Analysis of Heavy Metals in Five Different Baby Foods
CHAPTER ONE
Objectives of Study
The aim of this study is to assess the level of heavy metals present in the five different samples of baby foods sourced from the Eke-Awka market. Objective of the study includes:
- To ascertain the level of heavy metals present in the baby foods samples
- To compare the result obtained with the WHO recommended standard
- To check if some baby foods in the market are safe from heavy metal contamination
- To give data on the heavy metal contaminant in baby foods.
CHAPTER TWO
LITERATURE REVIEW
Conceptual Review
Heavy metals
Heavy metals may be defined as metallic elements that have a relatively high density (greater than 5g/cm3) compared to water (Fergusson, 1990). They have specific gravity that is at least 5 times greater the specific gravity of water and cannot be degraded or destroyed which are persistent in all parts of the environment. The specific gravity of water is 1 at 4 or 39 . Specific gravity is the measure of density of a giving amount of solid substances when it is compared to equal amount of water.
With assumption that heaviness and toxicity are inter-related, heavy metals also include metalloids, such as arsenic, that are able to induce toxicity at low level of exposure (Duffus, 2002). In recent years, there has been an increasing ecological and global public health concern associated with environmental contamination by these metals. Also, human exposure has risen dramatically as a result of an exponential increase of heavy metal use in several industrial, agricultural, domestic and technological applications.
Although heavy metals are naturally occurring elements that are found throughout the earth’s crust, most environmental contamination and human exposure result from anthropogenic activities such as mining and smelting operations, industrial production and use, and domestic and agricultural use of metals and metal-containing compounds. Environmental contamination can also occur through metal corrosion, atmospheric deposition, soil erosion of metal ions and leaching of heavy metals, sediment re-suspension and metal evaporation from water resources to soil and ground water. Natural phenomena such as weathering and volcanic eruptions have also been reported to significantly contribute to heavy metal pollution. Industrial sources include metal processing in refineries, coal burning in power plants, petroleum combustion, nuclear power stations and high tension lines, plastics, textiles, microelectronics, wood preservation and paper processing plants.
It has been reported by World Health organization that metals such as cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn) are essential nutrients that are required for various biochemical and physiological functions. Inadequate supply of these micro-nutrients results in a variety of deficiency diseases or syndromes.
CHAPTER THREE
MATERIALS AND METHODS
Materials
The materials used include
Nutriend
Cerelac
Frisogold
Nutribom
Golden morn
Apparatuses used
Spatula
Beaker
Round-bottom-flask
Electronic Weighing balance (model AE166)
Heater
Sample bottles
Filter paper
Foil
AAS machine (buck scientific 210/211 model)
Reagent used
100ml of Aqua regia (70% HCL and 30% HNO3)
Methods
Method of Sample collection
The five different samples of baby food were sourced from Eke-Awka market, Anambra state. They are all cereal-based type of baby food.
Sample Digestion
10g of each baby food sample was weighed using Metler analytical weighing balance (model AE116) and was transferred into a digestion beaker. 100ml of Aqua regia (70% HCL and 30% HNO3) was added to the sample and placed in a heating chamber inside a fume hood at the temperature of about 550C. the sample was digested for about an hour until a clear solution was obtained and the volume reduced by half. The digested sample was allowed to cool, filtered and made up to 100ml in a sample bottle for the AAS analysis.
CHAPTER FOUR
RESULTS AND DISCUSSION
Discussion
A number of five different samples of baby foods were analysed for the presence of Cr, Cd, Cu, Pb, and As. All the results were compared with the data from their label and proposed guideline published by WHO in 2013 ( see Table 4.1.2)
Pb and As were not detected. The five samples, A to E contain the highest amount of Cu (141.6, 174.0, 207.7, 136.9, 132.0mg/kg) respectively, which is a traced element and it is within the provisional maximum tolerable daily intake of 50 to 500mg/kg set by WHO. Cr was only detected in only three samples, A B and C (6.4,6.3,10.0mg/kg) respectively, and it within the provisional tolerable monthly intake of 25mg/kg set by WHO . Cd was detected in all the five samples A, B,C,D,E ( 3.9,3.2,2.2,3.0,4.9) and it is also within the provisional tolerable monthly intake of 25mg/kg set by WHO.
CHAPTER FIVE
CONCLUSIONS AND RECOMMENDATIONS
Conclusion
The accumulation of heavy metals in the body could be very destructive especially to infants. Studies on the heavy metal contamination of baby foods and infant formulas are very necessary.
In this reach work, after carrying out an analysis on five different samples of baby foods, it was observed that lead and arsenic which are very dangerous to health was not detectable . The five samples contains the highest amount of copper which is a trace element and it is needed in the body. Chromium was only detected in three samples (A,B,C only) and was not detected in sample D and E. cadmium was detected in all the five samples.
Recommendation
We suggest that further thorough studies be carried out on all the baby food available in the market to detect those ones that contain toxic heavy metals which are detrimental to health of the child which contributes to the high level of child mortality rate in the country.
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