chicken meat) in different age-groups (children, adolescent, adult, senior) and six areas of Niger Delta, Nigeria (Choba, Khana, Eleme, TransAmadi, Uyo, and Yenogoa). The health risk assessment was performed by estimating the weekly or monthly intake of metals from foods and Margin of Exposure (MOE) approach by using established benchmark dose levels (BMDLs). Regarding As, cow and chicken meat products contributed to As exposure intake especially in children resulting in values higher than BMDL

BACKGROUND: Mothers who feed their children with infant food have increased have over the years leaving a large percentage of children who consume other types of liquid food for supplementation or as alternatives. AIM: Determining the levels of essential trace metals in these formulae with the aim of ascertain their appropriateness is considered important. METHODS: Iron, zinc, manganese, chromium and cobalt in 26 infant formulae purchased from Port Harcourt city, Nigeria were determined by Atomic Absorption Spectrophotometry. The estimated daily intake EDI and percentage of EDI to the recommended daily allowance of these essential trace metals were used in the exposure assessment. RESULTS: The highest mean concentration of Mn, Cr and Co was found in the milk based (0.15 ± 0.09 mg/kg), (0.61 ± 0.70 mg/kg), (0.12 ± 0.32 mg/kg) compared to the cereal based and cereal mix based but the differences was also not significant. The EDI of chromium in the infant formulae exceeded the RDA. CONCLUSION: Infant formulae may add to the chromium body burden of infants in Nigeria.

Proper identification of hazards and creation of a safe working environment is a major challenge faced by management of many industries today. Hazard assessment is thus carried out in workplaces to identify dangerous events and conditions that may lead to accidents in the industries. This study, which was carried out in both a petrochemical and an oil refining companies of Nigeria, identified industrial hazards and assessed safety measures in the Chemical Industry (CHI) of Nigeria. A well-structured questionnaire instrument was used for data collection. The study was carried out amongst technical staff and management staff of the chemical industry whose day-to-day duty is such that they are exposed to one form of hazard or the other in the industry. The questionnaire was administered to 96 technical staff and management staff in the CHI out of which 84 (88%) were completed and returned. The study focused on types of hazards, hazards and risk awareness, implementation of control measures and effectiveness of safety hazards and risk management programmes in the chemical industry of Nigeria. Modified Proportional Importance Index (PII) and a four-point Likert scale were adopted in data analysis. Results revealed that loud noise (PII = 3.2; respondents = 92%), working at heights (with PII = 3.1; respondents = 89%) machines and equipment vibration (PII = 3.0; respondents = 87%), high voltage areas (PII = 2.9; respondents = 84%) and chemical spills (PII = 2.5; respondents = 55%) are the most high ranking hazards in the chemical industry. A high level of safety hazard awareness was found among workers in the industry (p < 0.05, 95%Cl.; PII = 3.1 - 3.5). The outcome of the intervention showed that Chemical Industry Number 1 (CHI-1) improved from 87.90% to 98.09%, Chemical Industry Number 2 (CHI-2) improved from 81.53% to 95.54% on worker’s knowledge on the identification and assessment of hazards and risk in the chemical industries. These hazards pose threats to the safety of workers and should be effectively controlled to reduce associated risks to as Low as Reasonably and Practically Achievable (ALARPA).

The hospital is a high risk environment for the transmission of infections to health care workers, visitors, patients and the surrounding community. Healthcare workers are exposed to a variety of hazards which predisposes these “indispensable carers” to various life threatening infections and diseases. This study is aimed at evaluating the occupational hygiene and infection control practices in Federal Medical Center (FMC) Owerri and FMC Yenayoa, both located within southern Nigeria. Descriptive cross sectional study using a structured questionnaire and walk-through safety checklist was employed. A total of 379 healthcare workers were selected through disproportionate stratified sampling from the two facilities. The questionnaires were self-administered and analyzed using SPSS Version 22.0. Frequencies, chi-square were computed and multivariable logistic regression analysis was used to identify the predisposing factors to which health workers are exposed; 60.7% of respondents were male, dominant age group; 30 – 39yrs, nurses represented a larger proportion (34.8%) of healthcare workers in this study; 51.7% and 48.3% of respondents in FMC Yenagoa and FMC Owerri respectively had a good knowledge of hazards and controls. There was a significant difference with chi-square as, 9.710 p-Value

The rainfall Intensity-Duration-Frequency (IDF) relationship is widely used for adequate estimation of rainfall intensity over a particular catchment. A 25 year daily rainfall data were collected from Nigerian Meteorological Agency (NIMET) Abuja for Akure station. Twenty five year annual maximum rainfall amounts with durations of 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 300 and 420 minutes were extracted and subjected to frequency analysis using the excel solver software wizard. A total of six (6) return period specific and one (1) general IDF models were developed for return periods of 2, 5, 10, 25, 50 and 100 years using Gumbel Extreme Value Type-1 and Log Pearson Type -3 distributions. Anderson Darling goodness of fit test was used to ascertain the best fit probability distribution. The R2 values range from 0.982 to 0.985 for GEVT -1 and 0.978 to 0.989 for Log Pearson type -3 while the Mean Squared Error from 33.56 to 156.50 for GEVT -1 and 43.01 to 150.63 Log Pearson Type III distributions respectively. The probability distribution models are recommended for the prediction of rainfall intensities for Akure metropolis.

The design of water resources engineering control structures is best achieved with adequate estimation of rainfall intensity over a particular catchment. To develop the rainfall intensity, duration and frequency (IDF) models, 25 year daily rainfall data were collected from Nigerian Meteorological Agency (NIMET) Abuja for Abeokuta. The annual maximum rainfall amounts with durations of 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 300 and 420 minutes were extracted and subjected to frequency analysis using the Excel Optimization Solver wizard. Specific and general IDF models were developed for return periods of 2, 5, 10, 25, 50 and 100 years using the Gumbel Extreme Value Type -1 and Log Pearson Type -3 distributions. The Anderson-Darling goodness of fit test was used to ascertain the best fit probability distribution. The R2 values range from 0.973 – 0.993 and the Mean Squared Error, MSE from 84.49 – 134.56 for the Gumbel and 0.964 – 0.997 with MSE of 42.88 – 118.68 for Log Pearson Type -3 distribution, respectively. The probability distribution models are recommended for the prediction of rainfall intensities for Abeokuta metropolis.

Technological developments have led to exposure to various substances that are harmful to the environment and public health, including heavy metals. In the environment, these grades of metals are usually diverse mixtures shown to cause physiological, biochemical and neurological dysfunctions in humans and laboratory animals. Cadmium, Lead, and mercury have been envisaged to exhibit their hepatotoxic effects by oxidative induction damage and synthesis of reactive oxygen species (ROS). The current work evaluated the protective activity of aqueous leaf extract of Costus afer (ALECA)) on liver damage arsing from exposure to trace metal mixture (TMM): cadmium chloride (CdCl2), lead chloride (PbCl2), and mercury chloride (HgCl2). Five groups of weight matched Sprague Dawley rats were treated for 90 days. Metal mixture and deionized water were used to treat the 2 groups of rats whereas the other 3 groups were treated with various doses of the ALECA through oral gavage alongside the metal mixture. Hepatic function parameters, oxidative biomarkers, inflammatory cytokines, Morphological changes and trace metals (concentrations were monitored in the liver). TMM treatment resulted in significant increase in ALT, AST, ALP, bilirubin, IL-6, MDA, but decreased albumin, total protein, IL-10, SOD, CAT and GSH levels. TMM also caused some morphological changes and increased the heavy metal (Pb, Cd and Hg) concentrations in the liver. The leaf extract gave a reasonable protective effect on the hepatotoxicity caused by trace metal mixture - through the mechanisms of metal chelation, anti-inflammatory, and antioxidant although this depends on the dosage to the rats. ALECA may be beneficial in the management of liver toxicity.

This study was aimed at determining mainly the concentrations of As and other metals (Cd, Cu, Hg, Pb, V and Zn) in samples of feed, soil, plants and foods (fish, chicken, goat and cow meat) grown and consumed in six areas of Niger Delta, Nigeria (Choba, Khana, Trans Amadi, Eleme, Uyo and Yenagoa). Principal Component Analysis (PCA) models were used for identifying groups of variables (i.e., elements) based on the loadings and groups of samples (i.e., plants, soil, fish, meet, feed) according to the scores that contributed most to the environmental pollution in each Nigerian area. In Choba and Khana sites, the results showed a cluster of elements like As, Pb, V and Zn, mostly associated with samples of goat and cow meat, as well as soils, and separated from another cluster of metals composed by Cu and Hg with different origin. In Trans Amadi area, a clustering of As, Cd and V was found associated to different types of meat (chicken, goat, and cow) located in the opposite side of Cu and Hg, which correlated to plants and soil. In Eleme, the strongest loadings were obtained for V and Zn associated with soil and meat (goat and cow) samples and separated from As and Cd. Finally, in Uyo and Yenagoa, dominant elements were As, Cu, Pb and Zn, with proximity to cow and goat liver samples, while Cd and V corresponded to a different pollution pattern. Lead intake trough meat and fish consumption for adults and children were much higher than the tolerable limits set by international organizations. The results of this study should allow a better understanding of the complex phenomenon of metal pollution in the feed-to-food chain and human health in Nigeria, which should help to manage a pollution reduction strategy and give priorities of research and monitoring.

Hazards identification and creation of a safe working environment is a major challenge faced by management of many industries today. Hazard assessment is thus carried out in workplaces to identify dangerous events and conditions that may lead to accidents in the industries. Gap analysis on hazard identification alongside safety management in the industries was carried out in order to showcase the level of incompleteness in recent studied on the subject and the need to close the gaps in future studies. This study, which was carried out in both a petrochemical and an oil refining companies in Nigeria, identified industrial hazards and assessed safety measures in the Chemical Industry (CHI) of Nigeria. A well-structured questionnaire instrument was used for data collection. The study was carried out amongst technical staff and management staff of the chemical industry whose day-to-day duty is such that they are exposed to one form of hazard or the other in the industry. The questionnaire was administered to 96 technical staff and management staff in the CHI out of which 84 (88%) were completed and returned. The study focused on types of hazards, hazards and risk awareness, implementation of control measures and effectiveness of safety hazards and risk management programmes in the chemical industry of Nigeria. Modified Proportional Importance Index (PII) and a four-point Likert scale were adopted in data analysis. Results revealed that loud noise (PII = 3.2; respondents = 92%), working at heights (with PII = 3.1; respondents = 89%) machines and equipment vibration (PII = 3.0; respondents = 87%), high voltage areas (PII = 2.9; respondents = 84%) and chemical spills (PII = 2.5; respondents = 55%) are the highest ranking hazards in the chemical industry. A high level of safety hazard awareness was found among workers in the industry (p < 0.05, 95%Cl.; PII = 3.1 - 3.5). The outcome of the intervention showed that Chemical Industry Number 1 (CHI-1) improved from 87.90% to 98.09%, Chemical Industry Number 2 (CHI-2) improved from 81.53% to 95.54% on worker’s knowledge on the identification and assessment of hazards and risk in the chemical industries. These hazards pose threats to the safety of workers and should be effectively controlled to reduce associated risks to as Low as Reasonably and Practically Achievable (ALARPA).

Electrical resistivity method was used to study the movement of municipal solid waste landfills leachate of Niger-Cat, Donparkar and Orhuwhorun dump sites in Warri Metropolis, Southern Nigeria. Landfilling remains the cheapest and one of the most widely practiced method for the disposal of Municipal Solid Waste (MSW) in both developed and developing nations. Both Electrical Resistivity Profiling and Vertical Electrical Sounding (VES) were carried out using Schlumberger array configuration. Surfer 10 and ArcGIS 10.3 software packages were used to interpret resistivity profiling data to produce apparent resistivity contour maps of study sites while IPI2Win software package was used to interpret VES data. This computer program automatically generated model curves using initial layer parameters (resistivity and thickness) derived from partial curve matching of the field curves with standard curves, and calculated the true layer parameters of the geo-electric section. The results revealed that at Niger-Cat dump site, leachate had migrated from dump into surrounding soil and contamination had advanced up to a depth of 19.12m which is within the local groundwater system of the area. At Don-Parkar dump site, results showed leachate migration from around the edges of dump site into surrounding soil and contamination had advanced to a depth exceeding 20.7m. At Orhuwhorun dump site, result of resistivity contour map showed leachate migration on the south of the dump; however VES results showed no contamination; thus groundwater in the vicinity is currently safe. There is need for waste managers to adopt engineered sanitary landfill for solid waste disposal and government policy should address this issue to help safeguard the groundwater resources in the area.