Public Health and Paediatric Risk Assessment of Aluminium, Arsenic and Mercury in Infant Formulas Marketed in Nigeria

Objectives: Infant formulas are useful alternatives to breast milk in many circumstances but may pose health risks to infants and children due to contamination by potentially toxic metals. This study aimed to determine the aluminium, arsenic and mercury concentrations and carry out an exposure health risk assessment in commonly consumed infant formulas in Nigeria. Methods: Different brands of both locally manufactured and imported infant formulas were purchased in March 2017 from stores in Port Harcourt, Nigeria. Analysis of metals in the samples was performed by atomic absorption spectrophotometry. The health risk was assessed by comparing estimated daily intake of aluminium, arsenic and mercury with the provisional tolerable daily intake acceptable by the Joint Food and Agricultural Organization/World Health Organization Expert Committee on Food Additives (JECFA). Results: A total of 26 infant formulas were analysed. The levels of arsenic were higher in cereal-based formulas compared to milkbased formulas, but the difference was not significant (P >0.05). The intake levels of aluminium, arsenic and mercury in infant formulas were found to be 8.02–14.2%, 437.1–771% and 23.7–41.8% of the provisional tolerable daily intake JECFA threshold values, respectively. Conclusion: Commonly consumed infant formulas in Nigeria may add to the body burden of arsenic in children.Keyword: Infant Formulas; Toxicity Test; Aluminum; Arsenic; Mercury; Health Risk Appraisal; Child Health; Nigeria

Appropriateness of Essentials Trace Metals in Commonly Consumed Infant Formulae in Nigeria

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

Effect of Waste Paper on Biogas Production from Co-digestion of Cow Dung and Water Hyacinth in Batch Reactors

The effect of waste paper on biogas production from the co-digestion of fixed amount of cow dung and water hyacinth was studied at room temperature in five batch reactor for over 60 days. Waste paper addition was varied for a fixed amount of cow dung and water hyacinth until maximum biogas production was achieved. Biogas production was measured indirectly by water displacement method. The production of biogas showed a parabolic relationship as the amount of waste paper (g) increased with a goodness of fit of 0.982. Maximum biogas volume of 1.11liters was observed at a waste paper amount of 17.5g which corresponded to 10.0% total solids of the biomass in 250ml solution. Thus, an optimum waste paper amount of 17.5g needs to combine with 5g of cow dung and 5g of water hyacinth in 250ml of water for maximum biogas production. Similar equivalents in kilograms and tonnes can be utilized in large-scale production of biogas which can provide decentralized source of fuel for university laboratories and also local supply of energy for electricity production. Also, the air pollution problems associated with open burning of waste papers can be eliminated. The biogas process has established to be cheap and practically feasibl

A Review Study on Stationary and Non-Stationary IDF Models Used in Rainfall Data Analysis around the World from 1951-2020

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

Effect of Waste Paper on Biogas Production from Co-digestion of Cow Dung and Water Hyacinth in Batch Reactors

The effect of waste paper on biogas production from the co-digestion of fixed amount of cow dung and water hyacinth was studied at room temperature in five batch reactor for over 60 days. Waste paper addition was varied for a fixed amount of cow dung and water hyacinth until maximum biogas production was achieved. Biogas production was measured indirectly by water displacement method. The production of biogas showed a parabolic relationship as the amount of waste paper (g) increased with a goodness of fit of 0.982. Maximum biogas volume of 1.11liters was observed at a waste paper amount of 17.5g which corresponded to 10.0% total solids of the biomass in 250ml solution. Thus, an optimum waste paper amount of 17.5g needs to combine with 5g of cow dung and 5g of water hyacinth in 250ml of water for maximum biogas production. Similar equivalents in kilograms and tonnes can be utilized in large-scale production of biogas which can provide decentralized source of fuel for university laboratories and also local supply of energy for electricity production. Also, the air pollution problems associated with open burning of waste papers can be eliminated. The biogas process has established to be cheap and practically feasibl

STREAMFLOW AND WATER QUALITY REGRESSION MODELING OF IMO RIVER SYSTEM: A CASE STUDY

The upper reaches of Imo-river system between Nekede and Obigbo hydrological stations (a stretch of 24km) have been studied for the purpose of water quality and streamflow modeling. Model's applications on water supply to Nekede and Obigbo communities were equally explored with the development of mass curves. Possible sources of contamination of Imo-river system within Nekede and Obigbo hydrological stations watershed were traced. Consistency tests, trend analyses and mathematical modeling of water quality constituents and riverflow characteristics at upstream Nekede station and downstream Obigbo station show: consistent time-trends in degree of contamination; linear and non-linear relationships for water quality models against total dissolved solids (TDS), total suspended sediment (TSS), chloride, pH and sulphate; and non-linear relationship for streamflow and water quality transport models. Application of Microsoft Excel software on multiple regressions to the data yielded values of models' coefficients and those of correlation coefficients ranging from 0.9296 to 0.9999. Models' verifications added value to their validity for use in predictions. JMDMES Vol.2(1) 2003: 55-6

Water Quality Assessment on Physicochemical and Biological Parameters of Selected Lentic Ecosystem in Aboh Mbaise Local Government Area, Imo State, Nigeria

The aim of this study is to determine the suitability of the ponds in Aboh Mbaise Local Government Area, Imo State, Nigeria for domestic use. A cross-sectional study was carried out for the study. Composite sampling method was used, where three water samples were collected randomly from each station to ensure that the samples were representative of the entire station. Samples were collected during the rainy season, given that the ponds always dry up during the dry season. Physicochemical and microbial analyses were carried out on water samples of selected lentic aquatic ecosystems in randomly identified ponds in five communities of Aboh Mbaise. These ponds are used by the residents of these villages for various domestic and anthropogenic activities. Statistical analyses include: descriptive statistics, Analysis of Variance, Parallel coordinate plot, Pearson correlation, Agglomerative Hierarchical Clustering (AHC) and Water Quality Index (WQI) were carried out. Results indicate that pond water within the study area did not fall within the bracket of good water quality, as per the WQI range of 0 to 50, thereby affirming the poor quality of water. The WQI for the five ponds ranges from 1338.71 - 3322.81.  There is a direct correlation between the presence of Total Bacterial Counts from Shigella and Salmonella counts and the presence of fecal contamination from both human and animal wastes. Given the poor quality of the pond water, it is unhealthy for the inhabitants in the study area to use pond water for food preparation and other household tasks, except if it is treated

Climate Change and Trend Analysis of 24-Hourly Annual Maximum Series Using Mann-Kendall and Sen Slope Methods for Rainfall IDF Modeling

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

A Review on Current Trends in Heavy Metal Removal from Water between 2000-2021

Recent fiscal growth has necessitated diverse industrial processes to meet the growing demands around the world. Toxic chemicals such as micro-pollutants, personal care products, pesticides contaminate the effluents of these industries and find their way into the environment leaving dangerous levels of heavy metals in the aquatic ecosystem. These heavy metals such as arsenic, chromium, lead, mercury, cadmium and nickel bio-accumulate and are very harmful to humans. Several water treatment methods were reviewed from 111 published articles covering a period between 2000-2021 on the progress of Heavy Metal removal from waste water including the use of low cost agro based activated carbon and Bentonite clay as part of “green and sustainable chemistry”